Using Renewable Natural Gas in Common Appliances and Implications on Emissions, Fuel Stability and Operational Performance
This project will evaluate the stability, operational, and emissions implications of operating dual-fuel appliances that can use both pipeline natural gas and biogas.
University of California, Irvine
Recipient
Irvine, CA
Recipient Location
37th
Senate District
73rd
Assembly District
$247,028
Amount Spent
Completed
Project Status
Project Result
This project is completed and final report is published. The Recipient conducted burner testing of four different appliance burners and run simulations on nine. The recipient has also authored several journal papers that are available online and has presented at several conferences and stakeholder meetings. [br /]
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The researchers concluded there is a lack of standard test procedures for different appliances. Study shows in general, high percentage of either CO2 or H2 in natural gas causes ignition failure, CO2 addition into natural gas tends to increase CO and UHC emissions but decrease NOx emissions, and H2 addition into natural gas does not influence the emission performance, especially when the percentage added is low. Current limiting device for H2 is the low NOx water heater at 10 percent addition by volume. A cost effective retrofit could increase the limit to 20 percent.
The Issue
Biogas fuels are generated from a variety of sources such as anaerobic digestion processes at water treatment plants and dairies and biodegradation of materials in landfills. Using biogas fuels can help the State of California meet its goal to increase the adoption of renewable energy, yet many potential end-use appliances are undeveloped for use of this fuel as an alternative to natural gas.
Project Innovation
This project evaluates the stability, operational, and emissions implications of operating dual fuel appliances in homes and businesses that can use both pipeline quality natural gas and biogas. An overview of the market availability of these appliances will be provided along with a summary of existing test results and procedures used to evaluate these devices. Existing data, and new test data from a representative list of appliances collected in this study will provide information on stability, performance and emissions using various fuel mixture ratios and fuel intensities. Recommendations for burner design modifications will be made to enable use of larger amounts of biogas.
Project Benefits
Under previous CEC projects 500-08-034 and 500-12-004, UCI developed simulation methodologies that accurately predict stability and emissions as a function of fuel composition. This project will apply these validated methodologies to household appliances, which were not studied in the prior projects. The project's results on burner stability, mixture limits, and pollutant emission impacts will evaluate the implications of using more biogas in appliances and the impact on resultant air quality, equipment performance, and safety. The results can guide operational modifications to existing equipment. Results will be shared with policymakers to facilitate increased adoption of renewable fuels, which supports California's Renewable Portfolio Standard.
Environmental Sustainability
Residential/commercial gas appliances consumed approximately 53% of the ~13 billion therms of natural gas provided by Investor Owned Utilities in California in 2013. If one percent of this natural gas could be displaced with biogas, this could reduce CO2e emissions by more than 350,000 metric tons annually (assuming 0.00531 mt/therm). As the percentage of biogas is increased, the reductions in CO2e emission will increase correspondingly. testing
Key Project Members
