Life cycle assessment of bio-fermentation ethanol production and its influence in China's steeling industry

Conversion of Linz-Donawitz Gas from steeling industry into ethanol (LDG-ethanol) was demonstrated to be a promising route for value-added utilization of tail-gas. However, a systematic and objective understanding of the environmental impact benefits is still lacking. In this work, the environmental footprint of the technology is systematically evaluated by life cycle assessment (LCA) and compared with its competitors under different scenarios development. The assessment results show that LDG-ethanol route is the most environmentally benign option, whose environmental impact value is 22%–25% lower than that of Corn-ethanol and Coal-ethanol routes. More importantly, electricity as the key determining factor, the environmental footprint of LDG-ethanol can be further decreased by 15%–68% via lowering electricity consumption and introducing of green power. As grid decarbonization gradually, such interesting characteristics endowed LDG-ethanol with enormous potential to achieve the decarbonization goal. Based on the LCA analysis, the carbon reduction potential, economic benefits, and early opportunities of the LDG-ethanol technology are further analysed in the context of the Chinese steel industry to inspire heavy industries seek new technologies for re-use CO/CO2-containing waste gases.