Recycling of Waste Polyethylene Terephthalate (PET) into Feedstock Monomers
M.N. Siddiqui, H.H. Redhwi
King Fahd University of Petroleum & Minerals, SA
Keywords: recycling, plastics, poly(ethylene terephthalate) (PET)
Abstract:Plastics play a very important role in our daily life with a dramatical increase in the consumption of plastics worldwide. To produce in vast and increasing amounts of plastics in order to meet the current demand levels, it takes up around 8% of the world oil production. It has been estimated that almost 170 million tones of plastics were produced worldwide during the year 2003. The environmental consequences of the use of plastics are felt globally, with plastic debris contamination found from urban centers to remote island shores. Polyethylene terephthalate (PET) is one of the polymers with the most growing market with an estimated expansion rate of 8-10%. With increasing PET consumption, its recycling has received world wide attention for the preservation of resources and the protection of the environment. Saudi Arabia is one of the major producers of plastic in the world with total production capacity of around six million metric tons per year. Several degradation processes for PET have been put forward with different depolymerizing agents and operation conditions. It is assumed that the chemical recycling through depolymerization of PET into its monomer will be an ideal recycling method for Saudi Arabian waste PET because it could be recycled permanently. Several chemical degradation methods such as hydrolysis, aminolysis, glycolysis, methanolysis and saponifications of PET were carried out in our laboratory under various conditions. Excellent feedstock monomers were obtained. The authors are grateful to the King Abdulaziz City for Science and Technology (KACST), Riyadh, for providing the financial support through Research Grant No. AR-27-101 and KFUPM, Dhahran, Saudi Arabia, for providing facility support.