Effect of different gasifying agents (steam, H2O2, oxygen, CO2, and air) on gasification parameters

Two sensitivity analyses were performed in an Aspen simulation of fluidized bed gasification for five different gasifying agents such as steam, hydrogen peroxide (H2O2), pure oxygen (O-2), carbon dioxide (CO2), and air. In the first sensitivity analysis, the modified equivalence ratio (MER) was varied (0.22-0.36). For the varied modified equivalence ratio (MER), %hydrogen, H-2/CO molar ratio, and hydrogen yield were the highest in steam-gasification, but %carbon monoxide, %methane, CO yield, and the lower heating values (LHV) were the highest in CO2-gasification. In the second sensitivity analysis, the freeboard temperature was varied (500-900 degrees C). With increasing freeboard temperature, %hydrogen and %carbon monoxide increased while %carbon dioxide and %methane decreased for all the gasifying agents. Also, with increasing freeboard temperature, the LHV decreased and the hydrogen yield, CO yield, and the gas production rate increased for all the gasifying agents, but the H-2 /CO molar ratio increased only in oxygen, air, and CO2-gasification. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.