CHEMICAL RECYCLING ON TRIAL
Some plastics are difficult to recycle in mechanical processes. There is a need for other methods. “One method we are testing is chemical recycling where, in principle, all plastic can be recycled by means of gasification”, says Christer Forsgren, Head of Technology & Environmental Science at Stena Metall.
In a research project conducted together with Chalmers University of Technology and Borealis among others, Stena is testing how, by means of chemical recycling, plastic can be gasified and plastic waste recycled at the molecular level and then used as a raw material for new plastic. Different types of plastic waste are being tested at the Chalmers Power Central in Gothenburg. In 850° C generated by a gasifier, 200 kg of plastic is transformed into synthetic gas, which can then be used to manufacture propylene, ethylene and other types of hydrocarbons. These can then be used as a raw material in the manufacture of new plastic. The tests at Chalmers University of Technology are promising and the goal is to change the current situation where the majority of the plastic waste today is incinerated and leaves the natural cycle.
“What we at Stena are contributing is primarily knowledge about recycling and supplies of different plastic fractions that are not suitable for recycling. It’s very difficult to separate all the different types of plastic that exist using mechanical sorting. The good thing about gasification is that you can get round the problem”, says Christer Forsgren.
A long-term goal for Borealis is to build a refinery for plastic waste at their facility in Stenungsund. Every year, Borealis produces more that 600,000 tons of plastic pellets, which are used in the manufacture of everything from cables to sophisticated packagings. The company wants to reduce the need for virgin fossil raw material by using more recycled plastic.
“If it had been easy to recycle all plastic into new plastic, it would have already been done. I’m convinced that plastic waste won’t be incinerated in the future and instead be transformed into new plastic. But it will take time and maybe incentives will be needed to make recycled plastic raw materials competitive compared with plastic manufactured from cheap oil”, says Christer Forsgren.
He notes that there are studies showing that the manufacture of plastic in the world will quadruple by 2050 and will increase from 6 to 20 per cent of all the oil used for this purpose.
“If we can circulate the plastic waste to new plastic products, we will also be able to conserve the finite fossil resources. Today, plastic waste is a rapidly growing challenge for the business community and local authorities due to the rising demands of the world around us. Gasification of plastic waste could definitely be part of the solution when it comes to recycling the large volumes of plastic that today go to waste in the incineration plants”, says Christer Forsgren.
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