Asahi Kasei has started a demonstration of its biogas purification system at the Kojima Sewage Treatment Plant in Kurashiki, Japan, using zeolite-based CO2 separation technology.

The trial, launched in collaboration with Kurashiki City, aims to refine biogas by removing CO2 and recovering high-purity methane (biomethane) as a substitute for natural gas.

The System separates CO2 and methane from biogas using the optimum combination of a special zeolite as adsorbent that selectively adsorbs CO2 and a special pressure vacuum swing adsorption (PVSA) process technology. 

The zeolite is a crystalline aluminosilicate having regular channels (pores) controlled on the order of angstroms (ten-millionths of a millimeter) and cavities (voids) with a specific surface area exceeding several hundred square meters per gram.

Asahi Kasei’s PVSA process technology, which separates specific gases by changes in pressure, enables the removal of CO2 from biogas to refine high-purity methane gas (biomethane) at a high recovery rate. Biogas from sewage sludge, garbage, etc., consists of approximately 60% methane and 40% CO2.  While the use of biogas as a carbon-neutral fuel is rapidly expanding, it is also a source of biomethane as a substitute for natural gas in Europe, the U.S., and other regions1.

Commercialization of the System is expected around 2027 following additional trials in countries or regions where biogas purification is performed.

“We are excited to start the on-site demonstration trial of a biogas purification system using Asahi Kasei's zeolite and PVSA process technology,” says Osamu Matsuzaki, Senior Executive Officer of Asahi Kasei and Senior General Manager of Corporate Research & Development. “As the next step, by expanding co-creation partnerships globally, we will accelerate the advancement and practical implementation of this outstanding technology that can reduce environmental impacts, contributing to sustainability for the world.”