Installation of a Lean Burn Biogas Engine with Emissions Control to Comply with Rule 1110.2 at a Wastewater Treatment Plant in South Coast Air Quality Management District
Wet scrubbing of biogas-fired lean burn engine exhaust using effluent at wastewater treatment plants.
Biogas & Electric, LLC
Recipient
La Jolla, CA
Recipient Location
38th
Senate District
77th
Assembly District
$13,175
Amount Spent
Completed
Project Status
Project Result
Biogas & Electric was unable to demonstrate its emission reduction system at the Palm Springs and the project termed-out.
The Issue
Combustion of biogas in a low cost, lean burn combined heat and power (CHP) unit is vastly more economical than alternatives such as fuel cells, micro-turbines or conditioning biogas to pipeline quality. However, biogas fired internal combustion engines generate NOx and SOx, thus to obtain necessary air permits, biogas projects are required to deploy costly post-treatments such as selective catalytic reduction (SCR) to attain compliance. In addition to employing expensive catalysts, a downside of selective catalytic reduction -type systems is the need to maintain stocks of ammonia on hand to support the cleanup process.
Project Innovation
This project aimed to design, build and install a continuously operating commercial scale emissions reduction system for the lean burn biogas engine(s) at a municipal wastewater treatment plant in Palm Springs California. If successful, the project would have enable lean burn biogas engines to comply with existing and future air quality regulations when deployed at wastewater treatment plants, resulting in reduced flaring and net reductions in emissions.
Project Benefits
The technology that was to be demonstrated was a low cost NOx and SOx reduction wet scrubbing technology called NOxRx (a registered trademark) which can be used in conjunction with all biogas engines and anaerobic digesters in the market today. NOxRx has a patented method of utilizing the effluent stream from an anaerobic digester to reduce emissions from biogas engines. Unlike SCR, it does not produce N2O and does not require H2S removal or biogas conditioning prior to combustion. Therefore, NOxRx represents a significant cost savings over competing NOx reduction solutions. The goal of this project was to demonstrate the commercial viability of NOxRx for biogas-fired lean burn engines to comply with CARB NOx and SOx standards, and SCAQMD Rule 1110.2.
Affordability
If successful, this project would have enabled operators to deploy low-cost internal combustion engines for biogas generation by avoiding the need for pre-treatment and by replacing conventional selective catalytic reduction with a wet scrubber that uses the chemistry of the plant's available effluent rather than purchased or stored chemicals.
Environmental Sustainability
Cost-effective solutions for converting biogas to power would have enabled wastewater treatment facilities to reduce flaring to the atmosphere, and subject the products of combustion to post-processing that will reduce NOx and SOx emissions to tighter regulatory standards.
Key Project Members
Seth Burns
Subrecipients
BSK Associates
J.R. Filanc Construction
Montrose Environmental
Anaergia Technologies, LLC
John Dascomb, Ph.D.
Match Partners
Anaergia Technologies, LLC
