12.1.3 Legislative requirements
In the United States, legislative requirements related to plastics recy- cling are in effect predominantly at the state, rather than federal, level. There are almost no regulations related to biodegradable plastics at any level of government. There are federal regulations, as well as laws in a number of states, which require that plastic ring connectors used for bundling of beverage cans be degradable, but the materials in com- mercial use to satisfy this requirement are photodegradable rather than biodegradable. Legislation was passed in a few states in the late
1980s to require plastic bags to be biodegradable, but nearly all has since been rescinded.
Legislation and regulations related to plastics recycling fall into sev-
eral categories. A number of states have some kind of requirement that recycling opportunities be available to residents. Some require resi- dents to participate in recycling, requiring that the target recyclable materials be kept out of the waste stream and instead diverted to recy-cling. Some do not mandate recycling per se, but prohibit the disposal, by landfill or incineration, of the target recyclables. Others require that communities incorporate recycling as part of their solid waste management strategy. Still others simply require that consideration be given to recycling as an option.7,8
Several states have considered the establishment of taxes or fees to promote recycling. Bottle deposit legislation can be put in this cat- egory. States with mandatory deposits on certain containers, typical- ly carbonated beverages (see Table 12.1), achieve high rates of return, typically 90% or more, facilitating the recycling of the con- tainers. In 1993, Florida instituted an advance disposal fee on con- tainers which did not meet a minimum recycling rate. The fee had a
1995 sunset date, and was not extended. During the time this fee was in effect, major soft drink bottlers, including Coke and Pepsi, dis- tributed their products in bottles containing 25% recycled PET with- in the state. When the fee ended, so did the use of recycled content in soft drink bottles.
TABLE 12.1 Bottle Deposit Legislation in the United States7
State Containers covered Characteristics
Connecticut Beer, malt beverages, 5¢ deposit carbonated soft drinks,
soda water, mineral water
Delaware Nonalcoholic carbonated 5¢ deposit, aluminum
beverages, beer, and other cans exempt
Iowa Beer, soda, wine, liquor 5¢ deposit
Maine Beer, soft drinks, distilled 5¢ deposit, 15¢ on
spirits, wine, juice, water, wine and liquor, no
and other noncarbonated deposit on milk
Massachusetts Carbonated soft drinks, 5¢ deposit; containers
mineral water, beer, 2 gal or larger exempt
and other malt beverages
Michigan Beer, soda, canned cocktails, 10¢ deposit, 5¢ on some
carbonated water, mineral refillable bottles
New York Beer, soda, wine cooler, 5¢ deposit
water, soda water
Oregon Beer, malt beverages, soft 5¢ deposit, 3¢ on standard
drinks, carbonated and refillable bottles
Vermont Beer and soft drinks, liquor 5¢ deposit, 15¢ on liquor
bottles, all glass bottles
must be refillable
Note: California has a refund system for beverage containers but it is not a true deposit system.
A number of states have instituted grant or loan programs to assist in the establishment of recycling. Funds from such programs have been used in a variety of ways, from developing educational materials for children to convince them of the value of recycling to buying equip- ment for processing recyclable materials or for manufacturing prod- ucts from these materials.
Three states have passed laws requiring minimum recycled content in packaging materials, minimum recycling rates, or source reduction. Wisconsin requires plastic containers, except for food, beverages, drugs, and cosmetics, effective in 1995, to consist of at least 10% recy- cled or remanufactured material by weight.8 Reportedly, there is little enforcement of this legislation. Oregon requires rigid plastic contain- ers, except for food and medical packaging, to contain 25% recycled content, meet target 25% recycling rates (defined in a variety of ways), or be source-reduced by 10%.8 Since this law went into effect in 1995, the aggregate recycling rate for all plastic containers in Oregon has been above the required 25%, so all plastic containers satisfy the law’s requirements automatically. In 1996, the estimated recycling rate was
33.3% in the state.9
California has a law very similar to that in Oregon. In 1998, the California Waste Management Board determined that the aggregate recycling rate for rigid plastic containers in California fell below the required 25%, and began to ask a selected group of manufacturers to certify to the Board how they were meeting the requirements of the law.10 Early results from that survey indicate many companies failed to respond by the deadline, and a significant number of respondents failed to demonstrate compliance. The previous year, the Board had, after considerable controversy, adopted a recycling rate range that spanned the required 25%, so no enforcement of the law was needed. Manufacturers were surprised at the outcome in 1998, and expressed disbelief that the amount of plastics recycling in the state had fallen, as the survey figures suggested. Therefore, it seems likely that any enforcement activity by the Waste Management Board will be challenged.
The majority of U.S. states require coding of plastic containers to identify the type of resin used (Table 12.2). The regulations specify use of the coding system developed by The Society of the Plastics Industry (SPI), consisting of a triangle formed from chasing arrows, with a number code inside the triangle and a letter code underneath. This system has been controversial since its inception, with complaints by many environmental groups that consumers misinterpret the identifi- cation symbol as an indication that the container is recyclable, or even that it contains recycled content. The problem is aggravated by the use of the symbols on a variety of objects other than rigid plastic contain-ers. At the same time, the identification symbol has been criticized by recyclers as not providing enough information. For example, it does not differentiate between high- and low-melt flow grades of HDPE, even though the two are incompatible in a recycling system, and blending can result in a product which no end users find appropriate for their needs. There was a long series of meetings between repre- sentatives of environmental groups, recyclers, and plastics industry representatives to try to develop a solution to these problems, but the effort eventually failed.
As was mentioned, a different approach to MSW management and recycling was taken in Europe. Policies were put in place, first in Germany and then in the entire European Union, that made companies responsible for the proper disposal of the packages for their products, with requirements that certain percentages of such packaging be col- lected, and that a certain percentage of collected materials be recy- cled.11 Incineration with energy recovery is counted as recycling in some countries but not in others. In most cases, industry responded by forming industry organizations to collectively handle the collection and recovery of the packaging, so that they did not have to do it individually. The first such organization, in Germany, was Duales System Deutschland (DSD), commonly known as the Green Dot system. At this writing, some European countries have well-organized systems for col- lecting and recycling packaging waste, while others are just getting started. Manufacturers’ responsibility has also been implemented for automobiles, with a requirement that limits to 5% the amount of new cars that can be landfilled. Automobile manufacturers are responding by changing the design of their products to make them more recyclable, and are also using more recycled materials in their construction. The same philosophy is expected to be extended to household appliances.12
Canada has adopted a National Packaging Protocol, with a require-
ment to reduce the amount of packaging waste reaching disposal to
50% of 1988 levels by 2000.13 To the surprise of many, this target was
TABLE 12.2 States Requiring the Society of the Plastics Industry (SPI) Code on Rigid Plastic Containers7
Alaska Illinois Minnesota Rhode Island
Arizona Indiana Mississippi South Carolina
Arkansas Iowa Nebraska South Dakota
California Kansas Nevada Tennessee
Colorado Kentucky New Jersey Texas
Connecticut Louisiana North Carolina Virginia
Delaware Maine North Dakota Washington
Florida Maryland Ohio Wisconsin
Georgia Massachusetts Oklahoma
Hawaii Michigan Oregon
reached by 1996, when packaging waste disposal was reported to be
51.2% less than in 1988.14 Various Canadian provinces have their own regulations in support of this goal, including deposits and fees, landfill bans, and requirements for the use of refillable containers.15
Japan has had a deposit system for beer and sake bottles for many
years. In 1995, a law was passed to require businesses to recycle des- ignated packaging wastes, beginning in 1997. PET bottles and other containers are covered, and non-PET plastic containers will be included in 2000. Industry responded by creating the Japan Container and Package Recycling Association, a third-party organization, similar to the Green Dot system, which collects a fee in exchange for handling the recycling of the packaging waste.8
South Korea has a deposit system on most containers which is designed to encourage the use of reusable packaging and promote recy- cling of nonrefillable containers. It has also adopted guidelines intend- ed to reduce the volume of polystyrene cushioning used in packaging.8
One municipal council in Malaysia began in July 1997 to restrict the use of plastic packaging because of concern about disposal of plastics and about adverse effects on wildlife from littered plastics, especially those which enter bodies of water.16
Israel passed a law in 1997 which requires local councils to recycle at least 15% of their solid waste by the year 2000 and to recycle 25% by
2008. The recycling rate in 1996 was slightly over 25% nationwide.17
A variety of other countries around the world have adopted, or are adopting, policies aimed at promoting the recycling of packaging mate- rials and thus reducing their disposal burdens. In many cases, they are following the European producer responsibility approach.
12.2 Overview of Recycling
For plastics recycling (or recycling of other materials) to occur, three basic elements must be in place. First, there must be a system for col- lecting the targeted materials. Second, there must be a facility capable of processing the collected recyclables into a form which can be utilized by manufacturers to make a new product. Third, new products made in whole or part from the recycled material must be manufactured and sold. While the end uses differ substantially for different plastics, there are some similarities in collection and processing which can use- fully be discussed in a generic fashion.
12.2.1 Collection of materials
The first step in recycling, obviously, is to gather together the materi- als to be recycled. Here there are three main approaches: (1) go out and get the material, (2) create conditions such that the material will be brought to you, or (3) use some combined approach.
Plastics recycling in the United States got its start with the recy- cling of PET beverage bottles in states with deposit legislation. The 5 or 10¢/container deposit proved to be a sufficient incentive to get con- sumers to bring in 90% or more of the covered containers to central- ized collection points (retail stores). When there was a desire to increase recycling beyond PET soft drink bottles to other types of plas- tic containers, this was one model which could be followed. However, only Maine, to date, has expanded its deposit law much beyond car- bonated beverages. In 1990 Maine extended the law to containers for most beverages, excluding milk, explicitly to facilitate recycling of those containers. Deposit redemption centers most often involve a per- son who counts the containers and issues the refund, but systems using reverse vending machines have also been developed and are in reasonably widespread use. The primary advantages of deposit sys- tems are their high rates of return of the targeted containers, and rel- atively low levels of contamination, since each container is examined, at least superficially, by either a person or the scanning and verifica- tion functions built into the reverse vending machines. The primary disadvantages are the relatively high cost of such systems, and hygiene issues related to bringing in dirty containers to a retail estab- lishment, often one which sells food. The latter disadvantage would increase markedly in importance if containers other than those for car- bonated beverages were included.
The other primary way to get consumers to deliver their plastic objects for recycling is to establish drop-off facilities. In the 1980s, a number of multimaterial drop-off recycling centers were established, primarily by the beverage industry, as part of their efforts to prevent the passage of deposit legislation in additional states. These beverage industry recycling program (BIRP) centers typically accepted PET bot- tles along with glass bottles, newspaper, and sometimes other materi- als. They often provided a theme park atmosphere, in an effort to make a visit to the center fun and, therefore, likely to be repeated. This type of large attended drop-off center has mostly given way to a proliferation of smaller, simpler drop-off facilities, largely unattended, which attempt to encourage participation in recycling by being conve- niently located and readily accessible. Some are multimaterial centers, usually consisting of a collection of bins or roll-off containers. Others, such as the barrels for collection of polyethylene (PE) bags found in the front of many retail stores, accept only one material. Such drop-off facilities have the advantage of being reasonably low in cost, especially if they are unattended. Their primary disadvantages are relatively low rates of participation and relatively high rates of contamination with undesired materials. Drop-off facilities are the primary means of col- lecting recyclables in much of Europe. In the United States, BioCycle counted 12,699 drop-off recycling programs in 1997.1
In the United States, most recycling of postconsumer materials is done through curbside collection. A BioCycle survey counted 8937 curbside recycling programs in 1997.1 The U.S. EPA counted 8817 curbside recy- cling programs in the United States in 1996, serving 134.6 million peo- ple, 51% of the U.S. population.2 In these systems, households set their recyclables out for collection in much the same way as they do their garbage, often at the same place, and on the same day. Many of these sys- tems provide a bin (usually colored blue) to consumers as a collection con- tainer. In most systems, the consumer places a variety of recyclables in the bin, perhaps with others bundled alongside, and the materials are sorted in a material recovery facility (MRF). Sometimes the sorting is done at truckside instead. In other systems, the consumers must sort the materials into designated categories before they are picked up. Both the latter systems rely on the use of a compartmented recycling vehicle to keep the materials from intermingling. Some curbside systems use a bag (also usually blue) rather than a bin. In some of these, garbage and recy- clables are collected at the same time, in the same vehicle, and the recy- clables are sorted out after the load is dumped. One of the problems with curbside collection of plastics is the high volume occupied by the plastic, which is usually bottles, compared to its value. Many communities urge consumers to step on the bottles to flatten them before they are placed at the curb, though with only limited success. Even flattened bottles occu- py a lot of space. Some collection programs have used on-truck com- pactors to densify the loads. Others have experimented with on-truck grinders, but this leads to difficulty in effectively sorting the plastics, as will be discussed in Sec. 12.2.4. Many systems focus on collection of recy- clables from business or industrial generators, rather than from individ- ual consumers.
Because collection systems enhance convenience for the generator of the waste materials, participation in recycling is typically higher in these systems than in drop-off systems, where the individuals must make more of an effort to feed the materials into the recycling system. Deposit systems are an exception; here the added incentive of the mon- etary reward, plus the fact that the redemption center is typically located in a retail establishment, where the consumers will be going anyway to buy their groceries, more than makes up for the little extra effort involved.
In some countries, recycling collection occurs primarily through the activities of scavengers. Estimates of plastic recycling in India, for example, are as high as 2.2 million lb/day, all due to the activities of rag pickers who scavenge waste dumps, collecting 7 to 11 lb of plastics per day and selling them to one of several plastic waste collection cen- ters. In New Delhi, for example, about 5000 dealers trade in waste plastics and about 200 processors manufacture products from recycled plastics. Plastics may be recycled as many as 4 times.18
12.2.2 Processing of recyclables
Processing of recyclables is necessary to transform the collected mate- rials into raw materials for the manufacture of new products. While the details of the processing are often specific to an individual plastic, or even to an individual product, three general categories of process- ing can be identified: (1) physical recycling, (2) chemical recycling, and (3) thermal recycling.
Physical recycling. Physical recycling involves changing the size and shape of the materials, removing contaminants, blending in additives if desired, and similar activities that change the appearance of the recycled material, but do not alter (at least not to a large extent) its basic chemical structure. Within this category, the usual processing methods for plastic containers, for example, include grinding, air clas- sification to remove light contaminants, washing, a gravity-based sys- tem to separate components heavier than water from those lighter than water, screening, rinsing, drying, and often melting and pelleti- zation, perhaps with the addition of colorants, heat stabilizers, or oth- er ingredients. The vast majority of plastics recycling operations in existence today involve physical recycling.
Chemical recycling. Chemical recycling involves breaking down the molecular structure of the polymer, using chemical reactions. The prod- ucts of the reaction then can be purified and used again to produce either the same or a related polymer. An example is the glycolysis process sometimes used to recycle PET, in which the PET is broken down into monomers, crystallized, and repolymerized. Condensation polymers, such as PET, nylon, and polyurethane, are typically much more amenable to chemical recycling than are addition polymers such as polyolefins, polystyrene, and PVC. Most commercial processes for depolymerization and repolymerization are restricted to a single poly- mer, which is usually PET, nylon 6, or polyurethane.
Thermal recycling. Thermal recycling also involves breaking down the chemical structure of the polymer. In this case, instead of relying on chemical reactions, the primary vehicle for reaction is heat. In pyroly- sis, for example, the polymer (or mixture of polymers) is subjected to high heat in the absence of sufficient oxygen for combustion. At these
elevated temperatures, the polymeric structure breaks down. Thermal recycling can be applied to all types of polymers. However, the typical yield is a complex mixture of products, even when the feedstock is a single polymer resin. If reasonably pure compounds can be recovered, products of thermal recycling can be used as feedstock for new mate- rials. When the products are a complex mixture which is not easily separated, the products are most often used as fuel. There are rela- tively few commercial operations today which involve thermal recy- cling of plastics, though research continues. Germany has the largest number of such feedstock recycling facilities due to its requirements for recycling of plastics packaging.
A consortium of European plastic resin companies, the Plastics to Feedstock Recycling Consortium, has a pilot plant for thermal recy- cling in Grangemouth, Scotland, and hopes to use the technology in a full-scale commercial plant by late 2000. The system uses fluidized bed cracking to produce a waxlike material from mixed plastic waste. The product, when mixed with naptha, can be used as a raw materi- al in a cracker or refinery to produce feedstocks such as ethylene and propylene.19
Incineration with energy recovery is a thermal process which is not generally regarded as recycling, although it is a way of recovering some value from the discarded materials. Incineration without energy recovery is rarely practiced in modern facilities. Those facilities which do operate in this manner are typically old and lack modern emission controls, so they are slowly but surely being shut down, at least in the industrialized countries. Incineration is relatively common around the world, but almost always operates on a mixed waste stream, not on plastics alone.