Finland's VTT Project Evaluates Chemical Recycling
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.
Finland’s VTT technical research center provided an update on its two-year Business Finland WasteBusters’ project regarding chemical recycling. The group says that chemical recycling offers an ecologically sound alternative to incineration and possibly to mechanical recycling as well.
Anja Oasmaa, senior principal scientist at VTT, says that legislation in Finland and the EU does not recognize chemical recycling of plastics as being equal to mechanical recycling. As a result, VTT is compiling an account of chemical recycling of plastics for the Ministry of Environment.
In the WasteBusters project, long polymer chains of plastics and their mixtures were pyrolysed, i.e., heated in the absence of oxygen, and chopped into shorter chains and, in part, even to monomers. The group says that resulting pyrolysis wax or oil could be processed with traditional methods at oil refineries.
“Pyrolysis oil can be distilled into separate monomers, diesel and other fractions, some of which can be used directly as fuels and some as raw material for plastics and other chemicals,” Oasmaa says.
The project focused on pre-treatment and pyrolysis of plastic waste, and also somewhat on post-treatment of the product. According to Oasmaa, improvements of pre-treatment in particular are decisive for a cost-effective concept.
“There are all kinds of films as well as both dense and porous pieces together in plastic waste, which makes it difficult to handle,” she says. “We managed, however, to make it homogenous with the Modix-extruder developed by VTT.”
The supply of plastic waste in Finland has been considered too small for pyrolysis. Scientists, however, calculated in the project that a network of approximately 10 pyrolysis plants could prove profitable, if pyrolysis of plastic waste and wood waste were combined. They suggested that pyrolysis plants be attached to waste recycling plants.
VTT is already preparing additional studies on related topics, such as recycling of polystyrene; removal of hazardous compounds from plastic waste; and production of diesel fuels from plastic waste to be used in flexible power generation and marine transport.
”Companies are interested in the fact that plastic waste can be turned into other chemicals besides plastics, which will then replace virgin fossil raw materials in a sustainable manner. We want to develop this line of business with sustainable solutions in close cooperation with companies,” Oasmaa says.
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