Energy Recovery from Polyethylene Terephthalate(PET) Recycling Process

Abstract

Solid waste generation especially from plastics increase every year due to the current consumption habit in the society. The improper disposal of plastics has been a major concern to environment as they are not easily degradable. In this study, energy derived from Polyethylene Terephthalate (PET) plastic bottle recycling process were studied. Raw and used PET samples were produced by using injection moulding machine. The amount of energy recovered upon production was calculated by using Universal Testing Machine. The effect of temperature and pressure during production on raw and used PET plastics were measured. Temperature at 260 oC and 7 Mpa pressure gave highest energy production. The results of raw and used PET samples exhibit comparable amount of energy 0.8J and 2.044 x 10-4MJ/Kg - 2.0635 x 10-4MJ/Kg respectively. Generally, used PET (260oC and 6 Mpa) were to be reprocessed to regain the significant energy production that are lost upon discarding. Mechanical tests were conducted on the PET and were compared with HDPE to study the temperature effect on the mechanical properties. PET show decrement of average hardness value 8.99 % after filled with hot water at 100 ºC. The increased of hot water filling temperature subsequently reduced the tensile strength and hardness value for both HDPE and PET. From this experiment, it is expected that energy recovery derived through the PET recycling can be optimized as part of an integrated waste management strategy.