Catalytic pyrolysis for converting plastic waste to alkenes

Overview

This proposal addresses one of the most persistent barriers in plastics recycling: the cost and complexity of sorting mixed plastic waste streams and cleaning them to virgin-grade standards. Rather than attempting to mechanically separate and purify post-consumer plastics, the concept proposes using catalytic pyrolysis to chemically break polymers down into simple alkene monomers, the fundamental building blocks used to manufacture new plastics. These monomers can then be more easily purified and re-polymerized into virgin-quality polymers. Residual waste fractions, such as char from inks, dyes, glues, and labels, can be combusted to supply process heat, improving overall energy economics.

Technical specifications

• Core approach: Catalytic pyrolysis, a thermochemical process that uses a catalyst to decompose plastic polymers at elevated temperatures into smaller hydrocarbon molecules.
• Target output: Simple alkene monomers (e.g., ethylene, propylene) suitable for purification and re-polymerization into new plastics.
• Feedstock flexibility: Designed to accept mixed, contaminated post-consumer plastic streams without requiring prior sorting or intensive cleaning.
• Waste valorization: Non-polymer contaminants such as inks, dyes, adhesives, and labels are converted to char and combusted for process heat recovery.
• Key challenge: Identifying or developing the optimal catalyst that maximizes alkene yield while managing the diverse additive and contaminant profiles found in real-world plastic waste.

Technology readiness level

This is an early-stage research concept. The hypothesis has been articulated but has not yet been validated experimentally, and a detailed future validation plan is still to be determined. Significant catalyst development work, reaction optimization, and techno-economic analysis would be required before this approach could advance toward pilot- or commercial-scale demonstration.