Why is chloralkali industry important?

Answer 1

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. 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. 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. 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. 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 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. 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. 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. 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. 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. 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 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.

Answer 2

The products of the chlor-alkali are chlorine and sodium hydroxide, which have a variety of important uses. Chlorine is used as a disinfectant and in purifying water. Sodium hydroxide is used in making soap and in purifying bauxite.