To meet more stringent emission regulations, Orange County Sanitation District is upgrading two biogas conditioning systems with Clean Methane Systems as the supplier at the Fountain Valley and Huntington Beach locations in Southern California.
CMS also supplied the original systems.
With total siloxane levels of .9-15.7 ppmv, total VOCs of .9-15.7 ppmv, total VOCs of <150 ppm, and gas flow rate of 0-2,100 (Fountain Valley) and 0-3,200 scfm (Huntington Beach), CMS provided four larger vessels and was able to reutilize one of the original vessels. The more robust system means the 1.4 billion cubic feet of digester gas produced each year, will now be able to meet the strict air quality standards. That’s enough gas to power eight engines with a total capacity of 23.5 MW.
The CMS system incorporates three carbon-based media to filter the biogas. Media are stacked in each vessel with gas flowing into one vessel then onto the others. Based on this system, the average flow rate, and the makeup of the biogas, OCSD should only have to change out the media four times a year.
The initial project cost, built in 1994, was $25 million. The project saves OCSD $3.5 million per year and has a 7.2 year payback period without incentives.