Hydrothermal carbonization of plastic waste: A review of its potential in alternative energy applications

The significant rise in plastic consumption and waste generation, coupled with the urgent need for sustainable energy solutions, has led to innovative research seeking to convert plastic waste into valuable resources. This review focuses on the application of hydrothermal carbonization as a promising technique for transforming plastic waste into valuable products. It highlights the suitability of hydrothermal carbonization for plastic waste conversion, and presents recent reports showing promising results, prospects, and a range of potential hydrochar applications, including solid recovered fuels, catalysts, direct carbon fuel cells and supercapacitors. This review further presents the challenges in utilizing plastic hydrochar across different applications, which include feedstock variability, contamination, scalability, material properties, and environmental considerations. The need for optimized synthesis methods, stable performance, and long-term sustainability is also emphasized. The critical evaluation of the applications of hydrothermal carbonization can contribute to advancing sustainable waste management and renewable energy production.