Design and operation of a radio-frequency heated micro-trickle bed reactor for consecutive catalytic reactions

A radiofrequency heated micro-trickle bed reactor with two adjacent thermal zones was designed. In the first thermal zone, citronellal is converted to isopulegol over a H-ZSM-5 catalyst at 80°C. This is followed by the second thermal zone where hydrogenation isopulegol to menthol occurs over a Pd/TiO₂ catalyst at 70°C. The two catalytic zones are separated by heating zones made of nickel ferrite particles that produce heat under radiofrequency field at 180kHz. The position of the catalytic zones was determined based on a one dimensional heat transfer model, in which the actual flow pattern was approximated. Such configuration allows achieving desired temperatures in the catalyst beds whereas the inlet and outlet gas temperatures are close to ambient temperature which increases energy efficiency of the system. The overall product yield was increased by 9 times as compared with a single thermal zone configuration.