Advanced Recycling Technologies for Plastic Waste: A Comprehensive Review of Thermal, Chemical, and Solvent-Based Strategies toward a Circular Economy.

The global plastic waste crisis has intensified the demand for sustainable and efficient waste management strategies, particularly those that recover energy and valuable materials from municipal solid waste (MSW) and plastic residues. This review synthesizes findings from recent studies on waste-to-energy (WTE) technologies and advanced recycling techniques, highlighting their technical feasibility, environmental impacts, and economic viability. Incineration and gasification have been widely explored for energy recovery from MSW and plastic waste, with studies indicating that technologies such as high-temperature steam gasification and fluidized bed co-gasification can yield hydrogen-rich syngas with high calorific values and reduced pollutant emissions. However, economic barriers, including high capital costs and unfavorable energy tariffs, often hinder large-scale adoption. Pyrolysis—particularly catalytic pyrolysis—has shown promise in converting plastic waste into high-quality fuels and monomers, though challenges remain in catalyst cost, deactivation, and regulatory classification. Dissolution–reprecipitation methods offer a non-destructive alternative for polymer recovery, yielding virgin-like plastics with minimal degradation, especially when bio-based solvents such as dimethyl isosorbide are employed. Solvent-based processes also enable selective separation of mixed plastic streams and effective additive removal, thereby enhancing recyclate quality. While each technology has unique strengths and limitations, an integrated approach—combining mechanical, chemical, and thermal methods—emerges as essential for achieving a circular plastic economy. Policy support, infrastructure development, and continued innovation in reactor design and solvent systems will be crucial for scaling these technologies sustainably. Recent advancements in chemical and photochemical recycling technologies offer promising solutions to the growing challenge of plastic waste management, particularly by enabling hydrogen production and recovery of valuable chemicals within a circular economy framework.