Depolymerization of Polyester and Nylon 6 in a Co-Process using Neutral Hydrolysis
Authors
Tony Yesodharan, Arjun ; Braun, Friederike Isabel Antonia
Term
4. term
Education
Publication year
2021
Submitted on
2021-05-28
Pages
82
Abstract
This study examines whether mixed polyester and nylon 6 can be broken back into their building blocks (monomers) by neutral hydrolysis, a process in which water splits polymer chains without added acid or base. The work is a literature and process-simulation study, and it concludes that co-processing the two polymers is feasible. Monomer recovery was modeled in Aspen Plus V9 with a focus on achieving high yield and purity through phase separation. Terephthalic acid (TPA) and caprolactam (CL) were identified as the main products, and a solid-liquid separation was designed to retrieve the monomers. The model recovers 605.3 kg TPA per hour at 99.9% purity and 484.7 kg CL per hour as a liquid at 91.2% purity. Separation of water and ethylene glycol (EG) was also modeled to enable partial recycling of process water. To improve energy recovery, a pinch analysis was performed to identify an optimal heat exchanger network (HEN).
Dette arbejde undersøger, om blandinger af polyester og nylon 6 kan nedbrydes til deres byggesten (monomerer) ved neutral hydrolyse, en proces hvor vand splitter plastkæder uden brug af syre eller base. Studiet er gennemført som et litteratur- og processimuleringsstudie, og konklusionen er, at sambehandling af de to polymerer er mulig. Genindvindingen af monomererne er modelleret i Aspen Plus V9 med fokus på højt udbytte og høj renhed via faseadskillelse. Terephthalsyre (TPA) og caprolactam (CL) blev identificeret som hovedprodukter, og en fast-væske-separation blev implementeret for at udtrække monomererne. Modellen viser genvinding af 605,3 kg TPA pr. time med 99,9 % renhed og 484,7 kg CL pr. time som væske med 91,2 % renhed. Derudover blev separation af vand og ethylenglycol (EG) modelleret for at muliggøre recirkulering af en del af procesvandet. For at forbedre energiudnyttelsen blev der udført pinch-analyse for at identificere et optimalt varmeveksler-netværk (HEN).
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords