Technology data has info on biogas upgrading plant costs: https://ens.dk/en/our-services/projections-and-models/technology-data/technology-data-renewable-fuels

Can integrate with electrobiofuel production, where biomass is directly combined with hydrogen to produce fuels with a higher carbon efficiency, and replace pure electrofuels with captured carbon from either biogenic sources or DAC.

see https://github.com/millingermarkus/pypsa-eur-sec

Thanks to @millingermarkus.