Computer-aided scale-up of a packed-bed tubular reactor

Abstract

Temperature control is crucial when designing a catalytic tubular reactor for exothermic reactions because hot spots in packed-bed tubes affect conversion, selectivity and lifespan of catalysts. To resolve the hot spot problem, a computer-aided scale-up method combining process modeling software, heat exchanger design software and computational fluid dynamics (CFD) analysis is proposed. The proposed method is composed of three steps as follows: firstly, the length and the number of tubes are determined to achieve a target production rate by the simulations of a single-tube reactor model. Secondly, the detailed geometry of a scaled-up reactor comprising multiple tubes is determined using heat exchanger design software. Finally, optimal operating conditions to control the hot spots are designated by CFD analysis. As a practical application, the method is applied to scaling up the single-tube reactor producing epichlorohydrin to a demonstration-scale reactor comprising 200 tubes so its optimal design and operating conditions are determined.