Kinetic analysis of dehydrogenation reaction of cyclohexane catalyzed by Raney-Ni under multiphase reaction conditions

• The kinetics of dehydrogenation reaction of cyclohexane was studied.
• The nature of “wet–dry” multiphase reaction was discussed.
• The dynamic energy balance control is important to the multiphase reaction system.
• The conversion of cyclohexane was up to 72.7% and purity of evolved H2 was 100%.

The kinetics of dehydrogenation reaction of cyclohexane catalyzed by Raney-Ni under “wet–dry” multiphase reaction conditions was studied in this paper. The influences of the heating temperature, feeding amount of cyclohexane and catalyst dosage on conversion of cyclohexane, apparent rate constant of reaction and retardation constant for aromatic product were investigated systematically. The experimental studies indicate that the control of the dynamic energy balance of reaction system is very important, there exists an optimal energy balance point in “wet–dry” multiphase reaction system, which depends on the combined action of heating temperature, feeding amount of cyclohexane and catalyst dosage. It was found that, with 0.5 ml cyclohexane feeding amount and 7 g catalyst dosage, at 320 °C the reaction system approached its optimal energy balance point, and the dehydrogenation conversion of cyclohexane reached its highest value of 72.7%.