Life Cycle Assessments of Energy Recovery from the Organic Fraction: Bio-Methane or Bio-Hydrogen, for Vehicle Fuel or for Electricity?

The recovery of clean energy in the form of methane-containing biogas is starting to receive tremendous attention in South Africa. However, it is unclear whether the transition from standard bio-methane production to waste-based bio-hydrogen production would improve or worsen the environmental and energetic performance as quantified by Life Cycle Assessment (LCA). The results of this study show that the use of bio-methane application in combined heat and power systems provide the most significant environmental benefits estimated at 20%, whereas natural gas stands at 36%. In the case of bio-hydrogen application in fuel cell systems for electricity generation, it appears that that bio-hydrogen has the worst performance which stands at 39%. In case of vehicle operations, application of bio-methane commands the worst environmental impact which stands at 49%, when compared to 27% for bio-hydrogen for application in fuel cell vehicles (FCV) and 46% is estimated for natural gas application.