Next months, these posts deal with the quest for bringing humane cities closer. These posts represent the most important findings of my e-book Humane cities. Always humane. Smart if helpful, updates and supplements included. The English version of this book can be downloaded for free here and the Dutch version here.
Plastics are versatile materials. However, their production contributes to greenhouse gas emissions and plastic waste threats our health. The way in which plastics have developed and are distributed illustrates that a circular economy stands or falls with product design. So far, the design of plastics reflects the ‘take-make-waste’ principle: Every year more than 300 million tons of plastic are produced worldwide, half of which are for single use. Only 10% or all plastics are made from recycled material. It can be different.
Plastic waste that ends up in nature degrades into micro plastics – plastic soup – and retains its chemical composition and toxic nature. Micro plastics eventually end up in the food cycle. More than 100 million tons of plastic already float in the oceans.
In the meantime, alternatives are being searched for, albeit far too late. Unilever leads the way. The company currently produces 700,000 tons of plastic packaging. This will be reduced by 100,000 tons in 2025. Moreover, the company wants that all its plastic packaging becomes reusable, recyclable or compostable and that at least 25% recycled plastic is used in the production of new plastic.
Below is a brief overview of the different options.
Preventing plastics from entering nature requires an extensive and costly system for collecting and separating waste and technology for high-quality recycling of the collected plastic waste.
The separation of waste
In case of a single-stream collection system, people throw plastic, glass, metals and paper into one collection bin. As a consequence, these items have to be separated. The video below shows the operation of a large-scale separation line.
As can be seen, quite a lot or human assistance is needed. New machines limit this unattractive work thanks to artificial intelligence. They are able to separate 20 different types of plastics.
One of the biggest hurdles in recycling plastics is its pollution, for instance as a result of added dyes. The Dutch company Ioniqa can chemically reduce PET waste to ‘virgin’ PET. Large plastic users like Coca-Cola intent to co-operate with Ioniqa. The video below shows how chemical recycling works.
Use of sustainable raw materials (biobased plastics)
The advantage of using sustainable raw materials (biomass) in the production of plastic is the reduction of CO2 emissions. However, biomass is becoming increasingly scarce and its production can compete with food crops and forestry. Moreover, most bio-based plastics are not biodegradable. If they end up in litter, the effects are as harmful as those of other plastics. For these and reasons mentioned below, there are quite some disadvantages associated with biobased plastics.
Biologically degradable plastics
Ideally, these biologically degradable plastics are biobased materials, which are safely broken down in nature in short time. PHA for example. Unfortunately, years of research have not yet led to its large-scale production.
Some other types of plastics such as PLA (biobased) and PBAT (not bio-based) are compostable, but only in an industrial environment. These types of plastics may be added to the organic waste. However, most consumers cannot distinguish between biodegradable, biobased and other types of plastics. As a result, many plastics unintendedly end up in the plastic soup.
If plastic had been designed for a circular economy from the start, the emphasis would undoubtedly have been on reuse. This also applies to industrial applications such as PVC. Thanks to a substantial deposit, the majority of all plastics could be reused than.
Back to reusable packaging?
Together with Coca-Cola, Proctor & Gamble, Nestlé, Unilever has joined Loop, a platform that develops refillable packaging. Supermarkets that deliver products at home can easily include them in their range. The video below shows how the system works.
Ban on some types of plastics
The collection of plastics still is still seriously inadequate and a large proportion of plastics ends up in nature as visual litter and return to our food chain as toxic plastic soup. This applies in particular to plastic bags, cups, trays for snacks and soft drinks bottles without a deposit. A ban seems to be the only way-out.