Process modeling for steam biomass gasification in a dual fluidized bed gasifier

Abstract Steam biomass gasification has been receiving a lot of attentions as a green process to produce hydrogen rich fuels. In this process, biomass is converted into product gas, which consists of mainly H 2 , CO, CH 4 , and other combustible gases, at elevated temperatures and under presence of air and steam as oxidizing agents. The product gas can be used directly as a gaseous fuel or upgraded to syngas (i.e., H 2 + CO) for production of other liquid biofuels and chemicals. Fluidized bed reactor has been preferable for biomass gasification due to excellence gas-solid contact as well as heat and mass transfer. Conventional fluidized bed gasifier involves air and steam in a single reactor, which normally yields product gas consisting of nitrogen at a high concentration. Consequently, heating value of the product gas is dramatically reduces. In contract, a dual fluidized bed concept can produce nitrogen-free product gas, which is advantageous for process up-scaling. In this study, a biomass gasification process with a dual fluidized bed technology is constructed in Aspen Plus software. Model validation is carried out using available experimental data. The model can provide in details the performance of the gasification process in terms of product gas distribution and heating value as well as the process efficiency.