Environmental impact comparison of typical and resource-efficient biomass fast pyrolysis systems based on LCA and Aspen Plus simulation

Few studies on biomass utilization have focused on resource perspective, particularly for integrated utilization systems. Resource utilization of biomass shows great importance of environmental impact and has a good application prospect. Biomass can be converted to value-added fuels or chemicals via thermochemical method. Typical biomass utilization (TBU) system involves conventional pyrolysis and bio-oil upgrading processes, while resource-efficient biomass utilization (RBU) system is a synthetically way to save significant energy. We compared the environmental impact of a TBU system and a RBU system based on life cycle assessment (LCA) and Aspen Plus simulation in this study to explore the environmental impact of biomass utilization. The two systems were simulated using 72 model compounds in Aspen Plus V8.8, and environmental impacts were compared based on the LCA method. Results showed that compared with the TBU system, the RBU system, which was designed to produce multiple high added-value products based on fast pyrolysis and rectification, had lower environmental impacts. The greenhouse gas emissions of the RBU system reduced by 29%, and the impact factors of ADP, AP, EP, ODP, and HTP reduced by 64.3%, 69.6%, 26.8%, 10.8%, and 63.3%, respectively compared with those of the TBU system. Although two systems had higher impact in some categories than open-field burning, such as ADP, ODP, and HTP, they had considerably lower GWP and EP impacts compared with those of open-field burning. Therefore, the way of biomass resource processing and reuse should be advocated. From the perspective of comprehensive environmental impact, it is necessary to reduce the open burning. Biomass production and fast pyrolysis were identified as the key factors for reducing environmental impacts. We aimed to provide insights into efficient exploitation of biomass resources by comparing the environmental impacts of the two systems. (C) 2019 Elsevier Ltd. All rights reserved.