Seminar

Abstract

The University of Denver was the first to successfully demonstrate an open-path spectrometer that was capable of remotely recording in-use vehicle tailpipe carbon monoxide and carbon dioxide emissions in 1987. Dubbed the Fuel Efficiency Automobile Test (FEAT), owing to its original funding from the Colorado Office of Energy Conservation, its first task was finding for repair high emitting carbon monoxide vehicles and thus improving their fuel efficiency. Since that time, additional sensing capabilities have been added to expand the number of exhaust gas constituents that can be measured and the technique has been applied to a wide range of "vehicle" types. The technique's strength lies in the ability to collect large numbers of in-use emissions measurements in a relatively short amount of time without prior warning or knowledge of the vehicle operators.

FEAT has been used to collect emission data measurements from many locations around the world (see www.feat.biochem.du.edu) and has several established long-term measurement sites in the US. The historical record from these sites will be used to show the dramatic reductions in vehicle emissions over the last two decades. As a result of these large reductions, the US fleet emission distribution has become increasingly skewed. With the recent announcement from the U.S. EPA that it is lowering the National Ambient Air Quality standard for ozone, there will be many urban areas which will need to lower ozone (Denver being one of those). Lowering volatile hydrocarbon (VOC) emissions certainly will assist in achieving this goal. Because of the skewed emissions distribution, VOC exhaust emissions are nowadays emitted by only a few broken vehicles. Typically a third of all the measured total tailpipe VOC emissions come from less than 1% of the passing vehicles.

FEAT is also the only vehicle emission measurement spectrometer capable of measuring nitrogen dioxide emissions. This has only recently become important with press revelations of a major automobile manufacturer admitting that their diesel vehicles have been emitting far more oxide of nitrogen emissions in-use than allowed on government certification tests. FEAT and its commercial counterpart instruments have collected multiple data sets in Europe and the US since 2007 that have been previously used to highlight this potential inconsistency and urge action. I will discuss some of the history leading up to these revelations and their importance.