Air Quality Implications of using Biogas (AQIB) to Replace Natural Gas in California
Evaluating air quality impacts from biogas generation
Regents of the University of California, Davis
Recipient
Davis, CA
Recipient Location
3rd
Senate District
4th
Assembly District
$775,064
Amount Spent
Completed
Project Status
Project Result
Combustion exhaust from biomethane has similar chemical composition to that of natural gas on standard target compounds, but the results from bioassay tests suggest that the potential health effects of biomethane combustion exhaust and natural gas combustion exhaust may differ. The most significant potential health impacts identified in the current study were DNA damage and mutagenicity. Increased levels of mutagenicity were correlated with a large number of chemical compounds outside the list of standard targets. Further testing should be conducted to verify these chemical components. Understanding the relationship between fuel composition and combustion exhaust mutagenicity could reveal new criteria that is currently not included in the list of standard target compounds, although is critical to protecting public health.
The Issue
Biogas/biomethane has great potential as a source of renewable energy for California, but this fuel often contains compounds that are not found in natural gas and that vary depending on the feedstock and the degree of purification. Some of the biological organisms and trace chemical compounds found in biogas/biomethane have the potential to adversely impact air quality either in their unburned state or after their combustion products age in the atmosphere. Testing of biogas/biomethane combustion exhaust at atmospherically relevant conditions is difficult and has not been carried out to date.
Project Innovation
The project measured biogas/biomethane chemical and biological composition over a range of possible applications. The sources of the biogas/biomethane include landfills, dairy digesters, and food waste digesters. The applications tested include mobile sources, in-home appliances, and on-site electricity generators.
Project Benefits
The study provides real emission data on raw biogas combustion, upgraded biomethane onsite power generation, and biomethane combustion in natural gas applications such as home appliances and vehicles. This information will assist state agencies such as the California Air Resources Board, utility companies, and renewable natural gas producers in developing future biogas adoption strategies while protecting public health and air quality for the residents of California. This goal directly supports the objectives of AB 32 and the Governor's Clean Energy Jobs Goal of 12,000 MW of localized energy production by providing information to stakeholders, such as gas producers, that may reduce barriers to allowing increased use of local renewable energy sources that produce or use biogas.
Key Project Members
