Manipulation of Bulk Reactions in Multiphase Systems by the Use of Microheterogeneous Media

Abstract

It is well known that the rates of fast, multiphase reactions, that occur in the diffusion zone near the interface, may be enhanced by the use of an additional, emulsi® ed phase, which shows a high af® nity for the rate limiting solute. However, the effect of such an additional phase on the rate behaviour of systems where slow reaction occurs dominantly in the bulk, well mixed region has not been assessed so far. This effect can be of great signi® cance, especially in situations, where the reaction kinetics depend upon the reactant concentration in a complex way (e.g. substrate inhibition) and may be of particular importance in biochemical systems. In this study, the conversion behaviour of a model steroid system, namely, the biphasic, enzymatic conversion of testosterone in a batch reactor, has been explored in the presence of an emulsi® ed oil phase. The kinetic rate of reaction of this species displays a maximum with respect to its concentration. It has been shown that the presence of an emulsi® ed liquid phase can improve the substrate conversions signi® cantly and that the extent of such an improvement depends upon the solubilizing capacity of this phase as well as its hold-up. The use of a microheterogeneous media, in lieu of a plain reactive liquid, can therefore be used to drive the reactor towards optimal behaviour with a view to maximizing the substrate conversions.

Mathematical analysis of solid–liquid mass transfer in a batch reactor for the enzymatic transformation of testosterone to 4AD

“…The resulting formulation is then the same as that of the conventional theories of mass transfer with chemical reaction. An analysis of the system at hand for such cases may be found in Patel and Mehra (1999).…”

The kinetics and thermodynamics of a novel efficient mixed water–1,4‐dioxan solvent for the effective complexation of a neutral ruthenium complex with carbon monoxide at atmospheric pressure

“…The rates of fast multiphase reactions occurring in the diffusion zone near the interface can be enhanced [10] by the use of an additional emulsified phase, which shows a high affinity for the rate-limiting solute. Microheterogeneous medium significantly contributes to the manipulation of bulk reactions in multiphase systems.…”

“…(9) and (10), respectively. [Ru] T = [RuCl 2 (PPh 3 ) 3 ] + [RuCl 2 (PPh 3 ) 2 (S)] (9) [PPh 3 ] T = [RuCl 2 (PPh 3 ) 2 (S)] + [PPh 3 ] added(10) …”