An integrated system for the conversion of biomass to renewable natural gas and then to methanol and other value-added products is provided. The integrated system includes a compressor that receives biomass gases from a biomass source and a series of purification stations that produce purified gas from the biomass gases. Characteristically, the purified gas has an enhanced amount of methane. A gas-to-liquids plant converts the purified gas to a product blend that includes methanol.