refNum 58 – Light-duty fleet composite organic gas emission profiles derived from ARB in-use surveillance data (Paul Allen - Air Resources Board)

Current Status – Completed Data

This page last edited: 7/5/2007

The document 'ogexh04.doc' ( download => 6,145k )(this is a very large file) shows the methodology for preparing light-duty fleet composite organic gas emission profiles from  ARB in-use surveillance data. 

This report covers the data for 1994 testing and the methodology was then applied to 1996 test data. Profiles from the 1996 testing were used for the MTBE fuel and were also used as part of the basis for constructing the organic gas profiles for EtOH (ethanol) 2% O (oxygenate) gasolines.

The methane fraction in catalyst exhaust was clearly seen to increase as exhaust THC decreased.  This relationship, as seen in the MTBE gasolines, was also used to project yearly methane fractions for ethanol gasolines.  All other exhaust compounds are renormalized.  Organic gas profiles for all other emission categories vary only with fuel composition.

The 1996 test data, from which the MTBE and EtOH containing fuel profiles were derived (via the adjustments in 'ogexh04.doc') are shown in the documents, below (note, especially, Attachment A2):

Main Report - Air Quality Impacts of the Use of Ethanol in California Reformulated Gasoline (PDF - 148k) or (DOC - 356k)

Main Report Update (12-30-99) (PDF - 180k)

Appendix A - Emissions (PDF - 201k) or (DOC - 2,086k)

Attachment A1 - Peer Review of Organic Gas Emission Profiles (PDF - 1,238k)

Attachment A2 - Tables of Organic Gas Emission Profiles (PDF - 146k) or (DOC - 352k)              

Attachment A3 - Tables of Organic Gas Profiles from Emission Testing (PDF - 149k) or (DOC - 479k)

For additional documentation, please visit the ARB web site: