Plastic scrap can make a meaningful contribution to society in many ways. Opinions, however, differ greatly when comparing the merits of treating it through mechanical recycling, chemical recycling or energy recovery (incineration). Let’s review the case.
French start-up Carbois is hoping to make a difference for polyethylene (PET). It opened a demonstration plant in September at Clermont-Ferrand where it is pioneering an innovative method of chemical recycling relying on an enzyme to treat the plastics. The testing facility features a 20 cubic metre reactor that can hold two tonnes of plastic, the equivalent of about 100 000 ground-up bottles.
This is broken down into the building blocks of PET – ethylene glycol and terephthalic acid – in 10 to 16 hours. The resulting monomers can then be purified and strung together to make new plastics. Company researchers note that PET is typically a clean and homogenous waste stream to their process is not yet able to tackle mixed plastics.
As Recycling International saw at recent trade shows across Europe and North America, cutting-edge sorting solutions are gaining in popularity. Smart systems from Tomra, Bulk Handling Systems, Zenrobotics, Redwave and others could be a game-changer – though these don’t come cheap.
Cement with alternative fuel
Non-mechanical recycling options could be a complementary option for a ‘problematic’ plastic waste stream. The refuse-derived fuel market is projected to reach EUR 1.9 billion this year. Most of the world’s demand comes from Europe, which holds a 60% stake, according to market analysts at research firm Fact.MR. The pandemic caused a slight dip in the market of 1.5% but the sector ‘is set to get back on track’ with anticipated annual growth of 3.5% in the 2021-2031 period.
Plastic scrap offers a source of alternative fuel for the fast growing cement industry – valued at EUR 278 billion in 2020. Many big brands like Nestle, Unilever and Coca-Cola are grateful for the solutions provided by companies like Geocycle, the waste management division of cement manufacturer Holcim Group. Geocycle uses two million tonnes of plastic scrap for its annual production process and plans to expand the input to 11 million tonnes by 2040.
Substituting the burning of expensive coal with readily available scrap materials, ranging from textiles and tyres to sewage sludge, is hardly a new practice as it dates back to the 1970s. The uptake in large scale waste collaborations is expected to push the value of the cement industry past EUR 400 billion within seven years.
What does that mean for scrap? Today, the cement industry has enough capacity to incinerate all end-of-life plastic produced around the world. Geocycle puts total capacity at around 300 million tonnes annually. This figure far exceeds the global plastic recycling capacity, estimated to be around 46 million tonnes a year.
XL energy recovery
The same boom can be witnessed in the global energy recovery industry. Latest Statista data suggests the global value of the waste-to-energy market was over EUR 31 billion last year. By 2027, this will increase to EUR 45 billion, growing at a compound annual growth rate of 4.6%.
The US has built 86 waste-to-energy facilities to date while Europe has more than 400. There are another 300 in Asia, most of which are in China.
Meanwhile, Shenzhen city is constructing the world’s largest waste-to-energy plant. The state-of-the-art facility is scheduled to open its doors in mid-2022, with a capacity of up to 5 000 tonnes of per day. Rooftop solar panels spanning 40 000 square metres of the building will also generate renewable energy.
Officials report that the site will take on at least one-third of the city’s annual waste stream which is increasing by roughly 7% every year. Based on these numbers, investment is unlikely to be a long-term solution but rather a quick fix.
Keeping everyone motivated
Critics often debate whether or not encouraging the incineration of scrap is essentially moving landfills from the earth to the sky. And then there is the question of whether big brands will see incineration as an excuse to keep making hard-to-recycle products rather than taking sustainable design into account.
With the pandemic and its aftermath taking a significant bite out of the earnings of both recyclers and producers, it remains to be seen where new investments will flow and what technology will be utilised to shape our future.
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