(202f) A Process Systems Approach to Teaching Distillation

First principles modeling is a valuable instructional tool to help undergraduate chemical engineering students understand how a process works. Distillation is perhaps the most difficult process for students to understand. In this work, a methodology where distillation is approached from a process systems point of view is presented. This approach was implemented in a unit operations distillation lab where students were required to build a first principles model of the process, which they would later use in optimization to maximize the revenue of a hypothetical chemical plant. From a pedagogical point-of-view, a systems engineering approach is beneficial to students as it requires them to gain an intimate understanding of the process through modeling and allows them to develop basic skills in optimization. Furthermore, a systems-engineering approach allows students to see the full scope of the process, while incorporating lab results through model parameter estimation and constraint identification.

The student’s response to an open-ended versus a well-defined assignment is also studied. It is observed that, while the open-ended assignment is more difficult and time consuming, the understanding gained by this exercise is far greater. Additionally, this type of assignment compels the student to exercise more creativity and take a higher amount of ownership in the project, resulting in projects that are of higher quality and more diverse. In order for assignments of this nature to be successful, the proper balance must be established between keeping the assignment open-ended while giving students enough background information and guidance for the student to be successful.

In this work, evidence is presented comparing essentially the results from two semesters, one in which the assignment is predominantly instructor-directed, and another in which the assignment is largely student-directed. Although purely qualitative, evidence indicates that the student-directed methodology generally results in higher-quality work and a better learning experience.