N-desorption or NH3 generation of TiO2-loaded Al-based nitrogen carrier during chemical looping ammonia generation technology

As a terrific hydrogen carrier, NH3 can be wildly used as non-carbon gas fuel in energy area, because NH3 can store a high density of H2 and can be liquefied easily in ambient temperature and pressure. Chemical Looping Ammonia Generation (CLAG) is known to be a novel, efficient and environmentally friendly synthesis method for ammonia, in which the N-sorption/desorption of nitrogen carrier are included. The N-sorption step, which is known as the carbothermal reduction, is well studied while there are few reports on N-desorption step. Therefore, in this paper, stationary bed reactor and thermo-gravimetric analyzer (TGA) were used to study the N-desorption performance of the TiO2-loaded Al-based N-carrier and the corresponding NH3 generation during the N-desorption reaction. The results showed that, TiO2 performed a good catalytic effect on the N-desorption reaction, which is due to the good dissociative adsorption performance of H2O on TiO2 surface, and the released hydroxyl (OH) plays an important role in the N-desorption reaction. The conversion amount of aluminum nitride and the yield of NH3 increased with the TiO2 loading in the reactants, the reaction temperatures and the steam concentrations in the atmosphere, while the conversion efficiency of NH3, which is significantly affected by temperature, didn't affected by the TiO2 loadings.