(180a) Pyrolysis: Filling the Gap in Recycling Waste Plastic

Recycling, or material recovery, is the key to sustainability. Depositing useful material in a landfill, as is common practice for municipal waste, is counter productive.

The state of the art of separating the components of waste streams continues to improve and is key to sustainable material recovery. Sorting adds value by making it possible to recover all components of the waste stream at the highest value. Equally important is having viable processes for effective conversion, meaning consistently producing a valuable material at a high conversion rate, of sorted streams into high value products.

Plastics are particularly difficult to recycle because the characteristics that make them so useful can make them challenging to recover. There are hundreds of formulations custom designed for unique applications. The legacy plastic recycling techniques work only for a single polymer. These are referred to as “Mechanical Recycling” because the material is ground to a powder and then extruded into pellets. This limits the material that can be recycled and complicates recovery resulting in low recycling rates. The current focus for a circular economy has revived interest in pyrolysis, a technology that can greatly expand the range of plastics that can be recovered, producing synthetic oil and gas that can be used for petrochemical feedstocks and fuel products. This is not a new process; there has been a substantial amount of research, pilot plants, and even a few commercial plants implemented over several decades.

The presentation will review the history and current state of the pyrolysis technology, its relevance to material recovery and plastic recycling, the process design, feedstock requirements, and products. In addition, the presentation will explore the synergy of using pyrolysis and other processes to improve the rate of plastic recycling from a Municipal Solid Waste stream.