Techno-economic Comparison of Technologies for Biogas Upgrading

Biomethane from biogas is an alternative energy currently gained attention to be used as substitution for vehicle fossil fuels. Despite its outstanding properties in terms of flexibility in application and environmental friendliness when compared with other alternative energy, the main obstacle to the development of commercial biomethane production is the uncertain value of investment. This research reveals the pros and cons in terms of specific energy used in production of biomethane from biogas, specific production cost and the current investment cost of biogas upgrading techniques including pressurized water scrubbing, chemical scrubbing, cryogenic separation, pressure swing adsorption and membrane separation. It was found that the specific energy used in the production of biomethane from biogas varies in the range of 0.05 - 0.62 kWh/m3 biogas. Increasing production capacity, the investment cost decreases while the energy consumptions for all production techniques increases, except for cryogenic separation which remain constant. Comparison of the specific production cost and the price of fossil fuels shows that to make the production of biomethane from biogas economically worthwhile, a development for more efficient technology to reduce production costs is of paramount importance.