|Case by Case
Finding a substitute to limit harmful emissions
Until 2003, Carpenter SAS used dichloromethane to produce the polyurethane foam for furniture, bedding and automobile and recreational equipment.
The compound, which is classified as harmful to the environment and public health, was employed as a foaming agent and mostly released into the air as a gas.
Eager to improve employee working conditions, Carpenter began researching a substitute for methylene chloride, dichloromethane’s other name, in the 1980s. Another goal of its initiative was to get a jump on regulations limiting volatile organic compounds (VOCs).
EQUAL OPERATING COSTS
In 1998, a first step to substitute CO2 for dichloromethane took place in Huningue, France, in a horizontally integrated plant. The Noyant facility (Maine-et-Loire) has a manufacturing unit with vertical lathes. It is trickier to manage, but can turn out cylindrical blocks. The switch from methylene chloride, which can be worked at ambient pressure, to CO2, which requires pressures of 60 to 70 bars, demanded more precise control of the reaction. A full year and two test phases were needed to develop a technology similar to Huningue’s. ADEME, contacted by the company, provided financing for the R&D and the modifications of the production base. “We had to change the whole system for moving the products to the injection nipples”, explained Philippe Vincent, engineer in ADEME’s Pays-de-la-Loire regional delegation.
The facility now uses a hundred metric tonnes of CO2 each year from the industrial production of ammonia. The initiative’s environmental consequences are significant. “There are no more VOC vapours,” says a happy Laurent Nicou, head of Carpenter’s engineering. “The substitution process works 100% and operating costs are unchanged.” “In addition, the change reduced the company’s annual greenhouse gas emissions by 1,600 metric tonnes of CO2 equivalent”, stresses Philippe Vincent. Lastly, lighter protective equipment for operators has made for more comfortable working conditions.
The initiative is part of Carpenter’s environmental policy, which helped it earn ISO 14001 certification in 2005.