Life-cycle assessment of Fischer–Tropsch products from biosyngas

Abstract

This article addresses the life-cycle assessment of an energy conversion system for the coproduction of fuels and electricity from a gasification-based biosyngas feedstock via Fischer–Tropsch synthesis coupled with a combined-cycle process. Inventory data obtained mainly through process simulation are used to evaluate the environmental performance of the system in terms of abiotic depletion, global warming, ozone layer depletion, photochemical oxidant formation, land competition, acidification, and eutrophication. Furthermore, the cumulative non-renewable energy demand of the system is quantified and used in the calculation of the life-cycle energy balance of the system, which is found to be positive.Biosyngas generation arises as the main source of impact, with a much higher contribution than the rest of processes (production of catalysts, waste treatment, etc.). Electricity, diesel, gasoline and surplus hydrogen are the products of the system. The environmental profiles of these bioproducts are calculated and compared with those of fossil diesel, rapeseed biodiesel, soybean biodiesel, fossil gasoline, corn bioethanol, steam-methane reforming hydrogen, and the EU electrical grid. Overall, the bioproducts from the evaluated system are found to be promising alternatives to current energy products from a life-cycle environmental perspective.