The kinetically selective vacuum pressure swing adsorption (VPSA) process was modeled to recover CH,from a CH(4)56, CO(2)40, (N-2+O-2)3, and H2O 1 mol % biogas contaminated with H2S, higher hydrocarbons, organo-Cl compounds and NH3, by using Takeda Chem. Industries' carbon molecular sieve MSC-3K172 by reason of diverse diffusivities of CO2 and CH4 in sieve micropores, to yield a 9293 mol% CH4. The biogas collected, compressed to 650-700 kPa and cooled to condense water to be disposed of, is passed through a Sulfatreat bed to remove H2S and NH3 and through 0.3 x 1.2(diam.)-m Al2O3 and 2.5 x 1.2(diam.)-m active C sieve beds (temperature swing adsorption). The gas leaving the VPSA unit will serve to regenerate the sorbent at 423 K at 1 atm. The energy required to make 1000 m(3) of a 0.5-MPa 92-95 vol.% CH4 gas (in 78-87% yield) is 200-250 kWh. The estimated outlay to collect 10,000 m(3) (SAP) biogas/hour, to purify the gas, and to recover and transfer CH4 into a medium gas pressure network, is $(1.25-1.75) x 10(6) (as for 2002 year).