A team of scientists has detected a class of compounds called enols – never before observed in flames. The discovery could lead to cleaner-burning fuels in the future.
Discovery may help produce cleaner-burning fuel
A team of scientists, including chemical engineering professor Phillip R. Westmoreland of the University of Massachusetts Amherst, has detected a class of compounds called enols – never before observed in flames. The discovery could lead to cleaner-burning fuels in the future. The findings were announced on May 12 in an article in Science Magazine titled “Enols Are Common Intermediates in Hydrocarbon Oxidation.”
“Knowing these compounds, which have been missing from present-day computer models, might make it possible to design cleaner, more energy-efficient engines and furnaces,” says Westmoreland, head of the UMass Amherst chemical engineering department and a key member of the team that engineered the new apparatus used to see them. The team also includes UMass chemical engineering doctoral student Matthew Law.
The compounds were discovered using a new flame-analysis spectrometry apparatus at the Advanced Light Source facility at Lawrence Berkeley National Laboratory in California that UMass scientists helped design and build. It has unique, complementary capabilities relative to the other 11 similar molecular-beam mass spectrometry (MBMS) machines around the world – two of them at UMass Amherst – and is a result of an international collaboration between the laboratory and researchers from Cornell University, Sandia National Laboratory, the University of Bielefeld and the National Synchrotron Radiation Laboratory in Hefei, China.
MBMS is a technique that continuously samples reacting gases in a cooled beam of molecules, which are then analyzed for chemical composition. The novel MBMS apparatus in Berkeley, which is 40 times more precise than other MBMS machines in key energy measurements, takes advantage of intensely bright beams from the laboratory’s Advanced Light Source, producing illumination 100,000 times brighter than the sun. Single photons of such light can hit single molecules and ionize them, thus making them detectable through mass spectrometry.
“This new method has been called the Hubble Telescope of mass spectrometry. Demystified, it means that we’ve identified a class of chemical compounds in combustion that haven’t been detected before,” says Westmoreland, who has been using MBMS technology since 1979, longer than anyone else in the United States. “Thus, they aren’t currently contained in the models used to improve combustion efficiency and cleanliness.” Enols are the first major discovery made possible by the one-year-old Berkeley MBMS unit.
Enols were first predicted as possibilities in 1880. One enol, vinyl alcohol, was observed in a non-flame environment in 1973 and its reaction in liquids in well known. However, enols’ presence in flames had been little suspected before the Berkeley MBMS instrument literally brought them to light. Now, the resulting measurements reveal enols in most flames, as Westmoreland notes.
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Science article: Enols Are Common Intermediates in Hydrocarbon Oxidation