CaO-Assisted Alkaline Liquid Waste Drives Corn Stalk Chemical Looping Gasification for Hydrogen Production

Abstract

The chemical looping gasification (CLG) process is a promising pathway to produce hydrogen-enriched syngas with biomass. It is urgent to enhance the reactivity and thermal stability of oxygen carriers (OC) and capture the inherently separated CO ₂. This work presents the strategy of simultaneous modification of a Fe ₂O ₃/Al ₂O ₃ oxygen carrier and the supplement of an oxidant for corn stalk chemical looping gasification by introducing KNO ₃-containing ethanol liquid waste. CaO is employed to capture the generated CO ₂ and promote the reaction balance toward hydrogen production in a fuel reactor (FR). The highest carbon conversion reaction rate of 1.1 × 10 ^–4 mol/g could be obtained at the ratio of CaO to fuel carbon and the reaction temperature of 1.5 and 600 °C, respectively. The kinetics and thermodynamics analyses under the optimized condition are further discussed to verify the possibility and high efficiency of using alkaline organic liquid waste to boost solid fuel gasification for hydrogen production. This CLG strategy shows multifunctional merits, including organic liquid waste treatment, biomass CLG promotion, and hydrogen production enhancement.