According to the OECD, less than 10% of the plastic waste on Earth is recycled. Here are five things to know about recycling techniques and their evolution.
Mechanical recycling
according to the research institute IFP Energies nouvelles.
After being collected and sorted by family of polymers with optical sorters or flotation systems, the plastics are washed and ground into granules. And then melted down and reused.
This technique does not strip the plastic of its additives (colours). Food packaging plastic therefore cannot return to a quality that allows it to come into contact with food. Users are driven to make lower quality products, such as garbage bags. The recycling cycle is not complete.
Manufacturers therefore prefer to use new, cheap plastic than recycled plastic. And much of the waste from developed countries goes abroad, the NGOs say.
Under social pressure, the processes improve, especially for PET: thanks to polycondensation, the broken down molecules are restored and the impurities are evacuated by heating and under pressure. In recent months, water bottles made from recycled plastic have been found in Europe.
One plastic, one factory
Each molecule practically requires a specific type of plant and equipment. However, there are dozens of types of polymers: the most common, polyethylene (PE) is used for shampoo bottles and plastic films around packaging water bottles, which are made from polyethylene terephthalate (PET), said AFP Marc Madec, an expert in sustainable development for the association of French companies. plastics processors Polyvia. As for their caps, they are made of polypropylene (PP)!
Polyvinyl chloride (PVC) is used in construction for floors or windows. Polystyrene (PS) produces yogurt pots and, in expanded form, trays, while polyamide (PA) is reserved for textiles and cars. Polyurethane (PU or PUR) is for foams and insulation.
Hence the importance of investing upstream in quality sorting equipment to properly separate plastics, as Japan does. This can limit losses in nature, the WWF applauds, but regrets that this country is doing more incineration than recycling.
Since China closed its doors to Western waste at the end of 2018, some 70 major “plasticizers” (Dow, Exxon, Henkel, TotalEnergies, Mitsui Chemicals, etc.), support themselves in the collective “Endplasticwaste”, collection and sorting projects. particularly in India and Thailand, and recycling.
Europe, dear student, but could do better
Faced with a global recycling rate of 9% of plastic waste, often due to a lack of collection and sorting infrastructure, “just over a third (34.6%)” of plastics collected in Europe were sent to recycling by 2020, according to the OECD.
The northern countries – Germany, Sweden, Norway – lead the way, about 40%. France is at 24%, the OECD says. The specialized ENF directory lists 161 factories in Germany, 173 in Poland, 132 in Italy, 89 in Spain and only 46 in France.
But according to the European Patent Office (EPO), Europe and the United States together concentrate 60% of the world’s patents on plastic recycling or bioplastics. “Even in Europe there is still a huge step to climb, we need to get at least 50-60%”says Marc Madec.
Chemical recycling, desirable or worse?
Chemical recycling makes it possible to “depolymerize” plastic, by going back to basic molecules (monomers), or even going back further through remanufacturing “naphtha”an oily compound derived from petroleum and a precursor to plastic.
“It’s like, by adding a solvent to a cake, we’re going back to eggs, flour, and butter”explains Marc Madec. “We use the basic elements to remanufacture plastic of the same quality as virgin plastic from petroleum. †
The advantage is that it completes the recycling cycle for all molecules, PET, PE, PS, PP etc. However, the disadvantages are the enormous investment costs, especially for the separate collection and sorting of vulnerable parts such as jars of yoghurt. However, recycling only happens if it is profitable.
In addition, it costs a lot of energy and there are still many uncertainties about the emission of greenhouse gases and toxic by-products, underline the Heinrich Böll Foundation and other experts.
(AFP)