AUTOMOBILE RECYCLING IN THE UNITED-STATES - ENERGY IMPACTS AND WASTE GENERATION

Changes in the trends in the material composition of domestic and impo rted automobiles and the increasing cost of landfilling the non-recycl able portion of automobiles (automobile shredder residue or ASR) pose questions about the future of automobile recycling in the United State s. In response to these challenges, new and innovative approaches to a utomobile recycling are being developed. This paper presents the findi ngs of a recent study to examine the impacts of these changes on the l ife cycle energy consumption of automobiles and on the quantity of was te that must be disposed of. Given the recycle status quo, trends in m aterial composition and the viability of recycling the non-metallic co mponents of the typical automobile are of secondary importance when co mpared to the energy consumed during the life of the automobile. The e nergy savings resulting from small changes in the fuel efficiency of a vehicle overshadow potential energy losses associated with the adopti on of new and possibly non-recyclable materials. Under status quo cond itions, the life cycle energy consumed by the typical automobile is pr ojected to decrease from 599 million Btus in 1992 to 565 million Btus in 2000. Energy consumed during the manufacture of the typical car wil l increase from about 120 to 140 million Btus between 1992 and 2000, w hile energy used during vehicle operation will decrease from 520 to 48 0 million Btus. This study projects that energy saved at the recycle s tep will increase from 41 million Btus in 1992 to 55 million Btus in 2 000. This study also investigated the energy impacts of several potent ial changes to the recycle status quo, including the adoption of techn ologies to retrieve the heat value of ASR by incineration and the recy cle of some or all thermoplastics in the typical automobile. The study estimates that under optimistic conditions -i.e., the recycling of al l thermoplastics and the incineration with heat recovery of all remain ing ASR -about 8 million Btus could be saved per automobile -i.e., an increase from about 55 to 63 million Btus. In the more realistic scena rio -i.e., the recycling of easy-to-remove thermoplastic components (b umper covers and dashboards) -the potential energy savings are about 1 million Btus per vehicle. It is estimated that the annual quantity of ASR in the United States could be reduced from about 5 billion pounds to as little billion pounds of ash if all ASR is incinerated. Alterna tively, ASR quantity could be reduced to about 4 billion pounds if all thermoplastics in automobiles are recycled. However, in the case of r ecycling only thermoplastic bumper covers and dashboards, the quantity of ASR would be reduced by only 0.2 billion pounds. A significant red uction or increase in the size of the ASR waste stream will not in its elf have a large impact on the solid waste stream in the United States .