The removal of organic contaminants from industrial waste salts by pyrolysis and potential use for energy storage

• Published in: Journal of cleaner production 2023-11, Vol.425, p.138931, Article 138931
• Main Authors: Xi, Shaobo, Wei, Xiaolan, Ding, Jing, Wang, Weilong, Lu, Jianfeng
• Format: Article
• Language: English
• Subjects: Cleaner production; Energy storage; High-temperature pyrolysis; Industrial waste salts
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2023.138931

Industrial waste salt (IWS) treatment is a significant technology for current environmental protection and resource utilization, and the complex organic pollutants in waste salts seriously hamper the development of cleaner production. In this work, the kinetic mechanism of the organic pollutant removal by pyrolysis is investigated, and the energy storage performance of the recovered products is studied, which provides a new idea for the coupling of waste salt resource treatment and energy storage utilization. Experimental results and pyrolysis kinetic analysis show that high temperature pyrolysis can deeply remove the organic pollutants in IWS, and the total organic carbon (TOC) removal rate can reach more than 99%. The high temperature pyrolysis of waste salt is mainly divided into two stages, and the pyrolysis reaction mainly occurs in the high temperature section (270°C–330 °C) with lower activation energy. The obtained salt containing carbon material exhibits high light absorptance of about 82%, enhanced thermal conductivity of 0.39 W/(m·K) and specific heat of 1.49 J/(g·K), which can be employed as the low-cost and high-performance photothermal absorption and thermal storage material. •Organic pollutants in waste salt are deeply removed by high temperature pyrolysis.•Increase of pyrolysis temperature, heating rate and holding time benefit the removal.•Kinetic equation and activation energy of two main pyrolysis stages are studied.•The obtained salt containing flake carbon materials has high light absorptance.•The product can sensitively respond temperature change for better thermal property.