Guide rules for estimating split-fraction coefficients

Guide rules for estimating split-fraction coefficients 

The split-fraction coefficients can be estimated by considering the function of the process unit, and by making use of any constraints on the stream flows and compositions that arise from considerations of product quality, safety, phase equilibria, other thermodynamic relationships and general process and mechanical design considerations. The procedure is similar to the techniques used for the manual calculation of material balances discussed in Section 4.3. 

Suggested techniques for use in estimating the split-fraction coefficients for some of the more common unit operations are given below. 

The split-fractions for the reactants can be calculated directly from the percentage conversion. The conversion may be dependent on the relative flows of the reactants (feed composition) and, if so, iteration may be necessary to determine values that satisfy the feed condition. 

Conversion is not usually very dependent on the concentration of any inert components. The pseudo fresh feeds of the products formed in the reactor can be calculated from the specified, or estimated, yields for the process. 

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