PRAXAIR AWARDED INDUSTRY'S FIRST PATENT FOR RECOVERY OF GLOBAL WARMING GASES.

DANBURY, Conn.--(BUSINESS WIRE)--May 20, 1996--Praxair, Inc. (NYSE: PX) has been awarded a patent for a cryogenic system that recovers potential global warming gases that would otherwise be emitted to the atmosphere.

Praxair's Patent No. 5,502,969 is the industry's first patent for a system that allows the separation and recovery of gases known as perfluorinated compounds (PFCs) from an effluent gas stream.

While these PFCs -- halocarbons 116, 14, and 23; sulfur hexafluoride; nitrogen trifluoride; and perfluoropropane -- are essential to many manufacturing processes, many environmental scientists believe they may last as long as 50,000 years when released into the atmosphere.

"Semiconductor manufacturers purchased over 1.6 million pounds of PFCs in 1995, at an estimated cost of over 45 million dollars," according to Calvin Chang, senior industry analyst with Dataquest, San Jose, Calif. "This amount could double by 2000."

These gases are critical to the production of computer chips; no completely safe and effective substitute compounds are known to exist. Until now, semiconductor manufacturers have had two choices: exhaust PFCs into the atmosphere, or burn them at considerable financial and environmental cost.

"Our customers take stewardship of the environment seriously, and most have active programs in place to cut emissions of global warming gases from their manufacturing process," says Leonard M. Baker, Praxair's vice president of technology. "Praxair is proud to lead the way with next- generation technologies that are cleaner, more productive and less costly than the ones they replace. This patent is the most recent of our innovative solutions for industries striving to be both globally competitive and environmentally sensitive, and we have another generation of environmental technologies coming right behind it."

Recycling with Economic and Environmental Benefits

Praxair and ATMI EcoSys, Inc., an environmental solutions company based in San Jose, Calif. that produces point-of-use scrubbers, offer cost-effective options to isolate and recycle PFCs from the semiconductor fab exhaust stream.

The proprietary Praxair/EcoSys system takes the effluent stream from semiconductor process tools through a series of EcoSys scrubbers and Praxair cryogenic distillation columns to remove PFCs. The PFCs are then purified and packaged for reuse in the wafer fab -- eliminating the environmental threat while providing significant cost savings to the customer.

"For one large semiconductor manufacturer, we found that by reusing PFCs from the exhaust stream instead of purchasing new sources, the recycling system would pay for itself within the first year of operation," says Mark McClear, worldwide marketing manager, electronics. "Additionally, the system offers compliance benefits in areas where coming regulations are expected to limit PFC emissions. This system offers a compelling economic solution to a potentially significant environmental issue."

Praxair is the largest industrial gases company in North and South America, and one of the largest worldwide, with annual sales of more than $4 billion. The company produces, sells and distributes atmospheric, process and specialty gases, and high- performance surface coatings. Praxair is also the world's largest supplier of carbon dioxide and a recognized leader in the commercialization of new technologies that bring productivity and environmental benefits to a diverse group of industries.

CONTACT: Praxair

Donna J. Pierpont, 203/837-2135