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Project Status: complete

Report Published January 1995:

Title: NOx and VOC species profiles for gas fired stationary combustion sources

Principal Investigator / Author(s): Hansell, David

Contractor: Energy and Environmental Research

Contract Number: a132-104

Research Program Area: Emissions Monitoring & Control, Health & Exposure

Topic Areas: Stationary Sources, Toxic Air Contaminants


The California Air Resources Board is developing strategies for reducing ambient ozone concentrations in many parts of the State. These strategies include modeling efforts which require a reliable and comprehensive database of volatile organic compound (VOC) and nitrogen oxide (NOx) species profiles for a variety of source types. This project focused on developing these profile for gas fired stationary combustion sources, a key source category in California. Selected air toxic emissions also were quantified.

Eight gas fired sources were tested including three reciprocating internal combustion engines, a gas turbine, two refinery process heaters, a steam generator, and a utility boiler. Various fuel types were used including natural gas, refinery gas, landfill gas, and field gas. NOx control devices included selective catalytic reduction, low NOx burners, and exhaust gas recirculation. Over 100 substances were included on the target analyte list for each source including paraffins, olefins, acetylenes, naphthenes, aromatics, 1,3-Butadiene, aldehydes, ketones, NO, and NOx.

Of the 100 plus substances on the target analyte list, 21 were detected. Methane was the most prevalent VOC in the exhaust gases from each source. The reciprocating IC engines had the highest levels of total VOC emissions and the most detections. 1,3-Butadiene was detected at low levels at the landfill and field gas IC engines. Aromatics including benzene and toluene were detected at each of the sources except one of the refinery gas process heater and the utility boiler. Formaldehyde, acetaldehyde, and acetone were detected at each of the sources.

The IC engines had the highest NOx concentrations. In general, sources with NOx control devices had lower NOx emission concentrations. These sources also had the lowest ratio of NO to NOx. NOx emissions from sources without NOx control were almost entirely composed of NO.


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

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