Hydrogen & Caustic Soda-

Chlorine

Hydrogen Gas• Hydrogen is the most abundant element in the

universe, making up 75% of normal matter by mass and over 90% by number of atoms.

• Throughout the universe, hydrogen is mostly found in the atomic and plasma states whose properties are quite different from molecular hydrogen.

Sources of Hydrogen gas

•Natural gas (Methane) is the primary source for producing hydrogen.

• It can also be prepared from water through Electrolysis process.

Physical PropertiesColour Colourless

DensityAt 0 °C it is 101.325 kPa

i.e. 0.08988 g/L

Melting point -259.14 °C-434.45 °F

Boiling point -252.87 °C-423.17 °F

Specific heat capacity (25 °C) (H2) 28.836 J/mole.K

Chemical Properties

• Flamability: Hydrogen gas is highly flammable and

will burn in air. The enthalpy of combustion for hydrogen is −286 kJ/mol.

• Reactivity: Highly reactive in nature. Hydrogen and

air mixtures within the flammable range, can explode and may burn with a pale blue, almost invisible flames.

Application• In the chemical industry to synthesize

ammonia.• Hydrogenation of vegetable and animal

oils and fats.• In the metallurgical industry, hydrogen is

used to reduce metal oxides and prevent oxidation.• Hydrogen is used in the welding and

cutting of metals.• Hydrogen is also used by semiconductor

manufactures.

Caustic Soda-Chlorine

• Cautic soda-Chlorine is a combination of two compounds chlorine and soduim hydroxide.• This combination is termed as a chloro alkali.• They are formed by the electrolysis process

of brine solution which is the only commercially viable process for production of each one of the two.• Since both are manufactured together and

produced simultaneously as co-products they are studied together.

Caustic Soda• Caustic Soda is a versatile basic chemical with a

wide range of industrial applications. It is highly soluble is water and is practically insoluble in most organic solvents except alcohols.• It is available in the from of lye

(solutioninwater), as solid and as flakes.

Physical PropertiesSpecific gravity 2.13

Odour Odourless

Melting point320°C

(calcination)

Boiling point 1390°C

Hygroscopicity Hygroscopic and deliquescent

Solubility in water Highly soluble

Solubility in organic solvents Soluble in alcohols but insoluble in ether and benzene

Chemical Properties

Applications• Digestion of wood and bagasse for manufacture of

pulp and paper.• Digestion of wood for manufacture of viscose staple

fibre, viscose filament yarn and rayon tyre cord.• Manufacture of soaps and detergents.• Digestion of aluminium ore to make alumina as an

intermediate in the production of aluminium.• Dleaching & processing of cotton textiles.• Regeneration of ion-exchange resins in water

treatment plants.

End Uses of Caustic Soda

Packing , Handling and Storage

• Caustic Soda (Lye) is supplied in lorry tankers, Caustic Soda Solid is packaged in MS drums, and Caustic Soda Flakes are marketed in 50 Kg HDPE bags.• Caustic Soda is a highly corrosive substance

and requires careful handling. There should be no contact with bare skin. Caustic Soda flakes should be stored under dry conditions away from acids, organic chemicals, metals such as aluminium, tin, zinc, lead etc. and their alloys.

Liquid Chlorine• Chlorine is one of the most abundant

elements on this earth, and is a constituent of common salt, i.e., sodium chloride.

• It is a very reactive oxidizing and bleaching agent and has a wide range of applications

Physical PropertiesColour

Gas-Greenish Yellow Liquid-clear Amber

Odour Characteristic, suffocatingBoiling (liquefying) point -34°C (1 atm)Freezing (melting) point -101°C (1 atm)

Density - liquid - dry gas1.468 gms/cc at 0°C and 3.617 atm

3.209 g/L (0°C, 1 atm)

Vapour Pressure 3.617 atm (at 0°C)Latent heat of vaporisation 68.7 cal/gm at -34°C

Liquid - Gas volume relationshipOne volume of liquid chlorine weighs

as much as 457.6 volumes of gas at 0°C and 1 atm

Solubility in water Slightly soluble

Chemical Properties

• I - Flammability

1. Neither liquid nor gaseous chlorine is explosive or flammable.

• II – Reactivity1. A mixture of chlorine and hydrogen containing more than 5% of

either component, forms an explosive substance.2. It reacts with ammonia, alkalies and hydroxides of alkaline earth

metals.3. It reacts with organic compounds to form chlorinated derivatives

and hydrogen chloride. Some of these reactions, particularly those with hydrocarbons, alcohols and ethers may become explosive.

4. Dry Chlorine reacts with several materials.

Applications of Chlorine• Manufacture of 1. PVC, a versatile plastic, by chlorination of ethylene2. Pesticides and insecticides such as BHC, DDT, etc. 3. Solvents such as TCE, Chloromethanes, Chlorobenzenes,

Chlorotoluenes, etc. 4. Chlorofluorocarbons used in refrigeration, fire-fighting, etc. 5. Mono Chloro Acetic Acid (MCA), needed to make CMC used in

textile processing6. Hydrochloric acid, Chloro Sulphonic acid, metallic chlorides & other

chlorine based chemicals7. Chlorinated paraffin wax, a plasticiser & chlorinated rubber paints8. Drugs and pharmaceuticals• Bleaching of pulp, cotton textiles etc. Distinfection and water

treatment

End Uses of Chlorine

Packing and Labelling

• Packing, labelling & storage of Chlorine are governed by the Gas Cylinder Rules framed under the Explosives Act of the Government of India.

Storage• Chlorine is generally stored and sold in special grade

steel containers which are painted "golden yellow" as per IS:4379-1967

• Chlorine cylinders should be stored in upright position and secured against falling over. Tonne containers should be stored on their sides and should not be stacked.

• The valves on cylinders and tonne containers should be protected a stout metal cap securely attached to the cylinder body.

• The storage area should be separate. It should be dry, well-ventilated, clean and protected from external heal sources such as steam pipes etc.

Handling• Cylinders and tonne containers should not be permitted

to drop and no object should be allowed to strike them with force.• A flexible copper tubing connection between the

container and the piping should be used to draw gas from the container.• A barometric leg should be installed before the entry of

gas into the reactor.• Fire Hazards

There is no fire hazard, unless Chlorine comes in contact with Hydrogen, powdered metals, phosphorous and certain organic compounds like hydrocarbons, turpentine, ether etc.

Top Manufacturers in India

•Gujrat Alkalies and Chemicals Ltd.•Aditya Birla Chemicals Ltd.•Punjab Alkalies and Chemicals Ltd.•Chemfab Alkalies Ltd.• Jayshree Chemicals Ltd.•Lords Chloro Alkalies Ltd.

Top Caustic soda Manufacturers

In Metric Tonnes

Company Installed capacity

Production quantity Sales Quantity

Gujrat Alkalies and Chemicals Ltd 492,750 396,755

DCM Shreeram Consolidated Ltd. 274,670 185,805.00 180,547.00

Aditya Birla Chemicals Ltd. 105,000 83,562.00 84,587.00

Punjab Alkalies and Chemicals Ltd. 99,000 84,551.00 76,522.00

Chemfab Alkalies Ltd 42,000 29,229.32 29,003.57Lords Chloro Alkalies

Ltd. 84,150 32,414.00 32,027.00

Jayshree Chemicals Ltd. 22,500 24,413.00 24,308.00United

Phosphorus(Chloro alkalies )

10,430,929.00 10,378,254.00

Top Chlorine Manufacturers

Company Installed capacity

Production quantity Sales Quantity

Gujrat Alkalies and Chemicals Ltd 350,000 292,000DCM Shreeram Consolidated Ltd. 203,986 130,875.00 116,616.00

Punjab Alkalies and Chemicals Ltd. 87,714 57,842.00 57,475.00

Aditya Birla Chemicals Ltd. 63,000 44,288.00 44,243.00

Chemfab Alkalies Ltd 37,000 22,078.80 22,178.97Jayshree Chemicals Ltd. 15,500 13,888.00 13,938.00Lords Chloro Alkalies Ltd. 50,300 28,279.00 20,687.00United Phosphorus(Chloro alkalies )

10,430,929.00 10,378,254.00

In Metric Tonnes

Top Hydrogen Manufacturers

Company Units Installed capacity

Production quantity*

Sales Quantity*

National Peroxide Ltd.

Millions NM3 23.00 24,749,624.00 4,187,068.00

Punjab Alkalies and Chemicals

Ltd.

Lakhs NM3 277 20,850,000 2,071,000

DCM Shreeram Consolidated

Ltd.

Metric Tonnes 1,657 3,920,000 3,920,000

Andhra Sugars Metric Tonnes 1,000 2,171,683.00 2,168,920.00

Punjab Alkalies and Chemicals Ltd.

ProductsCaustic Soda

( 100% NaOH)

Chlorine (liquid)

Hydrogen Gas

Units Metric Tonnes

Metric Tonnes

Lakhs NM3

Installed capacity 99,000 87,714 277

Production quantity 84,551.00 57,842.00 208.5

In Metric Tonnes

Aditya Birla Chemicals Ltd.

Chemfab Alkalies Ltd.

Products Caustic Soda ( 100% NaOH) Chlorine (liquid)

Units Metric Tonnes Metric Tonnes

Installed capacity 42,000 37,000

Production quantity 29,229.32 22,078.80

Jayshree Chemicals Ltd.

Products

Caustic Soda

( 100% NaOH)

Chlorine (liquid)

Units Metric Tonnes

Metric Tonnes

Installed capacity 22,500 15,500

Production quantity 24,413.00 13,888.00

Lords Chloro Alkalies Ltd.

Products

Caustic Soda

( 100% NaOH)

Chlorine (liquid)

Units Metric Tonnes

Metric Tonnes

Installed capacity 84,150 50,300

Production quantity 32,414.00 28,279.00

Economic Scenario of Chloro-Alkali

Industry

Overview • Rs. 9,600 crore industry (US $ 2.2 billion) • Covers a wide spectrum of products - Soda ash,

Caustic soda, Sulphuric acid, Chlorine Calcium Carbonate, Hydrogen Peroxide, Potassium Chlorate, etc

• Inorganic chemicals are used mainly in the manufacture of detergents, glass industry, soaps, fertilisers, alkalies, etc

Major Chemicals Products

Installed Capacity

95 - 96 96 -97 97 -98 98 -9999 -

2000*

Soda ash 1865 1552.1 1540 1545.8 1560 1560

Caustic Soda

1964.5 1243.1 1250 1309.2 1320 1350

Liquid Chlorine

1031.1 709 715 702.9 715 740

Carbon Black

286.2 223.6 250.8 208.3 230 240

•'000 tonnes

Caustic Soda •Overview 1.Caustic soda industry saw a sudden surge of activity after

liberalisation 2.Reasons for capacity additions - a surge in demand for

chlorine (by product) 3.There are four processes for making caustic soda - diaphragm

cell, mercury cell, membrane cell and chemical process technology

4.Membrane cell the most energy efficient process and is being increasingly adopted. In all new plants, it is mandatory to use this technology

Caustic Soda • Industry 1.Capacity : 1964,500 tonnes; 98-99 production 1320,000

tonnes 2.Industry characterised by 45 players with turnovers ranging

from Rs. 15-20 crores (US $ 3.5 mn - US $ 4.5 mn) 3.Average plant size - 42,000 tpa 4.5 - 6 large players having an annual turnover of Rs 80 crores

(US $ 18 million) dominate the market 5.NaCl, a major raw material, available in Gujarat (60 % of

India’s salt production is from Gujarat) 6.NaCl accounts for 15 - 20% of cost of production of caustic

soda cost. 7.Many companies have captive salt farms

Chlorine•Overview 1.Chlorine is generated as a co-product with caustic soda 2.It is a toxic, hazardous chemical and is used in the

manufacture of PVC, pulp and paper, bleaching powder, etc.

3.Difficult to handle - has to be transported in heavy cylinders freight cost high. Hence sales are restricted to nearby locations.

4.Chlorine consumption likely to improve with increase in production and consumption of PVC / Plastics

•Industry 1.Installed capacity - 1031,000 tonnes 2.98-99 production - 715,000 tonnes 3.Industry characterised by over 40 players 4.Most manufacturers produce a wide range of

chemicals. Chlorine often a co-product of caustic soda

5.Companies located in the Gujarat belt

Chlorine

Environmental issues within the chloro-alkali

industry• There are several environmental concerns that

have made a significant impact on the growth of the chlor-alkali industry over the past twenty years and will dictate the future growth as well. • These issues are highly debated, and the

associated "chemophobia" is likely to adversely affect the chlorine consumption profile in the future.

Chlorine bleaching of wood pulp and dioxin emissions to the

environment

• Presence of dioxin, at parts per trillion (ppt) levels, in paper and paper based products and chlorinated organics in pulp mill effluents led to decreased chlorine demand. In the U.S., chlorine consumption in the pulp and paper industry, decreased from 15% in 1987 to 7% in 1998. The U.S. Environmental protection agency promulgated "Cluster Rules" in late 1998, mandating the use of elemental chlorine-free bleaching. These rules, which went into effect in April 2001, lowered the chlorine utilization in the North American pulp and paper bleaching operations in favor of sodium chlorate, hydrogen peroxide and oxygen.

Ozone layer depletion• Because of their contribution to the ozone layer depletion,

production of chlorinated fluorocarbons (CFC's), carbon tetrachloride (CCl4), and 1,1,1-trichloroethane was banned in 1997 following the Montreal Accord. Chlorinated methanes and ethanes are under great scrutiny due to the environmental and occupational concerns associated with them. Nevertheless, their production will continue because of their use in the manufacture of HCFC-22. HCFC-22 is less harmful than the CFC's towards ozone depletion and is an intermediate in the production of tetrafluoroethylene for use in the production of Teflon and other fluoro polymers. HCFC's are currently substituted for the CFC's, until they are phased out. HFC's containing no chlorine are not subject to this restriction.

Polyvinyl chloride plastic• In 1987, approximately 38% of all U.S. chlorine production was

consumed in vinyl chloride monomer (VCM) production to satisfy the growing polyvinyl chloride (PVC) demand. Through 2010, VCM demand is expected to grow annually because of the demand for PVC in the construction, packaging, and other industries. Nearly 85% of all ethylene dichloride (EDC) manufactured in the United States is used to produce VCM, and another 11% is exported, mostly for foreign VCM production. Even with increasing energy prices in North America, the EDC and VCM capacity is expected to keep growing, by 1.1%, through 2010. However, there are two major environmental issues with PVC, which include their lack of biodegradability and generation of dioxins when they are incinerated for energy recovery and for controlled waste recycling. Hydrochloric acid formation during the thermal decomposition of PVC is another issue that environmentalists are strongly invoking for the substitution of chlorine-free products for PVC.

Mercury emissions• Between 1930 and 1960, several tons of mercury waste was dumped in

Minamata Bay in Japan. Thousands of people living around the bay developed methylmercury poisoning through the consumption of contaminated fish. The victims suffered from severe neurological damage, which later became known as Minamata Disease. All told, thousands were afflicted and more than 900 died. As of April 1997, more than 17,000 people had applied to the government to be certified as Minamata victims, 12,615 have been officially recognized. Since then, there was a significant move away from mercury-cell technology to diaphragm and ion-exchange-membrane-cell operations and currently only 35% of the world capacity (mostly in western and center Europe and about 10% of U.S. production) of chlorine is produced using the mercury-cell process. There will be no new construction of mercury-cell plants. Existing plants are focusing on operating their plants at lower than the maximum mercury loss requirements of 1.9 gram/year/metric ton of chlorine as set by the Eurochlor- Best Available Technology. The Eurochlor - BAT plan for mercury emissions became effective in 2007. The goal was to reduce emissions to 1.0g Hg per tonne of Hg cell chlorine capacity. By 2005, the emissions level dropped from 1.09 in 2004 to 1.05g Hg/t chlorine capacity and by 2007 this goal was achieved

Asbestos • Asbestos is used as a separator material in diaphragm cells.

However, asbestos is a toxic material, causing lung cancer, asbestosis, and mesothelioma. As a result, in 2007, a bill was adopted to ban most uses of asbestos in the United States. Chlor-Alkali plants were exempt because few cost effective alternatives exist for this technology. However, the EPA could revoke this exemption if unreasonable risks to health or the environment are found. Some ways that the industry has avoided these risks have included surveillance and monitoring programs for asbestos related diseases and use of proper safety equipment and filtration systems during times of unavoidable exposure. In other countries, the use of asbestos in diaphragm cells had already been banned.

Even with all these constraints, the chlor-alkali industry is projected to grow at a rate of 1 to 3% depending on pessimistic or optimistic reasoning. Much of this will be dictated on how effectively the industry responds to the concerns of the environmentalists and the government agencies.