Integrating Risk Assessment in the Unit Operations Laboratory

In light of the practical needs of the chemical engineering discipline and the new AIChE/ABET program criteria requiring knowledge of process hazards, we are developing strategies for making process safety a student mindset by integrating risk assessment in our unit operations laboratory and design courses. We believe that with the early, practical, and direct exposure to risk assessment in the laboratory, students can later approach process design with increased appreciation for the value of considering process hazards and will be knowledgeable and experienced in the evaluation of hazards and risk in their work. In our approach, each group in the unit operations course is asked to perform a simplified Process Hazard Analysis (PHA) of a laboratory process before working on the experimental stand. Our units include small-scale and pilot-scale distillation columns for the separation of alcohol mixtures, an absorption column involving sodium hydroxide solutions, and an extraction column for the removal of propionic acid from kerosene. Students are required to construct an accurate flow diagram of each stand, consider general precautionary measures and operating limits for the process, perform “what if” analyses, take note of materials of construction and chemical compatibility for equipment components, identify physical properties of materials and their key safety data, and provide recommendations and a list of action items for future consideration. Compilation of a simple PHA in the succeeding process design course provides additional experience to the practice and reiterates its relevance in the planning and design stages. This is an approach that we expect to successfully address the new requirements of the AIChE Program Criteria; moreover, we expect that our students will graduate with abilities in process hazards analysis that will be of benefit in the workplace.