Solvay process Presentation

CHEMICAL PROCESS INDUSTRIES INDUSTRIE S-I ChE 506

Presented by:

DEPT. OF CHEMICAL ENGG.

10/Che/16 : Bipin Sharma 10/Che/17 : Vishal Rao 10/Che/18 : Annoy Roy 10/Che/19 : Riki Mandol 10/Che/20 : Koustav Ghosh 10/Che/22 : Md Dilshad 10/Che/23 : Pradeep Singh 10/Che/24 : Ravi Prakash Shiromani

Equipment & materials of construction in manufacturing of HCl

Hydrochloric acid(HCl) 

Industrial Name:-Muriatic acid



Hydrochloric acid is a clear, colorless solution of hydrogen chloride (HCl) in water. It is a highly corrosive, strong mineral acid

Material of construction: •

•

•

FRP, PVC, HDPE and/or rubber are the materials of choice for storage tanks. Metering pumps and other equipment that comes in contact with concentrated solutions of Hydrochloric Acid (Muriatic Acid)must also be constructed of acid resistant materials such as PVC, rubber, Teflon, ceramic and Hastolly C.

No wetted parts should contain any metals such as carbon steel, stainless steel, brass or aluminum.

Material of construction: Rigid pipingSchedule flanged poly vinyl chloride(PVC), polyethylene, CPVC, FRP, fluorocarbon or acid resistant rubber lined pipe, used for rigid piping.

Flexible pipingFlexible hose lined with acid resistant rubber, cross linked polyethylene or fluorocarbon lining is used.

ValvesThe valves must be made of acid resistant material (Teflon, Saran, Kynar, FRP, PVC, ceramic or graphite). Quarter turn PVC flanged ball bulb are widely used.

Material of construction:

GasketThe gasket are made of Teflon, Viton fluoroelastomer, EPR, PTFE or Kynar .

Level controlLevel control system should be protected with a diaphragm made of Viton, Teflon or Tantalum.

Equipment in HCl plant: HCl can be produced in 3 major processes: 1. Chlorination process 2. Reacting salt & sulfuric acid

3. Combustion of Chlorine & Hydrogen

Chlorination: 1. HCl is a by product in chlorination of hydrocarbons.

Reacting salt & Sulfuric acid: 1. Furnace to roast Salt & 76% Sulfuric acid. 2. Cooler, Cooler absorber to separate HCl from highly corrosive mixture of HCl and water. 3. Coke tower to separate suspension from HCl.

Synthesis: 1.

Water jacketed combustion chamber for burning of chlorine.

2. Burner for supplying heat & a flame arrestor to prevent flame to reach the pure hydrogen.

3. Karbate cooler for cooling the produced gas. 4. Cooler absorber & tail gas scrubber for making the acid from HCl gas.

Comparison of Solvay & modified Solvay process

SOLVAY PROCESS OUTLINE:

Sodium carbonate (soda ash) is commercially prepared by the Solvay process, which makes use of the fact that sodium bicarbonate is less soluble in cold water than sodium chloride. The raw materials reqd. for the process includes sodium chloride, limestone and gaseous ammonia.

Chemical interrelations of the Solvay process

Flow chart of solvay process:

Advantages of Solvay process: • • • • •

Can use low-grade brine Less electric power Less corrosion problems No co-products to dispose of Does not require ammonia plant investment

Disadvantages of Solvay process: • •

• • • •

Higher salt consumption Higher investment in ammonia recovery unit verses crystallization units for ammonium chloride Waste disposal of calcium chloride brine stream More steam consumption Higher capacity plant for economic break-even operation With current fertilizer shortage, all of the ammonium chloride will be used as a mixed chemical fertilizer ingredient, so co-product disposal no problem.

Modified Solvay process: This process was developed by Chinese chemist Hou Debeng. Here calcium chloride is replaced by ammonium chloride ( NH 4Cl). Instead of treating the remaining Calcium Chloride solution with lime, Carbon Dioxide and Ammonia is added to the solution until the solution is saturated at 40oC then cooled to 10oC, causing the ammonia chloride to be removed by filtration. The ammonium chloride is then recycled to be reused in the production of sodium carbonate.

Advantages of modified Solvay process : •

•

•

•

Replaces calcium chloride as a by-product with the ammonium chloride, which can be recycled to be reused in the process, refined and used as a fertilizer. Eliminates the need for waste beds and other disposal methods to take place, as the by-products can be used in other productions. Much more economical and environmentally friendly than both the Le Blanc and the original Solvay processes. As ammonium chloride is more useful than calcium chloride, it is more economically beneficial for Solvay plants to use Hou's Process in their plants.

Disadvantages of modified Solvay process: • •

More expensive than the Solvay Process. Requires existing machinery to be replaced or modified.

Comparison between the two processes :Solvay Process

Modified Solvay Process

Solvay Process

Blanc Process

Modified Solvay Process

By-products

Calcium chloride - relatively useless, most Ammonium chloride - very useful in

By-products

of it needs to be disposed chloride of. Calcium

Hydrogen chloride gas

the production of fertilisers.Ammonium It can and calcium sulfide - relatively useless, chloride - very useful in be recycled to re-use ammonia.

most of it needs to be disposed of.

the production of fertilisers. It can be recycled to re-use ammonia.

Thermal Pollution

Heat is released and absorbed into water Heat is released and absorbed into

Thermal Pollution Air Pollution

Air Pollution Energy Consumption

Energy Consumption

Heat is released and absorbed into water

Heat is released andwater absorbed into

Heat is released and absorbed into

water

water

Ammonia gas (toxic), however this is

Ammonia gas (toxic), however this is

Hydrogen chloride gas (highly acidic).

reused so loss is minimal

reused so loss is minimal.

Cannot be reused, must be stored.

Ammonia gas (toxic), however this is

Ammonia gas (toxic), however this is

reused so loss is minimal

reused so loss is minimal.

Relatively low, highest temperature

Lower than Solvay Process, highest

Very high. Coal oxides at 1000oC. Other

required is 300oC. Other reactions take

temperature required is 300 oC,

reactions take place at around 300oC.

temperature Lower than Solvay Process, highest place at +40 C.Relatively low, highest however other reactions take places at o

about reactions room temperature. required is 300oC. Other take temperature required is 300oC,

place at +40oC.

however other reactions take places at about room temperature.

Water Use Water Use

Large amountsLarge of water are neededof to amounts

Large are amounts of water requiredamounts to Larger amounts of water needed to to water needed toare Large of water areare required

keep machine parts cool. Water can be

parts cool. Water can be keep machine parts cool. Water can be keep machine parts keep cool.machine Water can be keep machine parts cool. Water can be

cooled and re-used.

cooled and re-used.

cooled and re-used.

cooled and re-used.

cooled and re-used.

Reference Shreve’s Chemical Process Industries by George T. Austin.



 Wikipedia.



Class notes.



Outlines of Chemical Technology - Dryden

