Chemistry and Kinetics of Biomass Gasification Using Carbon Dioxide

In recent years, gasification has originated as one of the better techniques to harness the energy from biomass. Syngas produced during gasification can be used as a feedstock in industrial applications for electricity, chemicals and fuel production. Air, oxygen and steam have been widely used as oxidizing medium in the gasification process. The use of Carbon dioxide (CO₂) as the oxidizing agent in biomass gasification has been explored in limited studies. Catalytic gasification of biomass can effectively improve the reaction rate and conversion efficiency compared to conventional gasification. However, very little is known about the catalytic gasification of biomass char with CO₂.

In this study, a widely accepted model for char gasification, the random pore model (RPM) is to be fitted onto data obtained from the experiments. Initially, unloaded biomass will be subjected to gasification using CO₂.  Using the evolution of CO in the gasification as basis for conversion, the values of parameters of the model are calculated. The biomass is then loaded with potassium and calcium catalysts and is to be subjected to the same procedure. The effect of the catalysts on these parameters is to be observed.

In a previous study, the chemistry of the biomass gasification using CO₂ was studied by operating the process at different temperatures in a bench scale fluidized bed reactor. The output syngas was analyzed and based on the trends of the component gases, a set of reactions dominating the process was postulated. A number of gas analysis instruments such as a GC/MS (Agilent 7890/5975), a micro GC (Agilent 490), a portable gas analyzer (Nova 7905AQN4), and an FTIR are used to collect necessary information.