A short-cut chemical looping hydrogen generation system by using iron-based material from steel industry

Abstract

An integrated high purity hydrogen generation process, short-cut chemical looping hydrogen generation, was proposed in this study. Iron dust of the steel industry, as the feedstock of iron-based material, was employed as the oxygen carrier. This study used second-metallurgy-reduced iron and analytical-reduced iron to validate the feasibility of oxidation performance with air and steam at different reaction temperatures. To obtain the fundamental data, thermogravimetric analyzer and packed-bed reactor had been used. Due to the difference in carbon composition and trace metal in the second-metallurgy-reduced iron, the reaction behaved completely different under different experiment conditions, especially at different converting temperatures. According to the apparent solid conversion and outlet gas concentration profiles, the oxidized reaction with air and steam would be divided into two stages, kinetically controlled regime and product diffusion regime. Besides, the purity of hydrogen produced by second-metallurgy-reduced iron and analytical-reduced iron could reach 99.2% and 99.9%, respectively. Overall, compared to analytical-reduced iron, using second-metallurgy-reduced iron provides a link between the waste recycling in steel industry to generate hydrogen with chemical looping concepts in the industrial level.