Simulation of two alternatives for SO2 removal from wet cement kiln exhaust gases

Abstract

This work aimed at simulating two processes for capturing sulfur dioxide from exhaust gases of wet clinker processes. The goal is to present a guide to cement manufacturers when selecting the most appropriate technology for wet processes in order to comply with environmental regulations. The available commercial technologies chosen for desulfurization process were: wet limestone and wet Cement Kiln Dust (CKD) removal processes. A commercial simulator (Aspen Plus v.2006.5) was used. The absorption tower -considered the core of the process- was simulated with an Aspen RadFrac model combined with Aspen RateSep calculations to provide better and more accurate simulation results than a simulation with the traditional equilibrium approach. This combination also allows better estimates for equipment sizing. The convergence issues, both for the absorption of sulfur dioxide and the overall process, were solved using Aspen Plus tools.