Investigation of the Synthesis and Reactor Evaluation of Alumina-Supported Cu Catalysts on CO Conversion in a WGS Reaction

Heterogeneous CuO-ZnO/Al2O3 is widely used in various petrochemical plants to synthesize a low-temperature water gas shift reaction. Six different synthesis routes, co-precipitation, deposition-precipitation, ultrasonic deposition precipitation, incipient wetness impregnation, urea-co-precipitation gelation method, and combined incipient wetness impregnation-urea combustion, were compared for the synthesis of a catalyst with 20/5/75 weight ratios for CuO-ZnO/Al2O3. The products were analyzed and compared through XRD, SEM, BET analysis, and an activity test. The catalyst prepared by the incipient wetness impregnation-combustion urea method (IWI-Urea) showed the highest activity for CO conversion (47%) among the other synthesized products, with CO conversion ranging from 1.3 to 39%, and a commercial catalyst with 8.8% CO conversion. Additionally, the optimum operational condition for the activity test, including reaction temperature, space velocity, and steam-to-CO ratio, was studied on the catalyst with the highest activity (synthesized through the IWI-Urea method). Experimental results also indicated that at lower temperatures, a feed space velocity of 30000 h−1 or higher led to the greatest CO conversions. Steam to CO ratio of 4 was also found to be optimum over the range of experimental conditions employed in this study. Reaction temperature was found to have the most significant effect on CO conversion compared with other operation factors employed in this study.