Catalytic wet air oxidation with a deactivating catalyst analysis of fixedand sparged three-phase reactors

A comparative analysis is made for a trickle-bed reactor, a packed-bubble c olumn, a three-phase fluidized bed and a slurry-bubble column with an activ e and moderately deactivating catalyst for the wet oxidation at high pressu re and temperature of organic-containing aqueous wastes. Compared to other mature industrial sectors where multiphase reactors are prevalent, the desi gn of three-phase catalytic reactors for wet air oxidation processes is sti ll at an emerging stage. This paper discusses, from a multiphase reactor en gineering perspective, the design of such contactors by setting an exhausti ve modeling framework of catalytic wet oxidation in which the molecular, pa rticle and reactor scales are integrated. The simulation results indicate t hat when wet oxidation is liquid-reactant limited, packed-bubble columns ou tperform trickle beds, whereas slurry-bubble columns are the most vulnerabl e to "coke" deactivation. (C) 2001 Elsevier Science B.V. All rights reserve d.