New technology to demonstrate cost-effective biogas use

By Katie Fletcher | July 03, 2014

A $1.6 million Public Interest Energy Research grant, recently approved by the California Energy Commission, helps a biogas project at Lawrence Berkeley National Laboratory come one step closer in commercializing a combustion system that can switch between biogas, propane and natural gas in real time. The system uses a combination of an energy-efficient low-swirl burner (LSB) technology from LBNL with fuel-sensor technology from the University of California at Irvine. The combined technology could make use of biogas from small source generators economically viable. “The sensor technology is critical in making fuel switching work with the very efficient, ultra-low emissions burner,” said David Weightman, energy commission specialist at the California Energy Commission. “The real time fuel switching hasn’t been developed for or demonstrated in a working combustion system for heater power that meets California emission requirements.”

This novel development was created out of a need in the biogas sector. Weightman describes one of the barriers of using biogas in the market is that there isn’t a consistent supply or quality. “We think this combustion system will expand the use of biogas and displace quite a bit of natural gas use in the state,” Weightman said.

The technology’s real time switching allows the system to continuously operate alleviating the inconsistent supply of biogas. “The system can continuously burn different fuels and when not enough biogas is available, natural gas or propane can be supplemented without shutting anything down,” Weightman said.

The current inconsistent supply of biogas is affecting many small scale generators of biogas that cannot produce enough to generate revenue. Virginia Lew, senior scientist with the California Energy Commission, believes this project will help find a solution to the problem. “I think this type of project could make even a company that produces a small amount of biogas supplement with other gaseous fuels and generate electricity making the system more cost-effective.”

The National Renewable Energy Laboratory has projected potential cost and energy savings with the combustion system. They estimate that the technology has the potential to produce 1.1 million tons of methane in the form of biogas from the sources in California each year. If they were fully utilized the biogas potential would offset 14.3 percent of statewide and industrial national gas consumption, which would equate to about 2 percent of the total statewide national gas consumption. By offsetting purchased natural gas with biogas California rate payers will save an estimated $280 million per year based on 2012 industrial natural gas prices. These are currently only ballpark estimates, and after measurement verification occurs a more accurate estimate can be procured and taken to the marketplace, according to Weightman.

One of the goals of the PIER program funding the project is to focus on energy efficiency and renewable energy technology. “This particular project uses renewable energy in its form of biogas allowing for a facility like a wastewater treatment plant or a feedlot or dairy to now have the use of biogas that can offset the use of natural gas or other fuels that they would normally use for heating,” Lew said.

The overall program is designed to fund innovation that cannot happen in the competitive marketplace. “We fill the gap by providing funding that the private sector would deem too risky to commit large amounts of capital to,” Weightman said.

The project is going to kick off with a meeting in September of 2014 with the first part of the project being the development of a demonstration plant. In May of 2016 a one-fifth scale system prototype will be completed followed by the development of the full scale system at the demonstration site at the Chiquita Water Reclamation Plant. The various phases of the project are expected to culminate in October of 2017 with the implementation of a technology transfer plant.