In a recently published research paper, Prof. Dr. Rainer Bunge of the University of Applied Sciences Rapperswil, Switzerland, argues that efforts to improve the recycling of plastics are not always the most environmentally beneficial. Often energy recovery is preferable. Here, the professor gives WMW readers a brief introduction to his findings...
Plastics recycling solves no problem in countries with proper waste management. In countries with an advanced waste management system, practically the entire amount of plastic waste is handled in the waste disposal system and is mainly disposed of in an environmentally sound manner (Fig. 1). Only two "leaks" remain through which the packaging plastic waste may still end up in the environment:
- Littering (illegal dumping of waste into the environment by consumers)
- Export of separately collected fractions (e.g. plastics of inferior quality) to emerging countries
The problem of littering can hardly be solved by forced recycling of plastics. Consumers who are unwilling to dispose of their waste in the nearest waste bin would not change their illegal behaviour due to an improved recycling system. Not a forced recycling, but the imposition of draconian penalties could be a solution to the littering problem.
The second "leak" of packaging plastics into the environment results from the export of collected plastic waste fractions from countries with a controlled waste management system to countries with an uncontrolled waste management system. A substantial part of these mass flows ends up in the environment (e.g. in the oceans as "plastic islands").
For reference: In 2016, EU member states shipped 46% of the plastics collected separately for "recycling" to the Far East. As plastic recycling is the very cause of this problem, an obvious solution in countries with a proper waste management system would not be an even more aggressive recycling of packaging plastics but rather the abolition of plastics recycling altogether. Consequently, the EU action plan (100% recyclable plastics in 2030) does not solve any problem connected with plastics discharge into the environment in countries with a controlled waste management system.
Plastics recycling is inefficient and ineffective
In Switzerland, most plastic waste is thermally utilized in municipal solid waste to energy incinerators and not physically recycled. Of the about 68,000 tonnes of plastic waste from households that are collected separately in Switzerland each year, 50,000 tonnes are PET bottles. The remaining 18,000 tonnes consist of other plastics from households, which are mainly collected by recycling systems that are voluntarily provided by retailers. The potential for increased plastics recycling was determined as an additional 120,000 tonnes per year.
Due to increasing political pressure toward plastics recycling, the federal government, several cantons, and environmental associations have commissioned a study on the ecological benefits and associated costs of plastics recycling.
Methods for life cycle assessment were used to quantify the ecological benefit of environmentally relevant measures. In Switzerland, the "method of ecological scarcity" is the most widespread. It involves assigning polluting activities with "environmental burden points", EBP. The mechanism is similar to the ecological evaluation of climate-relevant emissions using CO2 equivalents.
The ecological benefit of plastics recycling in Switzerland compared with MWI was calculated as 0.5Mio EBP/t. The additional costs of plastics recycling compared with MWI are around 500 CHF/t.
The benchmark chosen for assessing the eco-efficiency of plastic recycling was a comparison with the eco-efficiency of other recycling measures already introduced in Switzerland. Figure 2 shows that plastics recycling is at the lowest end of the eco-efficiency spectrum established in Switzerland and is therefore about 18 times less efficient than, for example, the recycling of large electrical appliances and electronics. For comparison, the SEBI for the purchase of one CO2 certificate for CHF 40 is shown in the figure. This, too, is about 10 times higher than for the collection of plastics.
Our study concludes that the collection of mixed plastic waste does generate a marginal ecological benefit at unreasonably high costs. But plastics recycling is not only inefficient, it is also quite ineffective. In Switzerland, the annual environmental benefit per capita would be equivalent to saving 30 kilometres of car driving or eating one barbecue-steak less.
Note that in countries with a controlled waste management system around 99% of the total environmental damage caused by the manufacture, consumption and disposal of a plastic-packed product is caused by the product itself. Only 1% is caused by the disposal of its packaging. Instead of introducing ever more intricate and costly schemes for reducing the 1% waste-related environmental damage of plastic packaging, it would be more productive to tackle the task of reducing the 99% consumption-related environmental impact.
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