(134a) Scalable, Hands-on, Problem-Based Learning in Unit Operations Lab to Improve Student Problem-Solving Skills

The benefits of hands-on, problem-based learning have been well documented in the literature, but implementation of such pedagogical practice is often difficult in typical chemical engineering curricula. The origins of the difficulty include institutional pressure to reduce time to graduation, lack of space, cost, large enrollments, and safety concerns. This presentation explains how a safe, hands-on, problem-based learning project was added to a typical senior-year Unit Operations Lab for moderate cost, without increasing credit hours, and in a way that is scalable to an arbitrary number of students.

The purposes of this lab are to give students practice solving a more open-ended problem than is typically found in the curriculum and to improve engineering intuition about real systems over what is obtained from book work or other labs. Concerning the former, the problems presented 1) require meeting multiple competing design constraints, 2) have many possible solutions, 3) allow real possibility for failure, 4) require learning new skills not taught in previous courses, and 5) require choices to be made at every stage of the process from initial planning to final reporting. Concerning the latter, students come to realize the skills and time needed by those who build real systems, gain firsthand knowledge of flow system behavior, and come to understand the interplay between different subsystems and pieces of equipment.

During this experience, student build a pilot-scale flow system involving pumps, pipes, flowmeters, valves, tanks, pressure transducers, etc. to meet specified design constraints. Multiple sizes and types of each piece of equipment are available, and students are required to satisfy the design specifications—which include flowrate maximums, costs, space constraints, total length of pipe, etc.—using these materials. There are many ways to satisfy the design goals, but students seek to do so using the most efficient system possible. Moreover, they must prove their choice is an optimal solution to the problem and share this proof in their written reports.

This presentation will describe the hands-on, problem-based learning project in more detail. It begins with an overview of the learning outcomes for the project. This is followed by a discussion of the problem statements presented to students and an explanation of the equipment and space available to the teams. Examples of student projects are then presented. Finally, survey-based data on the value of this pedagogical approach are presented. These surveys, taken by 85 students from 6 different sections taught since 2013, include responses of students obtained just after the class was taken and again after the students have taken the second half of Unit Operations Laboratory. Survey results are also presented from alumni (N=51) who took the course and are now working in industry or are in graduate school. All the data demonstrate the very high value that students place on the experience both during and after the course. Taken as a whole, the results reconfirm that hands-on, problem-based learning is a very effective pedagogical approach. More importantly, the work shows that the method of implementation is scalable and can be incorporated into most current curricula for moderate monetary and space costs.