ACTIVITY STUDY OF CU BASED CATALYTIC MATRIXES WITH ZNO AND/OR ZRO2 FOR ENHANCEMENT OF CATALYST ACTIVE LIFETIME AND METHANOL YIELD

A series of Cu/ZnO/Al2O3, Cu/ZnO/ZrO2/Al2O3 and Cu/ZrO2/Al2O3 catalysts were prepared for methanol synthesis study in Lurgi process. Apart from Cu and Al2O3, these catalysts would contain ZnO and/or ZrO2 as active Carbon monoxide (CO) hydrogenation sites. The preparation method was an alternative acid-alkali pH precipitation. The SEM-EDX data for the formulations with various atomic ratios showed high homogeneity, hence good intermixing of ingredients. TPR analysis was done on all prepared matrixes and industrial catalyst and showed the reduction temperature of 300 oC to 345 oC for all 3 types of catalysts prepared. Both Low and High Temperature peak obtained for Metal Surface Area (MSA) analysis showed that there is a general decreasing H2 adsorption trend with the increasing amount of Zirconia in the catalyst. Prepared catalyst sample A with no zirconia present showed highest low and High Temperature adsorption in comparison with commercial and prepared catalysts. This suggests that Cu-ZnO catalyst have higher activity as compared to Cu-Zirconia based catalysts. TGA analysis also reveals that prepared catalysts sample has higher thermal stability at Lurgi Operating Temperature of 250oC compared to Industrial catalysts sample. CO conversion study reveals that sample A with no Zr present has highest conversion of up to 4%. Also determined was that Zn offers higher activity in CO hydrogenation process in catalyst samples compared to Zr when present in the same atomic %. Also monoclinic Zr phase formed in catalyst type Cu/ZnO/ZrO2/Al2O3 gives higher MeOH Yield compared to catalyst sample where tetragonal Zr phase is formed. A consistent trend between CH4 formation during activity study and Carbon formation study by CHNS reveals the most likely route for Carbon formation was through CH4 decomposition to form Carbon on catalysts surface sample The analytical kinetic study conducted decided that coverage of O atoms should be 0.5 in the beginning of the reaction in order to maximize the initial rate of reaction..