Modeling, simulation and life-cycle assessment of the use of bio-oil and char in conventional refineries

In this article we address the environmental assessment of the coprocessing of biomass-based feedstock in crude oil refineries. In particular, we consider the coprocessing of bio-oil (from the pyrolysis of lignocellulosic biomass) in fluid catalytic cracking and hydrocracking units, and the cogasification of pyrolysis char (coproduced with bio-oil) with coke. In addition to a conventional fossil-based refinery used as the base case, we simulate three alternative case studies including different biofeedstock coprocessing layouts based on original models validated against experimental data. We use process simulation as a primary source of data for the life-cycle assessment (LCA) of each case study. The LCA results show that the system's carbon footprint per energy output is improved when including biofeedstock coprocessing, favoring the study with the highest biofeedstock use. However, the results for other life-cycle indicators such as the abiotic depletion of elements and eutrophication lead to unfavorable results for biofeedstock coprocessing, which is mainly due to the increased use of catalysts and the need for fertilizers. Hence, the suitability of a specific coprocessing layout will be ultimately conditioned by the performance indicators prioritized by the actors involved in the decision-making process. (c) 2019 Society of Chemical Industry and John Wiley & Sons, Ltd