|
Commodity thermoplastic resins are unique among commonly used materials in their ability to be recovered and recycled. In this report, recycling is defined to include mechanical (physical) recovery, chemical (depolymerization-to-monomer) recovery, thermal (pyrolysis-to-basic feedstocks) recovery and incineration-with-energy recovery. The chemical and pyrolysis processes have the potential to be very attractive recovery routes that eliminate many of the technical and quality limitations encountered with mechanically recycled plastic resins.
Recycling and reuse of postconsumer thermoplastic resins have been practiced since the early years of the plastics industry. Initially, resource recovery and waste avoidance provided economic incentives to recycle manufacturing scrap from plastics fabrication operations. In the last fifteen years, unsightly litter and tightening landfill requirements spurred legislation in the United States to reduce the amount of plastic waste generated and the amount that is discarded. These two incentives, combined with the opportunity to conserve nonrenewable resources, have driven the increases in recovery and recycling of plastic waste in the major industrialized countries.
Of the three major geographic regions, the U.S. approach to plastics recycling is the only one driven primarily by the free market, with limited stimulation from mandating legislation. As a result, the postconsumer plastics recycling market is subject to the economic cycles familiar to all commodities. As recently as 2000, recyclers were relatively profitable but, throughout 2001, the thermoplastic resin business environment drifted steadily downward along with virgin resin prices, weakening the recycling infrastructure and causing a number of reprocessors to suspend operations or go out of business. Ultimately, demand for recycled resin will take priority over its supply, especially in competition with virgin resin.
Japan disposes of over half of its plastic waste by incineration with or without energy recovery. Much of Western Europe and Japan view incineration as a valid recycling option. Quantitative comparison of recycling progress in the three regions is made difficult by the lack of consistent definitions and categories of recycled materials.
Postconsumer PET is the most recycled plastic in the three regions, with a well-developed recovery infrastructure. From 1990 to 2000, virgin PET enjoyed the highest growth rate among the commodity thermoplastic resins, driven by large penetration into the carbonated soft drink and mineral water packaging markets. Until 1996, the number of virgin PET producers was relatively small with the stable high price (and profitability) of virgin PET reflecting an undersupplied market. The primary influence on the price structure for PCR (postconsumer) PET has been, and will continue to be, the price and availability of prime and wide-specification virgin PET.
Collection of plastic recyclables will continue to be one of the most important challenges facing the global plastics industry. The passage of new legislation dealing with the recovery and reuse of plastic waste has slowed. To strengthen the collection infrastructure, additional legislation may be needed to provide more consumers with an economic incentive to recycle. If all else fails, a surcharge on domestic sales of thermoplastic resins might be needed to subsidize a variety of local collection and reclamation programs. But, regardless of the method used, the full upstream costs of recycling plastics eventually will be passed through to the ultimate consumer.
In the United States, collection of postconsumer bottles grew rapidly in the first ten years after recycling programs were initiated in the mid-1980s. However, collection growth has slowed substantially in recent years and has essentially plateaued since 1997. With the continuing strong growth in production of plastic bottles, slowed collection growth has been translated into declining recycling rates for each polymer, especially PET and HDPE. In 2000, 99.5% of all recycled postconsumer plastic bottles were PET (50.2%) and HDPE (49.3%). The remaining 0.5% represented only about 5 weight percent of all plastic bottles produced in 2000. Because of the relatively small volumes of these other bottle resins in the market, it will be difficult to impossible to achieve critical mass for these bottles in most recycling programs.
In Western Europe, the European Commission was expected to announce in early 2002 a radical overhaul of existing EU regulations that will incorporate higher targets for the recycling of packaging waste. This will likely include broader targets for reusable packaging, reductions in the total amount of packaging and use of the most environmentally friendly packaging to achieve more consistency across the European Union. In addition, the more fundamental problem of inadequate systems for collection and sorting of waste plastics will also be addressed.
A wide assortment of plastics recycling programs exist in Western Europe. A proposed new plastics packaging recycling target of 20% to be reached by EU members by 2006 would count chemical recovery (depolymerization) toward meeting this goal. Plastic recyclers argue that counting chemical recovery will dilute the quality of plastics material collected and exacerbate the problem of securing enough clean, high-grade waste at a fair price for mechanical recycling. With thousands of metric tons of packaging waste collected in Europe already being shipped to China and other Asian countries, the current 10% of Europe's plastics packaging waste being mechanically recycled could be difficult to increase.
The cumulative effect of plastics recycling on the global consumption of virgin thermoplastic resins since 1990 has been negligible in terms of virgin resin displacement. In the United States, recycled resins represented about 3.6% of total thermoplastic resin consumption in 2000 and this share is expected to decrease slightly by the year 2005. While mechanical recycling will remain the preferred option for higher-quality plastic recyclables, waste to energy is expected to become a more acceptable option for recovering lower-quality fractions. In a situation where 90% of the world's oil and gas consumption is used for power generation, heating and transportation, it seems logical that plastics, as one of the longer-life uses of these resources, should finally become an energy source after their useful life is over. The concept of borrowing oil for its material value and returning it as energy should make sense to most recycling stakeholders.
The increasing global substitution of plastics for other types of materials will keep plastic waste in the public spotlight for many years. The unrelenting introduction of new plastic packaging materials with unique compositions tailored to provide superior performance characteristics for specific applications will contribute to the increasing technical complexity of plastics recycling. The continued use of new materials, mixtures of materials and a diversity of container shapes will create new challenges for mechanical recyclers, making it more difficult and expensive for collectors and processors to match their output to available markets while creating new markets.
|
