The Development Of The Integrated Materials Applied To The Sorption-enhanced Steam Methane Reforming System

The traditional process for H2 production technology is steam methane reforming (SMR), but it still has some problems, such as, high reaction temperatures, high energy consumption and complex process operations. Due to high H2 yield, low reaction temperature and simplified process, sorpton-enchanced steam methane reforming (SE-SMR) has attracted much attention in the recent years.In this article, K2CO3-doped Li4SiO4 and Ni/?-Al2O3 were used in SE-SMR system, and their sorption ability and catalytic activity were respectively evaluated, firstly. The results show that K2CO3-doped Li4SiO4 had good sorption ability and stability at low CO2 partial pressure and moisture atmosphere, Ni/?-Al2O3 had high catalytic activity and can keep its stability under both low and high temperatures.In SE-SMR system, the coupling behaviors of sorbents and catalysts were tested under various conditions. The chemical equilibrium of SMR reaction was broken dramatically at the temperature range from 450? to 650?. In particular, H2 yield was enhanced from 78% in the SMR system to more than 95% in the SE-SMR system at 550?. The effects of packing ways, sorbent amount and particle sizes were also discussed. The results show that mechanically mixed packing way was prior to the layered packing way to produce higher H2 yield, H2 yield increased with the increasing sorbent amount and the particle sizes should be controlled above 40 mesh to avoid the deactivation of catalyst. Compared with traditional N2 desorption, the desorption rate using steam was much faster, and the sorbent also showed good stability in the steam regeneration condition.To further reduce the diffusion resistance and improve H2 yield, the preparation methods of integrated catalyst were studied. It's foud that K2CO3-doped Li4SiO4 prepared by impregnation-precipitation and sol-gel methods exibited excellent sorption behaviors, but they did not show any catalytic activity due to the formation of complex oxide from Li2O, Al2O3 and NiO. While using bentonite to combine the sorbent and catalyst, the integrated catalyst showed enhancement ability, but its enhancement ability was weaker than that using mechanically mixed package method because of the complex composition of bentonite.