Remote control of reaction rate by radiofrequency heating of composite catalyst pellets

• Published in: Chemical engineering science Vol. 134; pp. 721 - 726
• Main Authors: Zadražil, Aleš, Štěpánek, František
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 29.09.2015
• Subjects: Alumina; Ethanol dehydration; Heat transfer; Induction heating; Reaction on-demand; Ethanol dehydration; Reaction on-demand; Alumina; Heat transfer; Induction heating
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2015.05.055

The vapour-phase dehydration of ethanol over alumina has been considered as a model system for demonstrating a novel concept for the “remote control” of an endothermic catalytic reaction. Control of the reaction rate was achieved by forming composite catalyst pellets consisting of porous alumina with embedded metal (Fe) microparticles. Exposing such composite catalyst pellets to alternating magnetic field in the radiofrequency range (900kHz) resulted in localised heat generation within the catalyst pellets due to induction heating of the iron particles. The effect of the magnetic field power output and reactant flowrate on the steady-state conversion over a differential catalyst bed was systematically investigated. Transient On/Off operation of the reaction was then demonstrated by periodically changing the intensity of the magnetic field and thus controlling the local temperature of the catalyst. This concept enables the reaction product to be formed locally in short bursts, which provides opportunity for process intensification and on-demand synthesis. [Display omitted] •Composite catalyst pellets susceptible to radiofrequency heating were fabricated.•Effect of temperature and flowrate on reaction conversion was investigated.•Transient ON/OFF control of reaction rate was achieved.•The concept of “reaction on demand” was demonstrated.