폐소형가전의 유용자원 선별·회수에 대한 전과정평가 연구

Abstract

This study aims at life cycle assessment on valuable sorting/recovery from small household appliances was carried out. The recycling process mainly consists of 1st-stage crushing, manual dismantling, magnetic separation, 2nd-stage crushing and wet gravity separation process. This process is designed to process about 8 tons of used small household appliances per day, but it processes 800 kg per day for efficient sorting/recovery of the downstream wet gravity separation process. GWP was estimated to be about 9.24E+02 kg CO2-eq./f.u when each valuable resource was sorting/recovered from 1 tonne used small appliances. The environmental impacts on GWP among the environmental impact categories for sorting/recovery by valuable resources were about 65.7 % for PS/ABS 6.07E+02 kg CO2-eq., about 29.0 % for PP 2.68E+02 kg CO2-eq., about 2.9 % for ferrous metals 2.72E+01 kg CO2-eq., and 2.22E+01 kg CO2-eq. for copper And about 2.4 %. The effects of environmental and economic benefits are analyzed compared to the amount of virgin material recycled as recycled material, and the environmental impacts of 1.93E+03 kg CO2 yield were analyzed. If it translates into carbon emissions reduction, it will result in an economic impact of about 5,777 thousand won per year. In addition, environmental avoidance effects were analyzed to reduce carbon dioxide levels of about 237.8 tons per year. Recycling process including gravity separation techniques used in recycling process, which is used in the recycling companies, the environmental avoidance effect on the sorting/recovery of the final valuable resources is inefficient. In addition, when the wet gravity separation system for sorting plastics is applied, it is analyzed that the environmental load is caused by the use of the water and the treatment of the generated wastewater. It is urgently required to develop a crushing, disassembling technique and sorting technology in order to efficiently sorting and recover the valuable resources generated in the recycling process of used small household appliances made of various constituent materials.