February 16, 2025 – Solvent Dissolution Recycling: A Promising New Approach to Tackling Global Plastic Pollution
As global plastic production continues to soar, with projections indicating a doubling by 2050, the associated emissions and annual waste plastic output are set to increase significantly by 2060, posing a major challenge to the global environment. Amidst this backdrop, solvent dissolution recycling is emerging as a novel plastic recycling method, gradually garnering attention from the industry.
Traditional waste plastic processing techniques primarily encompass physical and chemical recycling. While physical recycling is energy-efficient and widely applied, it has limitations when dealing with certain types of plastics and struggles to completely remove inks, dyes, and other impurities, affecting the quality and market value of recycled plastics. Chemical recycling, including pyrolysis and depolymerization, offers certain advantages but still needs improvement in terms of the types of recyclable plastics and recycling yields.
In contrast, solvent dissolution recycling demonstrates unique advantages. According to AsiaMB, this technology achieves plastic recycling through two main approaches: dissolution layering and selective dissolution. Dissolution layering effectively recovers all components from multi-layer plastics, solar panels, and other composite materials by dissolving the adhesive between polymers and metals using solvents. Selective dissolution, on the other hand, separates polymers from contaminants, dyes, and other substances through solvents, broadening the recycling scope and enhancing efficiency.
In terms of commercial applications, numerous companies have achieved remarkable results. For instance, Polystyvert utilizes cumene oil to recycle polystyrene and acrylonitrile-butadiene-styrene copolymers, significantly reducing greenhouse gas emissions from recycled plastics. Purecycle employs supercritical butane technology to recycle polypropylene, with an annual output reaching tens of thousands of tons. As the first commercial recycler of multi-layer plastics in the industry, APK incorporates air classification technology to process various types of multi-layer plastics.
Looking ahead, solvent dissolution recycling holds great promise, yet it faces certain challenges. Currently, the cost of recycled plastics generally exceeds that of virgin plastic production, necessitating efforts to achieve commercial maturity and price competitiveness. Additionally, the high cost of solvents and anti-solvents remains a key issue. However, with continuous technological advancements and innovations, more environmentally friendly and economical solvents are expected to be adopted in the future, driving the development of this technology.
In terms of equipment, dissolution devices and purification and recycling equipment are crucial for the solvent dissolution recycling process. Twin-screw extruders and dissolution tanks, as primary dissolution equipment, effectively mix plastics with solvents and achieve dissolution. Filtration units and devolatilizers are used to remove impurities and volatile solvents, ensuring the quality of recycled plastics.
In summary, solvent dissolution recycling offers a new perspective and approach to plastic recycling. Despite facing challenges, with the continuous development and improvement of technology, it is believed that this method will play an increasingly important role in addressing the issue of plastic pollution.