The Differential Recycle Reactor for Efficient Kinetic Measurements in Heterogeneously Catalyzed Gas–Liquid Reactions

Abstract

Obtaining reliable kinetic data for heterogeneously catalyzed gas–liquid reactions under industrially relevant conditions is difficult because conventional laboratory reactors often provide limited control over hydrodynamics and yield little kinetic information per experiment. This work presents a differential recycle reactor (DRR) for rapid kinetic measurements in gas–liquid fixed-bed catalysis. The reactor enables controlled gas and liquid flow through the catalyst bed, operation at elevated temperatures and pressures, and time-resolved kinetic data from a single batch experiment. Two reactor designs were developed and evaluated based on bed structure, fluid distribution, and suitability for kinetic analysis. Model-based sensitivity studies identified operating windows in which the DRR approaches ideal batch-reactor behavior, enabling accurate kinetic evaluation with a simplified batch model. The predicted behavior was validated experimentally through an industrially relevant core hydrogenation. The results show that the DRR is a practical method for efficient macrokinetic measurements under realistic operating conditions and is suitable for routine kinetic studies and future coupling with online analytics.