More treatment is needed for sulfur recovery unit tail gas, due to its high pollution. In this research, an Iranian petroleum refinery was selected as a case study. In the proposed refinery, incineration is used for treatment of tail gas. As incineration is not an environment-friendly process, an amine-based process has been selected as the best method for treatment of tail gas. The selected process was simulated with HYSYS and Aspen-Plus software. Different parameters and their changes were investigated through the simulation and optimum conditions were achieved. Also, comparison of results of two simulation softwares was done.