Biogas upgrading –from Anaerobic Digestion

METHAGEN is a system based on VPSA (Vacuum Pressure Swing Adsorption) technology designed to purify biogas from Anaerobic

Digestion feed-stock such as:-
•Waste Water treatment plants
•Food and organic municipal waste
•Agricultural waste

VPSA Technology

Compressed biogas, after drying and desulphurisation, is fed to the METHAGEN upgrading unit, making use of VPSA technology to remove CO2, N2, O2 and residual H2O from the gas steam.

The METHAGEN system contains a set of columns packed with selective adsorbents. Each adsorption column undergoes a continuous flow of high purity, dry and pressurised biomethane.

The adsorbent regeneration step is assisted by a vacuum system to enhance process efficiency. The residual methane desorbed during the regeneration step is recycled back to the biogas inlet reservoir, resulting in a methane recovery rate close to 99%. The METHAGEN operation is fully automated and controlled by a PLC. The biomethane composition is continuously monitored by our multi-gas analysis system.


  • 100% CH4 recovery –Zero emissions (using METHABOOST)
  • Lowest OPEX –0.22 kWh/Nm3 of biogas
  • Lowest CAPEX
  • High CH4 purity –up to 99%
  • High recovery –up to 99.96%
  • Efficient O2 and CO2 removal
  • N2 reduction capability
  • Dry process (no water or chemicals)
  • Non-cryogenic technology
  • Water removal –Dewpoint < 50ppmv H2O
  • High reliability / high availability
  • Simple installation and operation
  • Small footprint
  • Fast plant operational readiness
  • Quick start and stop
  • 4.0 Enabled –remote control & dynamic reporting
  • Full turnkey upgrading solutions
  • CO2 recovery option (CCU)



The METHABOOST option is a post-treatment stage based on Vacuum Swing Adsorption (VSA) technology, enabling recovery of residual methane from the off-gas stream of the METHAGEN process.

  • An efficient alternative to expensive catalytic oxidation systems, RTO (Regenerative TermoOxidation) or low PCI boilers.
  • Enabling near 100% recovery, zero methane loss/emissions and pure CO2 production.
  • Specially recommended for CO2 inertizationof batch digester.