Think Outside the Trash: Infinite Plastic Recycling

One man’s trash is another man’s treasure, plastic trash that is. Only 9% of the world’s plastic is recycled causing the problem of waste accumulation. Without recycling, our lands and oceans are suffocated by plastic, and one of the main culprits is plastic bottles, made up of mostly polyethylene terephthalate (PET). The recycling rate of PET bottles and jars was 29.1% in 2018, mostly by melting down as a result of combustion. The PET hydrolysis is an advanced recycling technology that turns plastic polymers back into their original molecules, purified terephthalic acid (pTA) and ethylene glycol (EG), so they can be processed and used again and again. These monomers can take on a new life having the potential to be reintroduced into the plastic manufacturing process without losses in structural quality. Our process implements a novel method to chemical recycling by using ionic liquids that facilitate the hydrolysis reaction, with a projected 96.5% conversion of PET and an 85.8% yield of pTA. Ionic liquids have the added advantage of being easily separated from the product and can be reused without a significant decrease in performance. Thus, our design team developed an environmentally friendly approach to PET chemical recycling, validated by a successful software simulation of the process. The plant is designed to achieve a production capacity of 6.8 million lb/yr of pTA by processing 8 million lb/yr of waste consumer PET. It is projected that state-of-the-art advanced recycling methods, such as chemical recycling, will create a $162 billion market. Depolymerization will be a subsector of the billion-dollar industry by means of hydrolysis. An estimated annual revenue of depolymerization sales by 2030 is estimated to be $10 billion as a global market, where our plant expects $3.74 million per annum product sales.