BASIC DATA ON BIOGAS - Energikontor Sydost

Upgrading of biogasSwedish Gas Centre: Basic Data on BiogasTo increase the energy density of the biogas, it is possible to upgrade it withdifferent technologies. In practice, this is performed by removing themajority of the carbon dioxide. Examples of techniques are given in thetable below.Technique Function RegenerationPressure SwingAdsorption (PSA)Water scrubberChemicalabsorptionMembraneCryogenicseparationAdsorption of carbon dioxideon e.g. activated carbon.Absorption of carbon dioxidein water.Chemical reaction betweencarbon dioxide and amine –based solvents.Separation through amembrane that is permeablefor carbon dioxide.Cooling until condensation orsublimation of the carbondioxideDepressurisationDepressurisation andcounter flow of air.Heating--To increase the energy density even further, it is possible to condense thebiogas by cryogenic cooling. Liquified biogas is normally abbreviated LBG.8