Steam gasification modeling of polyethylene (PE) and polyethylene terephthalate (PET) wastes: A case study

Abstract

This paper is the first to study the effect of adding PET, separator, and financials on a PE steam gasification plant based in Lebanon. The main aim is to shed light on the possibility of valorizing plastic wastes while reducing the environmental impact of landfilling and creating benefits. Using Aspen Plus, a plant that can turn plastic waste into syngas is designed and modeled. PE and PET model inputs of 797 and 500 kg/hr, respectively, were chosen based on Lebanese data. The addition of PET did not significantly improve the mole fractions of the end product when compared with PE only as an input feed. The final optimum conditions of this model were chosen based on sensitivity analyses of different parameters. There were concluded to be a temperature of 800 °C, pressure of 1 atm, Steam/Feed mass ratio of 0.57, water flowrate of 745 kg/hr, and syngas LHV of 9.45 MJ/Nm3. Calculations showed a total Net Present Value 6 times larger than the initial investment and a Payback Period of 2 years by implementing the model. Although based on a Lebanese case study, this research will urge the establishment of sustainable waste and financial policies in countries facing the same issues.