Study on Hydrogen Production of ZhunDong Coal Using Chemical Looping with Cu-Fe as Oxygen Carrier

The main problem of coal direct chemical looping hydrogen generation (CLHG) is that coal ash and oxygen carrier (OC) cannot be effectively separated, which makes the OC activity is reduced after multiple cycles. In this study, a double plate-fixed bed reactor is adopted. The gasification of coal and the reduction reaction of oxygen carrier were integrated in the same furnace, and the hydrogen production characteristics of ZhunDong coal by chemical looping were studied. Cu-Fe composite oxygen carrier was prepared by chemical synthesis method. The results show that the higher the copper oxide content and the smaller the coal particle size, the better the effect of hydrogen yield. The potassium can promote the rate of coal gasification and increase oxygen carrier reduction rate, but faster reduction reaction rate will aggravate the formation of carbon deposition. The oxygen consumed in reduction of OC is preferentially from CuO, while Fe/FeO reacts with H2O prior to Cu/Cu2O in the hydrogen production stage. Compared with Cu-Fe OC, the implantation of MgAl2O3 plays an important role in stabilizing the redox ability and mechanical properties of OC.

Automated summary

This study investigates the hydrogen production characteristics of coal using a double plate-fixed bed reactor, where the Cu-Fe composite oxygen carrier significantly affects the hydrogen yield and potassium promotes the coal gasification rate. However, carbon deposition has a negative impact on the activity of the Cu-Fe oxygen carrier.