Application Of Microchannel Reactors In The Preparation Of CuO/ZnO/Al₂O₃ Catalysts For Methanol Steam Reforming

Methanol hydrogen production technology has significant advantages in the medium and small-scale hydrogen production industries,and cooper-based catalysts have been widely used in methanol hydrogen production due to their high activity and low cost.The cooper-based catalysts prepared by co-precipitation method in traditional stirred tanks usually have an uneven particle size and their reaction conditions are hard to control.On the other side,microchannel reactors with high micromixing efficiency and precise residence time might be able to make up for the shortcomings of traditional stirred tanks.In this work,the methanol steam reforming activity of CuO/ZnO/Al₂O₃catalysts prepared in microchannel reactors and stirred tank reactors,respectively,was compared;The influence of preparation process on the preparation of CuO/ZnO/Al₂O₃catalysts in microchannel reactors was discussed.The reaction activity evaluation and a series of characterizations such as TEM,TPR and BET of the catalysts prepared under different process conditions were carried out,and the results showed that the optimum process conditions of the preparation of CuO/ZnO/Al₂O₃catalysts in microchannel reactors were as follows:feed flow rate at 120 m L/min,aging temperature at 50℃,precipitation p H=7～8.The effects of reaction conditions on the activity of CuO/ZnO/Al₂O₃catalysts prepared by microchannel reactors were also discussed,and the differences in the structure and performance of the catalysts before and after the reaction were compared by a series of characterizations such as XRD and TEM.The results showed that the optimum reaction conditions were as follows:reaction temperature at 260℃,reaction pressure at 0.5MPa,methanol mass fraction of 45%,space velocity 0.5 h^-1.Under this condition,the methanol conversion rate of the catalysts prepared in the microreactors is 71.87%,and the hydrogen selectivity is 98.57%.