Navigation Links
New NIST screening method identifies 1,200 candidate refrigerants to combat global warming

Researchers at the National Institute of Standards and Technology (NIST) have developed a new computational method for identifying candidate refrigerant fluids with low "global warming potential" (GWP) the tendency to trap heat in the atmosphere for many decades as well as other desirable performance and safety features.

The NIST effort is the most extensive systematic search for a new class of refrigerants that meet the latest concerns about climate change. The new method was used to identify about 1,200 promising, low-GWP chemicals* for further study among some 56,000 that were considered. Only about 60 of these have boiling points low enough to be suitable for common refrigeration equipment, an indication of how difficult it is to identify usable fluids.

The ongoing NIST project is a response to U.S. industry interest in a new generation of alternative refrigerants that already are required for use in the European Union.

The refrigerants now used in cars and homes are mainly hydrofluorocarbons (HFCs). They were adopted a generation ago in the effort to phase out chlorofluorocarbons (CFCs), which deplete the stratospheric ozone layer. An example is R-134a (1,1,1,2-tetrafluoroethane), which replaced ozone-depleting chemicals in automobile air conditioners and home refrigerators. R-134a now is being phased out in Europe because HFCs remain in the atmosphere for many years, yielding a high GWP. A compound's GWP is defined as the warming potential of one kilogram of the gas relative to one kilogram of carbon dioxide. R-134a has a GWP of 1,430, much higher than the GWP of 150 or less now mandated for automotive use in Europe.

Promising low-GWP chemicals include fluorinated olefins, which react rapidly with atmospheric compounds and thus will not persist for long periods.

"What industry is trying to do is be prepared, because moving from a GWP in the thousands or tens of thousands to a GWP of 150 is an enormous challenge, both economically and technologically," says NIST chemist Michael Frenkel. "We decided to leverage the tools NIST has been developing for the last 15 years to look into the whole slew of available chemicals."

The affected industry is huge: The U.S. air conditioning, heating and refrigeration equipment manufacturing industry ships about $30 billion in goods annually, according to the U.S. Bureau of the Census.

NIST has extensive experience evaluating alternative refrigerants, having previously helped the refrigeration industry find replacements for CFCs.**

The new NIST method estimates GWP by combining calculations of a compound's radiative efficiency (a measure of how well it absorbs infrared radiation) and atmospheric lifetime, both derived from molecular structure. Additional filtering is based on low toxicity and flammability, adequate stability, and critical temperature (where the compound's liquid and gas properties converge) in a desirable range. The method was applied to 56,203 compounds and identified 1,234 candidates for further study. The method, which was validated against available literature data, is accurate and fast enough for virtual screening applications. The approach is similar to the large-scale virtual screening and computational design methods for discovering new pharmaceuticals.

The screening is the initial stage of a larger study funded by the U.S. Department of Energy. The next step will be to further narrow down the candidates to a couple dozen suitable for detailed investigation in refrigeration cycle modeling.


Contact: Laura Ost
National Institute of Standards and Technology (NIST)

Related biology news :

1. Eliza Corporation and BlueCross BlueShield of South Carolina Drive Awareness and Healthier Behavior to Increase Colorectal Cancer Screenings by 45 Percent
2. Screening technique uncovers 5 new plant activator compounds
3. A drug-screening platform for ALS
4. Screening horticultural imports: New models assess plant risk through better analysis
5. Parents seen as critical stakeholders in expanding newborn screening
6. New review outlines screening strategies for osteoporosis in young adults
7. New drug-screening method yields long-sought anti-HIV compounds
8. New screening technique yields elusive compounds to block immune-regulating enzyme
9. Trial seeks improved lung-cancer screening by combining imaging and biomarkers
10. New clinical trial explores novel noninvasive colon cancer screening test
11. Chemists develop reversible method of tagging proteins
Post Your Comments:
Related Image:
New NIST screening method identifies 1,200 candidate refrigerants to combat global warming
(Date:11/17/2015)... , November 17, 2015 Paris ...   --> Paris from 17 th ... DERMALOG, the biometrics innovation leader, has invented the first combined ... on the same scanning surface. Until now two different scanners ... one scanner can capture both on the same surface. ...
(Date:11/12/2015)... 12, 2015  A golden retriever that stayed healthy ... (DMD) has provided a new lead for treating this ... Broad Institute of MIT and Harvard and the University ... Cell, pinpoints a protective gene ... disease,s effects. The Boston Children,s lab of Lou ...
(Date:11/10/2015)... About signature verification Signature ... identify and verify the identity of an individual ... secure and accurate method of authentication and is ... because each individual,s signature is highly unique. Signature ... signature of an individual is compared and matched ...
Breaking Biology News(10 mins):
(Date:12/1/2015)... -- Cepheid (Nasdaq: CPHD ) today announced that, ... Healthcare Conference in New York City ... outlook for the fourth quarter of 2015 and initiating ... term business model expectations. John Bishop , ... be the fastest growing company of the major market ...
(Date:12/1/2015)... 2015 ) ... U.K. Virology and Bacteriology Testing Market: Sales ... Supplier Shares by Test, Innovative Technologies, Competitive ... --> ) has announced ... and Bacteriology Testing Market: Sales and Volume ...
(Date:11/30/2015)... MIAMI (PRWEB) , ... November 30, 2015 , ... Global Stem Cells Group ... new clinics in the cities of Arica and Iquique in northern Chile. The facilities are ... clinics offer the most advanced protocols and techniques in stem cell medicine to patients from ...
(Date:11/30/2015)... , Nov. 30, 2015  Culprits beware, a ... chemistry professor Jan Halámek, is taking crime scene ...   -->   ... --> --> ... have discovered a straightforward concept for identifying whether ...
Breaking Biology Technology: