Key Words:Coal tar;Carbon black - Computer software - Conversion efficiency - Energy conversion - Hematite - Nitrogen oxides - Pyrolysis - Temperature

Abstract:A chemical looping pyrolysis (CLP) system using coal tar as the fuel and Fe<inf>2</inf>O<inf>3</inf> as the oxygen carrier (OC) was established using Aspen Plus software. The variations in reaction rate and product yield in a fuel reactor (FR) and an air reactor (AR) under different operating conditions were measured and analyzed. Then, the simulation results were verified by performing experimental studies. The results show that during the CLP process in FR, the yield of carbon black (CB) and energy conversion efficiency first increased and then decreased with the increase in operating temperature and OC/coal tar ratio. The residence time of reactants in the FR had an insignificant effect on CB yield, whereas the yields of sulfur oxides and nitrogen oxides gradually increased with the increase in operating temperature and residence time. The yield of nitrogen oxides significantly increased with the increase in OC/coal tar ratio, whereas the yield of sulfur oxides remained unchanged. In the AR, with the increase in air/OC ratio, the oxidation rate of reduced iron-based OCs first increased and then maintained a steady value, whereas the temperature had a slight effect. The yield of nitrogen oxides increased with increasing temperature and air/OC ratio. The operating parameters of the method were optimized as a temperature of 950 °C, an OC/coal tar ratio of 3, a residence time of 2 s in FR, and an air/OC ratio of 2.4 and a temperature of 1100 °C in AR.<br/> © Copyright 2018 American Chemical Society.

Volume:33

Issue:1

Translation or Not:no