Doctoral themes 2023

Plastic Waste Management by recycling and product redesign 

Supervisors

Ana Paula Ribeiro, apribeiro@tecnico.ulisboa.pt

Ana Filipa Cristino, ana.cristino@tecnico.ulisboa.pt

Luísa Martins, luisammartins@tecnico.ulisboa.pt

Registration Institution

Instituto Superior Técnico

Project description

The world is producing around 1.1 Gt/a of consumer waste (municipal solid waste or MSW), with production varying from <1 kg/capita per day for low-income countries to >2 kg/ capita per day for high income ones. MSW typically contains 10 wt % plastics, amid food scraps, yard trimmings, textiles, paper, and other inorganic waste. The ∼10 wt % of plastics consists mainly (∼60 wt %) of the polyolefins HDPE, LDPE, LLDPE, and PP, the remaining fraction being PET, PVC, PS, and other minor polymers. 

Plastic recycling consists mainly of mechanical recycling and is focused on the three dominant packaging polymers PE, PP, and PET. The recycling processes rely on cautious sorting of the clean and pure monostream fraction, compounding it to granules, and blending them with a virgin polymer of the same family, together with compatibilizers and additives.

In this proposal we want to produce recycled plastic, using bioaditives such as biopolymers and during production collect the by-products with Industrial interest, such as ethylene glycol (EG). This is a heat transfer fluid that is being studied for several applications. 

During this PhD the recycled materials, particularly postconsumer plastics, will be fully studied regarding chemical and mechanical properties, to know the performance of the recycled ones. Also, the by-products that will form will be studied and its potential uses identified.

In this PhD proposal the student will need to do internships abroad, in laboratory environment, but also will be working with industry, in the recycling of plastics in larger scale.

Keywords

Plastic

Recycling

Energy

Biodegradation

Design for recycling