Simulation of gas condensation process from pyrolysis of used tires

Abstract

Waste tires, composed of rubber, have caused negative environmental problems. There have been problems regarding an increase in the accumulation of tires in different sectors, together with the fact that waste management methods are obsolete. These problems have awakened interest in their study and thermal degradation. Tires composed of rubber represent a material with an important potential for recycling and utilization, together with the conversion of these wastes into energy, value-added products or for the improvement of raw materials. The technique used to carry out thermal degradation is called pyrolysis and consists of heating the organic matter in the absence of oxygen at a specified rate or heating rate, up to a maximum temperature known as pyrolysis temperature, and maintaining it there for a specified time. The products of pyrolysis correspond to: liquid, condensable gases and solid char or ash; for its part, the condensable gas can be further decomposed into non-condensable gases (〖CO, CO2, H2 and CH4), liquid and char. This work aims to contribute with the design and simulation of the condensation cycle of the gases obtained from pyrolysis. Particularly, for the condensation of these gases, the ASPEN HYSYS process simulator was used, where the adaptation of a shell and tube heat exchanger allowed to carry out the condensation. The feed containing these gases comes from tests in a pyrolytic reactor with favorable results. As a result of this condensation and the operating conditions, it is observed that, for a range between 80 and 90 °C, the condensation of gases such as i-Butene and Propylene is favored. This study aims to take up existing research in this area and make a proposal for the condensation of pyrolysis gases, generating an idea of the feasibility and recovery of tire waste with a circular economy approach.