Biogas technology is one of the widely applied anaerobic digestion approaches to harvest methane from different wastes such as wastewater treatment sludge, agriculture residue, and other biomasses.
Biogas can be further purified utilizing biogas upgrading technology so it can be applied as biomethane in vehicles and for gas grid injection. Recently, methane loss from biogas plants and its environmental and economic consequences have been underlined, but not thoroughly researched.
In this investigation, process related CH4 loss from nine different commercially operating biogas upgrading plants such as water scrubber, amine, and membrane-based plants was examined. The result of the measurements showed an average of 0.7% methane loss with respect to supplied methane to the upgrading plants. A methane loss up to 1.7% has been detected in water scrubber methane upgrading technology, while 0.037 % methane loss was detected in amine based upgrading, thus the water scrubber has shown the most detrimental effect as regards methane loss.
Finally, the regenerative thermal oxidizer was further applied to reduce CH4 emission by 99.5 % of the amount of CH4 in the waste gas from the upgrading unit.