(59e) Sustainable Unit Operations Laboratory: Project-Based Learning Incorporating Life Cycle Analysis

Carbon footprint evaluation is one of the standard approaches in estimating the emission of an enterprise or an institution. Most of the life cycle analysis is done for the whole building, and each activity's contribution is recorded and analyzed ¹. They considered all greenhouse gases and expressed all emissions in terms of CO₂ equivalent. These emissions are calculated based on the amount of activity and CO₂ emission intensity. The contribution of individual research activity or undergraduate laboratory teaching is not analyzed separately. The contribution of CO₂ emission from these lab activities is essential to provide best practices or action plans to reduce CO₂ emissions. However, this area has limited research to provide easy and robust approaches to analyzing carbon footprint and drive research and experimentation design. Note that research and educational activity in higher education differs from industrial settings in that the process usually operates at the most efficient point to maximize profits. In higher education, teaching/research activities aim to understand specific processes or fulfill the identified learning outcomes, so operation conditions are often varied and can be less economical.

Teaching laboratories are essential for higher education, providing students with hands-on experience and practical application of theoretical knowledge. However, these laboratories have a significant environmental cost, contributing substantially to energy and gas emissions, water consumption, and waste production. Recognizing this, efforts to minimize the environmental impact of laboratory operations have gained momentum. The Unit Operations Laboratory, in particular, stands out as a pivotal setting for students to not only grasp the theoretical aspects of their field but also to actively engage in sustainability practices. This laboratory, commonly utilized in science and engineering disciplines, allows students to understand the practical implications of their work on the environment and provides a unique opportunity to integrate Life Cycle Analysis. LCA is a systematic approach to evaluating the environmental impacts of a product, process, or service throughout its entire life cycle, from extraction of raw materials to end-of-life disposal. It assesses resource use, emissions, and energy consumption to identify areas for improvement and inform decision-making.

This study presents the case study of bioethanol production via yeast fermentation, incorporating the LCA into undergraduate laboratory problem-based projects. The undergraduate and master's students (taken toward their degree as the lab courses or thesis study) investigated CO2 emission in the existing operations, proposed alternative production pathways, and the subsequent distillation operation conditions. The results contributed to the experimental design of future projects for the undergraduate lab courses. The LCA analysis is conducted based on Scope 1 and Scope 2, following ISO 14040 and 14044 standards, using Defra GHG emission factors for 2022.

With a focus on the environmental impact of laboratory equipment operation, this paper/presentation aligns with global sustainability initiatives, clean energy efforts, and the commitment to achieving net-zero emissions by 2050. The findings show that using different substract can significantly reduce CO₂ emission (ie. refined sugar with yeast for bioethanol production reduces the carbon footprint by half compared to corn syrup feedstock). For the subsequent purification process, simply varying the steam heating pressure for the reboiler can reduce the CO₂ emission by 20-30%, depending on the reflux or flash operating conditions. Since there is variability in laboratory practices across different regions and institutions, international collaboration is necessary to test the robustness and scalability of common unit operations laboratory projects. For future work, collaborative efforts can provide diverse perspectives, validate findings, and contribute to the development of standardized practices in laboratory education. Two institutions, one in Canada and one in the US, worked together to test the LCA approach on four distillation columns, a 20 ft plate and packed distillation column in Canada and 35ft plate and packed distillation columns in the US, and 2 bioreactors of 80 L in another institution and 80 L in another one. Ultimately, this research work contributes to the broader goal of embedding sustainability principles within the educational framework, fostering a generation of professionals equipped with the knowledge and skills necessary to address environmental challenges.