Search Results

In an effort to reduce ambient ozone and carbon monoxide levels, the U.S. Environmental Protection Agency has mandated the use of oxygenated fuels under the Clean Air Act. These fuels may contain varying amounts of methanol, ethanol, or other alcohols, and ethers. The current reference method for the analysis of methanol in vehicle emissions involves sample collection with impingers that contain water and the subsequent analysis of this aqueous solution by gas chromatography/flame ionization detection (GG/FID). The impinger method is problematical in that it is both time consuming and inconvenient in a test facility in which it is the only “wet” chemical method employed. In response to this problem, two alternative “non-wet” methanol methods were evaluated against the impinger method and against each other. The first alternative method employed a switched two-column GC/FID analysis of gaseous samples.

This paper reports the results of an exhaust emissions characterization from the non-catalyst control systems employed on the Mazda RX-4 rotary, the Honda CVCC, and the Chrysler electronic lean burn. Throughout the paper, exhaust emissions from these vehicles are compared to those from a Chrysler equipped with an oxidation catalyst and an air pump. The emissions characterized are carbon monoxide, hydrocarbons, nitrogen oxides, sulfur dioxide, sulfates, hydrogen sulfide, carbonyl sulfide, hydrogen cyanide, aldehydes, particulate matter, and detailed hydrocarbons. A brief description of the sampling and analysis procedures used is included within the discussion.