Predicting the performance of emulsion polymerization reactors

The commercially used emulsion polymerization reactors (stirred-tank and continuous-loop) are designed to achieve perfect mixing. As will be discussed in Section 6.4.5, perfect mixing is not always achieved. Nevertheless, this flow model allows a good prediction of the emulsion polymerization reactor performance with a moderate mathematical effort, and it will be used here. Macroscopic balances (i.e., considering the reactor as a whole) are used. For the sake of generality, inlet and outlet streams are included in the balances. Both terms should be removed for batch operation, the outlet term should be eliminated in semibatch and both maintained in continuous processes. 

Equation 6.49 applies for the monomers, initiator, water, emulsifier and moles of each monomer incorporated into the polymer. Equation 6.49 also applies to the number of polymer particles, precursor particles and the moments of the MWD. The specific forms of the net generation rates were discussed in Section 6.3.2. Usually, the polymerization rate of monomer j is expressed as rate of monomer consumption (Rpj), and hence Rmj - pj  

For heat removal through the cooling jacket, Qremoval is given by  

The overall heat transfer coefficient includes several resistances in series, but the internal resistance usually controls the heat transfer rate. The internal heat transfer coefficient is a function of several factors as the impeller type and dimension, impeller speed, reactor diameter and physical properties of the reaction mixture. It can be calculated by means of empirical correlations based on dimensionless groups [80]. 

A practical method to determine the heat transfer through any cooling device is to measure the flow rate, and the inlet and outlet temperatures of the coohng fluid  

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