4. Promoting resource conservation

Resource conservation is an important—and challenging—element of sustainability for industry. WCC’s commitment to sustainable development includes the goal of energy and water conservation. As with other chemical sectors, chlor-alkali production is highly energy intensive, with electricity being an essential component in the electrochemical reactions involved. The industry uses energy resources both for fuel in the manufacturing process and as a raw material for electrolysis. While using natural gas, natural gas liquids, oil and coal to power its plants and processes, it also draws upon those same resources as primary ingredients in products. Efficient energy use has been an economic imperative for decades, leading companies to develop technologies to capture by-product hydrogen as a fuel or raw material for other production units, and to adopt co-generation of electricity during production processes. Water quality and scarcity concerns are driving similar innovations to reduce water consumption.

Top | Back To Index

Energy efficiency and greenhouse gas emissions

Through the American Chemistry Council’s Responsible Care® initiative, U.S. chlorine producers aim to strengthen energy efficiency and environmental performance. ACC Member companies have pledged an 18% reduction in greenhouse gas intensity by 2012 (using 1990 as a baseline), which is an important first step in addressing greenhouse gas emissions from chlorine production. As part of its sustainability program, Euro Chlor has set a goal of a 5% reduction in the industry’s energy consumption by 2010, based on both electricity and steam. As of 2005, a 3.7% reduction had been achieved.

Top | Back To Index

Corporate initiatives

A number of projects are underway at WCC-affiliated companies with the aim of improving energy and water efficiency.

Hydrogen projects:

• Akzo Nobel Base Chemicals started up a Proton Exchange Membrane (PEM) fuel cell system at a chlorine electrolysis pilot plant in early 2007. The project is in partnership with a PEM-fuel cell stacks producer. This is the first step towards development of fuel cell power plant in the 50 MW range at the firm’s Rotterdam site. PEM fuel cells, which convert hydrogen into electricity, have been installed with expected electrical efficiency of 50-55%.
• In 2004, The Dow Chemical Company and General Motors Corporation officially opened a new alternative energy facility adjacent to Dow’s freeport, Texas chlorine plant. The joint venture uses hydrogen, created as a byproduct of chlorine manufacture, in fuel cells that provide energy back to the production facility. Eventually, the companies plan to install 400 fuel cells that will generate 35 megawatts of electricity.

Energy from wastes:

• Since the mid-1990s, there have been high-performance incinerators at Solvay’s sites making use of the energy content from most of the unwanted chlorinated and fluorinated organic by-products produced. Since the early 1990s, the proportion of hazardous waste given to subcontractors for disposal in landfill has more than halved to about one-quarter. Organic wastes with a high energy content are processed using increasingly sophisticated methods, with a growing part played by recycling and incineration to make use of the energy content.

Innovative chlorine recycling:

• In 2008, Bayer MaterialScience is due to complete construction of the world’s largest hydrochloric acid recycling plant at its Shanghai facility, where the company plans to build world-scale isocyanate production plants. It will be the first time that the company uses the innovative oxygen depolarised cathode (ODC) technology to produce chlorine in a world-scale facility. Bayer’s first ODC hydrochloric acid electrolysis unit, with much smaller capacity, started up in Brunsbüttel, Germany, in 2003. The experience gained there paved the way for the new plant in China. The key advantage of the ODC process, described as “a quantum leap in the manufacture of chlorine from hydrochloric acid,” is that it saves energy, consuming about 30% less electricity than the diaphragm process used by Bayer for many years.

Water conservation

• At its Stade complex in Germany, Dow produces chlorine for use in propylene oxide production and other processes. These processes use 30 million m3 of water taken from the Elbe and five million metric tonnes of salt per year. Through its Responsible Care® activities, Dow sought to conserve these resources, improve environmental performance and reduce operational costs. It has achieved a world first with development and implementation of a closed loop process for brine, chlorine and propylene oxide production. The project resulted in conservation of 7m m3/year of river water and 600,000 metric tonne/year of salt and a 23% reduction of annual salt discharge and of total organic carbon discharge to the river Elbe, with €500,000/year savings in waste water fees. Moreover, the €3.3m project costs were recovered by pay back of wastewater fees after approval by the authorities in early 2004.
  
  Technological improvements and an industry-wide commitment to reuse waste streams are critical factors in the continuing effort toward sustainability. As for other activities, many of the initiatives to promote resource conservation take place at the regional level, where they can be tailored to fit local priorities. Examples are described in regional inserts that complement this report.

Top | Back To Index | Next