(424e) CO2 Enhanced Gasification of Biomass Char - Catalytic Effects of Na, K, Ca, and Mg

Authors: 
Sadhwani, N., Auburn University
Eden, M. R., Auburn University
Adhikari, S., Auburn University

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. 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 the current study, unloaded biomass char was gasified using CO2 at five different temperatures between 800oC – 950oC in a fixed bed reactor. Using the evolution of CO in the gasification process as basis for conversion, the conversion-time data was fitted to three different solid-gas reaction models. The Random Pore Model (RPM) gave the best fit and the kinetic parameters for the same were calculated. In the second part of the study, acetates of Sodium (Na), Magnesium (Mg), Potassium (K) and Calcium (Ca) are used to load the char with metal catalysts and subjected to the same gasification procedure. The effect of catalysts is studied using the variation in kinetic parameters obtained using the RPM.

Instruments such as a CHNS analyzer, inductively coupled plasma (ICP), Scanning Electron Microscope (SEM) are used to analyze the composition and properties of char. Additionally, a micro GC is used to analyze the syngas at the output.