Selective hdpe-to-wax conversion via catalytic supercritical CO₂ processing

Overview

This cutting-edge process leverages supercritical CO₂ as a green solvent to selectively depolymerize recycled high-density polyethylene (HDPE) into valuable waxes. By using supercritical CO₂, this method capitalizes on its superior solvation and tunable transport properties, allowing for precise control over the depolymerization process. The introduction of catalysts further enhances the selective breakdown of HDPE, resulting in a more energy-efficient and environmentally friendly conversion process that supports a circular economy.

Technical specifications

• Supercritical CO₂: Acts as a solvent with low viscosity and tunable density, improving heat and mass transfer during processing.
• Catalytic depolymerization: Catalysts are injected to promote controlled chain scission of HDPE, targeting specific molecular weights with minimal by-products.
• Process monitoring: Molecular weights and wax yields are tracked using Gel Permeation Chromatography (GPC) and Gas Chromatography (GC).
• Reactor setup: High-pressure batch reactors are used to maintain conditions above the HDPE melting point, optimizing depolymerization.

Technology readiness level

Currently at TRL 3, this technology is undergoing experimental proof of concept. Future validation phases include catalyst screening, depolymerization trials, kinetics measurement, and environmental assessments to further develop and scale the process.