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Politics Fig. 4: Waste

Politics Fig. 4: Waste incineration plant in Vienna, Austria, designed by Friedrich Hundertwasser So-called ‘oxo-degradable plastics’ are not suitable for organic recovery So called ‘oxo-degradable plastics’ (i.e.: polyolefines with metal-containing additives) are sometimes advertised as being ‘biodegradable’ or even ‘compostable’. Such claims are misleading if they are not substantiated by showing compliance with the relevant standards EN 13432, EN 14995, ISO 17088 or ASTMD-6400. These define the requirements for materials which can be called ‘compostable’. In the case of packaging, such claims are bound by legal definition to the compliance with EN 13432 in several EU countries. There are no known ‘oxodegradable’ materials in the marketplace which fulfil either of these standards. Claims of compostability for such products are therefore wrong and untrustworthy. In Italy and Australia for example, lawsuits resulted in fines for using misleading claims in the marketing of such products. Thermal Recovery ‘Thermal recovery’ is the term for all exothermic waste management processes which yield energy and/or heat. Incineration is the most prominent example. The high calorific value of bioplastics and the clean product composition allow all bioplastics to be recovered thermally. In case the incineration plant (Fig. 4) is equipped with an energy recovery unit, the energy resulting from burning renewable resource based bioplastics will be considered ‘greenhouse-gas neutral’. Mechanical Recycling Mechanical (or physical) recycling is understood as the recycling back into plastics. It will only lead to high quality products when the input material is very pure. This is the case e.g. for the reprocessing of production waste: Converters of plastics usually have facilities installed to recycle the production scraps as a valuable raw material and feed them back into the production process. Only a small proportion of the total plastics market is currently being recycled back into plastics. Recycling usually becomes much more complicated when mixed post-consumer plastics waste is used. The typical situation is that post-consumer plastic waste collection schemes deliver a mixture of polymer types (fractions of PE, PP, PVC, PS, PET, etc. including laminates, compounds, coated products etc.). These products are often contaminated with various labels, inks, glues, residues etc., so that the resulting recyclates are of limited quality. With rising environmental concerns and during times of high raw material prices, investments in recycling and sorting technologies increase. Sorting and pre-treatment technologies have been improved and now allow the selection of quite pure plastic waste. Bioplastics are adding to the variety of plastics on the market. However, owing to comparably low market volume, mechanical recycling of bioplastics is currently of no significance. With growing volumes, it will be possible to install specific collection, separation and recycling technologies for bioplastics as well. Solutions can be based e.g. on the available NIR (near infra-red) technology which can detect virtually every plastic type, including different bioplastics. It has been shown that this technology allows for example the automatic sorting of PLA bottles from PET bottles [3]. Chemical Recycling The conversion of plastics back into monomers, which can then be polymerized to plastics again, is called chemical recycling [2] This recovery route can for example be applied to convert PLA back into lactic acid. It must be noted though, that due to the so far little amounts of post consumer PLA, this option cannot be judged so far concerning technical and economic feasibility. 22 bioplastics MAGAZINE [02/09] Vol. 4

1 2 3 Fig. 5: NIR sorting (Schematic: Titech) (Oder ein echtes NIR-Spektrum) 1 2 3 unsorted material input scanning and processing separation chamber Landfill Landfilling is not considered a ‘recovery’ option. It should be seen as a waste of resources and it should be reduced or terminated wherever possible. Due to the The European Landfill Directive 1999/31/EC for example the amount of municipal waste going to landfills has already been significantly limited in some European countries and will be further reduced considerably. As waste from bioplastics represents only a very low share of this waste (well below 1 %) and as bioplastics market volume will be growing at the same time as municipal solid waste is more and more being diverted from landfill, it is expected that the amount of bioplastics waste going to landfill will remain extremely low. Landfilling of waste is generally not considered a ‘solution’, therefore the focus for bioplastics should firmly be on the development of recovery systems, either for the biological recovery, incineration with energy recovery or recycling. Conclusions It is and will continue to be the task of all parties involved in plastics waste management and of governmental institutions to work out best practice recovery solutions for both bioplastics and conventional plastics. It has to be kept in mind that bioplastics have only a very small share of the current 250 Mton total plastics market (global). They represent a new material group which can make use of all the established recovery and recycling technologies for conventional plastics and moreover offer the new option of organic recycling. There is time and opportunity to develop solutions because bioplastics are still in their infancy with low market volume. Recycling issues should not lead to hampering the development of bioplastics. The focus should be on the establishment of practical solutions for legislation, communication, sorting and recycling technologies, amongst other issues. Most bioplastic products are composted today and do not interfere with recycling. Composting is and will remain an important recovery route for many short-life bioplastic products. Thermal recovery processes can handle bioplastics without any problems. Mechanical or chemical recycling represent promising future options for some bioplastics, yielding potentially high quality recyclates. The intention must be to establish eco-efficient recycling systems by making use of all available recovery methods according to the particular product, thereby avoiding negative interference on existing plastic recycling schemes. As bioplastics volumes are currently very low, methane emissions from bioplastics are not a relevant issue. Anyway, Bioplastics – and much more importantly, organic food waste - should not end up in landfills. Stopping landfill of untreated organic waste will decrease the problem of methane emissions and improve ecology, therefore many countries worldwide aim at establishing specialized systems for the separate collection, sorting and treatment of waste. Bioplastics can contribute to such waste policies e.g. by enabling consumers to collect their organic waste separately in compostable bags. [1] European Bioplastics FAQ paper on bioplastics php?download=Bioplastics_FAQ.pdf [2] Harper, C.A., Modern Plastics Handbook, McGraw Hill, 1999 [3] Sawyer, D., The Benefits and Issues of Sorting Plastics for Improved Recycling — With Special Emphasis on PLA (www. bioplastics MAGAZINE [02/09] Vol. 4 23

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