In Practice: The ‘world-first’ closed-loop glass recycling facility

Knauf Insulation's aim to ensure that recycled contents are embedded into the products it manufactures has seen the company strike a long-term partnership with waste specialists Veolia to create a closed-loop system for glass waste.


The Challenge

Veolia has committed to invest more than £1bn on new infrastructure between 2012 and 2018, all of which focus on the circular economy in way that preserves the scarcity of raw material. While the waste management firm has a range of innovative solutions to utilise water and select waste streams as a resource, the company was looking to secure demand for recycled glass.

Just across the road, Knauf Insulation was looking for ways to secure a supply for recycled content for its insulation products – which are likely to see an increase in demand as  Minimum Energy Efficiency Standard (MEES) for commercial properties take effect as of 1st April 2018.

The Solution

In 2017, Veolia and Knauf Insulation entered into a 10-year contract to create a state-of-the-art glass cullet processing facility, which would be situated next to Knauf’s manufacturing plant in St Helens, Merseyside.

The new £10m facility, a world first, will dry and refine glass collected and processed by Veolia which is recycled into small glass fragments cleaned to at least 98% purity. The cullet is then fed into a furnace where it is melted and spun into glass mineral wool, which is used by Knauf to produce energy-saving insulation products.

The state of the art machinery used in the process includes vibrating screens for size sorting, magnets to extract ferrous materials and eddy current separators for non-ferrous materials.

Annually, more than 60,000 tonnes of used glass bottles and jars – which could otherwise end up in landfill or littered, will be reused and transformed.

The Benefits

The project will reduce the use of raw materials, lessen energy demand in buildings, cut carbon emissions and limit the amount of materials that are being sent to landfill. The partnership helps Knauf secure its glass supply to ensure that up to 80% of recycled content is used in Glass Mineral Wool product solutions.

The new facility enables Knauf Insulation to secure its glass supply and maximise the use of recycled materials instead of virgin minerals. Also, the proximity of the new facility will save approximately 375,000 miles of road journeys and associated emissions.

As well as reducing the amount of waste ending in landfill, the solution will reduce carbon and energy use by creating more insulation. The recycled glass actually produces less CO2 than traditional raw material extraction from quarries and the process itself uses less energy than traditional methods of manufacturing mineral wool insulation.

Associated energy savings from recycling a single glass bottle equal to powering a 100-watt light bulb for almost an hour, according to Veolia. Just 5% of the recycled glass, listed as fine particles, are sent to the aggregate industry to be used, with the remaining 95% turned into cullet and sent to Knauf. In comparison, the UK average for glass recycling is 67.1%.

According to the two firms, the £10m facility, which is now fully operational, will help avoid the release of 12,000 tonnes of CO2 equivalent annually, which is the same as removing 7,000 cars from the road. The facility will also save 76,000MWh of energy, enough to make 20 million bottles of wine from scratch.

The facility has also created 18 new and permanent jobs in the region.

The Future

One area of collaboration between the two firms to keep an eye on is the development of Ecose. The technology is used to bind all Glass Mineral Wool solutions and the majority of Rock Mineral Wool products. The Ecose technology is 70% less energy intensive than chemical-based binders and is made from bio-based materials instead of traditional petroleum-based chemicals.

The products can also be compressed so more can be loaded onto trucks, which reduces packaging and fleet miles as a result.

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