Efficient Biogas Upgrading Technology Based on Metal-Organic Frameworks

An important pathway for California to reach its ambitious climate and environmental goals is to increase the use of biogas produced from waste resources, particularly through upgrading it to renewable natural gas to displace fossil fuel-derived natural gas. The high content of carbon dioxide in raw biogas makes removing it the most cost- and energy-intensive step in the upgrading process. Cleaning and upgrading systems need to be more cost-effective, more energy efficient, and less complex.
This project developed a highly efficient biogas upgrading technology based on novel solid scrubbing materials. Compared to conventional liquid-based scrubbers, the solid-scrubbing technology developed is able to remove biogas more efficiently, resulting in reduced operating cost, and with smaller scrubber volume required, resulting in reducing capital costs. A first-generation of the novel solid materials was developed and manufactured and its ability to purify methane from simulated biogas was validated. The team built and used a simulation tool to predict the performance of the material at scale and design a concept separation process. Technoeconomic assessment of the concept separation process indicates that this technology can reduce operating costs by 38 percent and capital costs by 15 percent compared to aqueous amine scrubbing at commercial scale. Additional development work on the novel solid material and on the separation process, including a field pilot, could lead to commercialization of this technology in four to six years.