Return to the ground floor of this tower
Return to the Main Courtyard
Return to Fort Freedom's home page
]]]]]]]]]]] DOUBTS RAISED ON SUBSTITUTES FOR CFCs [[[[[[[[[
(3/7/1989)
Problems Abound in Development, Use as Ban Looms
By Amal Kumar Naj
Staff Reporter of The Wall Street Journal
(From The Wall Street Journal, 6 March 1989, p. B4:3)
[Kindly uploaded by Freeman 10602PANC]
[Note by 10602PANC:
That CFCs are harmful to the ozone is not yet settled science,
though this article, like most journalistic articles about CFCs
and ozone, assumes that it is. For more, see AtE Jan (pp. 3-4),
Sep (p.1:1), Oct (p.3:2), Nov (p.3:2) 1987; Jan (p.4:2), Feb
(p.2:1), Jul (pp.1:1-2:1; correction in Dec, p.4:1), Nov (p.1:1),
Dec (p.4:1) 1988; Feb (p.4:2), Mar (p.3:2) 1989.]
As Western countries agree to speed the phase-out of
ozone-depleting chlorofluorocarbons, users and makers are raising
serious doubts about substitutes for these chemicals, which allow
safe and efficient applications ranging from refrigerators to
aerosol spay cans.
The substances are being rushed to market, prompted by
international efforts to ban production of all CFCs. Last
Friday, President Bush aligned the U.S. with the 12 European
Community member nations, which agreed to a ban by the year 2000
-- sooner than timetables set in previous international treaties.
The latest agreement puts even more pressure on chemical
companies to find substitutes, which can take several years to
develop and many more years until users can adapt them.
Yesterday, Du Pont Co., the largest U.S. maker of CFCs, announced
two possible substitutes for CFC-113, which is used as a cleaning
agent mainly in the electronics industry. Cleaning agents
account for one-fifth of all CFCs.
While DuPont and others have announced substitute chemicals
for the whole range of CFCs, problems abound in using them.
General Motors Corp. has considered and abandoned two
substitutes to replace the CFC that is used as a coolant in auto
air conditioners. Another substitute, which GM believes is
promising, will require the auto maker to redesign the
air-conditioning system -- and probably its cars, as well -- at a
cost of hundreds of millions of dollars.
Northern Telecom Ltd. of Canada is replacing equipment in
several of its plants with newly designed systems that use water
rather than CFCs to clean electronic circuit boards. And
American Telephone and Telegraph Co. has developed a technology
that simply eliminates the cleaning process in circuit-board
manufacturing.
The lack of appropriate substitutes has raised the prospect of
sweeping changes for industry, as well as in daily life: CFCs are
pervasive in the U.S. economy, contained in 100 million
refrigerators, 90 million cars and trucks, 40,000 supermarket
display cases, and 100,000 commercial building air conditioners.
Du Pont estimates that banning CFCs would render useless or
require altering capital equipment valued at $135 billion in the
U.S.
While the CFC substituted are believed to be harmless to the
Earth's ozone layer, they are either toxic to humans or corrode
the metal machinery in which they must work, or they are simply
inefficient coolants. Some are potentially explosive. CFCs
haven't any of these characteristics. Their problem is that in
the stratosphere, the chlorine atoms in the CFCs break down
ozone, which protects the Earth from the harmful effects of
excess ultraviolet rays from the sun, which can cause skin cancer
and damage crops.
The EC's accord on a ban by 2000 came as a surprise, because
under an international treaty concluded in Montreal in late 1987,
CFC production would only be halved by July 1998. President Bush
said the U.S. would meet the stricter schedule, provided ``safe
substitutes are available.''
This qualification underscores the problems associated with
replacing the chemicals with successful substitutes. ``It's a
very optimistic goal,'' Charles McCain, alternatives development
manager at Du Pont, said. ``It's going to be difficult to
develop substitutes by the turn of the century.''
Even as Du Pont announced its latest two substitutes, rounding
out its lineup of potential replacements for all CFCs, Mr. McCain
acknowledged these products' drawbacks. One would require the
users to buy new machines, and the other is flammable.
Such concerns are what prompted Northern Telecom to retool
some plants to use water for cleaning circuit boards. Margaret
Kerr, vice president, environment, health and safety, at Northern
Telecom, said the company tried a substitute made by another
company and is similar to that produced by Du Pont, but the
solvent was flammable at high pressure.
For autos, some of the substitutes for CFC-12 used in air
conditioning are 134a and HCFC-22, and a three-part blend of
these two and 142b. They are being marketed variously by Du
Pont, Allied-Signal Inc. and Imperial Chemical Industries PLC of
Britain among others. A big problem with HCFC-22 is that its
molecules are small and can easily leak out of air-conditioning
hoses and other parts. To use this substitute, GM will have to
develop a new air-conditioning unit ``from scratch,'' said Gerald
Stofflet, assistant director, automotive emission control, with
GM's environmental activities staff. The 142b-blend has the same
characteristics as HCFC-22 with the added problem that it is
flammable.
At GM, where one of its own research scientists invented CFCs
about 60 years ago, the company is testing 134a as a substitute
coolant and hopes to use it in some autos by 1993 or 1994, Mr.
Stofflet said. But to use 134a, GM will require an all-new
lubricant to be mixed with the refrigerant. Mr. McCain of Du
Pont, one of the several companies that are marketing the
substitute, said, ``Nobody has developed a lubricant that works
in the entire temperature range, low temperatures to as high as
90 degrees.''
To accommodate 134a, which has different cooling
characteristics than the CFC-12 it would replace, GM will have to
develop a larger evaporator and condenser and redesign the
compressor on its air conditioners. This will mean changes in a
car's grill area and will take space in the engine compartment,
which already is jammed with accessories and various controls and
exhaust systems. ``It isn't changing just one piece,'' GM's Mr.
Stofflet said. ``It will ripple through the whole car.''
``Hopefully, we can do all this without squeezing down the
passenger compartment,'' he said. ``But fuel economy and design
may have to be compromised to make this refrigerant work.''
CFC-11 is used in big commercial refrigerators and insulating
foam, which has uses including housing. Chemical makers have
created substitutes such as HCFC-123 and HCFC-141b; these still
have chlorine atoms but chemists have inserted hydrogen in the
CFC molecule so that these altered chemicals break down in the
lower atmosphere before they reach the ozone layer. But HCFC-123
attacks the inside wall of the refrigerator, causing corrosion,
and HCFC-141b is explosive. Neither has good insulating value,
and their toxicities haven't been determined, Du Pont's Mr.
McCain said.
* * *
Return to the ground floor of this tower
Return to the Main Courtyard
Return to Fort Freedom's home page