Polyethylene terephthalate, better known as PET, is a common material for the packaging of food and drink products such as Coca-Cola bottles.
But only around 20% of it is recycled owing to the complex processes required for different forms of the material – removing the colouring from waste PET has been a challenge.
That could be about to change. Processing pioneer Ioniqa has developed technology that can convert any type of PET, including coloured PET, back into virgin feedstock. A demonstration plant has been operating in Rotterdam for two years, producing 1,000 litres a year, and a new plant due to open soon will scale that up by a factor of 10.
The process uses iron oxide particles functionalised with catalysts that depolymerise the PET in the presence of ethylene glycol. The iron oxide particles capture some of the colourants, and a magnetic field recovers the catalyst for reuse.
“This opens the way for fully circular PET recycling, whereby PET can be endlessly reused. That has benefits for both the packaging industry and the environment,” says Ioniqa founder Tonnis Hooghoudt.
The company has now teamed up with consumer goods giant Unilever, and has secured an investment from Coca-Cola, which is planning to create packaging made out of at least 50% recycled material by 2030.
“Partnering with Coca-Cola is a further validation of our journey to launch this unique process for transforming hard-to-recycle PET waste into high-quality, food-grade material,” says Hooghoudt.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.
Read more related articles