Asahi Kasei chemical company is set to build a biogas purification system at a sewage treatment plant in Kurashiki City, Okayama, Japan. The facility will separate and recover CO2 and methane emissions.
During a trial held on 15th September, Asahi Kasei demonstrated the system, which uses its K-GIS zeolite adsorbent to selectively adsorb CO2 from biogas released from sewage. According to the company, “K-GIS differs from conventional adsorbents by adsorbing almost no methane, enabling the system to efficiently separate and recover high-purity methane while recovering high-purity CO2”.
Waste-derived biogas is made up of around 60% methane and 40% CO2. After passing through the system, it can be used in its upgraded form – biomethane – as a substitute to natural gas. The importance of biogas as a natural gas alternative has been emphasised by UK-based Anaerobic Digestion and Biogas Association (ADBA) , which recently called for the country to increase investment into waste-derived biogas as a response to the ongoing Russian gas crisis, which has sent EU countries scampering for energy alternatives.
According to ADBA Chairman Chris Huhne, the EU plans to double biogas output to meet 9% of last year’s gas demand. “By contrast, in the UK, current government plans would meet less than 1% of our 2021 consumption,” he said. Adopting biogas and biomethane could also help meet or advance in ambitious net zero targets.
By combining biomethane production using their system with carbon capture and utilisation and storage (CCUS), Asahi Kasei revealed that it could create a carbon negative cycle. In the demonstration trial, the separated gases are recombined to biogas as fuel for generating electricity.
The facility is programmed to be installed in May next year, and the partners aim to begin operations at the end of 2023. Following additional trials, the Asahi Kasei intends to commercialise its purification system by 2025 or 2026.