University of Warwick engineers have developed a process that can cope with plastic waste, and can break some polymers back into their original monomers.
According to a University of Warwick release, researchers have used support from AWM's Science City funding to devise a unit that uses pyrolysis in a “fluidized bed” reactor. The release notes that tests recently completed have shown that the researchers have been able to put a wide range of mixed plastics into the reactor, which can be reduced to useful products, many of which can then be retrieved by simple distillation.
Products that Warwick engineers have been able to reclaim from the plastic mix include: wax that can then be used as a lubricant; original monomers such as styrene that can be used to make new polystyrene; terephthalic acid, which can be reused in PET plastic products; methylmetacrylate, which can be used to make acrylic sheets; carbon, which can be used as carbon black in paint pigments and tires; and the char left at the end of some of the reactions, which could be sold to as activated carbon.
University of Warwick researchers note that the research could have a significant impact on the budgets of local authorities and produce considerable environmental benefits. The university says that lab-scale tests successfully produced distilled liquids and solids that can be used for processing into new products. Engineers are now working with the University’s technology transfer arm, Warwick Ventures on the next step of the project.
“We envisage a typical large scale plant having an average capacity of 10,000 metric tons of plastic waste per year. In a year, tankers would take away from each plant over £5 million (US$7.8 million) worth of recycled chemicals and each plant would save £500,000 (US$780,000) a year in landfill taxes alone. As the expected energy costs for each large plant would only be in the region of £50,000 a year, the system will be commercially very attractive and give a rapid payback on capital and running costs,” says Engineering Professor Jan Baeyens, University of Warwick’s lead researcher on the project.