Upcycling of polyvinyl chloride to hydrocarbon waxes via dechlorination and catalytic hydrogenation

Upcycling of polyvinyl chloride to hydrocarbon waxes via dechlorination and catalytic hydrogenation

Converting polymer waste to marketable products is a promising method to incentivize the development of competitive waste upcycling processes. Polyvinyl chloride (PVC) waste streams pose a unique challenge in this regard because of the presence of Cl atoms in the molecule. To address this issue, we...

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Bibliographic Details
Published in:Applied catalysis. B, Environmental Vol. 338; p. 123065
Main Authors: Svadlenak, Scott, Wojcik, Sophie, Ogunlalu, Oluwafemi, Vu, Makayla, Dor, Maoz, Boudouris, Bryan W., Wildenschild, Dorthe, Goulas, Konstantinos A.
Format: Journal Article
Language:English
Published: Elsevier B.V 05-12-2023
Subjects:
Polymer upcycling
PVC recycling
Solvent effects
Polymer upcycling
PVC recycling
Solvent effects
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Summary:Converting polymer waste to marketable products is a promising method to incentivize the development of competitive waste upcycling processes. Polyvinyl chloride (PVC) waste streams pose a unique challenge in this regard because of the presence of Cl atoms in the molecule. To address this issue, we report here a method to upcycle PVC plastics and produce a polyethylene wax in a mixed amine-water system, using hydrogen and a heterogeneous catalyst. We demonstrate that alkylamines as homogeneous catalysts and as Cl- sequestration media successfully dechlorinate PVC to a polyene, which is hydrogenated over a Pt/C heterogeneous catalyst. At optimal conditions, hydrocarbon wax yields greater than 70 % with melt temperatures above 80 °C were achieved. We use X-ray tomography to illustrate the PVC dissolution and reaction and quantify the product by differential scanning calorimetry (DSC). Characterization of the product reveals complete dechlorination and hydrogenation, as well as partial C-C bond scission, indicating a product similar to polyolefin adhesive waxes. [Display omitted] •Alkylamines dechlorinate polyvinyl chloride (PVC) and sequester chloride ions as alkylammonium chloride salts.•Polyene intermediates are hydrogenated to hydrocarbon waxes over a Pt/C catalyst•Hydrogenation and hydrogenolysis reactions over Pt determine the melt temperature of the waxes•The waxes produced in this process are appropriate for use as hot melt adhesives
ISSN:0926-3373
1873-3883
DOI:10.1016/j.apcatb.2023.123065