The cocurrent downflow contactor–a novel reactor for gas‐liquid‐solid catalysed reactions

Abstract

AbstractThe Cocurrent Downflow Contactor (CDC) has been developed as a mass transfer and reactor device, with and without addition of tangential (swirl) flow, giving gas hold‐up (Eg) values of 0.5–0.75, interfacial areas in the range 1000–6000 m2m−3 liquid and kLa values in the range of 0.15–1.55 s−1 for absorption using the O2/H2O system. It has been studied as a catalytic slurry reactor for the hydrogenation of (i) itaconic acid and (ii) triglycerides catalysed by Pd and Ni catalysts. The reactions were observed to be largely surface‐reaction rate controlled, due to the very efficient mass transfer (kLa up to 11.75 s−1 under reaction conditions) and application of swirl flow‐enhanced reaction rates. The CDC has recently been found to be capable of operating as a fixed bed reactor, thus eliminating a downstream catalyst separation problem (therefore more cost effective), and is superior in its mass transfer characteristics to other known devices. Scale‐up can be undertaken without loss of performance efficiency.