MaterialDistrict

New ‘plastic surgery’ process promises better recycling

Researchers at IBM developed a catalytic chemical process that digests certain plastics, like PET, into a substance that can directly be reused in the manufacturing of new plastic.

PET is one of the most commonly produced plastic polymers, yet only a small part of all this material is recycled. 8 million tons of this plastic ends up in the ocean every year.

Traditional recycling requires the plastic to be sorted by colour and translucency. It then has to be washed and then be processed individually. Afterwards, it is difficult to recycle again.

IBM’s process, called VolCat (short for Volatile Catalyst), is a chemical process that digests polyester plastics into a white, powdery substance that can directly be reused in plastic manufacturing machines. There is no need for sorting or even cleaning the material, and even polyester fabric can be recycled this way.

The process starts by heating PET and ethylene glycol in a reactor with the catalyst. After the depolymerisation is complete, the catalyst is recovered by a distillation process using the heat of reaction. The remaining solution is filtered, purified and then cooled, while the solid monomer product is recovered by filtration. The liquid can be reused in the next process.

IBM aims to implement their process in five years on a large scale, turning “plastic into a renewable resource”.

Photos: IBM

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