SEMIPAR - Parallel Reactions in a Semi-Continuous Reactor

1 SEMIPAR - Parallel Reactions in a Semi-Continuous Reactor 

A semi-continuous reactor is used to carry out the parallel reaction shown below. It is of interest to investigate how the amount of desired product, P, depends on the differing orders of the two reactions and on the feeding rate. 

Set nAi = oa2 and bi obi- Run the reactor in two ways semi-continuously with slow feeding of B and as a batch reactor with all of B initially in the reactor. Compare and explain the differing amounts of desired product P, obtained. 

Study the semi-batch case ubi riB2 for various constant feed rates. 

A semi-continuous reactor is used to carry out the following parallel reaction, where P is valuable product and Q is unwanted waste. The problem is to optimise the feed strategy to the reactor such that the maximum favourable reaction selectivity is obtained, for similar systems but of differing kinetic rate characteristics 

5 Simulation Tools and Examples of Chemical Engineering Processes 

The relative magnitudes of the orders of reaction, nei and nB2. determine whether the concentration Cb in the reactor should be maintained at a high or low level. For optimum selectivity, the total reaction time must be adjusted such that P is obtained at its maximum concentration as affected by the rate at which B is fed to the reactor. 

Note that at high rates of feeding, the maximum reactor volume may be reached before the simulation time is complete. Under these conditions, the feed of B to the reactor will stop. The reaction then continues batchwise until the simulation is complete. 

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