PVC recycling by application

Profiles and pipes
Profiles are the largest application for PVC, representing about 1.4 million tons of resin sales annually in the EU-27.

Almost 105,000 t of window profiles and other profiles were recycled in 2011 as part of the schemes funded by VinylPlus. Pipes are the second largest application for PVC, and approximately 1.2 million tons of PVC pipes (including fittings) are manufactured annually in the EU-27. About 24 000 t of waste pipes were recycled in 2011 as part of the schemes funded by VinylPlus, mainly back to pipes.

Collection and recycling schemes were initially created to deal with waste streams from specific applications, mirroring the way the converting industry is organised. This was changed to enhance efficiency.

The demand for recyclate in these applications is exceeding supply, allowing further development, all the more as available waste is below expectations. The main reasons appear to be longer than anticipated life time for pipes and re-use of still functional windows being replaced by better ones. Export of waste - therefore decreasing availability in Europe - also has an impact.

Flexible PVC construction materials
Until 2003, recycling of roofing membranes was essentially focused on the German market. The waste was processed in a dedicated cryogenic plant owned by several membrane manufacturers. A new collection scheme was launched in Germany in 2003 and was extended to the Benelux, Austria and France in 2004. The cryogenic plant was closed down in December 2004.

Recycling is done in specific dedicated plants by specialised recyclers. As for roofing membranes, flooring recycling started several years ago in Germany, through a dedicated plant. The collection schemes were extended to Austria, Switzerland, Belgium and France.

A significant R&D programme involving flooring manufacturers as well as universities focused on high value applications for flooring recyclate produced in the Vinyloop© Ferrara plant. Application by coating as well as calendering has been successfully demonstrated. Melt filtration was also investigated, but proved to be economically unattractive. However, production of drainage sheets by conventional mechanical recycling has been demonstrated.

The amounts recycled by the schemes co-funded by VinylPlus are still small (about 1600 t of roofing membranes and 2800 t of flooring in 2011), but are increasing . Besides, some additional recycling takes place outside these schemes.

Coated fabrics
Recycling of coated fabrics is especially challenging because of their composite nature. Waste coated fabrics have been collected in France since 2000. A separate scheme started in Germany at the end of 2004. Development of a specific recycling technology called Texyloop®, based on the Vinyloop© process, progressed to the point where a 2000 t/a pilot plant is now operational.

Conventional mechanical recycling by a German company into tarpaulins and automotive parts has been initiated mid- 2004. The technology involves the mechanical shredding, partial separation of polyester fibres and compacting (or agglomeration) of post-consumer waste fabrics A study on the availability of artificial leather waste identified furniture and luggage as the only ones having some potential, but volumes are generally low and the various types of waste cannot be recycled together.

Cables – Vinyloop© process
The Vinyloop© process developed by Solvay is a mechanical recycling process using an organic solvent to separate the PVC compound from other types of plastic waste or from the other materials in a PVC composite.

A special solvent is used to dissolve the PVC waste selectively in a closed loop batch process under pressure. The impurities are separated in a filter from the PVC solution; all the constituents of the PVC waste such as PVC, plasticiser, filler, stabiliser and pigments are present in the filtrated liquid. The secondary material is washed to eliminate virtually the entire dissolved PVC compound and afterwards stripped with steam to recover all the solvent. The liquid is recovered in a precipitation tank, where steam is injected to completely evaporate the solvent.

All the components of the original PVC formulation are recovered in the form of an aqueous suspension. The suspension is split by a decanter into cake and process water. The humid PVC compound is dried with hot air and is then ready to be reused. The solvent is regenerated by a multi-step condensation and separation process, and is entirely recycled.

A first Vinyloop© plant, located in Ferrara (Italy), was built in 2001 to treat post-consumer PVC cable waste. In 2011, about 7500 t of waste PVC, mainly cables, were processed in the Vinyloop Ferrara plant. Besides cables, trials are going on to demonstrate the feasibility of recycling other types of waste PVC.

Feedstock recycling
In Europe, a process called REDOP® was developed to recycle mixed plastic waste into blast furnaces. A mixed plastics/paper fraction is recovered from municipal waste and further separated into a plastics and a paper fraction. The former is de-halogenated by a new process patented by DSM Research: a slurry of waste in water is heated in a stirred reactor. The released HCl is neutralised by addition of a diluted water-soluble base. The non-halogenated plastics melt into droplets, the size of which is determined by the stirring and by the traces of cellulose still present.

Upon cooling, the plastic droplets solidify, yielding mixed plastic (MP) granules having size and characteristics well suited to pneumatic injection in the blast furnace. The chlorine content is comparable to coal and the calorific value is at least equivalent. One ton of REDOP pellets was successfully produced in 2004 and tried out in a commercial blast furnace in the Netherlands.

Generating new chemical raw materials or energy – gasification
By thermal cracking at high temperatures, PVC waste can be recycled into gas components such as hydrogen chloride, hydrogen and carbon monoxide, which can be put to use. The Japanese PVC industry has been working to demonstrate gasification technologies to treat various plastic wastes including PVC, jointly with Nippon Steel, Daicel and Sumitomo Metals. Hydrogen and carbon monoxide can be used for ammonia and methanol production or as fuel gas for power plants. Hydrogen chloride is widely used as chemical raw material or as industrial chemicals.

Reuse of hydrogen chloride - as raw material for VCM
The company Dow has been operating since 1999 a commercial feedstock recycling plant at its site near Leipzig (Germany). Chlorine containing waste, including PVC, is treated in a rotating furnace, yielding hydrochloric acid which is re-used on site for production of vinyl chloride monomer. 1000 tonnes of PVC waste were successfully processed in 2002-2003.

Recycling of plastic residential construction and demolition waste
Vinyl 2010 and APME/PlasticsEurope worked since 2001 with the Association of Cities and Regions for Recycling (ACRR) to improve the recycling of plastic waste collected by local authorities. Pilot trials in Spain and Portugal confirmed that demolition projects of old buildings yield only very small amounts of heavily contaminated plastic waste.

On the other hand, the trade and SME sector as well as packaging from construction sites have proven to be a significant source of plastic waste. A “Best practices” guide for plastics waste management by local authorities was issued in February 2004 in English, French, German and Spanish.

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A follow-up project to research and promote the collection and recycling of plastic waste from the construction and demolition sector, named APPRICOD, was launched in December 2003 and was completed mid-2006. It was partly funded by the EU LIFE programme and Vinyl 2010 is providing technical assistance. In 2005, about 20 pilot trials were conducted covering construction, renovation and demolition activities in four European regions.