Sustainable Research Of Biomass Pyrolysis And The Subsequent Hydrodeoxygenation Based On Process Simulation

As an important part of easing the world energy crisis and shifting the energy development strategy, the development and utilization of bio-energy is necessary, such as fast pyrolysis of biomass and upgrading of bio-oil. In recent years, progress in theory and engineering application of biomass thermal conversion has attracted more and more attention, the simulation research is one of the research methods.It will be an important guiding significance, if we do some simulation for the whole process such as mass balance and energy balance, coupling with energy efficiency, environment, economic analysis before industrialization.In this paper, the Aspen plus software is usedto simulate the whole process including fast pyrolysis of biomass and hydrodeoxygenation of bio-oil. The overall process is divided into drying, pyrolysis condensation, combustion, mild hydrodeoxygenation and depth hydrodeoxygenation unit operation. Then, the exergy analysis of the whole process is also researched to find out the inefficient part and improve it. Finally, we can find that biomass is more sustainable comparing with fossil energy according to the exergy analysis of the process. The results show that: the most inefficient unit of fast pyrolysis is burning unit. Pressure drop has little effect on the exergy efficiency. Combustion ratio of the char is a key factor to improve the exergy efficiency. Exergetic efficiency can be improved significantly from 69% to 75.6% when char is partially combusted to match the minimum heat requirement for pyrolysis reaction and the remaining unburnt fraction can be collected as solid product. Overall exergetic efficiency of the entire plant is 57.2%, which is higher than that of gasification with Fischer-Tropsch synthesis and lignocellulosic ethanol processes. Bio-energy is more sustainable than fossil fuels according to Environmental Compatibility Factor and Sustainable Resource Utilization.