Liquid-solid mass transfer for cocurrent gas-liquid upflow through solid foam packings

This article presents the liquid-solid mass transfer characteristics for cocurrent upflow operated gas-liquid solid foam packings. Aluminum foam was used with 10, 20, and 40 pores per linear inch (PPI), coated with 5 wt % Pd on -alumina. The effects of gas velocity (ug = 0.1-0.8 m m s-1) and liquid velocity (ul = 0.02 and 0.04 m m s-1) are studied using the Pd/Bi catalyzed oxidation of glucose. The volumetric liquid-solid mass transfer coefficient, klsals, is approximately the same for 10 PPI and 20 PPI solid foams, ranging from 2 × 10-2 to 9 × 10-2 m m s-1. For 40 PPI solid foam, somewhat lower values for klsals were found, ranging from 6 × 10-3 to 4 × 10-2 m m s-1. The intrinsic liquid-solid mass transfer coefficient, kls, increases with increasing liquid velocity and was found to be proportional to u. Initially, kls decreases with increasing gas velocity and after reaching a minimum value increases with increasing gas velocity. The values for kls range from 5.5 × 10-6 to 8 × 10-4 m m s-1, which is in the same range as found for random packings and corrugated sheet packings.