Teaching practice on a compact desktop experimental system to enable facile hands-on learning of residence time distribution

Abstract

To enhance student learning outcomes during the teaching of residence time distribution (RTD) theory, a compact open-source desktop RTD measurement device has been constructed for chemical reaction engineering (CRE) education. A safe, miniature CO₂ cylinder serves as the fluid source, and ambient air, which is easily collected in situ, functions as the tracer gas. A Raspberry Pi®–based portable thermal conductivity detector (TCD) is employed as the detector, achieving RTD measurements with sufficient resolution. Low-cost PTFE tubes and put-in fitting connectors are used to easily construct different forms of reactor models for RTD experiments. The total cost of the experimental materials is approximately $200. During teaching practice, students are encouraged to construct the experimental device by themselves, measure RTDs for specified and self-designed reactors, and address a reactor diagnosis problem. The experiment does not require a laboratory setting, allowing students to conduct it at their convenience, anytime and anywhere. Through engaging and practical hands-on learning, students achieve comprehensive educational outcomes. In summary, the desktop RTD measurement device and the associated experimental contents represent an innovative approach in CRE education, addressing the evolving need to train modern chemical engineers with multifaceted capabilities.