Info

Post-industrial waste

Post-consumer

(trade)

Post-consumer (household)

Ecological benefit ?

Figure 13.13. Dependence of waste management costs on waste quality plastics packaging.

alternative or not? A lot of questions, but no answers. What was realized rather soon was a tremendous increase in overall costs of recycling for society, without information about the ecological benefit obtained from these economic expenses (Fig. 13.13).

Typically plastic packagings are lightweight: 60% of all plastic packagings weigh less than 10 g, and their light weight reflects their outstanding performance. Only 10 wt% of the total packaging consumption are plastic packagings, while these packagings protect 42% of all goods in private households (of which 54% are food packagings) (Fig. 13.14).

The stringent requirements of the German Packaging Ordinance of those days, that is, to collect 80%, to sort 80%, and to channel 64% into material recycling forced the Dual System from the very start to sort, unlike in other countries, not only large plastic packagings (such as bottles and huge bags) but also small packagings (e.g., bags for chips, yoghurt cups) and utilize those packagings in material recycling, because large packagings (weight >10 g) merely account for 37% of the total market input of plastic packagings. Consequently, unlike in other countries, no individual return system was possible in Germany, but a high-cost cerbside collection system had to be implemented. Since it would have been too exacting for private households to cope with several containers for waste collection, the idea of the yellow bag—intended not only for plastics but also for composite packagings and metal tins—was born. However, the frequent abuse of the yellow bag with ordinary waste disposal was overlooked so that the actual contents of the Yellow Bag were as shown in Figure 13.15.

341.000 tonnes Large film items e.g. plastic bags

Figure 13.14. Plastics Packaging — Domestic Household Use in 1991, Germany (kt/y).

341.000 tonnes Large film items e.g. plastic bags

Figure 13.14. Plastics Packaging — Domestic Household Use in 1991, Germany (kt/y).

1,7% Other composites

Figure 13.15. Contents of the yellow bag, 1995.

1,7% Other composites

Figure 13.15. Contents of the yellow bag, 1995.

Regional analyses (Dresden, Lahn-Dill district) repeatedly confirmed this picture. Given such framework conditions, it becomes obvious why some two thirds of the total costs of plastics collection and recycling arise in the collection and sorting of lightweight and contaminated—and therefore difficult to utilize — waste, while just one third of the total cost falls to the share of recycling (see Fig. 13.13).

Total costs in the cycle management of plastic packagings from private households exceeded 2 billion DM per year in 1995, that is, more than 50% of the total costs of the Dual System. Referred to the final outcome — that is, 535,000 tons of recycled plastics — this results in a price of roughly 4 DM/kg of plastic. The total amount is covered by the payment of 27 DM per person, that is, a private household consisting of 4 persons pays annually some 100 DM alone for the disposal of 40 kg/household of purchased, mainly small-size plastic packagings. By contrast the annual fee payable for the remaining waste (4 x 283 kg = 1,132 kg/household) varied around 520 DM per year, depending on the municipality. The plastic materials thus obtained are three times as expensive as the purchase of new products (1.20 DM/kg approx.). Therefore the following questions are obvious:

• What are the advantages to the environment to justify such extra cost?

• Is there a savings potential that makes it possible to reach the same or almost the same ecological result at lower cost?

Opinions differ about the process with more ecological benefit. The public preference is for mechanical recycling since supposedly you save part of the processing energy. Industry emphasizes the low quality and the limited market of the products obtained from postconsumer plastics packaging and favors instead the most economical process of recycling in order to keep the cost of recycling low. In fact the most economical process is very often also the best ecological process since it uses generally at least less energy, but this could not be proven for the recycling of plastics packaging from household waste.

Life-Cycle Analysis of Recycling of Plastic Packaging Material in Germany In order to give a more specific answer to this problem German plastics industry initiated a life-cycle analysis for all presently known routes of recycling and recovery and gained financial support from the Association of Plastics Manufacturers in Europe (APME), Verband der Chemischen Industrie e.V. (VCI), and Duales System Deutschland GmbH (DSD).

The intent was to evaluate different established routes using different technologies of plastics recycling from an environmental point of view using life-cycle analysis (LCA) (Fig. 13.16). Approximately 20 companies participated. This means they were prepared to describe their process in detail and to inform on input of resources such as energy, feedstock, and the like and on output such as airborne and waterborne emissions, solid waste, heavy metals, and other environmentally important products. A secrecy agreement assured the companies protection of any proprietary information.

The German Agency on Environment participated as guest and the German TUV validated the individual data and their correct interpretation. The then present state of ISO rules on LCA was followed as closely as possible. The final report underwent a critical assessment as requested by ISO rules. The study was awarded the Oce' van der Grinten prize in 1997 and its findings were published [8].

Plastics recycling scenario

MR: mechanical recycling ER: energy recovery

FR: feedstock recycling MWI: municipal waste incineration

Collecting/ sorting

Mechanical recycling

Feedstock recycling

Energy recovery

Waste

Collection

Waste

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