Acid gas obtained from oil refineries contains large amounts of hydrogen sulfide, which are not allowed as the off-gas or burned to the atmosphere. The waste gas collected during the processes in the refineries contains a high amount of sulfur-bearing compounds, hence it should be sent to the sulfur recovery unit (SRU). Modified Claus process is the most common sulfur recovery process that is used around the world in the hydrocarbon processing industry. The thermal furnace is the most important part because the majority of the reactions occur in this unit. The aim of the current study is to investigate the possibility of using a reduced kinetic scheme in DSMOKE simulation environment. The hydrogen sulfide conversions are 75%, 80% and 86% obtained from plant data, detailed kinetic model and reduced kinetic model, respectively. Reduced kinetic model results agree with both detailed kinetic model results and plant data by 5% and 6% error.