Utilization of a two-phase reactor with pre-saturator for multiphase reactions

In common multiphase reactors (trickle-bed, slurry reactors) mass transfer resistances frequently lead to a strong decrease of the effective reaction rate compared to the chemical (intrinsic) rate [1]. In addition, many multiphase reactions like oxidations or hydrogenations are highly exothermic. So heat removal is difficult, and at least in case of trickle-beds an expensive recycle of the gas phase is frequently installed [2]. A new concept to avoid these problems is the so-called two-phase reactor with pre-saturator. In this case, the liquid phase is externally saturated with the gaseous reactant in a pre-saturator and subsequently fed to the catalytic fixed bed reactor (see Fig. 1). If needed, the liquid has to be (partially) recirculated to limit the temperature rise in the reactor; heat removal is then conducted in a heat exchanger within the liquid loop (see Fig. 1). The liquid recycle is also needed, if an insufficient gas solubility has to be compensated to assure a high degree of conversion of the liquid reactant. © 2004 WILEY-VCH Verlag GmbH and Co. KGaA. Weinheim.