Dating back to 1977, glass recycling in the UK is one of the more successful initiatives in the recycling industry

Problem Overview:

Waste management, particularly the need to facilitate waste reduction and recycling strategies, has led to a number of initiatives to minimize waste accumulation. Yet, many countries continue to struggle to find effective recycling systems.

Background:

Dating back to 1977, glass recycling in the UK is one of the more successful initiatives in the recycling industry. The system has been developed over the years and consists of placing bottle banks in accessible locations, where the public then deposits glass refuse. The refuse, otherwise known as cullet, is then collected by the municipalities and transported to the processing plants where glass products are manufactured. Over the last three decades, 17000 bottle banks have been established throughout England, Scotland, and Wales. Every local authority in the UK operates a glass collections scheme, and in 1993, 500,000 tons of glass were recycled. This meant that every glass product manufactured contained 30 per cent recycled glass.

In response to the need to reduce the amount of waste sent to landfill sites and reduce exploitation of natural resources, the glass industry of the UK set up a glass collection and recycling program. Municipalities first set up glass banks where the public deposited glass bottles and jars, which were subsequently collected by local authorities and transferred to processing plants where new glass products were manufactured. The glass cullet collected in the glass industry comes from two main sources: factory cullet and external cullet. Factory cullet is composed of rejects from the manufacturing process and external cullet consists of industrial cullet from other processing plants (i.e., beverage and food packagers) and domestic refuse.

Although the glass recycling scheme has been largely successful in reprocessing approximately 500,000 tons per year, there are several logistical factors which must be considered in developing a similar system. The first involves the method to bottle bank provision. Each bank should be distributed in such a way that it would provide the simplest and cheapest way of disposal and collection. The most feasible locations would be shopping centers, public transportation sites, street corners, and community centers. Supermarket centers may be the most convenient as shoppers can often combine their recycling with shopping in one trip. Bottle banks should not be located in or close to residential centers as there are many disturbances associated with the noise.

Transportation of the cullet is the second factor which must be considered. In the UK, there are two distinct systems for transportation in two different regions. The cullet is either collected from the banks by a contractor or delivered to the processing plant by a local authority in the south. If a contractor is hired for transportation, the glass manufacturing companies are obliged to purchase the cullet from the contractor. In the north, one of the glass container manufacturing companies runs the recycling system itself. Thus, it owns the most of the bottle banks, hires the contractor who transports the cullet from the banks to the processing plants, and then processes the cullet within their own plants. The company-owned system has proved to be more efficient, cost effective, and reduced the number of contaminations which can result when more parties are involved.

An important economic constraint which must also be recognized is that the cost of recycling must not increase the cost of glass production. In other words, the cost of collection and transportation of the cullet must not exceed that of the production of glass from other natural sources. The costs of the recycling program may include cullet handling and storage equipment (i.e, bottle banks, lorries, and processing equipment); the risk of wear and tear on the processing equipment; checking the cullet for foreign bodies which might impede production processes (i.e., ceramics, pyrex, porcelain, etc...) International competition and import of other recycled products might also disrupt the national market. The arrival of products with very low prices may severely effect the recycling industry. A similar scenario occurred in the UK when recycled products arrived from Germany and undermined the local paper and plastics recycling industries.

There are innumerable advantages to using cullet as a source for glass production. Estimates confirm that increasing the use of cullet in a furnace by 10 per cent results in an energy saving of approximately 3 per cent, and for every ton of cullet used, there is a savings of 1.2 tons of raw materials. First, extraction, processing, packaging, and transport savings made from not using natural sources are estimated at 100 liters of oil per ton. Second, reducing the amount of energy consumed through raw material production also reduces the volume of emissions and the level of dust contained in the gases. Finally, the reduction of municipal glass waste through recycling also saves a significant amount of landfill space.

British Glass has faced several technical considerations in the implementation and maintenance of the use of recycled glass in manufacturing processes. The industrial plant must be kept in good working order--metal waste from the closures and fittings of glass containers can damage equipment and disrupt electrical conductance. This may result in more rapid deterioration and a shorter life span for the furnace. It is important that the public is well informed as to proper disposal techniques to reduce the number of caps and metal closures. To this end, British Glass educates the public by promoting glass recycling through extensive advertisements. Second, due to specific requirements in production for varying shades of glass, it is important that the right proportions of mixed cullet are used. For example, green glass can absorb fairly large proportions of mixed cullet, whereas clear glass can only absorb a small amount of mixed cullet. Due to further experimentation by British Glass, there have also been several new applications of mixed cullet in other industries including road surfacing, the production of more durable bricks and insulated clay pipes for furnaces; vitrification of toxic wastes; cementing; weather resistant tiles; foam blocks; and decorative products.

Follow-up:

The recycling system is evaluated by British Glass and there continues to be research in more alternative uses of excess cullet

Contacts:

A. Morris
British Glass
Northumberland Road
Sheffield S10 2UA
United Kingdom

Information Date: 1994-01-01
Information Source: Industry and Environment, “Promoting Waste and Recycling, Part II”, vol. 17., No. 3, July-September 1994.