(416f) Incorporating Chemcad with Process Design: a Laboratory Method

            Chemical
engineering students who enter industry jobs are finding that companies are
commonly using simulation packages.  For
students at Mississippi State, the use of simulation packages was left up to
the teachers of the individual classes. 
With no standardization, some students graduated Mississippi State with
minimal simulation experience.  With the
realization that a hole existed in the students' education, a new class was
formed as a way to introduce simulation to every student.  A senior design class, Process Design, is
used to teach costing, troubleshooting, and basic principles needed to design
chemical processes and plants.  With the
addition of a one hour laboratory, the simulation package, ChemCAD, could also
be taught.

            ChemCAD is
a common simulation package available to universities and industry.  The program is loaded with features, which
means that a multiple week course is needed. 
The lectures were divided into different topics, to cover as much of the
core chemical engineering curriculum as possible.  To ensure all of the students began at the same place, the course
began with a lecture on using ChemCAD, which included adding components,
drawing a flowsheet, and running the simulation.  The Thermodynamics package within ChemCAD is very involved, so a
two week set of lectures was used to convey the importance of
thermodynamics.  Heat exchangers,
distillation columns, multiple types of reactors, controllers, and component
separators were also taught, with one topic covered per laboratory session.  Two of the biggest features of ChemCAD are
the sensitivity analysis and optimization. 
Sensitivity analysis, or the ability to determine how a process reacts
to a change in operating parameters and design variables, was covered by one
laboratory session.  Optimization, that
helps determine the best values for a given variable, was covered after the
lecture on sensitivity analysis, since sensitivity analysis is necessary to
determine what variables and parameters affect the process.  Finally, other features of ChemCAD were
covered, which included exporting data to Excel, creating and running recycle
loops, understanding and modifying convergence parameters, and producing spec
sheets and environmental reports.

            For the
students to learn how to use ChemCAD and the nuances of the program, homework
was assigned each week.  As an example,
the thermodynamics package consisted of two unique homework sets.  The first week used several different
mixtures, such as isopentane and n-pentane,
propane and benzene, and MIBK and water. 
These mixtures were graphed using multiple different models, to
demonstrate that what works for one compound will not work for another
compound.  The second week consisted of
a problem that resulted in ChemCAD's thermodynamics wizard choosing an
incorrect thermodynamic model.  The
students then had to identify which model would be most accurate for the system
being designed.  Homework was also
assigned for the other lectures, with some of the homework used to help the
students understand sensitivity analysis and optimization.  At multiple times during the semester,
projects were given that were designed to incorporate material from the Process
Design class and the laboratory.

            Since
ChemCAD has many features and unit operations that could not be covered, the
laboratory's purpose was to teach the students to use ChemCAD and troubleshoot
homework and design projects.  The
expectation is that the students will be prepared to use ChemCAD in their
industry jobs.