Microwave-activated structured reactors to maximize propylene selectivity in the oxidative dehydrogenation of propane

Abstract

Microwave (MW) heating has been applied to increase the selectivity to propylene in the oxidative dehydrogenation (ODH) of propane. The preferential heating of the solid monolith (made of SiC, a good microwave susceptor), allows working with a lower gas phase temperature, reducing the formation of undesired by-products in the gas phase via homogeneous reactions. Conversion levels of ~ 21% and selectivity to propylene up to 70% have been achieved with MW-heated straight channel monolithic reactors coated with a VMgO catalyst. These competitive values contrast with the more limited performance delivered by the same catalytic system when it is subjected to conventional heating in a fixed-bed reactor configuration, thereby corroborating the advantage of working under a significant gas–solid temperature gap to minimize the extent of homogeneous reactions.