Experimental study of CO2 corn stover char gasification using iron nitrate as a catalyst under a high-pressure environment

Abstract

As articulated by the Intergovernmental Panel on Climate Change (IPCC), limiting atmospheric concentration of CO2 is a major goal of the world. Reduction of CO2 to CO in an integrated gasification combined cycle (IGCC) using biomass gasification is a potential method of limiting atmospheric CO2 concentrations while producing energy, biofuels, or both. Gasification of biomass using CO2 requires high temperatures. Catalysts have the potential to limit the reaction temperature. Non-edible corn stover is one of the plentiful biomass and is used in this study. Corn stover char samples with a particle size less than 150 μm are mixed with iron nitrate through a wet impregnation technique. Experiments are conducted at three different temperatures (1110 K, 1160 K, and 1210 K) and four different pressures (1.3 atm, 4 atm, 7 atm, and 10 atm). In-line sampling is employed to measure CO mole concentrations in the exhaust gases at a 1 Hz rate. Measurements of the reactor wall temperature are used for gas temperature correction. CO mole production increases with increasing pressure and temperature. A significant finding of this study is that pressure increases above 4 atm do not show any benefits in CO mole production or char conversion. The use of catalyst allows gasification temperature reduction by 100 K, which may be beneficial for longer reactor life.