Development of Novel CuO/ZnCO3/Al2O3 Catalyst for Enhanced Methanol Synthesis in a Slurry Reactor
[Thesis]
Ye, Lujie
Lee, Sunggyu
Ohio University
2019
125 p.
Ph.D.
Ohio University
2019
A carbonate modified catalyst CuO/ZnCO3/Al2O3 for catalytic synthesis of methanol from syngas was successfully devised and developed applying a novel condensed-phase reactive modification technology to a commercial CuO/ZnO/Al2O3 catalyst. This modified catalyst was also experimentally investigated in a fully continuous, proof-of-concept mini-pilot scale system for a process engineering study of syngas-to-methanol process in a mechanically agitated slurry reactor (MASR). The preliminary experimental results have revealed that (1) the modified catalyst exhibits a good potential to maintain the initial catalytic activity for a prolonged time in a typical methanol synthesis reaction environment; (2) the catalyst exhibits high CO2 tolerance and significantly enhanced methanol productivity for the CO2-rich feed syngas; and (3) the catalyst possesses an enhanced particle attrition and mineral leaching resistance. This study has also shown that 1) supercritical carbon dioxide is an excellent medium and effective reactant to selectively convert CuO/ZnO/Al2O3 to CuO/ZnCO3/Al2O3; 2) the modified catalyst exhibits a reduced CuO crystallite size, and a larger specific surface area when compared with the original unmodified catalyst; 3) the ZnCO3 modified catalyst provides a better resistance to mechanical attrition of fine catalyst particles during reactor operation; and 4) the modified catalyst shows substantially enhanced anti-leaching characteristics for all catalyst component metal species against both water and slurry medium of high-boiling mineral oil. The current concept of pre-reduction modification of the catalyst enables the modified and reformulated catalyst to be commercially mass-producible as a stabilized form of the catalyst, which was not possible with the post-reduction modification technology.