Process for Recycling PVC to HDPE
This is a novel process for efficiently recycling PVC into a reusable chlorine-free polymer
Background
Approximately 40 million tons of polyvinyl chloride (PVC) are produced annually, making PVC one of the most widely produced synthetic plastic polymers. Waste materials that contain PVC are extremely difficult to recycle mechanically. Thermochemical methods such as pyrolysis are also undesirable because of hydrochloric acid and chlorinated organic byproducts that are produced by thermal decomposition of PVC. This process is a unique chemical method of converting PVC to a chlorine‑free polymer, such as high density polyethylene (HDPE), that is recyclable.
Technology Overview
The process involves mixing the PVC in a slurry with an appropriate amount of solvent, base, and catalyst in the presence of a reactive atmosphere. The temperature is elevated but maintained below a pyrolysis temperature for PVC. The process avoids the formation of chlorinated organic compounds and hydrochloric acid by instead producing chloride salts. The end product is a chlorine‑free polymer, such as HDPE in some configurations.
Stage of Development
Technology Readiness Level (TRL): 3 to 4
Benefits
- Extensive cleaning of feedstocks not required
- Better selectivity toward desired end products
- Avoids corrosive gas phase HCl
Applications
- Low temperature chemical upcycling
- Recycle of PVC waste and production residues
- Can produce HDPE and waxes for the hot melt adhesive market
Opportunity
This is early-stage technology tested and validated in a laboratory setting. The team is seeking development partners to improve TRL and commercialize.