INTERNATIONAL: Europe Manages Mountains Of Plastic Waste

Ann Kulik

Plastics contribute 7 percent by weight to western Europe's municipal solid waste stream (see pie chart). In Germany, close to two-thirds of the plastic in the household trash consists of packaging.

Europe's waste stream also includes plastics from various industrial sectors such as agricultural, automotive and construction businesses. Overall, the plastics fraction reportedly doubles every 10 years.

The Swiss are the third-largest consumers of plastics, at an annual rate of 1.25 million tonnes; only the Americans and Japanese consume more. Between 65 and 70 percent of the country's yearly total requires disposal, and quantities are increasing as short-lived plastic products proliferate.

To manage these mountains of waste, the Association of Plastics Manufacturers in Europe calls for resource optimization through reduction, reuse and recycling, with energy recovery at the end of the product's life. An eco-balance, or life cycle analysis, can determine how to achieve optimal recovery while minimizing environmental impacts.

Many European countries have reached high recovery levels by choosing the recovery approach best suited to the individual waste type. For example, in France, the preferred approach is mechanical recycling for plastic bottles and flasks; thermal recycling for film plastic and pouches; and mechanical recycling combined with energy recovery for mixed plastics from cups and blister trays. Denmark, Sweden and Switzerland also favor integration of mechanical and thermal recycling.

To overcome the ecological, technical and economic limitations of mechanical recycling, the European plastics industry is exploring other options including pyrolysis, hydrogenation, gasification and chemolysis. These technologies break plastics down into their constituent molecules for reuse in refineries or petrochemical and chemical production. This kind of recycling, unique to plastics, reduces the consumption of oil resources and does not degrade quality as mechanical recycling does.

Researchers at the French Centre Scientifique et Technique du Batiment have developed a chemical process to recycle polyethylene terephthalate (PET) bottles into a new generation of insulating materials for construction applications. The economic feasibility has yet to be proven through collaboration with industry.

Switzerland claims to be Europe's top recycler of PET bottles. In 1994, the Swiss collected more than 9,000 tonnes of PET at 12,000 locations, at an estimated rate of 75 percent. Striving to close the recycling loop, they have developed a PET bottle with an inner layer of up to 40 percent recycled PET. The two-year testing phase introduced this year is a first for Europe. A remaining hurdle is a Swiss law that prohibits the use of recycled plastic in objects that come into contact with food products.

A 1992 French decree mandates 75 percent recycling of plastic packaging by 2002. Polyvinyl chloride (PVC) bottles, commonly used for noncarbonated mineral water and other beverages, are collected in increasing amounts through Eco-Emballages, the French green dot system. Impurities such as caps, adhesives and labels are removed by a series of separation techniques.

In 1994, approximately 200 million French PVC bottles (8,000 tonnes) were reprocessed into pipes, fittings, profiles, floor covering, shoe reinforcements and other products. Recent developments include textiles made from PVC fibers, PVC-modified paint to improve friction and noise level in car parks, and high-performance sound protection walls made from recycled PVC.

To sort diverse polymer types for mechanical recycling, the Swiss firm Buhler has developed the Niriks system, a high-speed sensor. It uses a near-infrared spectrometer to identify the five most common polymer types (PE, PP, PVC, PS and PET) without physical contact.

Even Germany, until recently suffering from a recycling capacity shortage for nearly 1 million tonnes of plastic packaging waste consumed each year, now has the situation under control. Since 1993, plastics collected in Berlin and the state of Brandenburg have been delivered to a facility in Eisenhuttenstadt, where three separated fractions are processed into products including garbage bags and carts.

Pyrolytic, hydrogenation and gasification processes also are being tested and applied in Germany. Other plastics recycling efforts include a take-back system enabling expanded polystyrene manufacturers to reprocess their regranulated plastic.

As BASF points out, "the problem of waste is not a problem with plastics," which can be properly managed and do not belong in the landfills.