Clean Energy


EPA Emissions

ORNL research informs new EPA emissions standards

Oak Ridge National Laboratory (ORNL) has developed a streamlined method for determining vehicle emissions that will impact every new certification when upcoming US Environmental Protection Agency (EPA) Tier 3 standards take effect in 2017, aiming to improve air quality and public health.

Recently finalized EPA Tier 3 standards will reduce the sulfur content in gasoline as well as vehicle emissions of carbon monoxide, nonmethane organic gases (NMOGs), and nitrogen oxide. The new certification process EPA endorsed in the standard is enabled by a correlation developed by ORNL researchers Scott Sluder and Brian West during their work for the Department of Energy (DOE) Intermediate Ethanol Blends Test Program.

Sluder and West identified the correlation between fuel ethanol content and the resulting ratio of NMOG and nonmethane hydrocarbon (NMHC) emissions. They then derived a calculation to determine NMOG emissions levels through NMHC measurement, which reduces the regulatory burden on the automotive industry as NMHC emissions are simpler and less expensive to quantify than NMOG emissions. EPA adopted the method in the final ruling.

ORNL research for this project was funded by the DOE Vehicle Technologies and Bioenergy Technologies Offices.—Kim Askey

A previous version of this article originally appeared in ORNL’s Sustainable Transportation Update.

Image caption: ORNL’s analysis used more than 1,000 test results from emissions research conducted during the DOE Intermediate Ethanol Blends Test Program.


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