Formation of wax/oil from the batch pyrolysis of high density polyethylene and polypropylene wastes and resins for energy recovery

• Main Authors: Chan, David Jan C., Yap, Kenny M., Yeung, Evan W.
• Format: text
• Language: English
• Published: Animo Repository 2007
• Subjects: Plastics industry and trade > Waste minimization; Pyrolysis; Plastics recycling
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/9651
• Institution: De La Salle University

Pyrolysis is now considered an appropriate technology in dealing with waste problems, such as waste plastics. The pyrolysis of polypropylene and high-density polyethylene plastics was carried out in a quartz tube reactor using an electrical furnace for heating. The effect of temperature, sample size and type of plastic on the product yield was investigated. Experiments were carried out at temperatures 500, 550, and 600°C with varying sample size of approximately 2 and 0.5 mm. A total of 54 runs were performed. Plastics were pyrolyzed batch-wise and nitrogen was used as a carrier gas. The results showed the effect of temperature, type and size on the products obtained (wax/oil). At 600°C the main products were viscous and waxy substances, while at 500°C the products were low viscous substances. The yields of the wax/oil varied from as low as 9.89% to as high as 43.26% by weight basis. Result also showed that the wax/oil yields of polypropylene were relatively higher than that of the polyethylene. The waxes obtained were also analyzed using GC/MS method and analyses showed that the waxes were rich in aliphatic hydrocarbons of up to C₂₆.