NKT Pyrolysis Process

In Denmark, the discussion on PVC waste is probably one of the most tense in the EU. Denmark was one of the first countries to have a covenant aiming to avoid the landfilling of PVC from building waste applications. Whereas for waste flows like pipes and window frames mechanical recycling is a good option, the situation is a bit more difficult for PVC isolation from cables. The NKT process was initially developed 

This project has been presented to the management committee of Vinyl 2010 (the organisation that manages the EU PVC industries recycling initiatives) with a request for financial support to scale-up to commercial size. A decision should be taken by the end of 2002, taking into account the total available quantities of PVC waste and the development of alternatives technologies in Denmark. 

PVC is transformed into various chemical products/ raw materials. In the pre-treatment step light plastics such as PE, PP, wood and the like are sorted out, as are sand, iron, steel, brass, copper and other metallic pollutants. 

In a reactor at low pressure (0.2-0.3 MPa) and moderate temperature (375 °C) the PVC is chemically and thermally degraded. A particular feature of the process is that the chlorine in the PVC reacts in part with the fillers in PVC and is neutralised with the formation of CaCl2. In similar vein, metal stabilisers in PVC are converted into the respective metal chlorides (lead, cadmium, zinc and/or barium). At current PVC waste compositions these chlorides consist of 60% lead which can be purified and re-used. The reaction in the end results in the following solid, liquid and gaseous products. 

From the gaseous product, HCl is recovered by absorption in water. The other gases (CO, propane, ethane) are incinerated and released. The liquid phase is separated into an organic condensate and an aqueous condensate. Solutions containing HCl can be reused in the downstream separation process. The solid phase 

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