DuPont’s new HFO could replace R123

USA: DuPont has announced it is to start small scale production of a new low GWP HFO for the foam industry which could ultimately also have applications as a refrigerant.

The chemical company says it has established firm plans to start-up small-scale production this year of HFO1336mzz and is also planning for world-class commercial capacity to meet the long-term needs of polyurethane foam customers for high efficiency, low GWP solutions.

To be marketed as Formacel 1100 foam expansion agent, the new gas is described as a non-flammable liquid at ambient temperature, with a boiling point better suited to polyurethane foam chemistry, processes and equipment. Unlike lower boiling HFC options, Formacel 1100 can be handled like HCFC-141b, eliminating some of the challenges presented by lower boiling points.

More significantly for the refrigeration industry, the Cooling Post has learned that HFO1336mzz is another refrigerant being considered as both a replacement for the HCFC R123 in centrifugal chillers and as a working fluid in high temperature heat pumps.

As a potential refrigerant, it is perhaps better known under DuPont’s development name of DR-2. On top of its low GWP (less than 10), it is estimated to be of similar efficiency to R123 in chiller applications but has a volumetric cooling capacity 21% lower.

Introduced in the early 90s during the CFC phase-out, R123 was seen as an ideal alternative to R11 in centrifugal chiller applications. Hugely efficient, it had a very low ODP and, although not deemed significant at the time, a GWP of around 77. Although widely adopted in the US and elsewhere, it was, however, largely shunned in Europe due to its B1 toxicity after long-term inhalation was found to cause an increased incidence of benign tumours in the liver, pancreas, and testis of rats.

Being an HCFC, however, albeit with a negligible ODP, R123 is ozone depleting and is thus destined for phase-out under the Montreal Protocol.

Although not a drop-in replacement for existing R123 chillers, HFO1336mzz could be considered as an alternative along with R134a, R1234yf, and another DuPont refrigerant DR-11 (a blend of R134a and R1234yf). In addition there is a further HFO foam blowing agent currently under consideration, R1233zd(E), as revealed by the Cooling Post in October.

The COP of HFO1336mzz is said to be 4.6% higher that R134a, 7.2% higher than DR-11 and 9.5% higher than R1234yf.

Announcing the initial production of 1336mzz, Kathryn K. McCord, DuPont Fluorochemicals’ global business director, said “DuPont Fluorochemicals will continue to develop new offerings based on our breakthrough HFO technology and will pursue investments in large-scale and lower-cost production to enable adoption of DuPont™ Formacel 1100.”