A monolith CuNiFe/γ-Al2O3/Al catalyst for steam reforming of dimethyl ether and applied in a microreactor

Abstract

Structured CuNi/γ-Al2O3/Al catalyst exhibited a good stability in steam reforming of dimethyl ether (DME SR) system, but there was a high CO concentration in outlet gas (about 25%). For the problem, a series of CuNiFe/γ-Al2O3/Al catalysts with different Fe content were prepared through impregnation method. It is found that the CO concentration obviously decreased after the addition of Fe. When the loading amount of Fe was 12.5 wt%, the catalyst presented the best performance: the conversion of DME reached 100% and the H2 yield was over 0.9 in both the microreactor and fixed-bed reactor. Furthermore, cross-flow channels and parallel-flow channels were built respectively by mesh-type catalyst and plate-type catalyst in the microreactor. The gas/solid mass transfer limitations in both flow channels were investigated by Damköhler number (Da). The results showed that the Da values of cross flow were always <0.01, while the values of parallel flow were >0.01. It indicated that the diffusion over mesh-type catalyst was less influenced by temperature and reactor height, making it a more appropriate choice for the microreactor.