Life Cycle Costing and Eco-Efficiency Assessment of Fuel Production by Coprocessing Biomass in Crude Oil Refineries

Biobased liquid fuels are becoming an attractive alternative to replace, totally or partially, fossil ones in the medium term, mainly in aviation and long-distance transportation. In this regard, coprocessing biomass-derived feedstocks in conventional oil refineries might facilitate the transition from the current fossil-based transport to a biobased one. This article addresses the economic and environmental feasibility of such a coprocessing strategy. The biomass-based feedstocks considered include bio-oil and char from the fast pyrolysis of lignocellulosic biomass, which are coprocessed in fluid catalytic cracking (FCC), hydrocracking, and/or cogasification units. The assessment was based on the standardized concept of eco-efficiency, which relates the environmental and economic performances of a system following a life-cycle approach. Data from a complete simulation of the refinery process, from raw materials to products, were used to perform a life cycle costing and eco-efficiency assessment of alternative configurations of the coprocessing strategy, which were benchmarked against the conventional fossil refinery system. Among other relevant results, the eco-efficiency related to the system's carbon footprint was found to improve when considering coprocessing in the hydrocracking unit, while coprocessing in FCC generally worsens the eco-efficiency score. Overall, it is concluded that coprocessing biomass-based feedstock in conventional crude oil refineries could be an eco-efficient energy solution, which requires a careful choice of the units where biofeedstock is fed.