Chlorine Behavior of Waste Plastics Recycling Process Using Coke Ovens

Abstract

At the advent of the 21st century, mankind is facing a global environmental problem, and the industrial sector is required to take initiatives in the establishment of recycling society for efficient utilization of natural resources. To establish the waste plastics recycling method by using, iron-making process, waste plastics recycling process using coke ovens was developed by Nippon Steel in 2000. In this process, waste plastics are charged into coke ovens with coal, and carbonized at about 1200°C under the reducing atmosphere. Waste plastics are converted to chemical products, such as coke, tar and light oil, and coke oven gas.
However, waste plastics involves chlorine-contained plastics, such as polyvinyl chloride and polyvinylidene chloride, etc. It is generally known that such chlorine-contained plastics cause corrosion problem at the incinerator or gasification equipment.
Therefore, the behavior of chlorine content of waste plastics was investigated. As a result, it was found that the chlorine content of waste plastics is mostly pyrolysed during carbonization with coal in a coke oven and effectively captured by ammonia liquor.