Design of an Industrial-Size Airlift Loop Redox Cycle (ALRC) Reactor for Catalytic Alcohol Oxidation and Catalyst Reactivation

An industrial-size airlift loop redox cycle (ALRC) reactor was designed for the selective oxidn. of alcs. Selective catalytic alc. oxidn. produces valuable products for fine chem. applications, however, the catalyst, Pt/C, undergoes a factor of 10 loss in activity within hours as a result of overoxidn. The catalyst can be reactivated by contacting it with a reducing environment. The modeling and reactor design study shows that the ALRC reactor is a suitable option for achieving alternating contact of the catalyst with a reducing and oxidizing environment. The oxidn. of methyl-a-d-glucopyranoside (MGP) to 1-O-methyl-a-d-glucuronic acid (NaMG) on a carbon-supported platinum catalyst was the model reaction used in the study. The superficial slurry velocity and the inlet partial pressure of oxygen det. the reactor performance. A reactor design was developed on the basis of kinetic, hydrodynamic, and economic considerations, in which the catalyst activity remains high in the reactor. The ALRC reactor was compared with a stirred-tank reactor process involving alternating gas feed streams. The ALRC reactor is more economic in terms of reactor operation than the stirred-tank reactor process and can feasibly be used in selective oxidn. of alcs. while maintaining a high catalyst activity.