The industry changeover to a low-global-warming air-conditioning refrigerant—R-1234yf—has not gone smoothly. In fact, it hasn’t really happened at all, and a decision by the European Patent Office (EPO) to revoke a Honeywell patent for R-1234yf adds another bit of confusion to the picture.
The revocation, which occurred as the recent SAE World Congress was in session, was not the “instant game changer” it might seem to be. Honeywell quickly appealed the revocation, and further, it previously had filed numerous additional patents for R-1234yf. One OE automotive A/C engineer described legal attempts to get Honeywell patents revoked “like cutting off the heads of a hydra.” The revocation issue arose at the same time as new problems of refrigerant counterfeiting were raised by the U.S. Army, which asked for help from the SAE Interior Climate Control Standards Committee (ICCC) in a meeting during the SAE Congress.
Honeywell is in a joint venture with DuPont to produce the refrigerant, with initial mass production from a plant in China whose opening has been delayed, reportedly until October, by bureaucratic mandates that have to be met. As a result, there have been limited R-1234yf supplies from a small pilot plant and few automotive installations. A phase-out of R-134a, the long-used refrigerant, was scheduled to begin on new platform cars in Europe starting Jan. 1, 2011. However, European Community regulators recognized the supply problem and are holding off enforcement of the R-134a phase-out until Jan. 1, 2013, when they believe ample supplies will be available.
There are eventual possible effects from the EPO revocation, which was somewhat emphatic in that it occurred in the first day of a three-day schedule for the hearings, making it apparent they did not have to continue to indicate the patent was not to be upheld. Objections to the patent, which was granted in 2009, had been filed by seven companies—Arkema, Daikin Industries, Asahi Glass Co., Daimler AG, BMW AG, Mexichem, and Solvay Fluor, plus ACEA, the pan-European auto manufacturers association, and Michael Wallinger, a patent attorney.
The primary arguments were centered on objections that the patent lacked “novelty” and “inventive step(s),” and there were such technical issues as improperly added subject matter and “insufficiency” (inadequate supporting disclosure). An R-134a system was cited as an example of “common knowledge/practice” to show the patent lacked “inventive step(s).”
The EPO decision said the “patent is revoked under Article 101(2) EPC (European Patent Convention) as at least one of the grounds of opposition prejudices its maintenance unamended.” EPO concluded that “taking into account the amendments made by the proprietor (of the patent, Honeywell) during the opposition proceedings, the patent and the invention to which it relates do not meet the requirements of the EPC.”
R-1234yf is not a new discovery, so a patent has to indicate unique aspects to its use. Daikin publicly has pointed out that it had filed a patent application for the chemical as an A/C refrigerant some 20 years ago, although it did not follow through. The chemical itself was discovered many years before Daikin’s application.
This EPO decision, although not a trial, could be seen as weakening Honeywell efforts to prevail in an appeal and retain the ability to enforce remaining patents. This might be an incentive for another refrigerant manufacturer to decide the legal risks were worth taking and go into R-1234yf production, at least for the European market, likely to be the largest for some years to come. Arkema, for example, has consistently said—since well before the patent issue arose—that it intends to produce R-1234yf and noted it could complete its proposed plant within two years. Arkema spokesmen declined to assess the current situation officially but pointed to the company’s longstanding commitment and added that Arkema has a proprietary production process it could use.
Arkema also is suing to overturn a Honeywell U.S. patent for the refrigerant and last year asked the Federal Trade Commission to investigate the Honeywell/DuPont venture for possible restraint of trade. Arkema additionally has claimed publicly that it has attempted unsuccessfully to negotiate with Honeywell a “FRAND” (fair, reasonable, and non-discriminatory) patent access agreement. The EPO decision might revitalize FRAND negotiations, an ICCC committee member speculated.
R-1234yf had been evaluated as an auto A/C refrigerant by an SAE Cooperative Research Group, which was unaware of the Honeywell patent application, originally filed in 2005 to cover certain hydrofluoroolefins (HFOs), a class of chemicals characterized by a double carbon bond in the atomic structure. The application was modified in 2006, which included listing HFO-1234yf, the name prior to its R (refrigerant) designation.
A U.S. regulatory barrier to the use of R-1234yf is being removed with an EPA announcement at the committee meeting that it had approved the refrigerant tank fitting and that the rule will be final on May 21, so that refrigerant tanks and service equipment can legally be used. The fitting, an anti-backfill design with a 0.5-in (12.7-mm) Acme thread, has both vapor and liquid flow control valves.
The high price of R-1234yf (estimated at $100 kg to OE) and industry distaste for a single supplier of the low-global-warming refrigerant have led to consideration of a pair of non-azeotropic blend refrigerants proposed by Mexichem. And during the ICCC meetings at the SAE Congress, the Cooperative Research Group that formed to evaluate them presented data showing one of the two is even less flammable than R-1234yf and both have overall comparable LCCP (Life Cycle Climate Performance) environmental properties.
The auto industry has preferred to avoid use of non-azeotropic blends, which are blends that do not retain the same composition as they go through a phase change, as performance may change as a result of leakage of higher-pressure components. However, such blends are used in commercial and residential refrigeration, and modern automotive system leakage is far lower than in years past, so there are recognized ways for dealing with the issue.
A premium price for R-1234yf, partly accepted as a result of its more expensive feedstock and more complex manufacturing process, and recent issues of R-134a counterfeiting raised counterfeiting fears for R-1234yf at the ICCC meetings. Andrew Schultz and Jeffrey Marciniok, engineers with TARDEC (U.S. Army Tank Automotive Research, Development, and Engineering Center) told meeting attendees that the R-134a system in an Army “vehicle from theatre” (of operations) had been discovered to be contaminated with refrigerant containing more than 30% R-40 (methyl chloride). This is a highly reactive solvent that has been identified as the A/C refrigerant component that caused fatal explosions in cargo ships.
As a result, they added, the Army has told its maintenance operations personnel to procure R-134a only through approved supply channels vs. regulations that normally permit local sourcing of commodity products. Schultz and Marciniok declined to identify the type of vehicle or where it was being operated.
Peter Coll, Vice President of Neutronics Inc., a maker of refrigerant identification equipment, told the meeting that if R-134a, typically under $10 lb ($22 kg) is being counterfeited, “imagine what could happen with R-1234yf, which is so much more expensive.”
The company’s newest identifier is capable of detecting R-40, and some others in current use will indicate a form of system contamination. But to date, Coll added, there is no research data on what percentage is a problem, and there are no approved ways to evaluate or service contaminated systems.