Document Type
Article
Publication Date
3-4-2024
Department
Department of Mechanical Engineering-Engineering Mechanics
Abstract
Solvent-based recycling of plastic waste is a promising approach for cleaning polymer chains without breaking them. However, the time required to actually dissolve the polymer in a lab environment can take hours. Different factors play a role in polymer dissolution, including temperature, turbulence, and solvent properties. This work provides insights into bottlenecks and opportunities to increase the dissolution rate of polystyrene in solvents. The paper starts with a broad solvent screening in which the dissolution times are compared. Based on the experimental results, a multiple regression model is constructed, which shows that within several solvent properties, the viscosity of the solvent is the major contributor to the dissolution time, followed by the hydrogen, polar, and dispersion bonding (solubility) parameters. These results also indicate that cyclohexene, 2-pentanone, ethylbenzene, and methyl ethyl ketone are solvents that allow fast dissolution. Next, the dissolution kinetics of polystyrene in cyclohexene in a lab-scale reactor and a baffled reactor are investigated. The effects of temperature, particle size, impeller speed, and impeller type were studied. The results show that increased turbulence in a baffled reactor can decrease the dissolution time from 40 to 7 min compared to a lab-scale reactor, indicating the importance of a proper reactor design. The application of a first-order kinetic model confirms that dissolution in a baffled reactor is at least 5-fold faster than that in a lab-scale reactor. Finally, the dissolution kinetics of a real waste sample reveal that, in optimized conditions, full dissolution occurs after 5 min.
Publication Title
ACS Sustainable Chemistry and Engineering
Recommended Citation
Kol, R.,
Denolf, R.,
Bernaert, G.,
Manhaeghe, D.,
Bar Ziv, E.,
Huber, G.,
Niessner, N.,
Verswyvel, M.,
Lemonidou, A.,
Achilias, D.,
&
De Meester, S.
(2024).
Increasing the Dissolution Rate of Polystyrene Waste in Solvent-Based Recycling.
ACS Sustainable Chemistry and Engineering,
12(11), 4619-4630.
http://doi.org/10.1021/acssuschemeng.3c08154
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p2/579
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
Copyright © 2024 The Authors. Published by American Chemical Society. Publisher’s version of record: https://doi.org/10.1021/acssuschemeng.3c08154