Liquefaction of General Plastic Waste
Yoshiki Sato*, Kiyoshi Saito** and Hideaki Tachibana**Abstract
In Japan general plastic waste has been collected and separated by the local management sector under the containers and packaging recycling law and at present is mainly incinerated or disposed of in landfilling. However, this causes serious environmental and social problems from the production of dioxin and the other hazardous gases by incineration, contamination of pollutant materials in the soil and, finally, the lack of landfill site.
In this study, we review liquefaction, which produces clean fuel and useful chemicals from plastic waste by chemical recycling treatment. On the developed German degradation-hydrogenation process, cracking processes and thermal-catalytic cracking process, operating now in Niigata, Tomakomai and Mikasa cities respectively in Japan, we examined the present status of collection, separation, grinding and pelletting in the pretreatment section and depolymerization, cracking, catalytic cracking and hydrogenation in the liquefaction section. Technical subjects to be solved for effective and safe operation, property and utilization of the produced oil and future prospects on liquefaction are also discussed.
Key words: Liquefaction, General plastic waste, Depolymerization, Thermal cracking, Hydrogenation