Analysis of the energy feasibility of chemical recycling of plastic waste by simulating the pyrolysis process using Aspen Plus®

Abstract

In the present work simulations were performed to compare the results obtained, in terms of product compositions, with those present in the literature for this type of reaction and also to evaluate the influence of these results on the energy capacity of the products. The simulations were performed with the aid of Aspen Plus® simulation software, simulating the operation in a Gibbs Reactor. The simulated pressure and temperature conditions, which corresponded to those used in the literature to enable the comparison of results, were altered in order to identify their influence on the process. The data generated in the simulations was analyzed and, based on it, we were able to determine as ideal conditions of pressure and temperature 382 ºC and 0.14 MPa; in addition to the ideal composition of each polymer to be fed into the reactor (51% PE, 41% PP and 8% PS); the energy self-sufficiency of the process, using the gaseous stream of pyrolysis products to generate energy capable of melting the reactor supply current and supplying the energy requirement of the reactor: and the system's ability to produce useful work, through the application of  an Otto cycle, in the amount of 3,615 kW / kg.