Introducing Pollution Prevention and Life Cycle Analysis through Popcorn

An important aspect of sustainability is preventing environmental pollution, yet many consumers overlook the implications of food packaging. A significant concern is that many paper and cardboard food containers are coated with "forever chemicals." These chemicals create a barrier against oil but complicate recycling and reuse, resulting in increased waste. Based on the curriculum, chemical engineers are well-equipped to handle this challenging problem.

One important tool for chemical engineers in evaluating sustainability is Life Cycle Analysis (LCA). This analytical method assesses the environmental impacts of a process from beginning to end, incorporating frameworks like cradle-to-gate (from raw materials to production) and cradle-to-grave (from production to disposal). Through LCA, engineers can evaluate material and energy flows, allowing them to select environmentally friendly materials, minimize energy use, and enhance process efficiency. The insights gained from LCA help in designing processes that minimize environmental impact and promote responsible resource use. Topics like pollution prevention and sustainability are not commonly covered in school curricula. Our aim is to engage and educate students on these topics to bring awareness to this cause as well as to motivate them to pursue engineering as a career so they shall develop the skills and knowledge to tackle such large-scale global problems.

We achieved this using a popular snack like popcorn. Four methods for popping corn were compared: a Hot Air Popper, Microwave, Movie Theater Machine, and a stove with a Jiffy Pop container. The Hot Air Popper and Movie Theater Machine allow users to pour in kernels directly, opposed to the Microwave and Jiffy Pop which relies on prefilled bags and aluminum containers. While the convenience of microwave popcorn is appealing, our experiment highlighted the importance of evaluating each method's environmental footprint. During the experiment, students used a wattmeter to measure the energy consumed by each technology. They then compiled data to perform a streamlined LCA, assessing metrics such as energy used, time taken, waste produced, as well as taste. This practical application of LCA helped them determine which method was more sustainable. Additionally, the experiment included a discussion on the science behind popping popcorn. Students learned about the three primary heat transfer principles which were conduction, convection, and radiation. In the Hot Air Popper and Movie Theater Machine, heat is transferred through convection as hot air circulates around the kernels. Jiffy Pop used heat transferred from a hot surface through the aluminum pan that heats the oil. Finally the oil heats the kernels until the explode or pop. In contrast, the Microwave uses electromagnetic radiation to excite water molecules within the popcorn, generating heat that causes the kernels to burst. Understanding these scientific principles enriched the students' overall learning experience. At the conclusion of the experiment, students evaluated all four methods, considered the waste generated, energy used, and tasted the popcorn produced from each technique. This reinforced their learning about LCA, sustainability, and pollution prevention. Introducing these important chemical engineering concepts early in their academic careers will invite them to consider sustainable practices in their futures.