Abstract:

One way to enhance applied education in universities is through Final Degree Projects (FDP). Choosing topics based on real data that can, in turn, impact education or improve the lives of the population, leads students to experience this academic endeavor as a contribution to society.

The reduction of single-use plastics has posed a significant environmental challenge on the campuses of the Polytechnic University of Catalonia (UPC). This challenge stems from the large amount of waste generated by disposable cups used for hot takeaway beverages, as well as from the difficulties associated with their management and recycling. In response to this issue, the UPC launched the reusable cup service initiative; however, its implementation still faces several obstacles that limit its acceptance.

This project evaluate the environmental impact of the reusable cup service through a Life Cycle Assessment (LCA) and carry out an environmental comparison with disposable cups, to identify opportunities to reduce the environmental impacts associated with hot beverage consumption at the university.

To perform this assessment, the LCA methodology was applied, and two reusable cup service systems were defined. System 1 (S1) was based on the declared lifespan of the cup (200 uses) and a 100% return and recycling rate. System 2 (S2), on the other hand, was based on real data collected from university bars, considering 11 uses per cup and a 20% return and recycling rate. Both systems were compared with a reference system corresponding to paper cups coated with PLA of the same capacity (250 ml), which are currently used in UPC cafés.

The LCA made it possible to identify the stages and systems that contribute most to the environmental impact, revealing that S1 based on hypothetical consumption and return data has a lower impact than S2, which is based on real data. In S1, more than 93% of the impact comes from the use phase, while in S2 the greatest impacts are concentrated in the production phase, ranging from 14% to 93%, depending on the impact category.

This difference highlights the importance of the return rate: if cups are not returned, more units must be produced, increasing their overall environmental impact. Although S1 shows a lower impact than disposable cups (S3) across all categories, S2 still presents a lower impact in 16 out of 18 categories, thanks to the composition of the reusable cup, made from 60% waste material.

The collection of real data on service usage improved the accuracy of the environmental analysis. Determining the cup return rate made it clear that when cups are not returned, the environmental impact increases significantly. Moreover, estimating the level of service implementation established at 4.8% revealed that the adoption of the reusable cup remains limited within the university community.

Keywords:

Sustainability, life-cycle assessment, university education.