(622g) Teaching Residence Time Distribution Concept and Applications through On-Line Active Learning

Residence Time Distribution (RTD) theory and its application in the field of continuous reactor is one of the most concept-integrating and intellectually exciting course to give for a Chemical Engineering teacher. However, it is undoubtedly one of the hardest chemical engineering subject to teach, and more than often drives to a general feeling of disappointment from the lecturer. Its appropriation by the students requires a complete understanding of material balances for both reacting and non-reacting systems, as well as for steady-state and transitory flow systems. Advanced statistics, integral calculation, but also Laplace and Fourier transforms indeed represent a great deal of mathematical tools and concepts to handle properly, even for chemical engineering students approaching the end of their curriculum. The overall understanding by a student of the coupling between chemical reaction kinetics and the flow modeling through inert tracer perturbation requires time, maturation, and more than ever, dedication. This is certainly the reason why conventional ways of teaching, through lectures and classroom exercises, are usually failing in this field, as we have experienced over the past years.

In this work, we will present an active learning scheme that we have been using for two years and for two distinct populations, namely apprentices and students. It takes the form of a role play between groups of alumni and various teachers (or one teacher complying with various roles). Each group is part of an engineering office receiving an order from a customer who needs to comply with a specific conversion objective for its stirred industrial continuous reactor. Of course flow information is lacking, as well as the link between stirrer’s speed and flow structure. Each group will therefore need to build and validate a flow model by defining and ordering RTD runs to an experimental station (in fact, a teacher) possessing the same type of reactors at a much smaller scale. Data back-treatment as well as model breakdown, allow to address customer’s order through a formalized report.

All this is supported by an internet interface that allows exchange of information between groups, as well as the solicitation of an external expert, a role played by another teacher. The importance of the number of hits to the site is an indicator of the dedication and interest of the students. Basic knowledge tests performed at the end of the sequence, allow to validate the level attained by each alumnus. Both teachers and students are expressing their very positive experience of this way of teaching and learn.