“The thermochemical method used in Swedish research is in line with our approach to mixed plastic waste, which is breaking down into primary building blocks. But the result for mixed waste is still significantly lower than in the traditional petroleum process. ”
Stijn Dekeukeleire, as a business developer at the Laboratory for Chemical Technology of Ghent University, responds to a new Swedish technique to replace petroleum as a raw material for the production of plastic with plastic waste. Today, petroleum is the raw material of plastics, where steam crackers in a thermochemical process break down the hydrocarbon chains of petroleum into smaller building blocks to produce plastic.
The same quality as new plastic
Can plastic waste also serve as a raw material? "Our research shows that it is possible to use plastic waste as a raw material in steam crackers," said Professor Henrik Thunman of the Swedish Chalmers University. “Heating plastic waste to about 850 degrees brings it into a gaseous state where the plastic breaks down to a molecular level. This makes it usable as a raw material for plastic with the same quality as new plastic. The latter is important, because now recycled plastic is often of lesser quality. ”
Mixed versus pure fractions of plastic waste
The thermochemical process also offers opportunities for mixed plastic waste. “It may indeed be better to convert this into building blocks for chemistry via a thermochemical process,” says Dekeukeleire. “But the result for mixed waste is still significantly lower than in the traditional petroleum-based process. Moreover, this process requires a lot of energy. For pure fractions of plastic waste such as polyethylene, the current way of recycling scores better in terms of energy efficiency. ”