Kinetics and Product Selectivity (Yield) of Second Order Competitive Consecutive Reactions in Fed-Batch Reactor and Plug Flow Reactor

This literature compares the performance of second order competitive consecutive reaction in Fed-Batch Reactor with that in continuous Plug Flow Reactor. In a kinetic sense, this simulation study aims to develop a case for continuous Plug Flow Reactor in pharmaceutical, fine chemical, and related other chemical industries. MATLAB is used to find solutions for the differential equations. The simulation results show that, for certain cases of nonelementary scenario, product selectivity is higher in Plug Flow Reactor than Fed-Batch Reactor despite the fact that it is the same in both the reactors for elementary reaction. The effect of temperature and concentration gradients is beyond the scope of this literature. 1. Introduction Reactions in pharmaceutical (API—Active Pharmaceutical Ingredients and Drug Intermediates) and fine chemical industries are known for their complexities. Competitive consecutive reactions with intermediate product as the desired product are common in these industries. Many such reactions are conventionally carried out in Fed-Batch (semi-batch) mode, wherein one of the reactants is taken in a batch reactor and the other reactant is added over a period of time ( , in second, s) onto the reactant in the reactor, and maintained for a specific period of time, (s), till the reaction gets completed. Any choice between the types of reactors, if accompanied by improvement in product yield, will be industrially significant. 2. The Reaction System The following type of reaction system is a representation of second order competitive consecutive reaction: A, B, R, S, C, and D are various species involved in the reaction. R—Desired Product; S—Undesired Product. It should be noted that the species mentioned in the representative chemical equation (1) are not the only chemical components present in the reaction system. Most of the times, the reaction system would additionally have one or more solvents. The general pattern of concentration-time profile of competitive consecutive reaction of the type shown in (1) in an ideal batch reactor is given in Figure 1 [1], which shows that if all the 0 Figure 1: Concentration as a function of time. eactants are introduced into the reactor at reaction condition, the concentration of the desired product R initially rises and goes through a maximum, and then it reduces, whereas the concentration of undesired product S keeps rising with time. The concentration of reactants continuously decreases and will become zero at infinite time. As is the case with many industrial operations in Fed-Batch Reactor, when we