Corn-Stalk Chemical Looping Combustion Using tert-Butanol Waste Solution

Abstract

Inadequate fixed carbon conversion is the main culprit for low efficiency of solid fuel chemical looping combustion (CLC). To improve the efficiency, we report here a strategy to sufficiently converse fixed carbon during corn-stalk CLC by introducing tert-butanol solution to generate adequate oxidants (H2O and CO) in cascade reaction systems. The tert-butanol solution CLC was performed at the first reaction stage using Fe2O3/Al2O3 as the oxygen carrier (OC). Then, the products of the first reaction stage act as oxidizer to drive the gasification and combustion of corn stalk in the following reaction stage at 850 °C under different peroxidation coefficients (Ω), which is a proportional coefficient of the actual amount of Fe2O3/Al2O3 used in the reaction to the theoretically calculated amount required for complete oxidation of fuel. We demonstrated that the tert-butanol solution can directly promote the gasification of corn stalk and tune the oxidation state of the reduced OC for oxidizing the fuel gas during the CLC process, which not only transfers oxygen but catalyzes corn-stalk gasification. Reaction stoichiometry and thermodynamics analysis further implied that the reported tert-butanol solutioncorn-stalk cascaded CLC is thermodynamically feasible. Organic waste solution, biomass CLC, serves the dual purpose of organic waste treatment and solid CLC promotion.