(440e) Process Modeling of Fluidized Bed Biomass-CO2 Gasification Using Aspen Plus

Biomass can be converted to biofuels using various pathways which are broadly classified as biochemical or thermochemical. Gasification is a common thermochemical process that converts biomass to a gaseous product (syngas) which can be used for power generation, chemical production and as a fuel. The use of air, steam and oxygen as oxidizing agents in this process has been widely studied and reported. Improved CO concentrations have been observed when CO₂ is added as a co-reactive agent in the gasification of biomass.

In this work, a comprehensive model simulating the biomass gasification process using CO₂ in a fluidized-bed gasifier is developed using ASPEN Plus. The model utilizes additional reactors and mechanisms simulating various steps in the gasification process to predict the effect of operating parameters such as temperature and CO₂ flowrate on biomass conversion and syngas composition. A sensitivity analysis of product gas composition and a comprehensive sustainability assessment is conducted to evaluate the economic, environmental, and social performance of the biomass-CO₂ gasification process.

The results from this model are compared to published gasification experimental data obtained on a bench scale fluidized bed gasifier.