A feasible approach for the treatment of waste computer casing plastic using subcritical to supercritical acetone: Statistical modelling and optimization.

Autor: Preetam A; Supercritical Fluid Extraction Laboratory, Centre for Rural Development and Technology, IIT Delhi, 110016, India; Catalytic Reaction Engineering Laboratory, Chemical Engineering Department, Indian, IIT Delhi, 110016, India., Dwivedi U; Supercritical Fluid Extraction Laboratory, Centre for Rural Development and Technology, IIT Delhi, 110016, India; Catalytic Reaction Engineering Laboratory, Chemical Engineering Department, Indian, IIT Delhi, 110016, India., N Naik S; Supercritical Fluid Extraction Laboratory, Centre for Rural Development and Technology, IIT Delhi, 110016, India., Pant KK; Catalytic Reaction Engineering Laboratory, Chemical Engineering Department, Indian, IIT Delhi, 110016, India. Electronic address: kkpant@chemical.iitd.ac.in., Kumar V; Supercritical Fluid Extraction Laboratory, Centre for Rural Development and Technology, IIT Delhi, 110016, India.
Jazyk: angličtina
Zdroj: Journal of environmental management [J Environ Manage] 2023 Nov 01; Vol. 345, pp. 118549. Date of Electronic Publication: 2023 Jul 06.
DOI: 10.1016/j.jenvman.2023.118549
Abstrakt: Electronic waste (e-waste) usage has increased tremendously with the rapid evolution of technologies. The accumulated e-waste has now emerged as one of the crucial concerns regarding environmental pollution and human health. Recycling e-waste is commonly focused on metal recovery; nevertheless, a significant fraction of plastics (20-30%) are in e-waste. There is an indispensable need to focus on e-waste plastic recycling in an effective way, which has been mostly overlooked to date. An environmentally safe and efficient study is conducted using subcritical to supercritical acetone (SCA) to degrade the real waste computer casing plastics (WCCP) in the central composite design (CCD) of response surface methodology (RSM) to achieve the maximum oil yield of the product. The experiment parameters were varied in the temperature span of 150-300 °C, residence time between 30 and 120 min, solid/liquid ratio between 0.02 and 0.05 (g/ml), and NaOH amount from 0 to 0.5 g. Adding NaOH into the acetone helps to achieve efficient degradation and debromination efficiency. The study emphasized the attributes of oils and solid products recovered from the SCA-treated WCCP. The characterization of feed and formed products is performed with different characterization techniques such as TGA, CHNS, ICP-MS, FTIR, GC-MS, Bomb calorimeter, XRF, and FESEM. The highest oil yield achieved is 87.89% from the SCA process at 300 °C, in 120min, 0.05 S/L ratio, and 0.5 g of NaOH. GC-MS results disclose that the liquid product (oil) comprises single- and duplicate-ringed aromatic and oxygen-containing compounds. Isophorone is the significant component of the liquid product obtained. Furthermore, SCA's possible polymer degradation mechanistic route, bromine distribution, economic feasibility, and environmental aspect were also explored. This present work represents an environmentally friendly and promising approach for recycling the plastic fraction of e-waste and recovering valuable chemicals from WCCP.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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