Briefing: Developing a sustainable market for recycled glass

London Remade, the capital's recyclables market development agency, received £5·4 million Strategic Regeneration Budget (SRB) funding to drive innovation in remanufacturing and to overcome barriers to recycling in London. By working along the recycling supply chain and with a range of partners in the sector, it has helped double recycling rates in a number of London boroughs, invested and leveraged investment in new remanufacturing infrastructure and facilitated the diversification of markets for recycled materials within London.

Following the crash of the price for recovered green glass in 1999, London Remade investigated alternative uses and markets for recycled green glass, leading to the investment in a mixed-glass reprocessing facility. This initiative has been an important development in the stabilisation of markets for mixed and container glass.

The initial part of the SRB programme involved undertaking a study to prioritise materials around which London Remade's work would be centred. The study drew upon the experience of the Clean Washington Center in Seattle, developing a ‘prioritising matrix’ to identify the materials that should be given priority attention, on the basis of the following criteria.

• The need for market development (e.g. need due to oversupply of materials from recycling collections, regulatory drivers requiring high recycling, likely financial cost of current recycling programmes, or unstable current markets).

• The opportunity for developing markets (e.g. the potential to expand and strengthen existing markets for the material or potential to develop new markets).

• The ability of London Remade to influence markets (e.g. whether markets were driven by local factors and easy to access).

Four main material groups were identified as high priority: glass, organics (including food, produce and green wastes), mixed paper and wood waste.

At the time of the study, the consistent supply of glass from local authority and commercial recycling collections was being channelled into one major market for waste glass: container manufacture. Collectors and merchants of clear glass received a good price, as the majority of glass containers manufactured in the UK are clear, but green glass was not valued as the UK did and still does import a large quantity of its green glass in the form of containers for lager and wine, yet uses little in the domestic container market. Glass is bulky and costly to transport and as a large proportion of cullet was being reprocessed in South Kirkby, Yorkshire, recycling of this glass to meet both the packaging directive and challenging local authority recycling targets represented a burden on London's finances.

In 2000, total glass packaging waste arisings in London were estimated to be 446 000 t per year, 279 000 t of which was from the municipal waste stream, the remainder being from the commercial waste stream. Around 36 000 t of glass containers were being collected, mainly through local authority sites. These figures were estimated to grow considerably as the recycling and packaging targets began to bite.

The London Remade Glass Eco-Site Project was launched in February 2002 following formal agreement with the project partners. The project involved the construction of a plant to wash and crush up to 55 000 t per year of mixed glass bottles collected from London homes and commercial premises, producing a washed sand as an end-product—a replacement for traditional sharp sand, primarily for use in road construction and cable laying.

The premises of Day Aggregates, located in the London Borough of Greenwich in an area zoned for use by aggregate producers and users, were selected for the project site. The plant equipment, which uses technology developed and constructed in Austria and designed to the specification of Day Aggregates, became fully operational in August 2002.

Day Aggregates now receives, through the recycle-more-glass scheme and through the local authority contracts of Cory Environmental, waste glass containers collected direct from the capital's licensed premises and bottle banks. The glass from these collection points is taken to the processing plant, where it is crushed and washed.

The recycling process reduces the nominal glass particle size to under 5 mm. Corks, caps, lids and labels are removed from the glass sand. The resulting product is a clean, green-coloured sharp glass sand, safe and ready for use. It is a replacement for general-purpose sharp sand, for example in block paving underlay, free-draining trench backfill, cable and pipe laying and with asphalt. The glass sand conforms to BS 7533 Cat III for paving1 and has the advantage of good drainage properties and good packing density. Being 100% recycled it is not subject to any Aggregate Levy.

One of the objectives of the recycled glass project was to investigate other potential markets and products that could potentially use waste glass. Areas considered included glass sand in concrete with recycled construction and demolition waste, paving blocks, concrete tile products, shot-blasting sand and sand for golf course bunkers.

Raising awareness of the project among potential processors, users and specifiers has been achieved in a number of ways. In June 2001, Ken Livingstone launched the Mayor's Green Procurement Code to help stimulate demand for recycled products and recyclable materials in London. Operating with over 300 organisations, which include local and regional government, large corporations to small enterprises, not-forprofit and other public-sector organisations, a team of product and material brokers at London Remade work closely with recycled product manufacturers and procurement professionals to overcome the barriers to ‘buying recycled’. Highways and construction engineers, contractors and site supervisors have received advice from brokers or have attended technical workshops, demonstrations and events which have resulted in increased use of glass sand among the target audience.

Glass sand is now being used regularly in a number of the London boroughs, including Bromley, Camden, Hammersmith and Fulham and as a result of work through the Mayor's Green Procurement Code, Transport for London is now using glass sand in its highways work.

Smaller investments have also been made in other innovative projects. One of these has been with Freeform Arts Trust on its Green Bottle Unit project, based in Hackney, which develops high-value specialist products such as glass blocks for urban regeneration and shopping precinct redevelopments and a wide range of unique wall and floor tiles. Eight Inch, a design and manufacturing company, has also received assistance for the production of polished work surfaces of a composite material which contains 85% recycled glass.

The development of the Glass Eco-Site provides a long-term facility for the reprocessing of London's mixed glass and offers a product that can be used as a replacement for quarried material. Given the volumes of glass to be reprocessed, transport costs and the proximity to container reprocessing facilities, glass as an aggregate replacement in London has a significant role to play in helping meet Government-driven recycling targets. This project, while not being the sole influence, has also contributed to in a rise in the price paid for collected mixed glass which now sells for £10/t.