Petroleum Assignment - UOP Q-Max Cumene Process (FULL)
March 16, 2017 | Author: VPrasarnth Raaj | Category: N/A
Short Description
Download Petroleum Assignment - UOP Q-Max Cumene Process (FULL)...
Description
UNIVERSITY MALAYSIA SABAH SCHOOL OF ENGINEERING & INFORMATION TECHNOLOGY HK03 CHEMICAL ENGINEERING PROGRAMME SEMESTER II, 2012 / 2013 KC41803 PETROLEUM PROCESSING GROUP ASSIGNMENT TITLE: UOP Q-MAX CUMENE PROCESS
GROUP MEMBERS: KENNY THEN SOON HUNG (BK09110098) LEE CHEE HOE (BK09110001) DATE OF SUBMISSION: 29TH MAY 2013 LECTURER: ASSOC. PROF. IR. OTHMAN BIN ABDUL HAMID
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
TABLE OF CONTENTS: 1.0 HISTORY ON PETROLEUM REFINING..................................................... 1 1.1 The Malaysian Oil And Gas Industry: An Overview......................................... 3 1.2 Flow Diagram of Typical Refinery ............................................................... 10 1.3 Introduction On Cumene ........................................................................... 12 1.4 Cumene Production ................................................................................... 15 1.5 Cumene Properties .................................................................................... 16 1.6 Cumene Process........................................................................................ 19 1.8 Cumene Chemical Properties ...................................................................... 21 1.9 Uses Of Cumene ....................................................................................... 24 1.10 Description On Q-Max Process.................................................................. 25 2.0 REFINERY BALANCE ............................................................................. 27 2.1 Introduction .............................................................................................. 27 2.2 The Abu Dhabi Oil Refining Company (Takreer) .......................................... 28 2.3 Refinery Installations ................................................................................. 32 2.3.1 Refinery Units ..................................................................................... 33 2.3.2 Utilities, Off-sites, Terminal & ADR Technology ..................................... 36 2.4 Mass Balance Based 400,000 BPD of Middle East Heavy Crude ..................... 40 2.4.1 Mass Balance by Assumed Proportion of Refining Products is Double ...... 41 2.4.2 Mass Balance by Fraction Method ......................................................... 44 2.4.3 Mass Balance based on Total Production from while Middle East Countries .................................................................................................................. 46 2.5 Conclusion ................................................................................................ 51 3.0 GROUP PROJECT ................................................................................... 53 3.1 Introduction To Cumene Production ........................................................... 53 3.1.1 Cumene Project Definition.................................................................... 53 3.1.2 Cumene Manufacturing Routes ............................................................. 55 3.1.3 General Overall Material Balance for Cumene Process ............................ 58 3.1.4 Physical Properties .............................................................................. 59 3.2 Cumene Process........................................................................................ 60 KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.3.1 Technical Description ........................................................................... 61 3.2.1 Cumene Chemical Properties ................................................................ 62 3.3 Chemical Reaction Network........................................................................ 64 3.4 Various Processes of Manufacture .............................................................. 67 3.4.1 UOP Cumene Process .......................................................................... 67 3.4.2 Badger Cumene Process ...................................................................... 71 3.4.3 MONSANTO – LUMMUS CREST Cumene Process ................................... 74 3.4.4 CDTECH & ABB Lummus Global ............................................................ 75 3.4.5 Q-MAX Process .................................................................................... 82 3.5 Description On Q-Max Process ................................................................... 85 3.6 Description On Process Flow ...................................................................... 87 3.7 Process Chemistry Chemical Reactions........................................................ 89 3.7.1
Transalkylation Of DIPB ................................................................... 91
3.7.2 Side Reactions .................................................................................... 92 3.8
Process Flow Diagram (PFD) .................................................................. 94
3.9 Description ............................................................................................... 97 3.10 Cumene Plant Section .............................................................................. 98 3.10.1 Storage and pumping section ............................................................. 98 3.10.2 Preheating and vaporization section .................................................... 98 3.10.3 Reactor section ................................................................................. 99 3.10.4 Separation and purification section ..................................................... 99 3.11 Current Industrial Cumene Production Process: UOP Process ................... 100 3.12 UOP Process Description For Cumene Production .................................... 101 3.13 Description Of Process Units .................................................................. 103 3.13.1 V-201 Vaporizer............................................................................... 104 3.13.2 R-201 Reactor ................................................................................. 104 3.13.3 S-201 Separator .............................................................................. 104 3.13.4 T-201 Distillation Tower No. 1 .......................................................... 104 3.13.5 T-202 Distillation Tower No. 2 .......................................................... 104 3.14 Description Of Process Streams .............................................................. 105 3.14.1 Stream 1 ......................................................................................... 105 3.14.2 Stream 2 ......................................................................................... 105 3.14.3 Stream 3 ......................................................................................... 105 KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.14.4 Stream 4 ......................................................................................... 105 3.14.5 Stream 5 ......................................................................................... 105 3.14.6 Stream 6 ......................................................................................... 105 3.14.7 Stream 7 ......................................................................................... 106 3.14.8 Stream 8 ......................................................................................... 106 3.14.9 Stream 9 ......................................................................................... 106 3.14.10 Stream 10 ..................................................................................... 106 3.15 Reaction Mechanism And Kinetics Of Cumene Production ......................... 107 4.0 CAPACITY CALCULATION ................................................................... 108 4.1 Mass Balance .......................................................................................... 108 4.1.1 Introduction to Mass Balance ............................................................. 108 4.1.2 Material Balance of Major Equipment - Reactor ................................... 111 4.1.3 Material Balance of Propane Column ................................................... 117 4.1.4 Material Balance of Minor Equipment - Benzene Column ...................... 118 4.1.5 Material Balance of Minor Equipment – Cumene Column ...................... 121 4.2 Heat Balance .......................................................................................... 124 4.2.1 Introduction to Heat Balance .............................................................. 124 4.2.2 Heat Balance for Major Equipment - Reactor ....................................... 128 4.2.3 Heat Balance for Propane Column ...................................................... 138 4.2.4 Heat Balance for Minor Equipment - Benzene Column .......................... 144 4.2.5 Heat Balance for Minor Equipment - Cumene Column ......................... 149 4.2.6 Product Yield ..................................................................................... 154 4.3 Flow Summary for Cumene Production at Design Conditions ...................... 157 4.4 Flow Summary for Utility Streams ............................................................ 160 4.4 Equipment Summary with Capacity for Cumene Producition Process ........... 161 5.0 BEHAVIOUR OF CATALYSTS/SOLVENTS............................................. 164 5.1 Feedstock Considerations ........................................................................ 164 5.1.1
Impact Of Feedstock Contaminants On Cumene Purity ..................... 164
5.1.2
Impact of Catalyst Poisons On Catalyst Performance ........................ 168
5.2 Process Performance ............................................................................... 170 KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.3 Production Of Cumene Using Zeolite Catalysts .......................................... 172 5.3.1 Unocals technology is based on a conventional fixed-bed system ......... 172 5.3.2 The second zeolite process, which was developed by CR&L ................. 172 5.4 Disadvantages Of Using Solid Phosphoric Acid (SPA) Process ..................... 173 5.5 Disadvantages of Using Aluminum Chloride As Catalyst ............................. 173 5.6 Catalysts in Cumene Production Process ................................................... 174 5.7 Catalysts And Reactions ........................................................................... 176 5.8 Cumene Process And Catalysts ................................................................. 179 5.8.1 SPA Catalyst...................................................................................... 180 5.8.2 AlCl3 and Hydrogen Chloride Catalyst .................................................. 181 5.8.3 Zeolite Catalysts ................................................................................ 182 5.9 Future Technology Trends ....................................................................... 194 5.9.1 Catalysts. .......................................................................................... 194 6.0 PROCESS AND INSTRUMENTATION DIAGRAM .................................. 196 6.1 Introduction To P&ID .............................................................................. 196 6.2 P&ID Diagram ......................................................................................... 197 6.2.1 Symbols and layout ........................................................................... 198 6.2.2 List Of Pid Items ................................................................................ 199 6.2.3 Basic symbols.................................................................................... 200 6.3 Introduction to Valve ............................................................................... 204 6.3.1 Type of Valve .................................................................................... 207 6.3.2 Multi-Turn Valve ................................................................................ 208 6.3.3 Quarter-Turn Valve ............................................................................ 221 6.4 Introduction to Safety Valve and Relief Valve ............................................ 239 6.5 Relief Concepts ....................................................................................... 241 6.6 Location of Reliefs ................................................................................... 241 6.7 Relief Types ............................................................................................ 243 6.7.1 Spring-Operated Valves...................................................................... 244 6.7.2 Balanced-Bellows ............................................................................... 244 6.7.3 Rupture Discs ................................................................................... 245 6.8 P&ID for Reactor (Major Equipment) ........................................................ 248 6.8.1 P&ID for Reactor (Major Equipment) ................................................... 248 KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
6.8.2 Justification of The Control System Applied to the Reactor (Major) ....... 249 6.8.3 Justification of the Selection of the Type of Valve and Safety Valve to the Reactor (Major Equipment) ................................................................ 250 6.9 P&ID For Cumene Column (Minor Equipment) ........................................... 253 6.9.1 P&ID For Cumene Column (Minor Equipment) ..................................... 253 6.9.2 Justification Of The Control System Applied To The Cumene Column .... 254 6.9.3 Justification Of The Selection Of The Type Of Valve And Safety Valve To The Cumene Column (Minor) ............................................................ 255 7.0 HAZOP ANALYSIS ............................................................................... 258 7.1 HAZOP Analysis For Major Equipment - Reactor ........................................ 258 7.1.1 Recommendation HAZOP For Reactor ................................................. 271 7.2 HAZOP Analysis For Minor Equipment - Cumene Column ........................... 272 7.2.1 Recommendation HAZOP For Cumene Column .................................... 285 8.0 EXPLOSION ANALYSIS ....................................................................... 286 8.1 Introduction to Fire and explosions........................................................... 286 8.2 Distinction Between Fires And Explosions .................................................. 287 8.3 Mechanism Of Fire And Explosion ............................................................. 288 8.4 Fire Triangle ........................................................................................... 289 8.5 Sources And Causes Of Fire And Explosion In Cumene Plant ...................... 291 8.5.1 Sources Of Fuel ................................................................................. 291 8.5.2 Sources Of Ignition ............................................................................ 292 8.5.3
Sources of Oxygen......................................................................... 294
8.6 How To Identify Potential Fire And Explosion Sources ................................ 295 8.6.1 Fuel-Hydrocarbon Sources: Identifying And Documenting Hazards ....... 298 8.6.2 Oxygen Sources: Identifying And Documenting Hazards ...................... 300 8.6.3 Energy-Ignition Sources: Identifying And Documenting Hazards ........... 301 8.7 Reasons Why It Is Not Possible To Eliminate All Sources In Fire Triangle .... 304 8.8 Factors Affecting Ignitability Of Flammable Mixtures .................................. 307 8.9 Type Of Explosion Normally Happened In Cumene Plant ............................ 309 8.10 Fire And Explosion Analysis For Major Equipments ................................... 310 8.10.1 Fire And Explosion Analysis For Reactor ............................................ 312 KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
8.10.2 Fire And Explosion Analysis For Cumene Column ............................... 313 8.11 Identify Flammable Inventories And Locations In Cumene Plant ............. 314 8.11.1 Flammable Inventory: Propylene ...................................................... 314 8.11.2 Flammable Inventory: Benzene ........................................................ 316 8.11.3 Flammable Inventory: Di-Isoproply Benzene ..................................... 317 8.11.4 Flammable Inventory: Cumene ......................................................... 318 8.11.5 Flammable Inventory: Propane ......................................................... 319 8.12 Consequence Of Fire And Explosion Events ............................................. 320 8.13 Fire And Explosion Prevention And Control .............................................. 321 8.13.2 Minimization of Potential Amount Of Fuel .......................................... 322 8.13.2 Minimization Of Potential Sources Of Ignition .................................... 323 8.14 Additional Control Measures ................................................................... 325 8.15 Dust Control .......................................................................................... 326 8.16 Ignition Control ..................................................................................... 327 8.17 Damage Control .................................................................................... 328 8.18 Training Of Employees ........................................................................... 329 8.19 Management team ................................................................................ 329 9.0 ENVIRONMENT ANALYSIS .................................................................. 330 9.1 Introduction ............................................................................................ 330 9.2 Analytical Methods .................................................................................. 332 9.3 Emission Sources Of Cumene ................................................................... 333 9.3.1 Anthropogenic Sources ...................................................................... 335 9.4 Environmental Transport, Distribution, And Transformation ....................... 336 9.4.1 Cumene In Atmosphere ..................................................................... 336 9.4.2 Cumene In Water .............................................................................. 337 9.4.3 Cumene In Soil ................................................................................. 339 9.5 Environmental Levels And Human Exposure .............................................. 341 9.5.1 Environmental Levels ......................................................................... 341 9.5.2 Human Exposure ............................................................................... 344 9.6 Comparative Kinetics And Metabolism In Laboratory Animals And Humans . 346 9.7 Effects On Humans, Animals And Vegetation............................................. 349 9.7.1 Overview of Chemical Disposition ....................................................... 350 KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
9.7.2 Genotoxicity ...................................................................................... 352 9.7.3 Acute and Sub-Acute Effects .............................................................. 353 9.7.4 Sub-Chronic and Chronic Effects ......................................................... 358 9.7.5 Summary of Adverse Health Effects of Cumene Inhalation ................... 365 9.7.6 Effects on Vegetation......................................................................... 368 10.0 COMMERCIAL VALUE ........................................................................ 370 10.1 Cumene Market Survey .......................................................................... 370 10.1.1 Cumene Market Overview ................................................................ 370 10.1.1 Market Survey In Year 2010 (Price Report) ....................................... 371 10.1.2 Market Survey In Year 2011 (Price Report) ....................................... 372 10.1.3 Market Survey In Year 2012 (Price Report) ....................................... 373 10.2 Cost Estimation & Economics ................................................................. 375 10.2.1 Background & Objectives ................................................................. 375 10.2.2 Cost Evaluation ............................................................................... 375 10.2.3 Investment ..................................................................................... 377 10.2.4 Project Economic Evaluation ............................................................. 385 10.3 Cumene Commercial Value Report .......................................................... 389 10.3.1 US October cumene prices remain stable amid quiet trade ................. 389 10.3.2 US benzene and RGP markets are quiet ............................................ 390 10.4 Cumene Value Chain ............................................................................. 391 10.5 World Demand Of Cumene .................................................................... 393 10.6 Current Market Situation ........................................................................ 395 10.7 Cumene Market Outlook ........................................................................ 397 10.8 Petrochemicals: Global Markets .............................................................. 398 10.9 Feedstock Requirements ........................................................................ 399 10.10 Case Study .......................................................................................... 402 10.11 Commercial Experience ........................................................................ 404 11.0 CONCLUSION AND RECOMMENDATIONS......................................... 405 REFERENCES
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.0 HISTORY ON PETROLEUM REFINING
Prior to the 19th century, petroleum was known and utilized in various fashions in Babylon, Egypt, China, Persia, Rome and Azerbaijan. However, the modern history of the petroleum industry is said to have begun in 1846 when Abraham Gessner of Nova Scotia, Canada discovered how to produce kerosene from coal. Shortly thereafter, in 1854, Ignacy Lukasiewicz began producing kerosene from hand-dug oil wells near the town of Krosno, now in Poland. The first large petroleum refinery was built in Ploesti, Romania in 1856 using the abundant oil available in Romania. In North America, the first oil well was drilled in 1858 by James Miller Williams in Ontario, Canada. In the United States, the petroleum industry began in 1859 when Edwin Drake found oil near Titusville, Pennsylvania. The industry grew slowly in the 1800s, primarily producing kerosene for oil lamps. In the early 1900's, the introduction of the internal combustion engine and its use in automobiles created a market for gasoline that was the impetus for fairly rapid growth of the petroleum industry. The early finds of petroleum like those in Ontario and Pennsylvania were soon outstripped by large oil "booms" in Oklahoma, Texas and California. Prior to World War II in the early 1940s, most petroleum refineries in theUnited States consisted simply of crude oil distillation units (often referred to as atmospheric crude oil distillation units). Some refineries also had vacuum distillation units as well as thermal cracking units such as visbreakers (viscosity breakers, units to lower the viscosity of the oil). All of the many other refining processes discussed below were developed during the war or within a few years after the war. They KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 1|Page
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
became commercially available within 5 to 10 years after the war ended and the worldwide petroleum industry experienced very rapid growth. The driving force for that growth in technology and in the number and size of refineries worldwide was the growing demand for automotive gasoline and aircraft fuel. In the United States, for various complex economic reasons, the construction of new refineries came to a virtual stop in about the 1980's. However, many of the existing refineries in the United States have revamped many of their units and/or constructed add-on units in order to: increase their crude oil processing capacity, increase the octane rating of their product gasoline, lower the sulfur content of their diesel fuel and home heating fuels to comply with environmental regulations and comply with environmental air pollution and water pollution requirements.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 2|Page
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.1 The Malaysian Oil And Gas Industry: An Overview The Oil & Gas (O&G) industry has seen no small amount of attention during recent months. One item attracting attention is crude prices rising above USD50 per barrel (0.159m3) and the simultaneous rise of petrol prices due to reduction in government subsidies. News of discoveries of new potentially producing fields has increased interest in O&G related stocks, whether in suppliers to the industry or oil refineries. To encourage and maintain this level of interest, IEM held a symposium in July 2004, attempting to put forward a forum where people outside the O&G industry could be exposed to issues within the industry. Petroleum exploration in Malaysia started at the beginning of the 20th century in Sarawak, where oil was first discovered in 1909 and first produced in 1910. Prior to
1975, petroleum concessions were granted by state governments, where oil
companies have exclusive rights to explore and produce resources. The companies then paid royalties and taxes to the government. This state of affairs ceased on April 1, 1975 as a result of the Petroleum Development Act, whereby PETRONAS became the custodian of petroleum resources with rights to explore and produce resources.
The national oil company retains ownership and
management control in exploration, development and production of oil resources. Expenditure and profits are managed under instruments called Production Sharing Contracts (PSCs). The Production Sharing Contractor assumes all risks and sources
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 3|Page
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
all funds for all petroleum operations. The Contractor receives an entitlement through production.
Figure 1.1 Production Sharing Contractor Entitlement Each PSC may have different terms and conditions. For example, different time periods are allowed for exploration of acreage, developing and installing infrastructure to produce any hydrocarbons discovered, and the actual production period. Malaysia has the 25th largest oil reserves and the 14th largest gas reserves in the world. The total reserves is of the order of 18.82 billion barrels oil equivalent (boe), with a crude production rate of 600 thousand barrels per day.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 4|Page
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Figure 1.2 Historical Crude Oil Production (bbls : barrels per day. SB : Sabah contribution. SK : Sarawak Contribution, PM : Peninsular contribution.) The average natural gas production stands at approximately 5.7 billion standard cubic feet per day. Malaysia has 494,183km2 of acreage available for oil and gas exploration, with 337,167 km2 in the offshore continental shelf area, and 63,968km2 in deepwater. The acreage is split into 54 blocks, out of which 28 (a total of 205,500km2) are currently operated by Petronas Carigali Sdn. Bhd. plus seven other multinational oil companies.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 5|Page
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Figure 1.3 Historical Natural Gas Production
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 6|Page
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Figure 1.4 Increased production through rejuvenation There is also an opportunity to increase production by rejuvenation of existing production facilities. This concept can be applied both to topside and subsurface facilities. As an example, more than 50% of Malaysian assets have been producing for longer than 15 years. There are definite opportunities to debottleneck facilities, looking at design and current operating conditions, and maximising the use of existing equipment. New technologies may be retrofitted into existing equipment, increasing capacity at an acceptable cost.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 7|Page
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Figure 1.5 Competitiveness of the Industry Although there are few lower cost centres in this region, the international clients still
prefer Malaysia due to its high quality engineering produced and
availability of up to date technology knowledge. The Oil and Gas industry can be split into upstream and downstream sectors. The upstream sector includes the exploration and the extraction of crude oil. In the Malaysian Oil and Gas sector, it has been the upstream sector that has traditionally been developed. The Petroleum Development Act 1974 governs the upstream and the downstream sectors of the petroleum industry under which Petronas is party of. Petronas has a licensing system. All work which is contracted out in the upstream sector is through licensed contractors. One of the objectives of
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 8|Page
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
the Act was to make sure local players were involved. One of the requirements to obtain a licence is being a local company. It is because of this that the oil and gas engineering industry was fully developed by the mid 80s. From the mid 80s to late 80s, all engineering design work had to be done locally. According to Ir. Dr Torkil Ganendra, Secretary of MOGEC and Director of Aker Kvaerner Asia Pacific, the Oil and Gas industry in Malaysia is a regulated industry, thus all upstream engineering works have to be performed locally if there was local technical capability. Some specialised areas are done overseas.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 9|Page
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.2 Flow Diagram of Typical Refinery The image below is a schematic flow diagram of a typical oil refinery that depicts the various unit processes and the flow of intermediate product streams that occurs between the inlet crude oil feedstock and the final end products. The diagram depicts only one of the literally hundreds of different oil refinery configurations. The diagram also does not include any of the usual refinery facilities providing utilities such as steam, cooling water, and electric power as well as storage tanks for crude oil feedstock and for intermediate products and end products. There are many process configurations other than that depicted above. For example, the vacuum distillation unit may also produce fractions that can be refined into end products such as: spindle oil used in the textile industry, light machinery oil, motor oil, and various waxes.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 10 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Figure 1.6 Schematic Flow Diagram of typical oil refinery (Source: http://en.wikipedia.org/wiki/Oil_refinery)
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 11 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.3 Introduction On Cumene The cumene molecule can be visualized as a straight-chain propylene group having a
benzene ring attached at the middle carbon , C 6H5CH(CH3)2 . It is a
colourless liquid , bp 152.40C having a characteristic aromatic odor . It is isomeric with n-propylbenzene , ethyltoluene and trimethylbenzene.
Figure 1.7 Chemical Structure Of Cumene (Source: http://en.wikipedia.org/wiki/Cumene) Cumene is
the
common
name
for
isopropylbenzene,
an organic
compound that is an aromatichydrocarbon. It is a constituent of crude oil and refined fuels. It is a flammable colorless liquid that has a boiling point of 152 °C. Nearly all the cumene that is produced as a pure compound on an industrial scale is
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 12 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
converted to cumene hydroperoxide, which is an intermediate in the synthesis of other industrially important chemicals, primarily phenol andacetone. Thus cumene is also named as 1-methylethyl benzene or 2-phenyl-propane or isopropylbenzene. Cumene (C9H12) is a substituted aromatic compound in the benzene , toluene and ethylbenzene series. Cumene is a clear liquid at ambient conditions. High purity cumene is normally manufactured from propylene and benzene and is a minor constituent of most gasolines. It is the principal chemical used in the world wide production of phenol and its co-product acetone. Many consumer or industrial products such as plywood and composition board banded with phenolic resins, nylon-6, epoxy and polycarbonate resins and solvents, have origins that can be traud to cumene. Cumene processes were originally developed between 1939 and 1945 to meet the demand for high octane aviation gasoline during world war-II. In 1989 about 95% of cumene demand was as an intermediate for the production of phenol and acetone. A small percentage is used for the production of ∝-Methylstyrene. Before the devolopement of the cumene route to phenol and
acetone,
cumene had been used extensively during warld war2. It is a curious fact that although propylation of benzene by means of phosphoric acid and aluminium chloride have been the standard methods of manufacture for many years ,the first
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 13 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
plan used sulphuric acid as a catalyst. This was a war time expedient arising from uncertainity over phosphoric acid supplies. Almost all the worlds supply of cumene is now produced as an intermediate for phenol and acetone manufacture. Some refinery units still produce cumene for use as an antiknock constituent of gasoline but it is doubtful whether new plants would be constructed for this purpose . Neither does it seem likely that any large scale plant would be installed for manufacturing
the
hydroperoxide,
methylstyrene
,diisopropylebenzene,or
acetophenone ,although these cumene derived compounds are of considerable commercial importance. They occur as byproducts during cumene and phenol production, and are usually marketed by manufacturers .
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 14 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.4 Cumene Production Commercial
production
benzene with propylene.
of
cumene
Previously,
is
by Friedel–Crafts
solid phosphoric
acid (SPA)
alkylation of supported
on alumina was used as the catalyst. Since the mid-1990s, commercial production has switched to zeolite-based catalysts. Isopropyl benzene is stable, but may form peroxides in storage if in contact with the air. It is important to test for the presence of peroxides before heating or distilling. The chemical is also flammable and incompatible with strong oxidizing agents. Environmental laboratories commonly test isopropyl benzene using a Gas chromatography–mass spectrometry (GCMS) instrument.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 15 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.5 Cumene Properties
Cumene
IUPAC name (1-methylethyl)benzene Other names isopropylbenzene 2-phenylpropane Identifiers CAS number
98-82-8
PubChem
7406
ChemSpider
7128
UNII
8Q54S3XE7K
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 16 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
KEGG
C14396
ChEBI
CHEBI:34656
RTECS number
GR8575000
Jmol-3D images
Image 1
Properties Molecular formula
C9H12
Molar mass
120.19 g mol−1
Appearance
colorless liquid
Density
0.862 g cm−3, liquid
Melting point
−96 °C, 177 K, -141 °F
Boiling point
152 °C, 425 K, 306 °F
Solubility in water
Insoluble
Viscosity
0.777 cP at 21 °C
Hazards R-phrases
R10,R37,R51/53,R65
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 17 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
S-phrases
S24,S37,S61,S62
Main hazards
Flammable
Flash point
43 °C
Related compounds Related compounds
ethylbenzene, toluene, benzene
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 18 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.6 Cumene Process The Cumene
process (Cumene-phenol
process, Hock
process)
is
an industrial process for developing phenol & acetone from benzene and propylene. The term stems from cumene (isopropyl benzene), the intermediate material during the process. It was invented by Heinrich Hock in 1944 and independently by R. Ūdris and P. Sergeyev in 1942 (USSR).
This
process
converts
two
relatively
cheap
starting
materials, benzene and propylene, into two more valuable ones, phenol and acetone. Other reactants required are oxygen from air and small amounts of a radical initiator. Most of the worldwide production of phenol and acetone is now based on this method. In 2003, nearly 7 billion kg of phenol was produced by the Hock Process.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 19 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.7 Technical Description Benzene and propylene are compressed together to a pressure of 30 standard atmospheres at 250 °C (482 °F) in presence of a catalytic Lewis acid. Phosphoric acid is often favored over aluminium halides. Cumene is formed in the gasphase Friedel-Crafts alkylation of benzene by propylene:
Cumene is oxidized in air which removes the tertiary benzylic hydrogen from cumene and hence forms a cumene radical:
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 20 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.8 Cumene Chemical Properties Cumene is a colourless liquid, soluble in alcohol, carbon tetra chloride, ether and benzene. It is insoluble in water. Cumene is oxidized in air which removes the tertiary benzylic hydrogen from cumene and hence forms a cumene radical:
This
cumene
radical
cumene hydroperoxide radical,
then bonds with
an
which
in
oxygen
molecule
turn
to
give
forms cumene
hydroperoxide (C6H5C(CH3)2-O-O-H) by abstracting benzylic hydrogen from another cumene molecule. This latter cumene converts into cumene radical and feeds back into subsequent chain formations of cumene hydroperoxides. A pressure of 5 atm is used to ensure that the unstable peroxide is kept in liquid state.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 21 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Cumene hydroperoxide is then hydrolysed in an acidic medium (the Hock rearrangement) to givephenol and acetone. In the first step, the terminal hydroperoxy oxygen atom is protonated. This is followed by a step in which the phenyl group migrates from the benzyl carbon to the adjacent oxygen and a water molecule is lost, producing a resonance stabilized tertiary carbocation. The concerted mechanism of this step is similar to the mechanisms of the Baeyer-Villiger
oxidationand
also
the
oxidation
step
of hydroboration-
oxidation.[6] In 2009, an acidified bentonite clay was proven to be a more economical catalyst than sulfuric acid as the acid medium.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 22 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
As shown below, the resulting carbocation is then attacked by water, a proton is then transferred from the hydroxy oxygen to the ether oxygen, and finally the ion falls apart into phenol and acetone.
The products are extracted by distillation.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 23 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.9 Uses Of Cumene 1. As feed back for the production of Phenol and its co-product acetone 2. The cumene oxidation process for phenol synthesis has been growing in popularity since the 1960’s and is prominent today. The first step of this process is the formation of cumene hydroperoxide. The hydroperoxide is then selectively cleaved to Phenol and acetone. 3. Phenol in its various formaldehyde resins to bond construction materials like plywood and composition board (40% of the phenol produced) for the bisphenol A employed in making epoxy resins and polycarbonate (30%) and for caprolactum, the starting material for nylon-6 (20%). Minor amounts are used for alkylphenols and pharmacuticals. 4. The largest use for acetone is in solvents although increasing amounts are used to make bisphenol A and methylacrylate. 5. ∝- Methylstyrene is produced in controlled quantities from the cleavage of cumene hydroperoxide, or it can be made directly by the dehydrogenation of cumene. 6. Cumene in minor amounts is used as a thinner for paints, enamels and lacquers and to produce acetophenone, the chemical intermediate dicumylperoxide and diiso propyl benzene. 7. Cumene is also used as a solvent for fats and raisins.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 24 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
1.10 Description On Q-Max Process The most promising materials were modified to improve their selectivity and then subjected to more-rigorous testing. By 1992, UOP had selected the most promising catalyst based on beta-zeolite for cumene production and then began to optimize the process design around this new catalyst. The result of this work is the Q-Max process and the QZ- 2000 catalyst system. 1. Raw material propylene and benzene are used for the production of cumene. 2. These are stored in the respective storage tanks of 500MT capacity in the storage yard pumped to the unit by the centrifugal pumps. 3. Benzene pumped to the feed vessel which mixes with the recycled benzene. Benzenestream is pumped through the vaporizer with 25 atm pressure and vaporized to the temperature of 243degC, mixed with the propylene which is of same and temperature and pressure of benzene stream. 4. This reactant mixture passed through a fired super heater where reaction temperature 350degC is obtained. 5. The vapor mixture is sent to the reactor tube side which is packed with the solid phosphoric acid catalyst supported on the kieselguhr the exothermal heat is removed by the pressurized water which is used for steam production and the effluent from the reactor i.e., cumene, p-DIPB, unreacted benzene, propylene and propane with temperature 350oC is used as the heating media in the vaporizer which used for the benzene vaporizing and cooled to 40 oC in a water cooler, propylene and propane are separated from the liquid mixture of cumene, p-DIPB, benzene in a separator operating slightly above atm and KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 25 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
the pressure is controlled by the vapor control value of the separator, the fuel gas is used as fuel for the furnace also. 6. The liquid mixture is sent to the benzene distillation column which operates at 1 atm pressure, 98.1% of benzene is obtained as the distillate and used as recycle and the bottom liquid mixture is pumped at bubble point to the cumene distillation column where distillate 99.9% cumene and bottom pure p-DIPB is obtained. 7. The heat of bottom product p-DIPB is used for preheating the benzene column feed, All the utility as cooling water, electricity, steam from the boiler, pneumatic air are supplied from the utility section 8. The typical reactor effluent yield contains 94.8 Wt. % cumene and 3.1 Wt. % of diiso propylbenzene. The remaining 2.1 % is primarily heavy aromatics. 9. This high yield of cumene is achieved without transalkylation of diiso propylbenzene and is unique to the solid phosphoric acid catalyst process. 10. The cumene product is 99.9 Wt. % pure and the heavy aromatics, which have an octane number of 109, can either be used as high octane gasoline blending components or combined with additional benzene and sent to a transalkylation section of the plant where diiso propylbenzene is converted to cumene. 11. The overall yields of cumene for this process are typically 97-98 Wt. % with transalkylation and 94-96 Wt. % without transalkylation.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 26 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.0 REFINERY BALANCE 2.1 Introduction Changes such as structural and cyclical in our business environment have keep us on our toes. Our core businesses are changing in our historic home of Europe. The Consumption of both chemicals and petroleum products is down and new demands for more diesel and less gasoline, greener products and so on which are taking shape currently. We are not surprise to any changes that come to us. Since we had foreseen most of them and are now adjusting our production base accordingly, while deploying all our innovation capabilities to create a line of products in sync with our customers’ expectations. In addition, we are setting the stage for our expansion in regions of strong economic growth at the same time such as Asia, the Middle East and Africa, and adapting to the specific needs of those markets, by leveraging solid partnerships and the remarkable agility of all our activities. Total (37.5%) and Saudi Aramco (62.5%) are partners in SATORP, the company building the Jubail refinery in Saudi Arabia. This strategically important project will allow us to move closer to oil and gas fields and consumers.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 27 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.2 The Abu Dhabi Oil Refining Company (Takreer) Basically, The Abu Dhabi Oil Refining Company (Takreer) was established in 1999 in order to take over the responsibility of refining operations previously undertaken by the Abu Dhabi National Oil Company (ADNOC). There are several company’s areas of operation which include the refining of crude oil and condensate, supply of petroleum products and production of granulated Sulphur in compliance with domestic and international specifications. Moreover, this refinery can work for 85,000 bbl/day capacity.
Figure 2.1: The PMC contract is for the EPC phase of the base oils plant in Ruwais Industrial Complex.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 28 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Today, The Shaw Group Inc. had announced that their company has been awarded a contract by The Abu Dhabi Oil Refining Company (Takreer) to provide project management consultancy services during the engineering, procurement and construction phase of a base oils plant at the Ruwais Industrial Complex in Abu Dhabi. Basically, the planned facility will be capable of producing 500,000 tons/year of Group III base oils, as well as 100,000 tons/year of Group II base oils, and is scheduled to begin commercial production in 2013. Group II and III base oils are used for blending top-tier lubricants for car engines. Besides, an announcement was made by UOP LLC, a Honeywell company, that they have been selected by the Abu Dhabi Oil Refining Company, also known as Takreer, with the aim to supply technology and engineering services for an expansion at its Ruwais Refinery in the United Arab Emirates.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 29 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
The history of the refineries in Abu Dhabi Refinery which consists of 85000bbl/day is shown in Figure 2.2 below:
1976 Original Plant 15,000 BBL/day
1983 New Refinery 60,000 BBL/day
1996 Plant Expansion 85,000 BBL/day Figure 2.2: history of the refineries in Abu Dhabi Refinery which consists of 85000bbl/day
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 30 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
The history of the refineries in Ruwais Refinery which consists of 40000bbl/day is shown in below:
1981 Hydro-skimmer units 120,000BBL/day 1985 Hydrocracker units 2000 Condensate units 280,000 BBL/day 2006 Gasoline Units Figure 2.3: History of the refineries in Ruwais Refinery which consists of 40000bbl/day There are other facilities such as below: Power Geeration 660MW Water Desalination 14.0 MM Gallons/ day Hazardous Material Treatment, 26MMT/Year
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 31 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.3 Refinery Installations After the discovery of oil in Abu Dhabi in year 1958 and the first export shipments of Crude in year 1962, there are a plans to build a glass root Refinery with a capacity of 15,000 barrels per stream day (BPSD) to meet a growing local need for petroleum products. Basically, the construction work has begun in year 1973. This work cost around initial $45 million and this plant was inaugurated in the April of 1976. Therefore, we can see that the demand for oil products were grow rapidly. However, the work began almost on installing a new Refinery to process a further 60,000 BPSD and this was commissioned in year 1983. So, requirements has continued to grow in the fast-developing Emirate and ADNOC has decided to expand the capacity yet again with environmental considerations in mind and to include additional units for Gas Oil Desulphurization and Sulphur recovery. Therefore, the expanded Refinery with a capacity rate of 85,000 BPSD has been started up in December 1992. On the other hand, a Salt and Chlorine Plant has been commissioned at Umm Al Nar in the year of 1981 which was merged with the Refinery in year 1990 in order to form the Abu Dhabi Refinery and Chlorine Division. On 30th November 2001, it was permanently shut down. Two power plants, owned and operated by Umm Al Nar Power Company, and a Lube oil blending/filling plant, owned and operated by ADNOC Distribution, are located adjacent to the Refinery.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 32 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
The refinery is a Hydro Skimming Complex designed to process Bab Crude as well as a mixture of Asab-Sahil, Shah and Thammama Condensate. Finished products from the Refinery are as follows: Liquefied Petroleum Gases, Naphtha, Unleaded Gasoline, Aviation Turbine Kerosene, Domestic Kerosene, Gas Oil, Straight Run Residue, Liquid Sulphur. 2.3.1 Refinery Units Therefore, the refinery unit including: 1. Crude Distillation Unit (85,000 BPSD) 2. Naphtha Hydrodesulphuriser Unit (22,795 BPSD) 3. Kerosene Merox Unit (21,250 BPSD) 4. Catalytic Reformer Unit (14,000 BPSD) 5. Gas Oil Hydrodesulphuriser Unit (22,500 BPSD) 6. LPG Treating and Recovery Unit (3,480 BPSD) 7. Excess Naphtha Stabilizer Unit (3,325 BPSD) 8. Gas Sweetening Unit (35 tons/day H2S Removal) 9. Sulphur Recovery Unit (35 tons/day) 10. Jarn Yaphour Crude Oil Stabilization Plant (10,000 BPSD)
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 33 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.3.1.1 Crude Distillation Unit (85,000 BPSD) For initial step, prior to the actual distillation process, Crude Oil is passed through a Desalter Unit to remove the undesirable salts, water and sludge which are generally associated with any type of crude. After final heating in a furnace, the Crude is then fractionated in the Atmospheric Distillation Column into the basic raw petroleum fractions of Naphtha, kerosene, Gas Oil and Straight Run Residue.
2.3.1.2 Naphtha Hydrodesulphuriser Unit (22,795 BPSD) The Naphtha Hydrodesulphuriser sweetens the Straight Run Naphtha from Crude Unit. This unit has produced three products namely: Heavy Naphtha, Light Naphtha and Sour Liquefied Petroleum Gases.
2.3.1.3 Kerosene Merox Unit (21,250 BPSD) Mercaptans was converted by the unit in the straight run kerosene into disulphine in order to meet the final product quality for aviation kerosene.
2.3.1.4 Catalytic Reformer Unit (14,000 BPSD) The Reformer processes the Heavy Naphtha cut to improve its anti-knock properties prior to using it as a Gasoline blending component. KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 34 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.3.1.5 Gas Oil Hydrodesulphuriser Unit (22,500 BPSD): Gas oil sulphur content has been reduced by the Gas Oil Hydrodesulphurise to 0.15 wt% in order to improve the product quality.
2.3.1.6 LPG Treating and Recovery Unit (3,480 BPSD): In this unit, raw LPG from Naphtha Hydrodesulphuriser and Catalytic Reformer Unit are processed. The butane that produced in this unit is used as a blending component in Gasoline. Besides that, the butane also can blended with Propane in order to form LPG for domestic use.
2.3.1.7 Excess Naphtha Stabilizer Unit (3,325 BPSD): Excess Naphtha from Crude Unit is stabilized.
2.3.1.8 Gas Sweetening Unit (35 tons/day H2S Removal): Amine solution was used to sweetens the sour gas that produced in the refinery facilities so that to remove any hydrogen sulphide inn order to minimize sulphur oxide emissions.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 35 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.3.1.9 Sulphur Recovery Unit (35 tons/day): The acid gases produced from Gas Sweetening Unit are converted to liquid sulphur.
2.3.1.10 Jarn Yaphour Crude Oil Stabilization Plant (10,000 BPSD): The Oil/Gas Separation Plant is designed to stabilize Crude from Jarn Yaphour Wells, located some 30 kilometers from Abu Dhabi. The separated gas is further treated to remove hydrogen sulphide, water and hydrocarbon condensate before it is injected into GASCO’s Main Gas Network.
2.3.2 Utilities, Off-sites, Terminal & ADR Technology Additional Effluent Water Treatment facilities were installed to adhere to rigid oil in water specification of 10 ppm maximum.
2.3.2.1 Utilities Power and fresh was supplied from the adjacent plant of the Abu Dhabi Water and Electricity Authority to the refinery. Steam, Air, Nitrogen and Sea Water for cooling are all provided by the Refinery's own facilities. The Refinery’s Fuel Gas supply is supplemented by Natural Gas from the GASCO Main Network. KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 36 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.3.2.2 Off-sites The storage capacity of Abu Dhabi Refinery Tank Farm is 500,000 cubic meters, which includes facilities for Crude Oil, Intermediate Streams, Semi-Finished Products, Finished Products and Utility Fuel Oil. The Residue and Naphtha are shipped to Ruwais Refinery while most of the Refined Products from Abu Dhabi Refinery are sold in the ever expanding domestic market.
2.3.2.3 Marine Terminal The Refinery is served by a two-Berth Marine Terminal on the North Shore of the Island for loading and unloading of tankers. Maximum Draft is 9.5 meters; maximum Cargo is 30,000 tons.
2.3.2.4 ADR Technology Abu Dhabi Refinery completed the process of installing a fully integrated stateof-the-art Computerized System designed to Modernize Operations in the year 1994. In January 1993, the first level was achieved with the commissioning of a new Consolidated Control Room under the overall Refinery expansion project. The Refinery is equipped with a Distributed Control System (DCS).
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 37 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
DCS allowed for the introduction of an Advanced Process Control system as part of the Process Automation and Computerization project (PACS). PACS are designed to provide accurate and up-to-the-minute information on every aspect of the Operations in Support of Operational and Management Activities. On the other hand, the second level of the project includes the implementation of Advanced Process Control (APC) strategies and off-site Automation and Computerization. Third level involved the implementation of a plant-wide Data Base and Communications Network, leading to the use of a Computerized Decision Support System in laboratory management, Planning, Scheduling, Mass Balancing, Oil Accounting and Performance Monitoring.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 38 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
CRUDE DISTILLATION UNIT
85 000 BPSD From crude oil to fraction of naphtha, kerosene, gas oil and straight run residue
NAPHTHA HYDRODESULPHURISER UNIT
22 795 BPSD From straight run naphtha to heavy naphtha, light naphtha and sour liquefied petroleum gaese
KEROSENE MEROX UNIT
21 250 BPSD From mercaptans to disulphide
CATALYTIC REFORMER UNIT
GAS OIL HYDRODESULPHURISER UNIT
14 000 BPSD From heavy naphtha cut to gasoline blending component
22 500 BPSD Product: Reduced sulphur content of gas oil
ABU DHABI REFINERY LPG TREATING AND RECOVERY UNIT
EXCESS NAPHTHA STABILIZER UNIT
GAS SWEETENING UNIT
3 480 BPSD Product: Processed LPG
3 325 BPSD Product: Stabilized naphtha
35 tons/day H2S removal Product: Sweetened sour gases
SULPHUR RECOVERY UNIT
35 tons/day From acid gases to liquid sulphur
CRUDE OIL STABILIZATION PLANT
10 000 BPSD Product: Stabilized crude
Figure 2.4: Overall operation in Abu Dhabi Oil Refinery Company
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 39 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.4 Mass Balance Based 400,000 BPD of Middle East Heavy Crude By referring to US Petroleum Refinery Balance (Millions Barrels Per Day, Except Utilization Factor) as shown below:
Figure 2.5: US Petroleum Refinery Balance (Millions Barrels Per Day, Except Utilization Factor) KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 40 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.4.1 Mass Balance by Assumed Proportion of Refining Products is Double
Figure 2.6: By referring to the diagram above which consists of 200,000 barrels per day (Source: Environmental Aspects in Refineries and Projects, 2012)
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 41 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
It is found that if the feedstock which is the 400 000 BPD Middle East heavy crude and assumed that the proportion of the refining products is double and the number of the condensate is 560,000bbl/day, the final product will be shown in Table 2.1 below: Table 2.1: Calculation of final product from 400 000 BPD Middle East heavy crude Quantity Products
(200,000 BPD)
Mass balance Fraction
Percentage (%)
(400,000 BPD)
Gasoline
55000
0.138
13.836478
110000
Fuel oil
31000
0.078
7.798742138
62000
Jet fuel & kerosene
112000
0.2818
28.17610063
224000
Gas oil
89000
0.2239
22.38993711
178000
LPG
16000
0.0403
4.025157233
32000
Naphta
94500
0.2377
23.77358491
189000
Total
397500
1
100
795000
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 42 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Mass balance (400000bbl/d) (BPD) 900000
795000
800000
700000
600000
500000
400000
300000 224000 200000
189000
178000
110000 100000 62000 32000 0 Gasoline
Fuel oil
Jet fuel & kerosene
Gas oil
LPG
Naphta
Total
Figure 2.7: Comparison quantity of product produced
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 43 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.4.2 Mass Balance by Fraction Method Based on the production of Abu Dhabi Oil Refining Company (refinery plant) at the year of 1996, the mass balance is done using fraction method. Table 2.2: Calculation of final product from 400 000 BPD Middle East heavy crude Quantity Products
Percentage
Mass balance
(%)
(BPD)
Fraction (BPD)
Gasoline
46100
0.199222
19.92
79688.85048
Fuel oil
67000
0.289542
28.95
115816.7675
Jet fuel & kerosene
36200
0.156439
15.64
62575.62662
Gas oil
70000
0.302506
30.25
121002.5929
LPG
7100
0.030683
3.07
12273.12014
Asphalt
5000
0.021608
2.26
8643.042351
231400
1
100
400 000
Total
** This analysis is done based on a production rate from Abu Dhabi Oil Refining Company (refinery plant) using heavy crude oil
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 44 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
140000
120000
QUANTITY (BPD)
100000
80000
60000
40000
20000
0
PRODUCT Gasoline
Fuel oil
Jet fuel & kerosene
Gas oil
LPG
Asphalt
Figure 2.8: Comparison quantity of product produced
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 45 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.4.3 Mass Balance based on Total Production from while Middle East Countries There can be another analysis based on the total production from whole Middle East countries MIDDLE EAST COUNTRIES STATISTIC Table 2.3: Middle East Output of Refined Petroleum Products, 2005 (Thousand Barrels per Day) Energy Information Administration, International Energy Annual 2006 Table Posted: December 8, 2008 Distillate
Residual
Liquefied
Total Output of
Refinery
Fuel
Fuel
Petroleum
Refined Petroleum
Fuel and
Oil
Oil
Gases
Products
Loss
8.47
91.97
52.13
1.18
47.63
268.47
10.74
18.47
127.66
499.57
480.16
135.58
166.82
1,688.93
67.56
74.43
12.82
23.19
104.40
152.15
36.61
51.83
455.44
17.52
Israel
63.78
24.16
3.37
62.22
49.95
18.32
23.12
244.90
9.42
Jordan
14.33
7.04
4.89
28.53
27.91
3.87
5.15
91.73
3.53
Kuwait
65.48
50.27
128.30
245.77
179.47
149.41
222.99
1,041.68
40.06
0
0
0
0
0
0
0
0
0
Motor
Jet
Gasoline
Fuel
Bahrain
17.64
49.45
Iran
260.67
Iraq
Country
Lebanon
Kerosene
Other
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 46 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS Oman
14.84
3.69
0.23
14.61
34.92
2.42
0.48
71.20
2.85
Qatar
40.31
20.10
0.08
18.94
14.23
81.83
5.67
181.16
6.97
Saudi Arabia
347.63
143.98
81.51
647.59
487.58
34.90
343.49
2,086.68
83.47
Syria
31.95
4.80
1.14
74.96
88.01
10.77
43.19
254.81
9.80
United Arab Emirates
43.73
117.71
0
87.41
28.67
16.63
93.27
387.42
14.90
Yemen
27.93
8.02
2.31
19.61
8.24
3.09
6.73
75.93
2.92
1,002.71
460.50
381.16
1,895.59
1,603.44
494.59
1,010.36
6,848.35
269.73
Middle East
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 47 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Middle East Output of Refined Petroleum Product on 2005
other 15%
petroleum gases 7%
motor gasoline 15%
jet fuel 7% kerosene 5%
fuel oil 23% fuel oil 28%
motor gasoline
jet fuel
kerosene
fuel oil
fuel oil
petroleum gases
other
Figure 2.9: Fraction of Middle East Output on 2005 KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 48 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Table 2.4: Calculation of final product from 400,000 BPD Middle East heavy crude
Products
Quantity
Fraction
(BPD)
Percentage
Mass balance
(%)
(BPD)
Gasoline
1002.71
0.146416
14.64
58566.51602
Fuel oil
1895.59
0.276795
27.68
110718.0562
Jet fuel
460.5
0.067242
6.72
26896.98979
Kerosene
381.16
0.055657
5.57
22262.88084
LPG
494.59
0.07222
7.22
28888.12634
Asphalt
1010.36
0.147533
14.75
59013.33898
Residual fuel oil
1603.44
0.234135
23.41
93654.09186
TOTAL
6848.35
1
100
400 000
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 49 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Gasoline
Fuel oil
Jet fuel
Kerosene
LPG
Asphalt
Residual fuel oil
120000
100000
Quantity (BPD)
80000
60000
40000
20000
0 Product
Figure 2.10: Comparison quantity of product produced
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 50 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
2.5 Conclusion With the increasing world energy demand, this situation has pushed the oil producing countries, Middle East Countries, to start exploiting heavy oil reservoirs, which had been neglected or little used and to increase the oil exploration activities. Currently, there are some heavyweight producers such as Saudi Arabia, Venezuela and Iran produce large quantities of heavy (≈ API < 20) sour crude with high sulfur content. However, others such as Nigeria, the United Arab Emirates, Angola and Libya pump a higher quality, light sweet crude, with low sulfur content. Since the global energy demand is keep increasing, this has putting up pressure on the major oil producing countries to increase their production capacities. With Middle East Countries alone, the production capacity is expected to reach 4 million barrels per day (MBPD) by the year of 2020 has reach. It is important for the Middle East Countries to maintain its market share besides increase production capacity. However, heavy crude oil (API < 20) must be also used as gap filler. Basically, these current events are facing the oil industry in Middle East Countries with many decisions and technological challenges, including counteracting expected increased risk of corrosion and equipment failures during the production and refining of heavy crude oil. Inorganic salts, organic chlorides, organic acids, and sulfur compounds can be consider as the most damaging impurities.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 51 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Things might getting worst when many of the compounds are unstable during refining operations and they break into smaller components or combine with other constituents, concentrating corrodants in certain units, such as the breakdown of sulfur compounds and organic chlorides. However, most of the world refineries including Kuwait are equipped with alloys that capable of handling sweet light crude, which is most suitable for refining into petrol, gas oil and heating oil. On the other hand, refining of heavy crude is difficult and is associated with operational problems. Problem can be arise from the increased risk of corrosion, equipment failures, and downtime of process units. This problem are caused by the high sulfur and salt contents of these crudes including organic chlorides.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 52 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.0 GROUP PROJECT 3.1 Introduction To Cumene Production The
commercial
production
of
cumene
is
by Friedel–Crafts
benzene with propylene. In previously, solid phosphoric
alkylation of
acid (SPA) supported
on alumina was used as the catalyst. Therefore, since the mid-1990s, commercial production has switched to zeolite-based catalysts. Isopropyl benzene is stable, but may form peroxides in storage if in contact with the air. It is important to test for the presence of peroxides before heating or distilling. The chemical is also flammable and incompatible with strong oxidizing agents. Environmental
laboratories
commonly
test
isopropyl
benzene
using
a Gas
chromatography–mass spectrometry (GCMS) instrument. 3.1.1 Cumene Project Definition Isopropylbenzene, also known as cumene, is among the top commodity chemicals, taking about 7 – 8% from the total worldwide propylene consumption. Today, the cumene is used almost exclusively for manufacturing phenol and acetone. This case study deals with the design and simulation of a medium size plant of 100 kton cumene per year. The goal is performing the design by two essentially different methods. The first one is a classical approach, which handles the process synthesis and energy saving with distinct reaction and separation sections. In the second alternative a more innovative technology is applied based on reactive distillation.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 53 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Table 3.1 presents the purity specifications. The target of design is achieving over 99.9% purity. It may be seen that higher alkylbenzenes impurities are undesired. Ethyl - and butylbenzene can be prevented by avoiding olefi ns and butylenes in the propylene feed. N - propylbenzene appears by equilibrium between isomers and can be controlled by catalyst selectivity. In this project we consider as raw materials benzene of high purity and propylene with only 10% propane. As an exercise, the reader can examine the impact of higher propane ratios on design. Table 3.1: Specifications For Cumene
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 54 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.1.2 Cumene Manufacturing Routes General information about chemistry, technology and economics can be found in the standard encyclopaedic material, as well as in more specialized books. The manufacturing process is based on the addition of propylene to benzene (Alexandre, 2008):
Beside isopropyl benzene (IPB) a substantial amount of polyalkylates is formed by consecutive reactions, mostly as C6H5 - (C3H7) 2 (DIPB) with some C6H5 - (C3H7) 3 (TPB). The main reaction has a large exothermal effect, of − 113 kJ/mol in standard conditions. The alkylation reaction is promoted by acid - type catalysts. The synthesis can be performed in gas or liquid phase. Before 1990 gas – phase alkylation processes dominated, but today liquid - phase processes with zeolite catalysts prevail. Recent developments make use of reactive distillation. Cumene processes based on zeolites are environmentally friendly, offering high productivity and selectivity. The most important are listed in Table 3.2. The catalyst performance determines the type and operational parameters of the reactor and, accordingly the flowsheet configuration. The technology should find an efficient solution for using the reaction heat inside the process and and/or making it available to export. By converting the polyalkylbenzenes into cumene an overall yield of nearly 100% may be achieved.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 55 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Table 3.2: Technologies for cumene manufacturing based on zeolites
Figure 3.1 illustrates a typical conceptual flowsheet. Propylene is dissolved in a large excess of benzene (more than 5 : 1 molar ratio) at sufficiently high pressure that ensures only one liquid phase at the reaction temperature, usually between 160 and 240 ° C. The alkylation reactor is a column filled with fixed-bed catalyst, designed to ensure complete conversion of propylene. The reactor effluent is sent to the separation section, in this case a series of four distillation columns: propane (LPG) recovery, recycled benzene, cumene product and separation of polyisopropylbenzenes. The flowsheet involves two recycles: nonreacted benzene to alkylation and polyalkylbenzenes to transalkylation. The minimization of recycle flows and of energy consumption in distillation are the key objectives of the design. These can be achieved by employing a highly active and selective catalyst, as well as by implementing advanced heat integration.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 56 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Figure 3.1: Conceptual Flowsheet for cumene manufacturing by Dowkellogg process
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 57 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.1.3 General Overall Material Balance for Cumene Process Table 3.3 illustrates a typical material balance of a cumene plant using Dow-Kellog technology. The propylene may contain up to 40% propane, but without ethylene and butylene. Beside cumene, variable amounts of LPG can be obtained as subproducts. Energy is also exported as LP steam, although it is consumed as well as other utilities (fuel, cooling water, electricity). Table 3.3: Overall Process Material Balance After Dow-Kellog Technology
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 58 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.1.4 Physical Properties Table 3.4 presents some fundamental physical constants. Critical pressures of propane and propylene are above 40 bar, but in practice 20 to 30 bar are sufficient to ensure a high concentration of propylene in the coreactant benzene. From the separation viewpoint one may note large differences in the boiling points of components and no azeotrope formation. In consequence, the design of the separation train should not raise particular problems. Since the liquid mixtures behave almost ideally a deeper thermodynamic analysis is not necessary. The use of vacuum distillation is expected because of the high boiling points of the polyalkylated benzenes. Table 3.4: Basic physical properties of components in the outlet reactor mixture
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 59 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.2 Cumene Process The Cumene process (Cumene-phenol process, Hock process) is an industrial process for developing phenol and acetone from benzene and propylene. The term stems from cumene (isopropyl benzene), the intermediate material during the process. It was invented by Heinrich Hock in 1944 and independently by R. Ūdris and P. Sergeyev in 1942 (USSR).
This
process
converts
two
relatively
cheap
starting
materials, benzene and propylene, into two more valuable ones, phenol and acetone. Other reactants required are oxygen from air and small amounts of a radical initiator. Most of the worldwide production of phenol and acetone is now based on this method. In 2003, nearly 7 billion kg of phenol was produced by the Hock Process.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 60 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.3.1 Technical Description Benzene and propylene are compressed together to a pressure of 30 standard atmospheres at 250 °C (482 °F) in presence of a catalytic Lewis acid. Phosphoric acid is often favored over aluminium halides. Cumene is formed in the gasphase Friedel-Crafts alkylation of benzene by propylene:
Cumene is oxidized in air which removes the tertiary benzylic hydrogen from cumene and hence forms a cumene radical:
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 61 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.2.1 Cumene Chemical Properties Cumene is a colourless liquid, soluble in alcohol, carbon tetra chloride, ether and benzene. It is insoluble in water. Cumene is oxidized in air which removes the tertiary benzylic hydrogen from cumene and hence forms a cumene radical:
This cumene radical then bonds with an oxygen molecule to give cumene hydroperoxide radical, which in turn forms cumene hydroperoxide (C6H5C(CH3)2-O-OH) by abstracting benzylic hydrogen from another cumene molecule. This latter cumene converts into cumene radical and feeds back into subsequent chain formations of cumene hydroperoxides. A pressure of 5 atm is used to ensure that the unstable peroxide is kept in liquid state.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 62 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Cumene hydroperoxide is then hydrolysed in an acidic medium (the Hock rearrangement) to givephenol and acetone. In the first step, the terminal hydroperoxy oxygen atom is protonated. This is followed by a step in which the phenyl group migrates from the benzyl carbon to the adjacent oxygen and a water molecule is lost, producing a resonance stabilized tertiary carbocation. The concerted mechanism of this step is similar to the mechanisms of the Baeyer-Villiger
oxidationand
also
the
oxidation
step
of hydroboration-
oxidation.[6] In 2009, an acidified bentonite clay was proven to be a more economical catalyst than sulfuric acid as the acid medium.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 63 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
As shown below, the resulting carbocation is then attacked by water, a proton is then transferred from the hydroxy oxygen to the ether oxygen, and finally the ion falls apart into phenol and acetone.
The products are extracted by distillation. 3.3 Chemical Reaction Network The mechanism of benzene alkylation with propylene involves the protonation of the catalyst acidic sites [5, 6] leading to isopropylbenzene, and further diisopropylbenzenes and tri - isopropylbenzenes. By the isomerization some n propylbenzene appears, which is highly undesirable as an impurity. The presence of stronger acid sites favors the formation of propylene oligomers and other hydrocarbon species. Therefore, high selectivity of the catalyst is as important as high activity. It is remarkable that the polyalkylates byproducts can be reconverted to cumene by reaction with benzene. Below, the chemical reactions of significance are listed:
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 64 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 65 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 66 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.4 Various Processes of Manufacture Currently almost all cumene is produced commercially by two processes. The first type is A fixed bed, Kieselguhr supported phosphoric acid catalyst system developed by UOP (Universal Oil Products Platforming Process). The second type is A homogeneous AlCl3 and hydrogen chloride catalyst system developed by Monsanto. 3.4.1 UOP Cumene Process
Figure 3.5: PFD for UOP Cumene Process
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 67 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Propylene feed fresh benzene feed and recycle benzene are charged to the upflow reactor, which operates at 3-4 Mpa and at 200-260°C. The solid phosphoric acid catalyst provides an essentially complete conversion of propylene on a one-pass basis. The typical reactor effluent yield contains 94.8 Wt. % cumene and 3.1 Wt. % of diiso propylbenzene. The remaining 2.1 % is primarily heavy aromatics. This high yield of cumene is achieved without transalkylation of diiso propylbenzene and is unique to the solid phosphoric acid catalyst process. The cumene product is 99.9 Wt. % pure and the heavy aromatics, which have an octane number of 109, can either be used as high octane gasoline blending components or combined with additional benzene and sent to a transalkylation section of the plant where diiso propylbenzene is converted to cumene. The overall yields of cumene for this process are typically 97-98 Wt. % with transalkylation and 94-96 Wt. % without transalkylation.
3.4.1.1 Application To produce high-quality cumene (isopropylbenzene) by alkylating benzene with propylene (typically refinery or chemical Grade) using liquid-phase Q-Max process based on zeolitic catalyst Technology.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 68 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.4.1.2 Description Benzene is alkylated to cumene over a zeolite catalyst in a fixed-bed, liquid-phase reactor. Fresh benzene is combined with recycle benzene and fed to the alkylation reactor (1). The benzene feed flows in series through the beds, while fresh propylene feed is distributed equally between the beds. This reaction is highly exothermic, and heat is removed by recycling a portion of reactor effluent to the reactor inlet and injecting cooled reactor effluent between the beds. In the fractionation section, propane that accompanies the propylene feedstock is recovered as LPG product from the overhead of the depropanizer column (2), unreacted benzene is recovered from the overhead of the benzene column (4) and cumene product is taken as overhead from the cumene column (5). Diisopropylbenzene (DIPB) is recovered in the overhead of the DIPB column (6) and recycled to the transalkylation reactor (3) where it is transalkylated with benzene over a second zeolite catalyst to produce additional cumene. A small quantity of heavy byproduct is recovered from the bottom of the DIPB column (6) and is typically blended to fuel oil. The cumene product has a high purity (99.96 –99.97 wt%), and cumene yields of 99.7 wt% and higher are achieved. The zeolite catalyst is noncorrosive and operates at mild conditions; thus, carbon-steel construction is possible. Catalyst cycle lengths are two years and longer. The catalyst is fully regenerable for an ultimate catalyst life of six years and longer. Existing plants that use spa or ALCL3 catalyst can be revamped to gain the advantages of Q-Max cumene technology while increasing plant capacity.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 69 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.4.1.3 Economics Basis: ISBL US Gulf Coast
The Q-Max design is typically tailored to provide optimal utility advantage for the plant site, such as minimizing heat input for stand-alone operation or recovering heat as steam for usage in a nearby phenol plant.
3.4.1.4 Commercial Plants Seven Q-Max units are in operation with a total cumene capacity of 2.3 million tpy, and two additional units are either in design or under construction.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 70 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.4.2 Badger Cumene Process
Figure 3.6: PFD for Badger Cumene Process
3.4.2.1 Application
To produce cumene from benzene and any grade of Propylene—including lowerquality refinery propylene-propane mixtures—using the badger process and a new generation of zeolite catalysts from Exxonmobil. 3.4.2.2 Description
The process includes: a fixed-bed alkylation reactor, a fixed-bed transalkylation reactor and a distillation section. Liquid propylene and benzene are premixed and fed to the
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 71 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
alkylation reactor (1) where propylene is completely reacted. Separately, recycled polyisopropylbenzene (PIPB) is premixed with benzene and fed to the transalkylation reactor (2) where PIPB reacts to form additional cumene. The transalkylation and alkylation effluents are fed to the distillation section. The distillation section consists of as many as four columns in series. The depropanizer (3) recovers propane overhead as LPG. The benzene column (4) recovers excess benzene for recycle to the reactors. The cumene column (5) recovers cumene product overhead. The PIPB column (6) recovers PIPB overhead for recycle to the transalkylation reactor.
3.4.2.3 Process features The process allows a substantial increase in capacity for existing SPA, ALCL3, or other zeolite cumene plants while improving product purity, feedstock consumption, and utility consumption. The new catalyst is environmentally inert, does not produce byproduct oligomers or coke and can operate at the lowest benzene to propylene ratios of any available technology with proven commercial cycle lengths of over seven years. Expected catalyst life is well over five years.
3.4.2.4 Yield and Product Purity This process is essentially stoichiometric and product purity above 99.97% weight has been regularly achieved in commercial operation.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 72 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.4.2.5 Economics Estimated ISBL investment for a 300,000-MTPY unit on the Us Gulf Coast (2004 construction basis), is US$15 million. UTILITY REQUIREMENTS, PER TON OF CUMENE PRODUCT: HEAT, MMKCAL (IMPORT)
0.32
STEAM, TON (EXPORT)
(0.60)
The utilities can be optimized for specific site conditions/economics and integrated with an associated phenol plant.
3.4.2.6 Commercial Plants The first commercial application of this process came onstream in 1996. At present, there are 12 plants operating with a combined capacity exceeding 5.2 million mtpy. In addition, four grassroots plants and an ALCL3 revamp are in the design phase. Fifty percent of the worldwide and 75% of zeolite cumene production are from plants using the badger process.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 73 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.4.3 MONSANTO – LUMMUS CREST Cumene Process Dry benzene, fresh and recycle and propylene are mixed in the alkylation reaction zone with AlCl3 and hydrogen chloride catalyst at a temperature of less than 135°C and a pressure of less than 0.4 Mpa. The effluent from the alkylation zone is combined with recycle polyisopropyl benzene and fed to the transalkylation zone, where polyisopropyl benzenes are transalkylated to cumene. The strongly acidic catalyst is separated from the organic phase by washing the reactor effluent with water and caustic. The distillation system is designed to recover a high purity cumene product. The unconverted benzene and polyisopropyl benzene are separated and recycled to the reaction system. Propane in the propylene feed is recovered as liquid petroleum gas. The overall yields of cumene for this process can be high as 99 Wt. % based on benzene and 98 Wt. % based on propylene. But these processes have been used more
extensively for the production of ethylbenzene than for the production of
cumene.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 74 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.4.4 CDTECH & ABB Lummus Global 3.4.4.1 Overview The CDCumene® process, marketed by ABB, produces ultra high purity cumene using a proprietary zeolite catalyst that is non-corrosive and environmentally friendly. The CDCumene technology is one of a family of process technologies developed and commercialized by Catalytic Distillation Technologies (CDTECH®) for license to the petroleum refining and petrochemical industries. CDTECH is a partnership between ABB Lummus Global and Chemical Research and Licensing.
3.4.4.2 Application
Advanced technology to produce high-purity cumene from propylene and benzene using patented catalytic distillation (CD) Technology. The CD cumene process uses a specially formulated zeolite alkylation catalyst packaged in a proprietary CD structure and another Specially formulated zeolite transalkylation catalyst in loose form.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 75 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.4.4.3 Description
Figure 3.7: PFD of CDTECH & ABB LUMMUS GLOBAL The cd column (1) combines reaction and fractionation in a single-unit operation. Alkylation takes place isothermally and at low temprature. Cd also promotes the continuous removal of reaction products from reaction zones. These factors limit byproduct impurities and enhance product purity and yield. Low operating temperatures and pressures also decrease capital investment, improve operational safety and minimize fugitive emissions. in the mixed-phase CD reaction system, propylene concentration in the liquid phase is kept extremely low (99.9 mole% pure; liquid feed
3.14.2 Stream 2 95 mole% propylene; 5 mole% propane; liquid feed
3.14.3 Stream 3 2/1 benzene/propylene molar feed ratio
3.14.4 Stream 4 99% propylene conversion; 31/1 cumene/DIPB molar selectivity
3.14.5 Stream 5 Propylene + propane only
3.14.6 Stream 6 0 mole% propylene + propane
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 105 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.14.7 Stream 7 98.1 mole% benzene purity, balance cumene, sold as gasoline
3.14.8 Stream 8 0 mole% benzene
3.14.9 Stream 9 99.9 mole% cumene, balance DIPB; 100,000 tons/year production
3.14.10 Stream 10 100 mole% DIPB; sold as fuel oil
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 106 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3.15 Reaction Mechanism And Kinetics Of Cumene Production The following reaction mechanism are proposed for the alkylation of benzene for production of cumene. The major reactions taking place are alkylation and trans-alkylation. Side reactions which take place are isomerisation and dis-proportionation. The reaction mechanism and kinetics may vary depending on the catalyst used. The reaction can occur in presence or absence of carbonium ion intermidate.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 107 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.0 CAPACITY CALCULATION 4.1 Mass Balance 4.1.1 Introduction to Mass Balance Basically, mass balance or material balance is an application of conservation of mass to the analysis of physical systems. Mass flows can be identified which might have been unknown, or difficult to measure without this technique by accounting for material entering and leaving a system. The exact conservation law used in the analysis of the system depends on the context of the problem but all revolve around mass conservation, i.e. that matter cannot disappear or be created spontaneously (Himmelblau, 1967). So, in engineering and environmental analyses, mass balances are used widely. Mass balance theory can be used to design chemical reactors, analyses alternative processes to produce chemicals as well as in pollution dispersion models and other models of physical systems. Closely related and complementary analysis techniques include
the population
balance, energy
balance and
the
somewhat
more
complex entropy balance. These techniques are required for thorough design and analysis of systems such as the refrigeration cycle. Therefore, the general form quoted for a mass balance is The mass that enters a system must, by conservation of mass, either leave the system or accumulate within the system.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
108 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Mathematically the mass balance for a system without a chemical reaction is as follows: Input = Output + Accumulation above equation holds also for systems with chemical reactions if the terms in the balance equation are taken to refer to total mass i.e. the sum of all the chemical species of the system. In the absence of a chemical reaction the amount of any chemical species flowing in and out will be the same. This gives rise to an equation for each species in the system. However if this is not the case then the mass balance equation must be amended to allow for the generation or depletion (consumption) of each chemical species. Some use one term in this equation to account for chemical reactions, which will be negative for depletion and positive for generation. However, the conventional form of this equation is written to account for both a positive generation term (i.e. product of reaction) and a negative consumption term (the reactants used to produce the products). Although overall one term will account for the total balance on the system, if this balance equation is to be applied to an individual species and then the entire process, both terms are necessary. Input + Generation = Output + Accumulation + Consumption This modified equation can be used not only for reactive systems, but for population balances such as occur in particle mechanics problems. The equation is given below. Note that it simplifies to the earlier equation in the case that the generation term is zero.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
109 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
In the absence of a nuclear reaction the number of atoms flowing in and out are the same, even in the presence of a chemical reaction
To perform a balance the boundaries of the system must be well defined
Mass balances can be taken over physical systems at multiple scales.
Mass balances can be simplified with the assumption of steady state, where the accumulation term is zero
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
110 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.2 Material Balance of Major Equipment - Reactor
Propylene
Major Equipment
Cumene DIPB
Reactor
Unreacted Benzene
Benzene
The reactions for cumene production from benzene and propylene are as follows:
MAIN REACTION:
SIDE REACTION:
C3H6
+
C6H6
→
C6H5-C3H7
Propylene Benzene
Cumene
C3H6
C3H7-C6H4-C3H7
Propylene
+
C6H5-C3H7 → Cumene
Diisopropylbenzene (DIPB)
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
111 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.2.1 Assume 330 working days per year and 24 hours per day Basis: Per hour of operation (a) Assumption 330 working days per year and 24 hours per day Amount of cumene to be obtained = 1 M ton of cumene per annum. =106/330 tons per day of cumene. = 106/(330 x 24) tons of cumene per hr. = 126.26 x 103 kg of cumene per hr. (b) Justification Mass flow rate was converted to molar flow rate to ease the calculation of the mass balance. The molecular weight for the cumene was 120.19 kg/kmoles. Amount of cumene to be obtained = (126.26 x 103)/120.19 kmoles of cumene per hr. = 1050.50 Kgmole/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
112 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.2.2 Assume 97% conversion and 2% loss in the reactor. (a) Assumption 97% conversion and 2% loss in the reactor. (b) Justification The complete conversion of the reactants to the cumene is very hard to achieve since it require a very high operating temperature. However, it is very expensive to operate the reactor at elevated temperature. Besides, it is very dangerous to the worker too. The loss of the product In the reactor is normally due to the fouling of the product on the wall of the reactor or in the pipeline. Besides, it might due to leaking. For example, the flange which connect the inlet pipeline to the reactor is not screwed tightly. Thus, some of the product leak through the flangle. Hence: Cumene required = 1050.50/ 0.98 = 1071.94 Kgmoles/hr = 128836.32 Kg/hr Hence 128836.32 kg of cumene is required to be produced per hr. Propylene required =1071.94/0.97 = 1105.09 Kgmole = 1105.09 x 42 Kg/hr of propylene = 46413.78 Kg/hr of propylene
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
113 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.2.3 Assume Benzene required is 25% extra (a) Assumption benzene required is 25% extra Benzene required = 1105.09 x 1.25 Kmoles of benzene = 1381.3625 Kgmole/hr = 107746.27 Kg/hr (b) Justification Propane acts as an inert in the whole process. It is used for quenching purpose in the reactor. It does
not take part in the chemical reaction . Also
It is inevitably
associated with the propylene as an impurity as their molecular weight is very close. We assume propylene to propane ratio as 3:1.
Being an inert we are
neglecting propane balance in the material balance to avoid complexity.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
114 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
The unreacted propylene will be react to give DIPB (side reaction) Unreacted propylene available for side reaction = 1105.09-1071.94 = 33.15 Kmoles/hr is reacted to give DIPB Benzene required to give DIPB = 33.15/2 kmoles/hr = 16.575 kmoles/hr DIPB produced = 16.575 x 162 = 2685.15 Kg/hr Benzene in product = 1381.3625 – 1071.94 -16.575 = 292.85 kmoles/hr = 22820.85 kg/hr Checking: Total Input = 46413.78 + 107746.27 = 154160.05 Kg/hr Total Output = 128836.32 + 2685.15 + 22820.85= 154342 Kg/hr Input = output
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
115 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.2.4 Conclusion Of Mass Balance For Reactor
Propylene =46414.78kg/hr
Major Equipment
Reactor
Cumene=128836.32 kg/hr DIPB=2685.15kg/hr
Unreacted Benzene=22820.85kg/hr
Benzene =107746.27kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
116 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.3 Material Balance of Propane Column Propane Column is a Depropanasing column. Assuming almost all the propane is removed in depropanising column and sent to reactor for quenching. Hence material balance for depropanasing column is not considered.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
117 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.4 Material Balance of Minor Equipment - Benzene Column The function of the benzene distillation column is to remove the benzene from the product. The removed benzene is recycled back to the benzene feed tank to minimize the waste of the raw material. W = Cumene +DIPB
Minor
Feed, F = Cumene+Benzene+DIPB =154160 kg/hr
Equipment Benzene Column
D = Benzene F=D+W 154160 = D +W
F XF = DXD +WXw XF = 22820.85/154160 = 0.1480 Taking, XD = 0.9999 Xw = 0.05
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
118 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
154160 x 0. 1480 = D x 0.9999 +W x 0.05 3023.5 = .9999 D + (20374 – D) x 0.05
D = 15969.41 Kg/hr = Benzene
W = 154160 – 15969.41 = 138190.5 Kg/hr = cumene + DIPB
Checking: Total Input = 154160 kg/hr Total Output = 15969.41 + 138190.5 = 154160 kg/hr Input = Output
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
119 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.4.1 Assumption Assuming all the Benzene present in benzene column is recycled to the feed. 4.1.4.2 Justification Hence, considering negligible amount of benzene to be part of residue. This will avoid the complexity of multi component distillation in Cumene column.
Therefore amount of benzene recycled = 15969.5 Kg/hr. Therefore feed actually given to the system = 154160 + 15969.5 = 170129.5 Kg/hr 4.1.4.3 Conclusion of Mass Balance for Benzene Distillation Column
W = Cumene +DIPB =138190kg/hr
Minor
Feed, F = Cumene+Benzene+DIPB =154160 kg/hr
Equipment Benzene Column
D = Benzene
=15969.41kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
120 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.5 Material Balance of Minor Equipment – Cumene Column The function of cumene distillation column is to separate the cumene from DIPB.
W = DIPB
Minor
Feed, F = Cumene +DIPB =138190.5 kg/hr
Equipment Cumene Column
D
= Cumene
F = D +W 138190.6 = D +W
FXF = DXD + WXW XF =128836.3/138190.5 = 0.932 Taking XD = 0.995 XW = 0.01 KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
121 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
138190.5 x 0.932 = D x 0 .995 + W x 0.01 128793.54 = 0.995D + (138190.5 – D) 0.01
D = 129051 kg/hr
W = 138190.5 – 129051 = 9139.5 Kg/hr
Checking: Input = 138190.5 Kg/hr Output = 129051 + 9139.5 = 138190.5 Kg/hr. Input = output
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
122 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.1.5.1 Conclusion if Mass Balance for Cumene Column
W = DIPB =9139.5 kg/hr Minor
Feed, F = Cumene +DIPB =138190.5 kg/hr
Equipment Cumene Column
D = Cumene =129051kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
123 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2 Heat Balance 4.2.1 Introduction to Heat Balance Energy also conserved besides mass is conserved. The energy coming into a unit operation can be balanced with the energy coming out and the energy stored. Energy In = Energy Out + Energy Stored ΣER = ΣEP + ΣEW + ΣEL + ΣES Where, ΣER = ER1 + ER2 + ER3 + ……. = Total Energy Entering ΣEp= EP1 + EP2 + EP3 + ……. = Total Energy Leaving with Products ΣEW = EW1 + EW2 + EW3 + … = Total Energy Leaving with Waste Materials ΣEL = EL1 + EL2 + EL3 + ……. = Total Energy Lost to Surroundings ΣES = ES1 + ES2 + ES3 + ……. = Total Energy Stored Since forms of energy can be interconverted, energy balances are often complicated. For example mechanical energy to heat energy, but overall the quantities must balance. Besides that, energy also takes many forms, such as heat, kinetic energy, chemical energy, potential energy but because of interconversions it is not always easy to isolate separate constituents of energy balances. However, under some circumstances certain aspects predominate. In many heat balances in which other forms of energy are insignificant; in some chemical situations mechanical energy is KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
124 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
insignificant and in some mechanical energy situations, as in the flow of fluids in pipes, the frictional losses appear as heat but the details of the heating need not be considered. We are seldom concerned with internal energies. Therefore practical applications of energy balances tend to focus on particular dominant aspects and so a heat balance, for example, can be a useful description of important cost and quality aspects of process situation. When unfamiliar with the relative magnitudes of the various forms of energy entering into a particular processing situation, it is wise to put them all down. Then after some preliminary calculations, the important ones emerge and other minor ones can be lumped together or even ignored without introducing substantial errors. With experience, the obviously minor ones can perhaps be left out completely though this always raises the possibility of error. Energy balances can be calculated on the basis of external energy used per kilogram of product, or raw material processed, or on dry solids or some key component. The energy consumed in food production includes direct energy which is fuel and electricity used on the farm, and in transport and in factories, and in storage, selling, etc.; and indirect energy which is used to actually build the machines, to make the packaging, to produce the electricity and the oil and so on. Food itself is a major energy source, and energy balances can be determined for animal or human feeding; food energy input can be balanced against outputs in heat and mechanical energy and chemical synthesis.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
125 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
In the SI system there is only one energy unit, the joule. However, kilocalories are still used by some nutritionists and British thermal units (Btu) in some heat-balance work. Heat Balances The most common important energy form is heat energy and the conservation of this can be illustrated by considering operations such as heating and drying. In these, enthalpy (total heat) is conserved and as with the mass balances so enthalpy balances can be written round the various items of equipment. or process stages, or round the whole plant, and it is assumed that no appreciable heat is converted to other forms of energy such as work. Enthalpy (H) is always referred to some reference level or datum, so that the quantities are relative to this datum. Working out energy balances is then just a matter of considering the various quantities of materials involved, their specific heats, and their changes in temperature or state (as quite frequently latent heats arising from phase changes are encountered). Figure 1.2 illustrates the heat balance.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
126 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Heat is absorbed or evolved by some reactions in processing but usually the quantities are small when compared with the other forms of energy entering into food processing such as sensible heat and latent heat. Latent heat is the heat required to change, at constant temperature, the physical state of materials from solid to liquid, liquid to gas, or solid to gas. Sensible heat is that heat which when added or subtracted from materials changes their temperature and thus can be sensed. The units of specific heat are J/kg K and sensible heat change is calculated by multiplying the mass by the specific heat by the change in temperature, (m x c x ΔT). The units of latent heat are J/kg and total latent heat change is calculated by multiplying the mass of the material, which changes its phase by the latent heat. Having determined those factors that are significant in the overall energy balance, the simplified heat balance can then be used with confidence in industrial energy studies. Such calculations can be quite simple and straightforward but they give a quantitative feeling for the situation and can be of great use in design of equipment and process.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
127 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.2 Heat Balance for Major Equipment - Reactor Basis: Per hour of operation The gases viz. Propylene, propane, benzene enter at 25 °C and benzene enters at 80°C. To calculate the temperature of the mixture of gases after compression to 25 atm : Component
Cp values
(J/mole K) at avg temperature of 53 °C
A
Propylene
64.18
B
Benzene
82.22
C
Propane
73.89
Propylene in feed = 1105.09 kmoles/hr. Benzene in feed = Benzene fed + recycled Benzene = 1381.36 + 204.73 = 1586.09 kmoles/hr.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
128 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.2.1 Assumption (a) Assume Ratio of Propylene to Propane is 3:1 Assuming that propylene is accompanied with propane as impurity in the ratio of 3:1. Therefore propane in feed = 368.36 kmoles/hr. Hence, XA =0.3612 , XB = 0.5184 , XC = 0.1204
Cp avg =XACpA + XBCpB + XcCpc Cp avg = 0.3612x 64.18 + 0.5184 x 82.22 + 0.1204 x 73.89 = 71.38 J/mole K Temperature of the stream after mixing : Component
Cp value
J/kmole k at 300C
A
Propylene
64.52
B
Propane
70.17
C
Benzene
98.20
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
129 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
(1105.09 x 64.52 + 1381.36 x 98.20 + 368.36 x 70.17) x 103 x (T-25) = 204.73 x 86.22 x 103 x (80-T) or, 80 – T = 13.18 ( T-25 ) or, 14.18 T = 409.5 or, T = 290C
P1 =1 atm,
T 1= 290C
P2 = 25 atm,
To find T 2
Considering isentropic process, we have T 2 = T1 (P2 /P1 ) = 29( 25 /1 )
( R / Cp avg )
( 8.314 / 71.38)
= 42.19 °C Cp avg at 42.19 °C ≈ Cp avg at 53 °C =71.38 J/ mole K
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
130 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
(b) Assume Exit Stream from Pre-Heater Leaves at 100 °C Assuming that the exit stream from pre-heater leaves at 100 °C
For the products from the reactor, m = cumene+DIPB+Benzene+propane =1071.94+16.575+292.85+368.36 = 1749.72 kmoles/hr
To find Cp avg at ( 250+100) /2 =175°C ,Cp J /mole K Propane
107.76
Cumene
205.24
Di-isopropyl Benzene
302.97
Propylene
97.60
Benzene
121.19
Cp avg = 0.6126 x 205.24 + 0.0095 x 302.97 + 0.1673 x121.19 + 0.2105x107.76 = 168.22 J/mole K
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
131 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
For the reactants leaving the pre-heater :
m= propylene+benzene+propane = 1105.09+1586.09+368.36 = 3059.54 k moles/hr
4.2.2.2 Heat Balance Around The Pre-Heater 11749.72 x 168.22 (250-100)x103 = 3059.54 x 91.38 x (T –42.19)x103 T ≈ 200 °C The reactants have to be further heated to the reaction temperature of 250 °C before being fed to the reactor.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
132 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.2.3 To Find Saturated Steam Required Cp avg of reactants has to be determined at (200 + 250 )/2=225 °C Cp value
at average temperature of 2250C , J/kmole K
Propane
117.76
Propylene
97.60
Benzene
141.19
Cp avg= 0.3612 x 97.60 + 0.5184 x 141.19 + 0.1204 x 117.76 = 122.62 J/mole K
m Cp avg(250-100)=msteamλ 3059.4 x 122.62x103 x 150 = msteam x 2676 msteam = 21.028 x 106 kg /hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
133 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.3.3.4 Energy Balance Around The Reactor
Enthalpy of reactants + heat evolved = Q + Enthalpy of products ∑ m Cp dT reactants + heat evolved = Q + ∑ m Cp dT products
Heat evolved = 23.7683 K cal / g mole =99.3964 KJ/g mole
Moles of cumene produced = 1072 k moles /hr
Heat evolved =99.3964 x 1072 x 103 =106.63 x 106KJ/hr
∑ m Cp dT reactants = 1105.09 x 87.37x103 (250 –25) +1586.09 x 93.97x103 (250-25)+368.36 x 97.34 x 103 x (250-25) = 6.3326 x 1010KJ/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
134 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
∑ m Cp dT products = 368.36 x103x
(250 –25) + 292.85 x
93.97 x103(250
25)+1071.94 x 103x 177.07(250 –25) +16.575 x 103 x 267.19 x (250 –25) = 5.796 x 1010KJ/hr Hence, 6.3326 x 1010 + 106.63 x 106 = Q+ 5.796 x 1010 Q=54.698 x 108 KJ/hr
4.2.2.4 Total Propane Requirement for Quench
Latent heat of vaporisation of propane liquid at 25 atm (B .P =68.4 °C)=0.25104 KJ/gm =251.04 KJ/kg Heat removal by propane heat quench: Assuming that propane is removed completely in the depropanasing column and is sent for quenching . Propane i.e recycled = 368.36 kmoles/hr = 368.36 x 44 kg/hr = 16207.84 kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
135 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Cp of propane at T avg = (250 + 68.4) /2 = 159.2 °C is 2.56 KJ/kg°C Q = m λ + m Cp (250 –68.4) = 16207.84 x (251.04 + 2.56 x 181.6) = 11.603 x 106KJ/hr
Additional heat to be removed = 54.698 x 108 –11.603 x 106 = 54.58 x 108KJ/hr = Ql
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
136 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.2.5 Water Is Used For Additional Heat Removal
To find flow rate of water: B.P. of water at 25 atm = 223.85°C Latent heat of vaporisation = 2437 KJ/kg Assuming that water at 25 °C is used for quenching Cp of water at T avg = (25+223.8)/2=124.43 °C is 3.7656 KJ/kg °C Ql = m Cp (223.85 –25) + mλ 54.58 x 108 =m (3.7656 x 198.85 +2437) m = 1.713233 x 106kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
137 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.3 Heat Balance for Propane Column
To find the temperature at which the product stream is fed to propane distillation column: At
P1 = 25 atm,
T1 = 200 °C
At
P2 =1 atm
T2 = ?
Cp avg at 100 °C = 0.6126 x 163.42 +0.0095 x 243.76 + 0.1673 x 107.01 +0.2105 x 79.47 = 137.05 J/gm mole
T
2
= T1 (P2 /P1)
R/Cp avg
=100(1/25)8.314 / 137.05 =82.260C
This is further cooled to 25 °C and fed to the distillation column. F=1749.72 kmoles/hr D=368 kmoles/hr W=1381.72 kmoles/hr KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
138 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Enthalpy of vapor that goes as overhead: Hv= Latent heat of vaporisation + sensible heat As propane is the major constituent that goes with the overhead, taking λ and Cp values of Propane, Hv =V [λ + Cp (Tb –To )] Assuming a reflux ratio of 0.5, we have R=L/D =0.5 L=0.5 D =0.5 x 368 x 44 =8096 kg/hr V=L+D=8096+16192 =24288 kg/hr
Taking reference temperature as the temperature at which feed enters, T0=25 °C ; Tb= 42.1 °C , Cp =2.41 KJ/kg °C λ = 0.4251 KJ/gm =425.1 KJ/kg Therefore Hv =24288 [425.1 + 2.41 ( 42.1 –25 )] =11.3257 x 106 KJ/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
139 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
HD =DCp(Tb–T0) =16192 x 2.41 ( 42.1 –25 ) =6.673 x 105 KJ/hr HL=L Cp (Tb–T 0) =8096 x 2.41 (42.1 –25) =3.336 x 105KJ/hr
Taking enthalpy balance around the condenser, Hv= Qc+HD +HL 11.3257 x 106 = Qc+6.675 x105+3.336x 105 Qc = 10.325 x 106KJ/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
140 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.3.1 Cooling Water Requirement
Let us assume inlet and exit water temperature as 25 °C and 45 °C Cp=4.18 KJ/kg °C Therefore Qc= msteam CpdT 10.325 x 106= msteamx 4.18x 20 m=123.5 x 103 kg/hr
4.2.3.2 Total Enthalpy Balance
H F + QB = H D + Q C + H W To find HW: HW=WCp avg (Tb–T0) By using pi = XiPi and checking Pt= 760 mm Hg we found Tb = 1370C
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
141 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Cp avg = 0.776 x 176.32 + 0.01199 x 257.11 + 0.2120 x 110.73 = 174 J/mole K = 174 kJ/kmole K
Mavg = 111.72 kg/kmole
Therefore Cp avg = 174 / 111.72 =1.5575 KJ/kg K
Hw = 1381.72 x 1.5575(137-25) x 111.72 = 26.927 x 106 KJ/hr
HF = 0 [ because TF = T0 ] QB =HD + QC + H
W
- HF
= 6.673 x 105 + 10.325 x 106+26.927 x 106-0 =37.92 x 106 KJ/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
142 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.3.4 Saturated Steam Required
QB = msteam λ 37.92 x 106= msteamx 2256.9 msteam = 16801.5 kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
143 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.4 Heat Balance for Minor Equipment - Benzene Column
Benzene Distillation Column: F = 154160 kg/hr enters at 137 °C D = 15969.4 kg/hr W = 138190 kg/hr
Benzene vapor from the top is recycled. Assuming very small propane content to be a part of Benzene stream. Again assuming R = 0.5 = L/D Hence, L = 0.5 x 15969.4 =7984.7 kg/hr. V = L+D = 167954.1 kg/hr Enthalpy of vapor Hv=V[λ Cp(Tb –T0) ] Taking referenced temperature T0 = TF = 137 °C B.P. of Benzene at 1 atm = 80.1 °C = Tb
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
144 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
λ of benzene =94.14cal/gm mole = 393.8818 KJ/gm =393.88 x 103 KJ/kg
Cp of Benzene vapor at 80.1°C = 22.83 cal/gm mole = 95.52 J/gm mole K = 1.2246 KJ/kg °K
Hv= 167954.1 [ 393.8818 + 1.2246 ( 80.1 –137 )] = 64.94 x 106 KJ/hr
HD= 15969.4 x 1.2246 (80.1 – 137 ) = -1.1127 x 106KJ/hr.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
145 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
HL = L Cp (Tb–T0) = 7984.7 x 1.2246 (80.1 –137 ) = -0.55637 x 106 KJ/hr
Hv = QC + HL +HD 54.45 x 106= QC –0.55637 x 106 – 1.1127 x 106 QC = 56.12 x 106 KJ/hr
4.2.4.1 Cooling Water Requirement For Benzene Distillaton Column
Let us assume inlet and exit water temperature as 25 °C and 45 °C Cp=4.18 KJ/kg °C
Therefore, Qc= msteam CpdT 54.45 x 106 = msteam x 4.18 x 20 msteam = 67.128 x 104kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
146 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.4.2 Total Enthalpy Balance
HF + QB = HV + QC +Hw To find HW : w = 138190 Kg/hr T b = TF for cumene distillation column = 153.4 °C
Cp avg =Cp of cumene = 1.91 KJ/kg °C Hw= 138190 x 1.91(153.4 –137) = 3.0774 x 106KJ/hr HF = 0 [ because TF= TD]
QB= 54.94 x 106 + 65.11 x 106 +4.06 x 106 -12.245 x 106 = 11.46 x 107 KJ/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
147 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.4.3 Saturated Steam Required
QB = msteam λ 11.46 x 107 = msteam x 2256.9 msteam = 50.81 x 103kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
148 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.5 Heat Balance for Minor Equipment - Cumene Column
Cumene Distillation column: F = 138190 kg/hr D = 129051 kg/hr w = 9139 kg/hr
Enthalpy of vapor that goes at the top: As the cumene is the major constituent that goes with the overhead, taking λ and C p values of Cumene, Hv=V[λ Cp(T0 – Tb) ] Taking reference temperature T0 =TF = 153.4 °C B.P. of Cumene at 1 atm = 152.4 °C
λ of cumene =74.6 cal/gm = 312.1264 KJ/kg
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
149 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Cp of Cumene vapor at 152.4 °C = 0.4047 cal/gm °K = 1.6931 KJ/kg °K
V=D+L = 129051 + 68655.1 =197706.1 kg/hr
Hv = 197706.1[ 312.1264 + 1.6931 ( 152.4 –153.4)] = 61.3745 x 106KJ/hr
HD = D Cp (Tb–T0) = 129051 x 1.6931(152.4 –153.4) = -0.218496 x 106KJ/hr
HL = L Cp(Tb –T0 ) = 68655.1 x 1.6931(152.4 –153.4) = -0.116239 x 106 KJ/hr KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
150 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Hv = QC + HD +HL 61.3745 x 106= QC –0.218496 x 106 -0.116239 x 106 QC = 61.71 x 106 KJ/hr
4.2.5.1 Cooling Water Requirement
Let us assume inlet and exit water temperature as 25 °C and 45 °C Cp=4.18 KJ/kg °C Therefore Qc= msteamCpdT 61.71 x 106 = msteam x 4.18 x 20 msteam = 73.8148 x 103 kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
151 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.5.2 Total Enthalpy Balance
HF + QB = HV + QC +Hw To find HW : W = 9139 kg/hr Hw = W Cp avg (Tb–T 0 ) T b at xw = 0.2934 =184.5 °C
Cp avg at 184.5 °C = 0.013x 214.1952 + (1 –0.013) x 288.93 = 287.9584 J/mole °K = 2.88795 KJ/kg °K
Hw = 9139 x 2.8795(184.5 –153.4) = 81.84 x 104 KJ/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
152 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
HF = 0 [ because TF = T0 ] QB = HV + QC + HW - HF = 61.3745 x 106 + 73.8143 x 103 + 81.84 x 104 =62.2667 x 106 KJ/hr
4.2.5.3 Saturated Steam Required
QB = msteam λ 62.2667 x 106 = msteam x 2256.9 msteam= 27589.5 kg/hr
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
153 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.6 Product Yield 4.2.6.1 Overall Plant Material Balance
Chemical
Input
Output
molwt
kmol/h
kg/h
kmol/h
kg/h
BENZENE
78
1382.4
107,746.27
204.74
15,969.42
PROPYLENE
42
1105.09
46413.78
0
0
PROPANE
44
5.9
259.3844
5.9
259.3844
CUMENE
120
0
0
1075.43
129,051
DIPB
162
0
0
56.42
9139.5
TOTAL
-
-
154,160.05
-
145,371.2
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
154 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.2.6.2 Yield (In Percent, Kg, SCFD)
As 1 mole of cumene is produced from 1 mole of propylene the stoichiometry factor is 1
Moles of Cumene produced = 1075.43 Stiochiometry factor = 1 (from the equation) Moles of reactant fed = 1105.09Kmole
Yield of cumene based on propylene:
1. Yield (percent form) = (moles of product produced) (Stiochiometry Factor) / (Moles of reactant fed to process) = 1075.43X1/1105.09 = 97.31%
2. Yield (kg form) = 129,051kg/hr (from mass balance)
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
155 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
3. Yield (scfd form) Density of cumene = 862kg/m3 kg
scfd = 129,051 hr ×
24hr day
m3
3.28ft 3 ] 1m
× 862kg × [
scfd = 126,790.5 standard cubic feet per day
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
156 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.3 Flow Summary for Cumene Production at Design Conditions
Figure 4.1: P&ID for Cumene Production Process KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
157 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Table 4.1: Flow Summary Table for Cumene Production at Design Conditions (Based on Figure 4.1)
Stream No.
1
2
3
4
5
6
6a
7
Temperature (°C)
25
25
41
28
44
41
214.0
350
1.00
11.66
1.01
31.50
31.50
31.25
30.95
30.75
Vapor mole fraction
0
0
0
0
0.0
0.0
1.0
1.0
Flowrate (tonne/h)
8.19
4.64
16.37
4.64
16.37
21.01
21.01
21.01
105.00
-
205.27
-
205.27
205.27
205.27
205.27
Propylene
-
105.00
2.89
105.00
2.89
107.89
107.89
107.89
Propane
-
5.27
2.79
5.27
2.79
8.06
8.06
8.06
Cumene
-
-
0.94
-
0.94
0.94
0.94
0.94
P-Diisopropyl Benzene
-
-
-
-
-
-
-
-
105.00
110.27
211.89
110.27
211.89
322.16
322.16
322.16
Pressure (bar)
Benzene
Total (kmol/h)
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
158 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Table 4.1: Flow Summary Table for Cumene Production at Design Conditions (Based on Figure 4.1) (Cont.) 8
9
10
11
12
13
14
350
90
90
57
179
178
222
30.25
1.75
1.75
1.75
1.90
1.90
2.10
Vapor mole fraction
1.0
1.0
0.0
0.0
0.0
0.0
0.0
Flowrate (tonne/h)
21.01
1.19
19.82
8.18
11.64
11.08
0.56
Benzene
108.96
7.88
101.08
100.27
0.81
0.81
-
Propylene
8.86
5.97
2.89
2.89
-
-
-
Propane
8.06
5.27
2.79
2.79
-
-
-
Cumene
94.39
0.77
93.62
0.94
92.68
91.76
0.92
P-Diisopropyl Benzene
2.79
-
2.79
-
2.79
0.03
2.76
223.06
19.89
203.17
106.89
96.28
92.60
3.68
Stream No. Temperature (°C) Pressure (bar)
Total (kmol/h)
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
159 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.4 Flow Summary for Utility Streams
Table 4.2: Flow Summary Table for Utility Streams (Based on Figure 4.1)
hps to
condensate
mps to
condensate
hps to
condensate
E-801
from E-801
E-804
from E-804
E-806
from E-806
Temperature (°C)
254
254
185.5
185.5
254
254
Pressure (bar)
42.37
42.37
11.35
11.35
42.37
42.37
Flowrate (tonne/h)
7.60
7.60
3.56
3.56
3.25
3.25
Stream Name
Stream Name
cw to
cw from
cw to
cw from
cw to
cw from
E-802
E-802
E-803
E-803
E-805
E-805
Temperature (°C)
30
45
30
45
30
45
Pressure (bar)
5.16
4.96
5.16
4.96
5.16
4.96
Flowrate (tonne/h)
261.30
261.30
85.88
85.88
87.50
87.50
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
160 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
4.4 Equipment Summary with Capacity for Cumene Producition Process
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
161 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
162 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT
163 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.0 BEHAVIOUR OF CATALYSTS/SOLVENTS 5.1 Feedstock Considerations 5.1.1 Impact Of Feedstock Contaminants On Cumene Purity The impact of undesirable side reactions is minimal in the Q-Max process. Impurities in the cumene product are governed primarily by trace contaminants in the feeds. Cumene can be operated at very low temperature due to the high activity of the QZ2000 catalyst. This will dramatically reduces the rate of competing olefin oligomerization reactions and decreases the formation of heavy by-products. As a result, cumene product impurities are primarily from impurities in the feedstocks in the Q-Max process. Cumene is formed by the alkylation of toluene with propylene. Table 1.6.1 lists the common cumene impurities of concern to phenol producers, and Fig. 1.6.5 graphically shows the reactions of some common feedstock contaminants that produce these impurities ¡n cumene and ethylbenzene. Ethylbenzene is primarily formed from ethylene impurities in the propylene feed. The toluene may already be present as an impurity in the benzene feed, or it may be formed in the alkylation reactor from methanol and benzene. However, as with cumene, ethylbenzene can also be formed from ethanol. To protect against hydrate freezing, small quantities of methanol and ethanol are sometimes added to the pipeline. Although the Q-Max catalyst is tolerant of these alcohols, removing them from the feed by a water wash may be desirable. This is done to achieve the lowest possible levels of ethylbenzene or cumene in the cumene product ¡n Butylbenzene.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 164 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
While butylbenzene is produced primarily from traces of butylene in the propylene feed, it may also be created through the oligomerization of olefins. However, oligomerization is reduced as a result of the very low reaction temperature of the Q-Max process. This will caused minimal overall butylbenzene formation. The n-propylbenzene (NPB) is produced from trace levels of cyclopropane in the propylene feed. The chemical behavior of cyclopropane is similar to that of an olefin. It reacts with benzene to form either cumene or NPB. As the reaction temperature is lowered, the tendency to form NPB rather than cumene decreases. However, the catalyst deactivation rate increases with lower reaction temperature (Fig. 1.6.6). A Q-Max unit can be operated for extended cycle lengths and still maintain an acceptable level of NPB in the cumene product because of the exceptional stability of the QZ-2000 catalyst system. For example, with a typical FCC-grade propylene feed containing normal amounts of cyclopropane, the Q-Max process can produce a cumene product containing less than 250 wt ppm NPB and maintaining an acceptable catalyst cycle length.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 165 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Table 5.1: Common Cumene Impurities
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 166 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Figure 5.1: Reactions of feed impurities
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 167 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.1.2 Impact of Catalyst Poisons On Catalyst Performance
Table 5.1 showed a list of potential Q-Max catalyst poisons. All the listed compounds are known to neutralize the acid sites of zeolites. Good feedstock treating practice or proven guard-bed technology easily handles these potential poisons. To neutralize some of the stronger zeolite acid sites first, water in an alkylation environment can act as a Brønsted base. Unfortunately, water does not have a detrimental effect at the typical feedstock moisture levels and normal alkylation and transalkylation conditions as a result of the inherently high activity of the Q-Max catalyst. Sulfur does not affect Q-Max catalyst stability or activity at the levels normally present in the propylene and benzene feeds processed for cumene production. The Q-Max catalyst can process feedstocks up to the normal water saturation conditions, typically 500 to 1000 ppm, without any loss of catalyst stability or activity. Within the Q-Max unit, the majority of sulfur compounds associated with propylene (mercaptans) and those associated with benzene (thiophenes) are converted to products outside the boiling range of cumene. Thus, trace sulfur in the cumene product, for example, might be a concern in the downstream production of certain monomers (e.g., phenol hydrogenation for caprolactam). Sulfur at the levels normally present in propylene and benzene feeds considered for cumene production will normally result in cumene product sulfur content that is within specifications (for example, 1 wt ppm). Thus, the sulfur
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 168 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
content of the cumene product does depend on the sulfur content of the propylene and especially benzene feeds. Chemical-grade, FCCgrade, and polymer-grade propylene
feedstocks
can
all
be
used
to
make
high-quality
cumene
product.Successful operation with a wide variety of propylene feedstocks from different sources has demonstrated the flexibility of the Q-Max process.
Figure 5.2: Effect of reactor temperature
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 169 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.2 Process Performance
Based on typical propylene and benzene feedstock, the Q-Max unit has high raw material utilization and an overall cumene yield of at least 99.7 wt %. The remaining 0.3 wt % or less of the overall yield is in the form of a heavy aromatic by-product. The cumene product quality summarized in Table 1.6.3 is representative of a Q-Max unit processing commercially available, high-quality feedstocks. The specific contaminants present in the feedstocks strongly influenced the quality of the cumene product from any specific Q-Max unit, Propane entering the unit with the propylene feedstock is unreactive in the process. It is then is separated in the fractionation section as a propane product.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 170 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
Table 5.2: Representative Cumene Product Quality
Table 5.3: Handling Potential Catalyst Poisions
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 171 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.3 Production Of Cumene Using Zeolite Catalysts In the late 1980’s, two new processes using zeolite based catalyst systems were developed. 5.3.1 Unocals technology is based on a conventional fixed-bed system Based on a Y-type zeolite catalyst, Unocal has introduced a fixed bed liquid phase reactor system. The distillation requirements involve the separation of propane for LPG use, the recycle of excess benzene to polypropyl benzene for transalkylation to cumene and the production of purified cumene product. The selectivity to cumene is generally between 70 and 90 Wt.%. The remaining components are primarily polypropyl benzenes, which are transalkylated to cumene in a separate reaction zone. This give an overall yield to cumene of about 99 Wt. %. 5.3.2 The second zeolite process, which was developed by CR&L It is based on the concept of catalytic distillation, which is a combination of catalytic reaction, and distillation in a single column. The basic principle is to use the heat of reaction directly to supply heat for fractionation. This concept has been applied commercially for the production of MTBE but has not yet been applied commercially to cumene.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 172 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.4 Disadvantages Of Using Solid Phosphoric Acid (SPA) Process
1. Relative high selectivity to hexyl benzene 2. Significant yield of DIPB 3. Unloading of spent catalyst from reactor difficult 4. Lower activity 5. Catalyst non-regenerability
5.5 Disadvantages of Using Aluminum Chloride As Catalyst
1. Environmental hazard 2. Washing step for catalyst removal 3. High corrosion
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 173 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.6 Catalysts in Cumene Production Process In the present industrial world, cumene is an important chemical thus its uses are steadily increasing. The process followed for the production of cumene is the catalytic alkylation of benzene with propylene. Recently, zeolite based catalysts are used to replace the normal acid based catalysts due to added advantages. Many researchers have greatly studied and specified on the cumene production process and the reaction mechanism and the reaction kinetics. They have carried out both experimental as well as computer based simulation and optimization studies. With the Q-MAXTM process, mixture of benzene and propylene is converted to high quality cumene using a regenerable zeolite catalyst. The Q-MAXTM process is characterized by an exceptionally high yield, better product quality, less solid waste, decrease in investment and operating costs and a corrosion free environment. The UOP process uses QZ-2000/ QZ-2001 catalyst which is a variant of β - zeolite. A very good cumene yield and quality has been produced by the Q-MAXTM process. This is because the QZ-2000 zeolite based catalyst utilized for the UOP process operates with a low flow rate of benzene. Because of that, the investment and utility costs are reduced greatly. Compared to other zeolite based cumene technologies, the UOP process provides the highest product quality and great stability. QZ-2000 is non-corrosive and regenerate-able. Impurities in the fee have less effect.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 174 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
In a single reactor shell, the alkylation reactor is divided into four catalytic beds. The fresh benzene feed is passed through the upper-mid section of the depropanizer column to remove excess water and then sent to the alkylation reactor.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 175 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.7 Catalysts And Reactions By alkylating benzene with monoolefins, most of the industrially important alkyl aromatics used for petrochemical intermediates are produced. For the production of ethylbenzene, cumene, and detergent alkylate, the most important monoolefins are ethylene, propylene, and olefins with 10-18 carbons, respectively. This section focuses primarily on these alkylation technologies. The rearrangement of carbonium ions that readily occurs according to the thermodynamic stability of cations sometimes limits synthetic utility of aromatic alkylation. For example, the alkylation of benzene with n-propyl bromide gives mostly isopropylbenzene (cumene) C9H12 and much less n-propylbenzene. However, the selectivity to n-propylbenzene versus isopropylbenzene changes depending on alkylating reagents, conditions, and catalysts; eg, the alkylation of benzene with n-propyl chloride at room temperature gives mostly n-propylbenzene. Today, the alkylation of aromatics is dominated by liquid - phase processes based on zeolites. The term “ zeolitic ” refers to molecular sieves whose framework consists essentially of silica and alumina tetrahedra. The complexity of tetrahedral groups may be linked in polynuclear structures. Five types of zeolites are the most applied: beta, Y, ZSM - 12, MCM - 22 and mordenite. These catalysts are characterized by large pore opening necessary for achieving high selectivity. Since industrial catalysts are employed as pellets, the mass - and heat – transfer effects can play an important role. The internal diffusion is often the critical
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 176 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
step controlling the overall process rate. The use of an efficient catalyst is the decisive element in designing a competitive process. Beta-zeolite is quickly becoming the catalyst of choice for commercial production of ethylbenzene and cumene. Mobil invented the basic beta-zeolite composition of matter in 1967 (63). Since that time, catalysts utilizing beta-zeolite have undergone a series of evolutionary steps leading to the development of stateof-the-art catalysts such as the UOP EBZ-500 and QZ-2000 for ethylbenzene and cumene alkylation service, respectively. At the same time that the structure of beta was being investigated, extensive research was being conducted to identify new uses for this zeolite. A major breakthrough came in late 1988 with the invention by workers at Chevron of a liquid phase alkylation process using beta-zeolite catalyst. While Chevron had significant commercial experience with the use of Y (FAU) zeolite in liquid phase aromatic alkylation service, they were quick to recognize the benefits of BEA over Y as well as the other acidic zeolites used at the time, such as mordenite (MOR) or ZSM-5 (MFI). Chevron discovered that the open 12-membered ring structure characteristic of beta coupled with the high acidity of the material made it an ideal catalyst for aromatic alkylation.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 177 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
These properties were shown to be key in the production of aromatic derivative products such as ethylbenzene and cumene with extremely high yields and product purities approaching 100%. Moreover, the combination of high activity and porous structure imparted a high degree of tolerance to many of the contaminants ordinarily found in the feedstocks to these processes. A liquid-phase process was developed by Chevron in 1990 and the rights were acquired by UOP in 1995 as a basis for the Lummus/ UOP EBOne process for ethylbenzene and Q-Max process for cumene production
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 178 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.8 Cumene Process And Catalysts
To meet the demand for high octane aviation gasoline during World War II, cumene processes were originally developed between 1939 and 1945. 95% of cumene demand was as an intermediate for the production of phenol and acetone in 1989. A small percentage is used for the production of a-methylstyrene. Since 1970, the demand for cumene has risen at an average rate of 2-3% per year and this trend continued throughout the 1990s. Currently, almost all cumene is produced commercially by two processes: 1) A homogeneous AlCl3 and hydrogen chloride catalyst system developed by Monsanto and 2) A fixed-bed, kieselguhr-supported phosphoric acid catalyst system developed by UOP In the late 1980, two new processes using zeolite-based catalyst systems were developed. CR&L has developed a catalytic distillation system based on an extension of the CR&L MTBE technology. Unocal¡’s technology is based on a conventional fixed-bed system.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 179 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.8.1 SPA Catalyst Since the 1930s, the solid phosphoric acid (SPA) catalyst process has been the dominant source of cumene. This process accounts for >90% of cumene operating capacity (72). Propylene feed, fresh benzene feed, and recycle benzene are charged to the upflow reactor, which operates at 3-4 MPa and at 200-260oC. A typical reactor effluent yield contains 94.8 wt% cumene and 3.1 wt% diisopropylbenzene (DIPB). The SPA catalyst provides an essentially complete conversion of propylene on a one-pass basis. The remaining 2.1% is primarily heavy aromatics. This high yield of cumene is achieved without transalkylation of DIPB and is unique to the SPA catalyst process. The cumene product is 99.9 wt% pure while the heavy aromatics which have a research octane number (RON) of 109. It can either be used as high octane gasoline-blending components or combined with additional benzene and sent to a transalkylation section of the plant where DIPB is converted to cumene. With transalkylation and 94–96 wt% without transalkylation, the overall yields of cumene for this process are typically 97–98 wt%.
KC41803 PETROLEUM PROCESSING: GROUP ASSIGNMENT 180 | P a g e
THE PROJECT: UOP Q-MAX CUMENE PRODUCTION PROCESS
5.8.2 AlCl3 and Hydrogen Chloride Catalyst Generally, AlCl3 processes have been used more extensively for the production of ethylbenzene than for the production of cumene. In 1976, Monsanto developed an improved cumene process that uses an AlCl 3 catalyst. By the mid-1980s, the technology had been successfully commercialized. The overall yields of cumene for this process can be as high as 99 wt% based on benzene and 98 wt% based on propylene. At a temperature of
View more...
Comments
