Purdue EEE grad students came home with 1st and 2nd place awards from the American Center for Life Cycle Assessment (ACLCA) 2024 conference last month! Catherinne Mejia Melara won first place in the student poster competition, with Elizabeth Kelley in second. Their posters showcased research using life cycle assessment in conjunction with their masters’ theses.

The EPA defines a life cycle assessment (LCA) as “a tool that can be used to evaluate the potential environmental impacts of a product, material, process, or activity. An LCA is a comprehensive method for assessing a range of environmental impacts across the full life cycle of a product system, from materials acquisition to manufacturing, use, and final disposition.”

The application of LCA data can be as specific as one single pencil, or broadly assess an entire industry sector. Catherinne and Elizabeth’s projects are a good example of these possibilities within LCAs.

(Catherinne Mejia Melara (left) and Elizabeth Kelley (right) pose with Heather Liddell (center) in front of their winning posters. Photo Credit: Heather Liddell)

Elizabeth is looking at a physically extended environmentally extended input-output analysis (EEIO) model. Typical EEIO models report emission factors in monetary terms (kg CO2e/$). By physically extending data from an EEIO model, Elizabeth can show emissions in more precise and rigid terms. The metrics and data extrapolated from her model show emissions and environmental impact on a large scale, which according to her, is key to improving our nation’s sustainability.

“Because the dollar is so volatile, we don't have a great understanding of the emissions involved in each subsector. So, having it on a mass basis, like kilograms of CO2 or metric tons, provides that rigidity we need to really understand what’s going on in each subsector,” Elizabeth says.

In contrast, Catherinne’s project showcases LCA’s precise capabilities. She is conducting a process based LCA on drying alfalfa for dairy cows. Industry standard methods for drying alfalfa consume large amounts of time and energy. Catherinne is comparing this process with a new, quicker, more nutritious method of drying using Optimized Radio Frequency drying. Catherinne has been surprised by her results and what she has learned about the expansive nature of LCAs.

“The whole point of doing an LCA is, yes, to measure the inputs, like energy and resources used, and then the emissions from that energy consumption, but we consider every stage of a product’s life. If we have alfalfa that is more nutritious and digestible, it's going to have a positive impact on the digestive process of the animal, and that will impact the emissions like methane gases from the cow. Initially, a product might use more energy, but have less emissions overall.”

Catherinne and Elizabeth’s projects shed light into the breadth and depth capable through LCAs. It is evident though their awards at ACLCA that the growing field needs bright, hardworking researchers like them. Despite their own hard work, both students credit their achievements in part to their advisor ME/EEE professor Heather Liddell.

We echo professor Liddell who remarked on LinkedIn, “Congratulations to my amazing grad students Catherinne and Elizabeth … Way to represent Purdue University Environmental and Ecological Engineering and our lab! I could not be more proud of you and your hard work!”