THE COCURRENT DOWNFLOW CONTACTOR (CDC) - MASS-TRANSFER AND REACTION CHARACTERISTICS IN UNPACKED AND PACKED-BED OPERATION

A C.D.C. device has been developed which gives high gas-liquid mass transfer coefficients (k(L)a) in small operating volumes and short contact times via high interfacial area (1000-1500 m2/m3) and gas hold up (E(g) = 0.5-0.6). This has been employed to advantage in facile catalytic hydrogenation reactions when, with the C.D.C. as a slurry reactor it is possible to largely overcome hydrogenation mass transfer resistance, thus enabling the full activity catalyst to be employed. Preliminary studies have indicated that a similar performance may be obtained using certain packings which will eliminate a catalyst separation problem.