Background PVC waste is one of the focal points of the EU’s environmental policy. The incineration of PVC waste results in dioxin formation and generates flue gas cleaning residues that require depositing in landfills. Such depositing may release environmentally harmful substances into the water environment. In Denmark, it has been estimated that 1,000-2,000 tonnes of phthalates and 35-70 tonnes of heavy metals related to PVC waste due to PVC deposits are the potential sources for pollution of the water environment. Additionally, the quantity of PVC waste generated annually in the EU Member States is significant adding to the urgent need to find alternative sustainable solutions to treat it. The European PVC industry has identified two processes to recycle PVC waste: • “Mechanical recycling” consists of specific methods, whereby one pure type of PVC waste is recycled to produce the goods that generated the waste, and; • “Feedstock recycling” converts PVC waste of mixed types into other useful chemical products that may be recycled in turn. The PVC hydrolysis concept is one of four techniques used in feedstock recycling and is considered to be potentially the most promising by the European PVC industry. Objectives The objective of the project was to study the continuous thermal hydrolysis of PVC waste and the recycling of the reaction products. The project also aimed to establish whether this recycling process could be achieved at a relatively low cost in a treatment facility with a capacity of around 60,000 metric tons of PVC waste per year. Results The project succeeded in erecting a treatment facility for PVC with an estimated capacity of 60,000 ton per year. It demonstrated that continuous thermal treatment of PVC is feasible, but continuous operation of all steps in the treatment has not yet been demonstrated. For this reason full-scale recycling of end-products has also not yet been demonstrated, though it is believed to be feasible. The main obstacles for the continuous operation have proved to be the PVC content of metal waste, stemming from residues of cables etc. This type of waste creates considerable problems in the hydrolysis tube, and as a result it was necessary to introduce extensive pre-treatment in the process. A final financial assessment of the treatment method has not yet been published, but preliminary results indicate that the thermal treatment (hydrolysis) of PVC is approximately twice as high as presently used alternatives (deposition and incineration). The project also resulted in technological spin-off in the area around Stigsnæs as well as in various European companies that have supplied machines and treatment packages to the project and have become more competitive as a result. Stigsnæs is located in an area with high unemployment, local companies were provided with the means to take on more permanent staff. For example, advanced welding and high pressure techniques were needed.