Experimental study of heat transport in catalytic sponge packings by monitoring spatial temperature profiles in a cooled-wall reactor

• Spatial temperature profiles in catalytic sponges and particle beds upon exothermal reaction.
• Assessment of effects of packing type, material, porosity and pore density on heat transport.
• Conductive heat transfer plays the dominant role.
• Sponge packings are superior to packed beds of particles.
• Strong impact of the thermal conductivity coefficient of the solid material.

The heat transport characteristics of catalytically coated sponge packings and of a packed bed of spherical shell-catalysts were investigated by performing the exothermal hydrogenation of benzene in a tubular reactor with cooled wall. Temperatures inside the catalyst beds were monitored at up to 108 different positions. Steady-state temperature distributions in the catalyst beds were used to elucidate effects of support type and, in case of sponges, of pore density, porosity and thermal conductivity coefficient on heat transfer. Smoothed temperature profiles and reduced hot spot temperatures at equal operation conditions and, in particular, at states of equal over-all heat production by reaction are indicative of enhanced heat transport to the cooled reactor wall. The results show that sponge packings exhibit better heat transfer properties than packed beds of particles. When sponge supports are compared among each other, the thermal conductivity coefficient of the solid material was found to have the strongest impact on heat transfer.