Page 228 - Sustainability in the Process Industry Integration and Optimization

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9.5.4 CHEMCAD
The CHEMCAD software tool for simulating chemical processes
includes libraries of chemical components, thermodynamic methods,
and unit operations (Chemstations, 2009). Its purpose is to facilitate
the simulation of steady-state continuous chemical processes from
laboratory-scale experiments to full-scale operations; see Figure 9.8
for the user interface. This software package has recently been
upgraded to allow for the dynamic analysis of flowsheets. It offers
operability assessment, proportional integral derivative (PID) loop
tuning, and operator training as well as online process control and
soft-sensor functionality. Models for nonstandard unit operations
can simulate the behavior of a process under varying feed rates,
product rates, temperatures, pressures, and compositions.
The program contains the 1500-component Design Institute for
Physical Property (DIPPR) database as well as a separate, user-
defined database. Components are selected by ID number, formula,
synonym, or class. The program also includes routines for predicting
the properties of components not included in the database. Crude oil
feeds may be characterized by American Society for Testing and
Materials (ASTM) or true boiling point (TBP) curves and then
represented in the simulation by a series of pseudocomponents (cuts)
with different boiling points.
The flowsheet representing the plant layout is input graphically,
and data describing each feed stream and unit operation is entered
via pull-down menu options. Automatic error checking is used to
preclude overspecification or missing data entries. The interactive
interface also permits individual unit operations to be run separately

FIGURE 9.8 CHEMCAD software interface.