Innovative approaches for enhancing the cost-efficiency of biological methane abatement

Abstract

Methane (CH4), which is considered the second most important greenhouse gas (GHG), represents nowadays 18 % of the total EU-28 GHG emissions and possesses a global warming potential 25 times higher than that of CO2 (in a 100 yr horizon). The methane produced during the anaerobic digestion of organic waste (wastewater and organic solid waste) can be collected and combusted for the generation of electricity and/or heat, thus replacing fossil fuels. However, methane can be only used for energy generation when its concentration in the emission is higher than 20 %. Unfortunately, more than 56 % of the anthropogenic CH4 emissions contain CH4 concentrations below 5 %, which significantly limits the implementation of energy recovery-based treatment technologies. Therefore, cost-efficient abatement methods to mitigate the pernicious environmental effects of residual CH4 emissions are required.