Techno-Economic and Environmental Assessment of Biofuels Production Based on Chemical Looping Gasification

This paper presents the results of a techno-economic and environmental impact analysis for the biomass chemical looping gasification process coupled with Fischer-Tropsch synthesis for liquid fuel production. A 200MWth thermal input of biogenic feedstocks (i.e., pelletised forest residues and wheat straw) is assumed. The biofuel synthesis process that is composed of CLG, syngas cleaning, water gas shift reaction (WGSR), acid gas removal and FT synthesis units is modelled and simulated using ECLIPSE simulation software. Detailed results of mass and energy balance are used to perform capital cost estimation and techno-economic assessment of synthetic liquid fuel production from biomass. We also perform a sensitivity analysis to determine how various economic conditions (feedstock and utilities prices, plant occupancy, discounted cash flow rate, etc.) influence the plant economic and environmental performance. For each analysed system we compute the corresponding economic (net present value, break even selling point) and environmental (damage to human health, ecosystems, and resource availability) indicators. The evaluation results also compare the best system performance with that of more traditional fluidized bed gasification systems. The results show that the production of synthetic biofuels through CLG and FT synthesis is economically attractive and competitive compared to the current market price of biofuel, despite its higher initial investment cost. The LCA results indicate that the production of biofuels has a low environmental impact, and, due to the better process performance, pine forest residue is the more sustainable feedstock.