Research Projects

Project at a Glance

Project Status: complete

Title: Development of an analyzer for exhaust from methanol/hydrocarbon-fueled motor vehicles

Principal Investigator / Author(s): Luu, Derhsing

Contractor: Global Geochemistry Corporation

Contract Number: A4-150-32

Research Program Area: Emissions Monitoring & Control

Topic Areas: Mobile Sources & Fuels


In order to obtain accurate data for the content of unburned methanol in exhaust gases of vehicles fueled 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 the 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. It consists of the modulator and an electronics module that uses a microprocessor for modulator control and for processing of the output signal of the FIA. The unit is simple and compact, has a response time of 10 seconds, precision of ± 2 % of full-scale (which is set on the FIA and has the same range options), accuracy of ± 2 mv, and gives two separate simultaneous outputs, either analog or digital, for hydrocarbons and methanol. The unit was tested at the ARB Haagen-Smit Test Facility with good results and is installed there as the contract deliverable.


For questions regarding this research project, including available data and progress status, contact: Heather Choi at (916) 322-3893

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