THERMAL-REACTIONS OF TOLUENE BY USE OF A CLUSIUS-DICKEL TYPE THERMAL-DIFFUSION COLUMN AS A REACTOR

Thermal reactions of toluene were investigated in the temperature range from 1290 to 1410 K under atmospheric pressure in a Clusius - Dickel type thermal diffusion column. The main product of the reaction was benzene, the selectivity of which increased with the rise of reaction temperature, reaching over 50% under most of the reaction conditions studied. The reactions of toluene were characterized by two features; the high selectivity of benzene, and a remarkable change in the selectivity of benzene and bibenzyl with the change of toluene conversion. These two features should be attributable to the thermal diffusion and convection, which caused the hydrogen evolved during the reaction to concentrate around the heater, and subjected toluene to hydrogenolysis without adding hydrogen as a reactant. The experimental results with regard to the change in benzene selectivity can be explained qualitatively by the theories developed for the separation column.