Technologies for biogas to electricity conversion

Abstract

Biogas is a renewable energy resource that can play a leading role in the sustainable energy transition through green electricity generation. Biogas can be converted to electricity and renewable fuels through different technologies and prime movers. Prime movers that can be used for biogas power generation include gas and steam turbines, diesel engines, Otto cycle engines, Stirling engines as well as direct conversion in fuel cells. Since biogas has high octane rating, it can be used directly or with minimal modifications in spark ignition or petrol engines, but needs several modifications for use in dedicated diesel biogas engines or dual fuel engines and bi engines. The dual fuel mode which uses biomethane or biogas and diesel requires little or no engine modifications unlike the conversion to a dedicated gas engine. The performance of biogas prime movers is greatly enhanced if enriched biogas or biomethane is used in place of raw biogas. Other than use in various engines, biogas can be cleaned and used in fuel cells and manufacture of renewable hydrogen. As renewable natural gas, biogas in the form of biomethane can be injected to the natural gas grids for domestic and industrial application as natural gas substitute in applications which include power generation.

Keywords

• Biogas production
• Electricity from biogas
• Fertilizer from biogas
• Biogas engines
• Fuel cells
• Hydrogen production