Environmental Life Cycle Assessment of Biobutanol Production by Electrofermentation

Butanol is currently produced on an industrial scale, primarily from fossil-based raw materials. An alternative method involves gas fermentation. To improve the efficiency of microbial processes, one promising approach is electrofermentation, which involves the application of an electric current to stimulate microbial growth or modulate metabolic pathways. This study examined the production of biobutanol from gas fermentation supported by electrofermentation, as assessed through a Life Cycle Assessment (LCA). The LCA was conducted for a biobutanol production technology developed within the framework of the BesTECH project, funded in the ERA-NET Bioenergy programme. Two environmental impact assessment methods were applied: ReCiPe 2016 and IPCC 2021 GWP 100 (with CO2 absorption considered). The results of the LCA indicated that the most significant environmental impact is associated with greenhouse gas emissions from fossil fuel combustion used to generate electricity (based on Austria’s energy mix). An additional environmental burden is related to the production of the fermentation medium. Sensitivity analysis revealed that the environmental performance of the process is strongly influenced by the source of electricity used in biobutanol production.