The magical process of giving your used glass another chance at a meaningful existence begins at the bottle bank, the big metal container where your neighbours judge you for the sheer volume of wine bottles you deposit. But tossing your glass in here is the easy part. Behind the scenes, local authorities and recycling companies scurry to collect these bottles and jars to transport them to a recycling facility.
This part begins when the used glass is collected from bottle banks, which are split into clear and coloured sections in the Brussels region. The Brussels region waste authority, Bruxelles-Propreté, collects some 26,000 tonnes of used glass per year, and it is all delivered to a storage space alongside the canal, next to the region’s incinerator.
From here, the glass is loaded onto river barges of 1,000 to 1,700 tonnes and ferried north on the Willebroek Canal, through interconnected waterways until it reaches the Albert Canal, which runs from Antwerp to Liège. The final destination, GRL Glass Recycling, is in Lummen near Hasselt, around the midpoint of the canal, and just 35km from the Dutch border.
“I think glass is one of the most wonderful products to recycle because you can recycle it over and over again,” says GRL Managing Director Martine Meuws. “For paper and cardboard, for example, after six or seven times, you need to use primary material because it's finished. With glass, you can use it thousands of times and it doesn't lose its specifications.”
Lummen is one of Europe’s biggest glass recycling plants processing up to 200,000 tonnes of waste glass a year. It is not directly on the canal, so the glass still has to be trucked from the docked barges. However, a new €39 million facility in Beringen, 10km away, will replace Lummen later this year. It fronts the canal, so the glass can be unloaded directly from the barges, allowing them a 40% increase in barge transporting.
Screening
Once at the facility, the glass undergoes rigorous screening, because, let’s face it, not all recyclers are responsible. The first step is the removal of large contamination pieces. “This includes diapers, shoes and other things that you wouldn’t imagine you would find,” says Meuws, a 30-year veteran of the recycling business.
The other steps in the glass sorting are done by hand at the Lummel facility, but at the new one, it will be done by magnets, eddy current separators and optical sorters.
Beringen’s magnets pull out ferrous waste, while the eddy current separators remove nonferrous objects such as aluminium pieces attached to bottlenecks (which can then be recycled separately).
Recycling park in Beringen under construction
Optical sorters, using sensors and cameras to check each item, are applied to sort out the ceramic stones and porcelain (CSP). These sensors figure out the material type, shape and colour, which helps the machine quickly sort them into different categories.
The CSP needs to be removed because of different melting points. Coloured glass melts at 1,400°C but at 2,000°C for CSP, so if it is in the mix, it won’t melt and there will be small pieces of CSP in the newly made bottles.
GRL’s clients have stringent quality control specifications. For instance, they are allowed just 20 grams of CSP per tonne of glass waste. The optical sorter also identifies heat-resistant glass, which is also unusable since its melting point is too high. The one thing that the optical sorter cannot currently do is recognise black glass, so it rejects luxury bottles such as those used for cava or perfume.
Greener glass
Both plants have the next stages, where the glass waste is broken into smaller pieces with a shredder before going through several sieves to sort them out by size.
The shreds then head into furnaces. The glass is not washed at any point, but it is cleaned in the furnaces, which are heated to 200° C. This is followed by a de-labelling machine: rows of rotating hammers remove all the organic matter such as labels.
The final product that GRL sells is called cullet, which are the clean pieces of broken glass used to make new bottles and jars. Very little is lost in the processing: some 95% of the material that comes into GRL from Brussels emerges as cullet, which is then bought by glass producers across Europe and South America.
Glass Recycling Bottles
Producers prefer cullet as it melts at a lower temperature than raw materials, which means less energy is used to create new glass. It’s mixed with fresh raw materials – and, soda ash, and limestone – and heated into a molten state. This glowing, lava-like mixture is then moulded into new bottles, jars, or even fibre insulation. And just like that, your recycled beer bottle might return to you in another form.
“So, it's a very sustainable and economic way to make new bottles because they don't need as much energy to use cullet as they need with primary materials,” Meuws says.
GRL’s new facility will be more eco-friendly: as well as being on the waterfront, it has 15,000 square metres of solar panels on its roofs which will generate 40% of its electricity needs. And instead of burning gas to heat the furnaces, the Beringen plant is connected by pipes to a nearby incinerator: the steam generated by the incinerator will fuel GRL’s furnaces.
While glass is 100% recyclable – and can be endlessly recycled with no loss of quality – this can only happen if there is a dedicated system to collect and process the glass. That is now the case in Belgium, and across Europe.
“The days of most everything going into landfill are over,” Meuws says. “I think we can be very proud in Belgium for where we are. We are one of the top countries in recycling for a lot of materials: plastics, paper, metals, and, of course, glass,” she says.
