PARTIAL WETTING OF CYLINDRICAL CATALYTIC CARRIERS IN TRICKLE-BED REACTORS

The use of a modified Thiele modulus, as a correlating parameter for p artially wetted catalyst pellets, is compared with the exact solution of the diffusion and reaction problem. The study of a variety of parti ally wetted cylindrical catalyst pellets for first- and second-order k inetics indicates that the manner in which particles are externally we tted does not significantly influence the value of the effectiveness f actor External and internal partial wetting of industrial-size porous extrudates is determined in a bench-scale hydrotreater at real hydropr ocessing conditions by simulating the system response to a step change of feed using the sulfur compounds of a petroleum fraction as tracer molecules. To solve the corresponding mass balances in the interpartic le and intraparticle domain, two different numerical methods are compa red.