Heat pumps could reduce biogas carbon footprint by 36%

Heat pumps could reduce biogas carbon footprint by 36%, research suggests. (Image: Pixabay CC0) An alternative source of heat could significantly reduce the carbon footprint of a process which turns food waste into power, new research suggests. A University of Glasgow-led team of scientists have demonstrated that using air-source heat pumps to support anaerobic digestion could cut the carbon emitted during the production of biogas by more than a third. Their findings could help support ongoing efforts to decarbonise national electricity grids and enable remote communities to produce their own low-carbon power locally. Anaerobic digestion uses microorganisms in oxygen-free conditions to break down biodegradable materials like food waste and sewage sludge to release biogas - a mixture of methane and carbon dioxide which can be burned to turn turbines, generating low-carbon electricity. Machines called bioreactors are used to maintain the optimal temperature during anaerobic digestion to maximise the amount of biogas generated. The researchers set out to investigate how the carbon footprint of bioreactors heated by air-source heat pumps - which draw ambient heat from the air in a low-carbon process - would compare over the length of their lifetime to conventional heating systems which use boilers powered by natural gas.