How We teach: Unit Operations Laboratory

One of the truly distinctive elements of a chemical engineering undergraduate experience is working with larger-scale process equipment in a laboratory setting. Unit Operations courses seek to expose students to the type and scale of equipment they are likely to see in industry and to equip them with the ability to analyze the behavior of these systems as well as have a true “feel” for how they work (or don’t work quite as expected). For the 2017 survey, the AIChE Education Division Survey Committee focused on the laboratory portion of the chemical engineering undergraduate curriculum. Over 70 programs completed the survey, which asked about course structure, hours, and experiments. The typical undergraduate takes one or two laboratory-focused courses within chemical engineering, completes experiments as part of a team, and has at least some exposure to pilot-scale equipment. Virtual experiments make up about 10% of control system experiments and are otherwise relatively uncommon. This paper reports on the survey’s key findings as well as some of the highlights of innovative laboratory experience and pedagogy discussed in the results. Introduction This paper presents the results of the ninth survey since the reconstitution of the AIChE Education Division Survey Committee in 2009. These surveys seek to define the state of the art in a given area of undergraduate chemical engineering instruction. Departments use survey results to inform curricular discussions and benchmark their program against national trends. Survey results are also useful for instructors as they select topics, software, and instructional approaches for their courses. Past surveys have considered first-year programs [1], Kinetics and Reactor Design [2], Material and Energy Balances [3], Capstone Design [4], Electives [5], Transport [6], Process Control [7], and the curriculum as a whole [8]. In the coming survey cycle, the survey committee will be considering chemical engineering thermodynamics and thereafter loop through the proceeding topics. While each instructor may have a clear concept in mind when they say “instructional laboratory” or “lab,” the activities and educational outcomes associated with these experiences vary so widely that it’s easy to be misunderstood. The term “lab” may be applied to learning experiences that are replications of precise instructions, discovery-based experiences, simulations, or programming; they may occur from benchtop to pilot scale; they may imply a different activity every week or a single semester-long project. United States Department of Education guidelines suggest that the credit hours for lab is typically one half of the credit hours accorded for the same contact hours in class [9], implying that there is a precise distinction between lab and lecture that may have eroded in an age of active learning and readily available computing. For the purposes of this survey, the definitions shown in Table 1 were used to characterize “laboratories” and associated terms. Respondents were asked to restrict their answer to courses taught by the department, therefore laboratories taught within chemistry and physics are not included in this work. The survey committee explicitly did not bound the activities that constitute “lab” but relied on each department’s own judgement. Table 1: Definitions Term Operational Definition Laboratory A setting where students are primary actors in experimentation, design, operation, and/or control of equipment. Data collection is a key aspect of a laboratory experience. Courseassociated lab A laboratory that is typically taken concurrently with a particular course; for example “organic chemistry 1” and “organic chemistry lab 1”. These may be courses that students register under the same or different course numbers. Independentlab-course or lab course A course whose primary mode of instruction is laboratory. This should be reflected in the relative distribution of laboratory to lecture hours. This course may not be associated with concurrent registration in a specific lecture course. “Unit Operations Lab” or “Junior / Senior Lab” are common examples of this type of course. This survey is primarily focused on courses of this type. Clinic An integrative experiential hands-on-course that serves as the experimental lab for all other courses taken that semester. This survey is not focused on experiences of this type. Lab / Bench / Pilot Scale The definition of what constitutes “pilot” scale varies by industry and type of product. For the purposes of this survey, we will define “pilot” scale as one with working volumes significantly in excess of those one would typically encounter in a chemistry undergraduate laboratory If students are working with equipment that operates at a scale of the order of 1-100+ L, that will be considered “pilot” for purposes of this study. There is broad agreement in the sciences and engineering that laboratory instruction is an essential element of undergraduate education. At the same time, physical laboratories require significantly more space, money (for consumable materials and equipment), and instructional personnel than lecture-based courses. Significant prior work has been devoted to characterizing the educational outcomes from laboratories that justify this additional investment [10–16]. A significant portion of the present study focuses on characterizing the educational objectives of chemical engineering lab and its assessment. The last published survey on unit operations laboratory in chemical engineering was published by Woods and Patterson in 1978 [17], as part of the activities of the first Survey Committee (1957-1994). Methods An email invitation was sent to all members of the chemical engineering chairs list (173 schools). Of these, 70 degree-programs responded to at least part of the survey and form the numerical basis for the data set. In some summaries, the total number of responses is less than 70 because not every respondent chose to address every question. After the online survey, preliminary results and analysis were presented at the 2017 AIChE Annual Meeting, which was followed by a small-group discussion of the topic with AIChE attendees. This paper represents a more complete analysis of these results as well as reflections drawn from the discussion.