Medium Temperature Shift Reaction Over Copper-Ceria Catalyst in Fixed-Bed and Microchannel Reactors

One of the effective catalysts for the hydrogen purification and production via medium temperature shift reaction, is cu-ce solid solution. cu0.1ce0,9o1.9 was produced using the co-precipitation method and then was utilized as support for the 5cu/ce0.9cu0.1o1.9 catalyst which was synthesized employing the wet impregnation method. the x-ray diffraction (xrd) analysis showed that the crystalline sizes of ce0.9cu0.1o1.9 and 5cu/cu0.1ce0,9o1.9 were 9.22 and 18.33 nm respectively. the catalysts were evaluated in medium temperature shift reaction at 300-390 °c and at the gas hourly space velocities (ghsv) of 12000 and 30000 h^-1, in a fixed bed reactor. due to the higher concentration of cu and the positive synergic effects of both the active metal and support, the 5cu/cu0.1ce0,9o1.9 catalyst showed a better performance. it was also concluded that, because of the short residence time at high levels of ghsv, increasing ghsv would lead to a decrease in the co conversion. then 5cu/cu0.1ce0,9o1.9 was evaluated in a microchennel reactor in 2 ghsvs of 12000 and 30000 h^-1 and results were compared with thoes of the fixed-bed reactor. it can be concluded that the microchannel reactor is better in higher ghsvs (shorter residence time of the gas flow). a microchannel reactor provides a high surface-to-volume ratio and gases pass over the thin layer of catalysts on the coated plates. hence, due to the better access to the catalytic bed, the reactants react even in a short time, which improves the performance of the microchannel compared to that of the fixed bed reactor.