Experimental Study on Separation of Metal Layer in Aluminum-plastic Packaging by Employing Hydrothermal Process

Plastic waste in is accounted for only one-third of the organic waste fraction in Indonesian municipal solid waste (MSW), but its huge discharge of about 5.4 million ton per year and nondegradable properties pose an environmental problem in the near future. The focus in this study is to separate the plastic packaging containing aluminum sheet into aluminum and plastic, since this type of packaging is usually not recycled and undesirable for scavengers. The separated aluminum can be reused as feeding material in smelters, and the plastic part can be recycled or used as fuel. The experiments employed hydrothermal process in 2.5 L reactor using saturated steam of about 200 °C in 60 min. Subsequent liquid-solid product separation was conducted, and the solid product was examined in thermogravimetry analyzer to obtain the remaining plastic in the aluminum part. It was observed that the aluminum-plastic separation yield better result at higher temperature of 225 °C. The plastic content in the aluminum part was reduced to 25 % of its original, and the aluminum part became brittle and having higher density compared to raw plastic waste, reducing the waste volume.