VTT finds better plastics recycling method

VTT Technical Research Centre of Finland complements the selection of sustainable recycling methods with chemical recycling based on pyrolysis, which will turn nearly all plastics and their mixtures into oil – the raw material of fuels, plastics and other chemicals.

Mechanical recycling suits the most common plastic bottles, bags and wraps. They are sorted, washed, melted and moulded into new products. However, 40 to 60 per cent of separately collected plastic waste in Finland ends up incinerated. Apart from economic reasons, there are technical reasons for mechanical recycling to fail. It can be difficult and occasionally even impossible to separate various types of plastics used, for example, in multi-layer plastic films. The quality of plastic also weakens with use and the number of recycling loops and eventually it proves unfit for use.

"By chemical recycling, however, plastics and their mixtures can be broken down into separate raw materials, whose quality is equal to that of respective virgin materials," explains VTT Senior Principal Scientist Anja Oasmaa.

VTT demonstrated in its two-year Business Finland WasteBusters' project that chemical recycling offers an ecologically sound alternative to incineration and possibly to mechanical recycling as well. Oasmaa points out that legislation in Finland and the EU does not recognise chemical recycling of plastics as being equal to mechanical recycling. VTT is currently compiling an account of chemical recycling of plastics for the Ministry of Environment.