Dechlorination of polyvinyl chloride electric wires by hydrothermal treatment using K2CO3 in subcritical water. (1st February 2020)

• Record Type: Journal Article
• Authors: Gandon-Ros, Gerard; Soler, Aurora; Aracil, Ignacio; Gómez-Rico, María Francisca
• Is Part Of: Waste management. Volume 102(2020)
• Page Start: 204
• Page End: 211
• Publication Date: 2020-02-01
• Subjects: Hydrothermal process -- Dechlorination efficiency -- PVC electric wires -- Alkaline additive -- Potassium carbonate; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2019.10.050
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: K2 CO3 was used to improve the dechlorination process of PVC wires. Use of different temperatures and K2 CO3 concentrations was studied. At 250 °C, 99.1 wt% of chlorine of PVC wires was removed after 4 h. Solid residues obtained can be used as high-quality fuel. Abstract: Polyvinyl chloride (PVC) waste generation has significantly increased in recent years and their disposal is considered a major environmental concern. Removal techniques of chlorine from PVC waste are being studied to minimize a negative environmental impact. In this work, the use of K2 CO3 as an alkaline additive to improve the dechlorination efficiency (DE) in the hydrothermal degradation of PVC wires was studied. Different experiments were carried out varying both temperature (175, 200, 225, 235 and 250 °C) and K2 CO3 concentration (0.025, 0.050 and 0.125 M), using a solid/liquid ratio of 1:5 in order to determine the evolution of the dechlorination efficiency with time. About 4.66, 21.1, 24.4, 45.7 and 92.6 wt% of chlorine in PVC wire was removed during hydrothermal dechlorination (HTD) with an additive/chlorine ratio of 1:25 (K2 CO3 solution of 0.050 M) at 175, 200, 225, 235 and 250 °C, respectively. Optimal additive/chlorine ratio decreased to 1:50 (K2 CO3 solution of 0.025 M) at 250 °C, obtaining a dechlorination degree of 99.1% after 4 h without the need of metallic catalysts. Concerning the solid phase behavior during dechlorination, a linear correlation between the DE reached and the weight loss of PVC was found.