Fig. 2
From: Production routes to bio-acetic acid: life cycle assessment
Sources contributing to the global warming potential of the biorefinery in each scenario. Global warming potentials for natural gas, lignin, and biogas are from the combustion of each fuel. Fugitive emissions are natural gas emissions that are assumed to leak/escape from various stages of biorefinery operations. Wastewater treatment (WWT) includes CO2 emissions for both anaerobic digestion and aerobic digestion. Anaerobic digestion produces CH4 which is sent to the boiler for combustion (and ultimately emitted as CO2)