Performance Analysis and Optimization of the Biomass Gasification and Fischer-Tropsch Integrated Process for Green Fuel Productions

摘要

Continuous increase in fuel prices driven by high energy demand and limited fossil fuel resources has been presently considered a major problem. Moreover, gas emissions from internal combustion engines lead to air pollution and global warming issues. Therefore, the development of clean, alternative energy is required in order to relieve the fossil fuel shortage and environmental impact. A biomass-to-liquid (BTL) process is recognized as a promising technology to convert biomass to liquid fuels. This study focused on the theoretical analysis of the BTL process consisting of a gasification unit for synthesis gas production and a Fischer-Tropsch (FT) unit as a downstream process for synthesis gas conversion to liquid fuels. Rice straw, one of the most biomass residuals found in Thailand, was considered a feedstock. The integrated model of the BTL process consisting of three major sections, i.e., the gasification based on the reaction kinetics of char gasification, the gas conditioning process including tar steam reforming and water gas shift reaction, and the FT synthesis was developed and used to investigate the influence of gasifying agents on the product distribution and the overall energy consumption. Two gasification systems using different gasifying agents, i.e., oxygen/steam and air/steam were considered and compared. The suitable conditions that provide the highest yield of a high-valued diesel product were identified.