TDA Research wins EPA award for biogas purification system

By Erin Voegele | August 13, 2012

The U.S. EPA has awarded Colorado-based TDA Research Inc. a $300,000 contract under its Small Business Innovation Research program competition to support the demonstration of proprietary biogas purification technology. The award is for Phase II work. TDA was awarded funding under Phase I of the program in 2011.

According to information published by the EPA, TDA is developing a vacuum swing adsorption system to upgrade biogas to pipeline specification. The technology uses a novel, low-cost, high-capacity CO2 adsorbent. The system results in low methane loss, as more than 95 percent of the methane that enters the system is sent to the pipeline. In addition, the technology features very low capital and operating costs.

Phase I of the project focused on bench-scale work. TDA also demonstrated economic viability of the technology through process simulations and engineering analysis. During Phase II of the project, TDA will demonstrate the technology in the field. The company has partnered with Washington-based CDM to demonstrate the process in combination with an anaerobic digestion system that will be built and operated at the Air Force Academy in Colorado Springs, Colo.

Ambal Jayaraman, a senior engineer at TDA leading the project, said TDA developed the proprietary adsorbent over several years. It is specifically designed to remove CO2 from gas streams, he continued.

In a biogas system, the technology has been shown to remove 95 to 98 percent of the CO2 from biogas, which brings the composition in line with pipeline specifications. In addition, TDA’s material is also able to remove water from the biogas. According to Jayaraman, biogas generally contains between 2 and 3 percent water. The adsorbent is able to reduce the moisture content to 150 parts-per-million.

To date, TDA has completed economic analyses showing that the system is economical for use in anaerobic digestion system that produce 2,000 to 5,000 cubic meters of biogas per day. Jayaraman said that analyses of larger biogas production systems, such as landfill gas projects, will be conducted in the future, and that the system is expected to be economical at those scales as well.

The demonstration project in Colorado is scheduled to kick off in 2013, and operate for 6 to 12 months. Jayaraman estimates that the technology could be available commercially in 2014 or 2015.

CO2 removal is not the only biogas purification technology TDA is developing. Jayaraman noted that the organization has also developed a system to remove sulfur and siloxane impurities from biogas.