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In-Depth Information
Figure 10.4
Component relative yield specifications.
produces the same results as Example1, which demonstrates that the yield distribution
is independent of the numerical values of the yields, but merely on the component
ratios. This is easily verified by temporarily changing the yield data in RYieldExam-
ple1, executing, and comparing results to those in the file RyieldExample1.txt, which
is based on the original specifications.
The same set of reactions is used to demonstrate the component mapping option
of the RYield block. No reaction stoichiometry is employed. A reaction can be char-
acterized as lumped, in which case a list of reactants are lumped together to form
a specified product. Each of the reactants is assigned a coefficient which defines the
weight fraction of the reactant converted to the product.
When a reaction is characterized as delumped, the reactant selected produces a
specified list of product components, and similar to lumping, each product is assigned
a coefficient which represents the weight fraction of the reactant that is converted to
each product. An example of the use of the component yield option may be found
at Examples/RYieldExample2. Figure 10.5 shows the implementation of component
mapping for the benzene chlorination example. Selecting a reactant and choosing Edit
permits selection of the lumping or delumping coefficients.
In both block options selection of inconsistent yield factors or component mapping
factors may produce material balance discrepancies. In this case, Aspen Plus normalizes
the results to maintain the material balance while maintaining the component ratios
calculated.
10.3 REquil BLOCK
The REquil block is used when the reaction stoichiometry is known and some of
the reactions reach chemical equilibrium. Additionally,
the block imposes phase
