Research progress of industrial by-product gas-fueled chemical looping hydrogen generation technology
Industrial by-product gas is an important resource for hydrogen production with a huge annual output in China.Due to the high impurity content,the recovery of hydrogen from by-product gas by conventional approach suffers from high energy penalty,high cost and low efficiency.Compared with the traditional method,the chemical looping hydrogen generation technology provides a promising way to convert industrial by-product gas into high-purity H2 with shorter process.In this review,the technical advantages of chemical looping hydrogen generation technology from industrial by-product gas were discussed and the effects of different reducing gases were summarized systematically.During chemical looping hydrogen generation process,the reaction activity of H2 was better than CO,while the reaction process of CH4 was more complicated.Temperature had a more significant effect on the reaction characteristics of different gases,and the impurity gases,i.e.,N2 and CO2,had a negative effect on the reduction process.For oxygen carriers,high activity and stability carriers were the focus of research,and the methods such as designing composite materials,doping heterovalent elements and loading ionic conductors were important ways to improve the performance.In general,the chemical looping hydrogen generation technology had achieved rapid progress,which can also provide a reference for other chemical looping technology.