Shell Gasification Process

The Shell Gasification Process

A company of ThyssenKrupp Technologies

Uhde

  k   t

The Shell Gasification Process

Contents 1.

Company P rof ile

2.

Introduction

3.

Process Configurat ion

3.1

Basic Reac tions

3.2

Ma in T echnology Steps

3.3

Advantages Advantages of the Shell Gasification Process (SGP)

3.4

Reliability Data

4.

Gasification Gasification Process Flexibility

4.1

SGP and Integrated Integrated Gasification Combined Cycle (IGCC)

4.2

SGP and Chemical Chemica l Products

5.

Shell Pernis – World’s First Oil Based IGCC / H2 Plant

6.

Uhde and Gasification

7.

Reference Reference List Shell Gasification Process

... / 1 1.

Company Profile

To date the Dortmund-based engineering contractor, with its highly specialised workforce of around 3,500 and its international network of subsidiaries and branch offices, has successfully completed over 2,000 projects around the world.

Uhde's international reputation has been built up on the successful application of Engineering with ideas to produce cost-effective, high-tech solutions for its customers. The increasing importance placed upon process and application technology in the fields of oil & gas, chemicals, fuels, energy and environmental protection is met by a combination of process development, specialist know-how, all-around service packages, top-quality engineering and impeccable punctuality.

Uhde provides more than 250 different processes covering many different sectors and providing intelligent solutions for the refining, petrochemical and chemical industries.

Shell Global Solutions International B.V. is owner and licensor of the Shell Gasification Process (SGP). Uhde is Shell’s engineering partner for the SGP, which can be applied for the production of synthesis gas from all liquid and gaseous feedstocks.

... / 2 2.

Introduction

The growing demand for lighter and cleaner fuel products, the heavier crude oil sources for the refineries and the economical situation inside the refineries to downgrade the bottom more and more are changing the configuration of the refineries.

The introduction of stringent environmental legislation in the United States and in Europe, coupled with global restrictions on the level of aromatics and sulphur permitted in automotive fuels, will change the internal hydrogen balance in refineries. New developments in fuel cell technology will also lead to future market opportunities for hydrogen. But whilst refineries work to satisfy the increasing demand for hydrogen worldwide, they are also looking to find the best technological and most cost-effective way to dispose of their final residues.

Refineries are also searching for a global solution to their emission problems and are gradually replacing the old furnaces used for the production of power, steam and heat.

Off-gases, such as those produced in catalytic reformers, have traditionally been the principal source of hydrogen in refineries. However, the compulsory reformulation of gasoline has limited the level of aromatic constituents permitted. This change has reduced catalytic severity leading to an increase in the liquid yield, but a decrease in the hydrogen yield.

The bulk of hydrogen produced today is generated when light hydrocarbons, particularly natural gas or LPG, undergo a steam reforming process.

During the refining stages, heavy metals – in particular, vanadium, iron and nickel, which are present in all crude oils – are accumulated in the bottom products. In fact, these residues, which have the highest metal concentration, are the cheapest feedstocks for gasification units.

... / 3

Nevertheless, gasification is a very versatile process which can be used for converting even the heaviest “bottom of the barrel” refinery residues into clean synthesis gas.

This gas can subsequently be used to produce hydrogen, power, f uel gas or steam for any refinery purposes, as well as producing gases for the chemical industries (Fig. 1).

Sour  Water 

Sour Water  Treaters

Sulfur Recovery Plants

Tail Gas Treating Units Sulfur  Fuel Gas LPG

Isomerization Units Gas Treating Plants

Crude

Crude Units

Naphtha Desulfurizers

Catalytic Reformers

Distillate Desulfurizers

Hydrocrackers & Cat Crackers

Resid & Heavy Oil Desulfurizers Vacuum Units

 Alkylation Units Gasolines

LPG, Napht ha & Jet Fuel Treating Units  Aromatics Extraction/ Fractionation

Cokers & Visbreakers

Kerosene Jet Fuel Diesel Fuel Hydrodealkylation Units

Benzene Fuel Oil/Coke Low Sulfur  Fuel Oil

Solvent Deasphalting

 Asphalt Plants

Gasification Plants

Bitumen Hydrogen Recovery

Hydrogen Syngas

Power Plants

Electric Power 

Figure 1: Gasification in the refinery environment 

The successful Shell Gasification Process, SGP, is a reliable, efficient and environmentally benign process. Over the last 40 years more than 160 SGP units have been built worldwide, many of them for the production of ammonia and methanol. However, at present the focus is more on power and/or hydrogen coproduction. An example of the successful implementation of such a project is the PER+ refinery upgrading project at the Shell Pernis refinery near Rotterdam in the Netherlands. The Pernis SGP plant has been operating successfully since the end of 1997.

... / 4 As a technology-oriented company, Uhde can rely on its extensive experience in the development, design and construction of oil and coal conversion plants. To date Uhde has designed and built almost 100 gasifiers around the world based on 5 different gasification technologies catering to all types of feedstock – solid, liquid and gaseous. These technologies include upstream and downstream processes such as heat recovery, gas treatment (including sulphur recovery), waste water treatment, and subsequent processes for the production of methanol, ammonia, hydrogen, oxo-chemicals and electrical power.

Uhde has built world’s largest IGCC Power Plant (318 MW  e, net   ) in Puertollano, Spain 

... / 5 3.

Process Configuration

The Shell Gasification Process has a long track record of optimum performance over many years of operation.

The SGP process, initially developed in the 1950s, was primarily used with fuel oil and bunker C oil as feedstocks. By the 1970s vacuum (short) residue had become the standard feed. In the 1980s vacuum residues were concentrated even further by visbreaking and C4/C5 deasphalting. Over time, the feed became heavier and more viscous, and contained higher levels of sulphur and heavy metals. Shell’s continuous developments in this field over the years underpin its dedication to this particular technology. 3.1

Basic Reactions

Gasification or partial oxidation is a non-catalytic process; a combination of exothermic and endothermic reactions, thermal cracking, steam reforming etc.

The net reaction

2CHn + O2 à 2 CO + nH2 (1 < n < 4) is exothermic and produces a gas which containing mainly CO and H 2. The raw synthesis gas (or syngas) contains small quantities of CO2, H2O and H2S and impurities, such as CH4, NH3, COS, HCN, N2, Ar and ash, the quantities being determined by the composition of the feedstock, the oxidant and the actual gasification temperature (1300 – 1400 °C). A small amount of unconverted carbon is also present and ranges from 0.5 to 1.0 %wt in liquid feedstocks or 50 – 200 ppm wt in gaseous feedstocks. Hydrocarbon fuels, such as natural gas, refinery gas, bunker C-oil, vacuum residue, vacuum-flashed cracked residue, asphalt, liquid waste and orimulsion can all be used as f eedstock for the gasification process.

... / 6 Operating pressures ranging from atmospheric pressure to 65 bar can easily be accommodated but depend upon the desired application of the syngas.

3.2

Main Technology Steps

The Shell Gasification Process consists of three principal stages (Fig. 2):

•

Gasification (Partial Oxidation), in which the feedstock is converted to syngas in the presence of oxygen and a moderating agent (steam) in a refractory-lined gasification reactor;

•

Syngas Effluent Cooler (SEC), in which high pressure steam is generated from the hot syngas leaving the reactor;

•

Carbon Removal, in which residual carbon and ash are removed from the syngas in a two-stage water scrubbing unit.

PROCESS STEAM

FEEDSTOCK SYNGAS

HP STEAM OXYGEN

FILTRATE BOILER FEED WATER

SOOT SCRUBBER REACTOR

SYNGAS EFFLUENT COOLER

SOOT QUENCH SOOT WATER

Fig. 2: The Shell Gasification Process (Gasifier and Syngas Effluent Cooler  manufactured by Standard Fasel Lentjes B.V., The Netherlands) The final stage involves a soot water processing section, Naphtha Soot Recycling Unit (NSRU) or Soot Ash Removal Unit (SARU), which recovers carbon from the

... / 7 wash water and separates the metal ash from the carbon to yield a valuable product.

Both the feedstock and the gasification agent, oxygen, are preheated prior to being fed to the burner which is a proprietary co-annular burner specially designed for viscous f eedstocks.

The reactor’s optimal design allows for complete gasification reactions. The burner is controlled by a managing system which includes a safeguarding system and a sequence logic block to enable fully automated start and stops and normal operation during all plant operating conditions. The recovery of sensible heat from the syngas is an integral feature of the SGP process. Primary heat recovery takes place in the Syngas Effluent Cooler (SEC) where high-pressure saturated steam is generated. Secondary heat recovery occurs in a boiler feed water economiser immediately downstream of the SEC.

The SGP process suspends the carbon (soot) produced by the partial oxidation of hydrocarbons in the gasifier, in a carbon slurry, which is an aqueous suspension containing up to 20 g/l of soot and ash. The soot particles and the ash are removed from the gas in t he two-stage water scrubber, comprising:

•

a quench pipe and soot separator and

•

a soot scrubber.

About 95% of the soot is removed by a direct water spray in the quench pipe.

The gas then enters the scrubber where it is scrubbed in counter-current flow in a packed bed using condensate return water and the filtrate from the soot water processing section.

After leaving the scrubber the syngas has a residual soot

content of less than 4 mg/Nm³.

The heavy metals and alkaline-earth metals entering the reactor are transformed into oxides, sulphides and carbonates, and because these compounds are only slightly soluble the ash follows the soot water process flow.

... / 8

The SGP process has been used successfully with two different technologies for separating soot from soot water; the most recent ones is shown in Fig. 3.

Naphtha Soot Recovery Unit O2

Gasification + Scrubbing

Oil/ HeavyResidue Steam

Raw Gas

Soot Water Oil/Carbon Oil Part Stream

Carbon/  Naphtha Extraction

  e    l   c   y   c   e    R   r   e    t   a    W

Soot Ash Removal Unit O2 Oil/Heavy Residue Steam

Gasification + Scrubbing

Raw Gas

Soot Water

Soot Water Filtration

Waste Water (Soot + Heavy Metals)

  e    l   c   y   c   e    R   r   e    t   a    W

Filter Cake

Waste Water Treatment

Filter cake Burn-off

Heavy Metal Sludge

Heavy Metal Ash

Fig. 3: Naphtha Soot Recovery Unit vs. Soot Ash Removal Unit 

In the Naphtha Soot Recovery Unit, NSRU, the soot water is mixed with liquid hydrocarbons (naphtha) in a proprietary extractor. The hydrocarbons force the soot particles to agglomerate and to rise and these agglomerates are then sieved-off in a special rotating sieve. The purified water is recycled back to the scrubbing section. The naphtha is recovered and the soot becomes a pumpable suspension in the fresh feedstock (soot oil) which can be recycled and used as feedstock for the reactor. The final stage of the NSRU comprises a Waste Water Treatment Unit in which the heavy metal compounds and the remaining soot are extracted from a small bleed stream leaving the NSRU. The latest SGP development in this field is the Soot Ash Removal Unit. This unit consists of a Soot Water Filtration section and a section for filter cake incineration. The soot water coming from the scrubber is depressurised and routed to a filter

... / 9 press. Filter cakes with a solid content of approx. 17 – 20 %wt can be attained. The filter cake is dried in a special incineration section and the remaining carbon is burnt off. The final product is a highly valuable heavy metal ash, which is sold to the metal reclaimer market.

3.3

Advantages of the Shell Gasification Process

The SGP process is a proven technology which is being utilised in a variety of commercial applications around the world. The benefits to our customers can be summarised as: •

maximum reliability

•

broad fuel flexibility

•

optimum efficiency

•

high operational flexibility

•

broad product flexibility

•

flexibility with regard to integration into existing and new plants

•

excellent environmental performance

•

standardisation based on years of experience.

One criteria is essential in ensuring the profitability of the gasification units:

R E L IAB IL IT Y . SGP’s optimum process availability and reliability is the result of more than 40 years’ experience in the design and operation of gasification units and a dedication to continuous technological developments. Key developments in the SGP process have resulted in high on-stream factors which are now routine in a variety of services. The optimised SGP reactor design allows relatively

moderate process

temperatures (1300 – 1350 °C). The relatively low gasification temperature is accompanied by minimal heavy metal eutectic formation. There is also very little

... / 10 soot formation and consequently there are fewer deposits on the refractory of the reactor and less fouling in the SEC. Another result of the moderate gasification temperature is the comparably low oxygen consumption. Furthermore, the superior efficiency of the SGP process results in a high CO content and a low CO 2 content. The development of a new generation of burners –  the co-annular burner – has paved the way for the gasification of highly viscous feedstocks. The inspection of the burner at high temperatures, a special safeguarding and control system and the integrated heat-up auxiliary burner have resulted in both very long operating periods (over 9000 hours) and easy maintenance. The special design allows parts which are subject to wear and tear to be repaired on site. The normal turn-down ratio of the burner is lower than 70%; lower is possible with special design. For the initial phase of the reactor heat-up an auxiliary burner is used. This burner is integrated with main burner, its insertion and removal is quick and simple. One of the key elements of the SGP process is the Syngas Effluent Cooler (SEC) which produces high-pressure steam (Fig. 4).

... / 11

REACTOR

SYNGAS EFFLUENT COOLER

Fig. 4.:  SGP Reactor with  Syngas Effluent Cooler  (manufatured by Standard  Fasel Lentjes B.V., The  Netherlands)

The SEC equipment operates with low fouling and high feedstock flexibility. In fact, intensive investigations were carried out to ascertain the current availabilities of the cooler, e.g. the special design of the inlet section of the cooler. Efficiency for electric power generation increases by approx. 5 percentage points, if an SEC is used instead of a gasifier operated with a direct water quench. The entire design of the cooler is extremely cost effective, e. g. there is no additional steam drum. The use of low-alloy steels combined with special design makes the investment costs for the SEC very low and the return on investment therefore extremely good. As a consequence, the SEC usually pays for itself within two years. Low maintenance costs are achieved since the standard maintenance and cleam-outs usually are required only after two years. The soot separation/handling system is a deciding factor in the trouble-free operation of the gasification plant. Over the last few years the development of the plant configuration has favoured the Soot Ash Removal Unit (SARU). Shell has developed a proprietary continuous dewatering process for soot and ash. The

... / 12 process uses a filter press and a carbon burn-off process which is completely reliable and which does not affect the availability of the gasification unit. The Soot Ash Removal Unit has the following advantages over a Naphtha Soot Recovery Unit: §

The SARU is a typical once-through system with spare capacity in cheap tanks rather than in expensive filtering systems.

§

Lower capital requirements and operating costs (automated operation, no use of naphtha)

§

Hardly any heavy metals in the waste water

§

No accumulation of heavy metals in the gasification feed. This prevents heavy metals from attacking the refractory of the reactor. It also prevents increases in the viscosity of the feedstock and creates less fouling of the Syngas Effluent Cooler.

§

The final product (metal ash) is a valuable product which is sold to metal reclaimers.

The latest development to the SGP process is the standardised Safeguarding and Control System. This system includes all the safety measures, which have been

implemented during the development of gasification technology. The special modular structure means that the commissioning and start-up of the gasification plant is extremely efficient. The highly automated control system supports the operator in all aspects of plant operation (start-up, shutdown, stand-by) and avoids trips of non-safety nature. In fact, this system enables the plant to be started automatically within 10 minutes and also minimises flaring of the gases produced during the initial phase of plant operation. It is even possible to replace the conventional blast burner with a co-annular burner in existing SGP plants. The Safeguarding and Control System can be easily adapted to the old plant configuration thanks to its unique modular structure.

... / 13 3.4

SGP and IGCC

Data obtained from SGP units already in operation have provided the following average figures for availability and replacements over a 10 year operating period:

•

The overall availability for a typical 4-train SGP is 96 %

•

Typical shutdown time for 1 train: Burner inspection/replacement Replacement of thermocouple in the reactor Upstream/downstream causes Non-scheduled shutdown Total

•

On-stream factor: 1 train 98 %: Gasifier and syngas efluent cooler Soot scubbing

98.4 % 99.6 %

Replacement schedule: Replacement of burner/internals Coils of the syngas effluent cooler Refractory gasifier

every year 5 - 8 years 5 - 8 years

•

days per year 4 1 1 2 8

Since the SGP IGCC/H2 cogeneration complex started operation in Pernis, further improvements to its availability and reliability have been observed.

... / 14 4

Gasification Process Flexibility

Many different gaseous and liquid feedstocks are used for the SGP process. Although the SGP process is standardised (see Table 1 – specific raw gas production data for the SGP process), any applications affecting the final product are tailored to the customer’s requirements using an optimum route for treating and purifying the syngas (Fig. 5).

The following applications are described in more detail •

SGP + IGCC

•

SGP + chemical products, such as ammonia, hydrogen, oxo-gas and carbon monoxide.

Hydrogen Chemicals Feedstock Clean Syngas for Refinery Use Gasification & Gastreating

Clean Syngas (CO + H2)

Oxygen

Fig. 5: Typical SGP applications 

• • • •

Boilers Furnaces (Electricity) (Steam)

Synthesis of Hydrocarbons

• Liquid Transportation Fuels

Integrated Gasification Combined Cycle

• Electric Power • Steam

... / 15 4.1

SGP and IGCC

What is an IGCC plant? 

Integrated Gasification Combined Cycle (IGCC) involves the integration of the

gasification island into a combined cycle power plant (fig. 6), comprising -

the gasification unit, in which the primary fuel is converted into raw gas. The solid and gaseous impurities are removed in a scrubbing section and in a gas treatment section;

-

the Combined Cycle Gas Turbine (CCGT) system, which converts the clean gas into electricity.

Oil/Heavy Residue Gasification

Air Separation

Oxygen

Syngas Effluent Cooler Soot Water

Air

Water

Soot Scrubbing

Filtrate

Soot Ash Removal Unit Blow

H2 S Removal Humidification

Metal Ash

Down

Waste Water Treatment

Water

Syngas Sour Gas

C

Air

T

Gas Turbine

Sulphur Recovery

Heat Recovery

Sulphur

Flue Gas

G

    W     F     B

   m    a    e     t      S

T

G Steam Turbine

Condenser

Fig. 6. SGP based IGCC power station 

An Air Separation Unit (ASU) is also required for the gasifier operation. As a rule, the oxygen for the gasification unit is more than 95 % pure which means the equipment needed for the gas path can be reduced in size. The nitrogen extracted is used in the gas turbine to reduce the NO x emissions which are formed by the combustion of the clean syngas in the gas turbine for power generation. The exhaust heat from the gas turbine is used to produce steam

... / 16 in a heat recovery steam generator, which, together with the steam generated in the Syngas Effluent Cooler of the gasification section, is routed to a steam turbine used to generate more power. This approach has the potential to raise the conversion efficiency above that of the conventional steam cycle if all elements of the plant are integrated optimally, that is: •

integration of extracted air for the Air Separation Unit from the gas turbine air compressor for reducing internal power consumption

•

integration of nitrogen as a by-product for reducing the NOx emissions

•

integration of the heat from the steam produced in the Syngas Effluent Cooler into the CCGT steam cycle for increasing conversion efficiency

•

optimum use of low-level heat from both the CCGT and the gas treatment section for preheating and saturation (moisturing) of the syngas for increasing conversion efficiency.

This optimum integration of the major elements in the power station results in highlevel efficiency (approx. 45 %, LHV-based). As far as environmental acceptability is concerned, this type of power station can compete with the most efficient conventional power stations based on other fuels (e.g. coal-fired power stations). The power station’s ability to supply clean gas for a number of applications (hydrogen, oxo-gas, carbon monoxide etc.), as well as the low-value feedstock used (high in sulphur and heavy metals), provides the plants with a much stronger market potential than cheap natural gas power generation. The integration of the IGCC into refineries leads to additional synergies for both plants – less emissions and lower investment cost by optimum integration of steam, power and fuel gas produced by the IGCC.

The following atmospheric emissions recorded for an IGCC with the SGP process emphasise its environmental advantages:

... / 17

NOx

– 25 mg/Nm³ (dry – 15 % O2)

SO2

– 10 mg/Nm³ (dry – 15 % O2)

CO

< 10 mg/Nm³ (dry – 15 % O2)

Particulates

< 1 mg/Nm³ (dry – 15 % O2).

Despite the poor quality feedstocks, the emissions are still extremely low. The sulphur recovery efficiency, defined as a ratio between the liquid sulphur recovered and the sulphur in the feedstock, is > 99.5 %.

Typical Data for SGP Feedstocks Feedstock Type

Natural Gas

Vacuum Residue

Liquid Coke

Liquid Waste

-

1.10

1.25

0.95

3.35

9.7

11.9

9.2

Sulphur , % wt

-

6.8

8.0

3.1

Ash, %wt

-

0.08

0.16

0.01

Feedstock [kg]

330

350

350

360

Oxygen Feed 99.5 % SGP Product Gas (150°C, 62 bar)

365

333

316

390

Hydrogen & Carbon Monoxide

95.3

92.9

92.8

94.0

H2 /CO Ratio ( mole/mole)

1.69

0.88

0.78

0.89

890

650

615

740

Feedstock Properties Specific Gravity , 15°C C/H Ratio, weight

Composition, % vol. ( Dry)

Steam Export [kg]

2)

Basis: Production of 1,000 m 3 (N)

1)

of CO+H 2

1)

m3 (N) = m 3 at 0°C and 1.013 bar

2)

steam production corrected by gasification steam consumption

Table 1: Typical data of the SGP process for different feedstocks 

Table 1 shows the characteristics of feedstocks, from vacuum-flashed cracked residues to liquid coke, produced by a visbreaker working in the Deep Thermal Conversion mode (DTC licensed by Shell Global Solutions International B.V.). In refineries, the SGP is particularly attractive when used in conjunction with power generation:

... / 18 -

Refineries which are under pressure to invest mainly in SO 2 and NOx reduction may find that the use of clean syngas in furnaces or boilers is a very costeffective way to avoid having to make i nvestments for environmental reasons.

-

A key factor in solving the global CO2 problem in the future will be linked to true energy pricing and competition. Improved efficiencies, closed product cycles and cogeneration are just some of the solutions to this problem. Cogeneration of Power and Hydrogen should be a must for any refinery wishing to solve future problems with heavy crude wastes, cleaner automotive fuels and emission reduction.

-

Refinery heat is often distributed at the level of MP steam. This heat can be supplied from the steam turbine process either directly from the heat recovery steam generator or by extracting heat from the steam turbine.

-

The SGP can handle any heavy feedstock. Consequently the refineries can utilise deeper conversion (see DTC) which leaves a residue that can yet be processed by SGP. It is possible for the refineries to increase their profits by using heavier sulphur and, co nsequently, cheaper crude.

4.2

SGP and Chemical Products

The SGP process was first used for the production of syngases used in the chemical industry (primarily ammonia and methanol). The following examples of various SGP process applications demonstrate its versatility:

-

SGP for ammonia

The total production capacity of the SGP-based ammonia plants around the world is over 35 million Nm³ (H 2+CO) per day. Ammonia is one of the most popular gasification products. -

SGP for hydrogen

Hydrogen will be in huge demand as a fuel in the future, either in fuel cells or in the automotive industry. The hydrogen demand in refineries is growing constantly as attempts are made to comply with global legislation dictating low sulphur contents. -

SGP for methanol

... / 19 The advantage of using the SGP for methanol production is that the gas can be produced at a pressure level suitable for modern low pressure synthesis processes without requiring further compression. The total production capacity of SGP-based methanol plants around the world exceeds 10 million Nm³ (H2+CO) per day. -

SGP for CO and Oxo-Gas

The high CO content (approx. 45 %) in raw synthesis gas makes the SGP a natural choice for the production of oxo-syngas and pure CO. The total production capacity of SGP based oxo-syngas and CO production plants is over 5 million Nm³ (H2+CO) per day. Which gas treatment and purification systems are to be used depends o n the purity requirements and the economics of the particular application. The SGP process provides an excellent opportunity for turning low-value liquid residues into high-value products by cogenerating electrical power and gaseous products. The use of syngas for refinery-based power generation increases the synergy with other refinery needs. In general, less than 10 % of refinery fuel is required to cover the hydrogen and energy demand of a typical refinery when using the SGP process.

... / 20 5.

Shell Pernis – World’s First Oil-Based IGCC / H2 Plant

The Shell Gasification Process used in the Shell Pernis Refinery in the Netherlands is a fine example of state-of-the-art technology (Fig. 7).

Fig. 7: World’s first oil-based IGCC / H 2  Plant in Pernis, The Netherlands 

The Shell Pernis plant is the first IGCC in the world to operate using heavy oil residue gasification. It produces about 115 MW electric power and 285 t/d of pure hydrogen. In a refinery environment, one of the most popular gasification products is hydrogen which can be used in hydrocracking- or hydrodesulphurisation units. Often, however, the residues used for gasification and for the refineries’ hydrogen requirements produce a surplus of syngas, which can then be used for highefficiency, combined cycle power generation, e.g. for power export “over the fence”. In Pernis, the three-train gasification plant has a capacity of 1,650 t/d (approx. 11,000 b/d) and uses a heavy, vacuum-flashed, visbroken residue as feedstock. About 1,600 t/d oxygen are supplied by a third-party source nearby. The main

... / 21 reason for having three gasification trains is that if one gasifier needs to be taken off-line, the hydrogen requirement for the hydrocracker can still be provided by the two remaining trains. The hydrocracker requires up to approximately 285 t/d hydrogen. In a normal threetrain operation, the syngas, which exceeds the requirements for hydrogen production, will be used as gas turbine fuel. The hydrogen plant consists of a two-stage CO shift (high temperature/low temperature), carbon dioxide removal and a methanation stage. A highly integrated gas treatment unit (Rectisol) was selected for removing H 2S from the syngas and for removing CO2 downstream of the low-temperature CO shift. The scrubber water (containing soot and ash) from the three trains is filtered and returned to the scrubber. Excess water is fed to water treatment facilities and the filter cake is processed for metal recovery. The Pernis SGP plant has been in operation since the end of 1997 and has been extremely successful in using the latest technological developments in the Shell Gasification Process, which are: 1. The development of the co-annular gasification burner enabling the processing of more viscous feedstocks. 2. The combination of the specific SGP reactor design with the co-annular burner permits the operation of the gasification unit with low soot make and relatively low operating temperatures resulting in a relatively low oxygen demand and CO2 production. 3. The development of an “open loop” soot/ash removal. T his enables the production of a marketable, concentrated, high-value vanadium/nickel ash and prevents the problems associated with heavy metal enrichment and increased feedstock viscosity.

... / 22 6.

Uhde and Gasification

Being a technology-oriented company, Uhde can rely on extensive experience in the development, design and erection of oil and coal conversion plants. This experience dates back approximately 65 years and has been improved continuously up to the present day. Figure 8 illustrates the development of Uhde’s experience in gasification technology development and realised plants: Winkler 1926 

= E,P,C by Uhde KT- 1941 Development 

= Milestone for reference KT- 1951 M a z in g a r b e , F  

K T ( o i l) - 1 9 5 2 Texaco - 1953

O u l u , F i n la n d  

She ll - 1953

T G P Li c e n s e  

S G P ( O i l)

KT- 1956 Tokyo, Japan 

KT- 1957 Puentes, Spain 

K T ( o i l) - 1 9 5 7 Zandvoorde, B 

Texaco - 1959

K T ( o i l) - 1 9 5 8

Las Palmas, S pain 

E s t a r re j a , P o r t .

Texaco - 1960

SGP - 1964

Lisbon, Portugal 

K U ’ s fi r s t S G P  

KT - 1962 P t o le m a is , G r .

KT (gas ) - 1965 Talkha, Egypt 

KT - 1965 M a e M o h , T h a i l.

K T ( o i l) - 1 9 6 8 Zeitz, Ge rmany 

Texaco - 1971 Lavera, France 

Texaco - 1971 R h o d e s , A u s t r a l ia  

T C G P - 1 9 73 D e v e lo p m e n t  

T C G P - 1 9 78 D e m o H o l t en , D  

T C G P - 1 9 86 Ob erhausen, D 

   )   e   c   n   e   r   e    f   e   r    l    l   e    h    S    (   s   r   o    t   c   a   e    R    P    G    S    8    6    1

KT - 1968 Kütahya, Turkey 

H T W - 1 9 73 S h e l l -K o p p e r s - 1 9 7 4 S t a r t o f D e v e lo p m e n t  

KT - 1975

D e v e lo p m e n t  

Modderfontein 

KT - 1976 Zambia 

KT - 1978 Talcher, India 

S h e l l -K o p p e r s - 1 9 8 0 Dem o Hamburg, D 

H T W - 1 9 78 Frechen 

KT - 1978 Ramagundam, I.

KT - 1984 Kütahya, Turkey  SCGP-1985 Houston, USA

H T W - 1 9 85 Berrenra th 

PRENFLO-1986 Fürstenhausen, D 

KT - 1986 Zeitz, Ge rmany 

KT - 1988 Indeco, Zambia 

H T W - 1 9 88 Oulu, Finland 

H T W - 1 9 89 W esseling 

Texaco - 1991 Oberhausen, D 

K o B r a ( n o t re a l . ) PRENFLO-1997 Puertollano, Spain 

SGP - 1997 Texaco - 1998

H T W - 1 9 93

SCGP-1994 Buggenum, NL

Pernis, NL

Bharuch, India 

SGP - 1998 S G P C o o p e r a t io n   S h e ll / K U  

S C G P - 19 9 9 Re-unified Co operation  She ll / KU 

H T W - 2 0 00 SHI, Japan 

H T W - 2 0 02 Vresova, Cz.

Fig. 8: Development of Uhde’s Gasification Portfolio 

... / 23 As shown in Fig. 8, Uhde has designed and built about 100 gasifiers worldwide based on 5 different gasification technologies (Shell, PRENFLO ® , Koppers-Totzek, High-Temperature Winkler, Texaco) catering to almost all feedstocks - solid, liquid and gaseous. These technologies include upstream and downstream processes, such as heat recovery, gas treatment, waste water treatment, and subsequent processes for the production of methanol, ammonia, hydrogen, oxo-chemicals and electrical power. Shell Global Solutions International B.V.

Shell’s expertise in refinery processes is unbeaten and the company can provide in-depth assistance throughout the project cycle, from the design studies to aftersales service. Synergies: Uhde and the Shell Gasification Process

Both Shell Global Solutions International B.V. and Uhde are world leaders in the development, design, construction and commissioning of their gasification technologies. Both companies have been involved not only in the technology development and front-end basic design of the plants, but also in the detailed engineering, commissioning, start-up and operation of gasification facilities for decades. This unique set-up ensures that the feedback essential for further process improvements and developments is readily available. This is further supported by extensive research and development work on all components in the gasification, gas treatment, refinery and chemical plants.

Uhde’s Affiliated Services

Uhde is dedicated to providing its customers with a wide range of services and to supporting them in their efforts to succeed in business. With our worldwide network of subsidiaries, affiliated companies, experienced local representatives and first-class backing from our headoffice, Uhde has the ideal qualifications to achieve this goal.

... / 24 Uhde places particular importance in interacting with the customers at an early stage to combine their ambition with our experience. We always aim to give potential customers the opportunity to visit operating plants and to personally evaluate such matters as process operability; maintenance and on-stream time. We aim to build our future business on the confidence our customers place in us. Uhde provides the entire spectrum of services associated with a technologyoriented engineering contractor. These range from the initial feasibility study, to financing and project management right up to the commissioning of units and grass-root plants. Our broad portfolio of services includes: •

feasibility studies / technology selection,

•

project management,

•

arranging financing schemes,

•

financial guidance based on extensive knowledge of local laws, regulations and tax procedures,

•

environmental studies,

•

basic / detail engineering,

•

utilities / offsites / infrastructure,

•

procurement / inspection / transportation services,

•

civil works and erection,

•

commissioning,

•

training of operating personnel,

•

plant operation / plant maintenance

•

R&D

The policy of the Uhde group and its subsidiaries is to ensure utmost quality in the implementation of our projects. Our head office and subsidiaries worldwide work to the same quality standard, certified DIN / ISO 9001 / EN29001. We remain in contact with our customers even after project completion. Partnering is our byword. We promote active communication between customers, licensors, partners, operators and our specialists by organising and supporting technical

... / 25 symposia. This enables our customers to benefit from the development of new technologies and the exchange of troubleshooting information.

February 1998: Symposium in Chennai, India “The Shell Gasification Process” 

We like to cultivate our business relationships and learn more about the future goals of our customers. Our after-sales service includes regular consultancy visits which keep the owner informed about latest developments or revamping possibilities. For more information contact one of the Uhde offices near you or see Internet: www.thyssenkrupp.com/uhde

... / 26 7.

Reference List Shell Gasification Process

The following list summarises all plants applying the Shell Gasification Process currently in operation. The total amount of SGP gasifiers licensed amounts to over 160.

Licenced Shell Location Gasification Process in operation at Companies

Feedstock

Product

Total H2+CO Nm³/day

Number of reactors

Started

Mitsubishi Petrochemicals

Yokkaichi, Japan

bunker C oil

syngas

400,000

2

1961

Kemira Chemicals Oy

Oulu, Finland

bunker C oil

specialities

300,000

1

1965

DEA Mineraloel AG

Wesseling, Germany

cracked residue

methanol

1,300,000

2

1969

Lucky Goldstar Chemical Ltd.

Naju, S. Korea

bunker C oil

ammonia

500,000

1

1969

Falconbridge

Santo Domingo, Dom. Rep.

bunker C oil

reducing gas

1,440,000

12

1971

Chemopetrol a.s.

Litvinov, Czech Republic vacuum residue

methanol, ammonia

3,600,000

6

1971

Ruhr Oel GmbH

Gelsenkirchen, Germany

vacuum residue

ammonia + methanol

4,300,000

4

1973

Hoechst Celanese Ltd.

Houston, USA

natural gas

oxo

2,100,000

3

1977

Fertiliser Corp. of India Ltd.

Sindri, New Delhi, India

heavy fuel oil

ammonia

2,100,000

3

1977

National Fertiliser Ltd.

Nangai, New Delhi, India

bunker C oil

ammonia

2,100,000

3

1978

Hindustan Fertiliser Corp. Ltd.

Haldia, New Delhi, India

bunker C oil

ammonia + methanol

2,100,000

3

1978

Hydro Agri

Brunsbüttel, Germany

vacuum residue

ammonia

4,500,000

4

1978

Exxon Chemical Company

Baton Rouge, USA

heavy fuel oil

oxo

570,000

3

1978

National Fertiliser Ltd.

Bathinda, India

bunker C oil

ammonia

2,100,000

3

1978

Ultrafertil S.A.

Araucária, Brasil

asphalt residue

ammonia

3,300,000

3

1979

National Fertiliser Ltd.

Bathinda, India

bunker C oil

ammonia

2,100,000

3

1979

Neyvell Lignite Corp. Ltd.

Neyvell, Tamil Nadu, India

bunker C oil

syngas

800,000

2

1979

Quimigal Adubos

Lavradio, Portugal

vacuum residue

ammonia

2,400,000

2

1984

... / 27 Licenced Shell Location Gasification Process in operation at Companies

Feedstock

Product

Total H2+CO Nm³/day

Number of reactors

Started

7,200,000

6

1985

715,000

2

1987

60,000

1

1991

Leuna Methanolanlage (MIDER)

Leuna, Germany

heavy residue

methanol

Qilu Petrochemical Ind.

Zibu, Shandong, China

vacuum residue

methanol + oxo

Fushun Detergent Chemical Plant

Fushun, Liaoning, China vacuum residue

oxo

Shell MDS (Malaysia)

Bintulu, Malaysia

natural gas

middle distilates

7,552,000

6

1993

JiuJiang Petr. Chem. Fertil. Comp.

JiuJiang City, Jiangxi, China

vacuum residue

ammonia

2,100,000

2

1996

Inner Mongolia Chem. Fertiliser Plant

Hohot, Inner Mongolia, China

vacuum residue

ammonia

2,100,000

2

1996

Lucky Goldstar Chemical Ltd

Yochon-City, S. Korea

bunker C oil

oxo

384,000

1

1996

Shell Nederland Raffinaderij B.V.

Pernis, Netherlands

heavy residue

H2 + el. power

4,662,200

3

1997

Lanzhou Chem. Industry Co.

Lanzhou, Gansu, China

vacuum residue

ammonia

2,100,000

2

1997

Further SGP licenses have been granted since 1997. These have not yet been added to the reference list. These plants are in various phases of realisation.