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Incineration is the ideal disposal method for flexible PU upholstery |
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Polyurethane, due to its versatility, finds application in a range of products including liquid coatings and paints, sports products, rigid insulation for buildings, flexible foam in mattresses and automotive seats, etc. Since polyurethanes have diverse daily use applications and industrial uses, they enter the municipal solid waste stream, usually by way of discarded consumer and industrial products. Interestingly, PU products are frequently durable goods such as upholstered furniture, mattresses and automobile parts. The various types of polyurethane waste products, consisting of either old recycled parts or production waste, are generally reduced to a more usable form, such as flakes, powder or pellets, depending on the particular type of polyurethane that is being recycled. The various recycling technologies for material and chemical recycling of PU materials have greatly contributed to improve the overall image regarding the recyclables of polyurethanes in recent years, by far the most important being regrinding and glycolysis. These technologies open an emerging, effective and economic route for recycling polyurethane rigid foams and composite. Polyurethane foam in automotive seating has been successfully recycled using regrind technology. Glycolysis of polyurethanes can be economically acceptable, but requires further development to tolerate more contamination in the post-consumer material. Current technologies can recover the inherent energy value of polyurethanes and reduce fossil fuel consumption. Energy recovery is considered the only suitable disposal method for recovered material. Increasing waste-to-energy and other thermal processing activities involving gasification, pyrolysis and two-stage combustion has contributed for the disposal of significant amounts of scrap PU without many difficulties. It is concluded that many of the plastic feedstock recycling processes appear to be technically feasible and robust enough to warrant further development in the future.
According to Europur, flexible polyurethane foam is widely used as an important component of upholstered furniture and mattresses and, therefore, needs to be taken into account when End-of-Life (EoL) issues are considered, in the light of the EU waste management policy.
At present discarded post-consumer upholstered furniture and mattresses are part of the Municipal Solid Waste (MSW) stream and are collected by municipal authorities with other MSW. A field study on separate collection of EoL mattresses, dismantling and recycling of the sorted materials in the Netherlands failed because of economic unattractiveness and environmental inefficiency. Suitable operational units for logistics, dismantling and recycling of the different materials at the level of municipal waste operators do not exist today.
Flexible polyurethane foam wastes (FPW) from EoL upholstered furniture and mattresses represent a minor material fraction of total MSW. According to a study done by the Union Europ�ene d� Ameublement (UEA) in 1999 for the EU15 the volume of that FPW is 0.3 mln tons or only 0.2 wt% of the total MSW volume of 180 mln tons. EUROPUR and ISOPA have decided to evaluate the best practices for recycling and recovering of FPW from EoL furniture and mattresses. Suitable technologies are already described and communicated in the relevant literature. The disposal of MSW in landfills continues to be practiced.
The following table shows a survey on the available technologies/processes:
Process / Technology |
Suitable type of waste |
Resulting Product / Market acceptance |
incineration |
organic plastics waste mixed with separated FPW |
energy as heat and electricity /
used successfully since years,
incineration capacity is growing EU-wide |
gasification |
municipal solid waste (MSW, containing EL furniture and mattresses) |
synthesis gas or reducing agent /
application in refinery processes or as reducing agent in blast furnaces, promising processes |
rebonding of foam flocks1) |
separated decontaminated FPW |
rebonded foam /
well-known product, the market for it is already saturated (130.000 t/a) |
powder milling1) |
separated decontaminated FPW |
PU-powder 50-70µ /
reuse in virgin foam possible, only a few milling facilities in operation |
| 1)At present trim foam is used for these industrial processes, untreated EoL-FPW is not applicable |
The disposal of EoL upholstered furniture and mattresses in landfills is an acceptable
solution if sufficient incineration capacity is not available and can be used as long as national legislation allows. In some EU Member States the phasing out of landfill for untreated MSW has already started. To confirm the low impact of EoL-FPW on the environment and to prevent possible changes of its waste classification leaching tests have to be performed.
Conclusions:
• Incineration with energy recovery is recommended as the preferred technology for the treatment of EoL upholstered furniture and EoL mattresses because of the best eco-efficiency compared to alternative routes. The availability of suitable incineration capacity varies significantly from country to country and investments in future capacity extensions are ongoing. The cost / benefit analysis (CBA) shows that the incineration with energy recovery is the most economic process (see Vito study 2001, final report).
• Controlled landfill could be utilised as long as allowed by national legislation, but
a phasing out has to be considered in medium to long term.
• A decision for waste stream recycling of EoL-FPW out of EoL furniture and
mattresses would require the built-up of a very costly furniture / mattresses collection
infrastructure and the separation of FPW from other waste materials by manual
dismantling. This waste processing route cannot be recommended because of the
excessive high costs involved. The recycling/recovery processes deliver either products with poor quality and limited application outlets (chemolysis � liquid recyclates) or are not yet fully established in the market (gasification � synthesis gas or reducing agent).
• EoL upholstered furniture and mattresses need not be separated from normal
solid domestic waste and they can be treated together. |
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