Development of an Analyzer for Exhaust from Methanol/Hydrocarbon-Fueled Motor Vehicles

摘要

In order to obtain accurate data for the content of unburned methanol in exhaust gases of vehicles fuelled on methanol mixtures during emissions testing, the California Air Resources Board initiated a study to develop an analyzer that would determine methanol and hydrocarbons separately. Global Geochemistry Corporation has designed and built an instrument for this, based on a 'modulator' which preferentially pulses the concentration levels of methanol in test gas and allows it to be differentiated from hydrocarbons, which are not modulated. It is also responsive to ethanol. The modulator is based on adsorption and desorption of methanol in a packed microtube, controlled by temperature pulses. The unit is a modification of a flame ionization analyzer (FIA) already in use for hydrocarbon analysis.