Simultaneous Catalytic Removal of NOx, SOx, and CO from FCC Regenerator

Abstract

Simultaneous catalytic removal of NOx, SOx, and CO under simulated FCC regenerator conditions was investigated over mixed oxide catalysts CuMgAlO (Cu-cat), CeMgAlO (Ce-cat), and CuCeMgAlO (CuCe-cat), which were prepared by coprecipitation and characterized by XRD, XPS, and N2 adsorption−desorption. At low temperatures (<340 °C), the presence of O2 or H2O enhanced the activity of CuCe-cat for NO and CO conversion but significantly suppressed the activity of Cu-cat and Ce-cat. At high temperature (720 °C), the presence of O2 or H2O had no adverse effect on the NO and CO conversions over these catalysts. However, the presence of SO2 in the feed deactivated Cu-cat and Ce-cat drastically while no deactivation of CuCe-cat was observed. The enhanced performance of CuCe-cat can be explained by a synergistic effect between copper and cerium ions, which results in the formation of large amounts of Cu+ ions and oxygen vacancies. Thermogravimetric studies show that this catalyst exhibits excellent performance for SOx adsorption in the SO2 + O2 system and can effectively release the adsorbed SOx in H2 + Ar atmosphere.