Life-Cycle Economy The principle of sustainable development and the missing landfill in Europe are reasons for the introduction of the closed loop economy in the European Union. Products have to be produced and used resource conserving and have to be recovered after use, if they cannot be avoided at all. Landfill of waste is not allowed anymore. Therefore the question of disposal already comes up during the development of a product. If easy to dispose materials are used for the production, the disposal cost will decrease and in consequence also the over all product costs. Bioplastics have been developed according to these guidelines, in which composting is considered to bet the most cost-effective method of disposal. Only by using renewable ressources an actual closed loop can be realized. Life cycle analyses: Assessing the environmental impactAssessments of the impact of products on the environment require objective and standardized criteria. Life-cycle analyses complying with ISO 14040 are a suitable means of quantifying the impact of products on the environment. Their primary use in industry is to optimise process-engineering aspects of production with regard to the environment.
© Plantic
There are other tools that companies can employ to help them assess production methods and product performance as a way of describing environmental impact, for example EPD – Environmental Product Declaration. Basically, the entire life cycle of the product has to be considered – manufacture, use phase and disposal. With bioplastics, it is primarily the use of annually renewable raw materials in production that positively influences on energy consumption and CO2 emissions. Life-cycle analyses so far have shown that the values are at least 20% better than those for commodity polymers. A preliminary calculation within the European Climate Change Program ECCP returns a primary CO2 savings potential of approx. 4 million tonnes of CO2 equivalents. This figure is based on the assumption that the bioplastics market, given the appropriate supportive framework conditions, will have grown to around one million tonnes.Recovery OptionsThe objective of the EU to close material cycles has led to a different understanding and handling of the term waste: waste can be regarded as "raw material for new after life options". Bioplastics have been designed on the idea of a closed loop material management – like it is found in nature.Bioplastics can be recovered and recycled like conventional plastics by all available methods: thermal recovery, back to plastics and chemical recovery.Unlike conventional plastics most bioplastics types can organically recycled by composting, provided that they comply with EN 13432 criteria. Diverse examinations and studies show that there is no "best" option in recovery and recycling for plastics. Ecological and economical evaluation results differ when regarding different application of plastics, even if the same resin type is regarded.Composting is a useful and often preferred method for mulchfilm and biowaste bags, lso for gardening articles and shoppers offering the "second life option" of being also a organic waste bag. In all these applications biodegradability is an added value. Used food packaging can be processed with high eco-efficiency by composting, especially when short life easily spoiled food is packed. Then the packaging can be recovered together with the spoiled content without further treatment. Nevertheless the eco-efficiency is depending also on the given infrastructure at a place or in a region.Short characterisation of recovery options for bioplastics:
Thermal recovery: Using the high calorimetric value of the substance to produce heat and electricity (criteria of the legislation have to be met) Organic recycling (composting): The resulting compost is used to improve the soil quality and as a replacement of fertilisers Chemical recycling: Can be an option especially for polyester types like PLA or PHA. By chemical treatment the polymer chain can be de-polymerised, the resulting monomers can be purified and polymerised again. Sufficient amounts of source separated collected plastic waste is a pre-condition to apply this method. The same arguments apply for recycling back to plastics.Composting Biodegradation of a bioplastic film© BASFMany types of bioplastics can be composted. Microbes, like bacteria or funghii with their enzymes are able to "digest" the polymer chain structure as a source of nutrition. The resulting end products are water and carbon dioxide CO2 and a little biomass. It is the chemical structure of a polymer, especially the type of chemical bond, that defines whether and to what extend in given time microbes can biodegrade the material. This is the reason why also certain synthetic polymers can be composted – but most others (polyolefines like PE, PP, PS, PET) not.The speed of biodegradation is depending on
Temperature (50-70°C are typical for a industrial composting process) Humidity – water is required for the process The number and types of microbes Only if all three pre-requirements are given the speed of degradation is fast. In the food supply chain, in supermarkets or at home biodegradation occurs at a very low speed in comparison to composting. If one is missing degradation is almost blocked.In a industrial composting facility certified bioplastic products are converted into biomass, water and CO2 within 6-12 weeks. Such facilities exist in many EU countries and regions, e.g. Germany, Netherlands, Scandinavia, parts of Belgium, Northern Italy – have a look on the website of the European Composting Network. Organic household waste is collected by source separation from residual waste, e.g. in biobins (Abbildung), and treated in composting plants to produce quality compost. 30% (weight) of the household waste is of organic origin, e.g. food scraps or gardening waste. Compostable bioplastic products can make use of the existing composting infrastructure and thus be recycled organically – in a very cost efficient way. However compliance with the composting system has to be proven: This has to be done by fulfilling the standardised test criteria of EN 13432. For the approval and labelling of bioplastics products based on EN 13432 the industry together and other involved parties have developed a certification scheme.The combined recovery and organic recycling of compostable bioplastic products (here: packaging) together with organic household waste has been examined in the Kassel project 2001-2003.LitteringLittering refers to careless discarding of rubbish. Bioplastics are often regarded as a possible solution to this dilemma as they can be decomposed by microorganisms without producing harmful or noxious residue during decomposition. Littering is not a legitimate means of waste disposal, therefore biopackaging alone does not provide an adequate solution. Compostable packaging is however optimised for recovery in composting operations. Temperatures of up to 70°C and higher humidity are required for their rapid decomposition in 6-12 weeks. Such conditions are virtually never existent in nature, which means that decomposition can take considerably longer. Even under ideal decomposition conditions, they remain recognisable as packaging for a period of time, and represent an unattractive blight on the landscape.It is imperative for the consumer to continue to be conscious of the fact that no matter what type of packaging, it must be subject to a regulated recovery process. This is the only possibility for re-use and recycling to occur.
