Facility For Producing Gaseous Biomethane By Purifying Biogas From Landfill Combining Membranes, Cryodistillation And Deoxo

A facility for producing gaseous biomethane by purifying biogas from landfill, comprising:

• a compression unit for compressing an initial gas flow of the biogas to be purified,
• a VOC purification unit arranged downstream of the compression unit to receive the compressed initial flow of the biogas and comprising at least one adsorber loaded with adsorbents capable of reversibly adsorbing VOCs to thereby produce a VOC-depleted gas flow;
• at least one membrane arranged downstream of the VOC purification unit to receive the VOC-depleted gas flow and subject the VOC-depleted gas flow to at least one membrane separation,
• a CO2 purification unit arranged downstream of the membrane to receive a retentate from the membrane, wherein the CO2 purification unit comprises at least one adsorber loaded with adsorbents capable of reversibly adsorbing the majority of remaining CO2 from the retentate to produce a CO2-depleted gas flow;
• a cryodistillation unit comprising a heat exchanger and a distillation column, arranged downstream of the CO2 purification unit to receive the CO2-depleted gas flow and subject the CO2-depleted gas flow to a cryogenic separation to separate O2 and N2 from the CO2-depleted gas flow and to produce a gas distillate,
• optionally a grid compressor,
• a deoxo arranged downstream the cryodistillation unit to receive the gas distillate from the distillation column capable of converting the O2 present in the gas distillate into CO2 and H2O to produce an O2 depleted gas flow,
• a dryer, especially a TSA (Temperature Swing Adsorption) arranged downstream the deoxo to receive the O2 depleted gas flow capable of removing H2O from the O2 depleted gas flow.