A novel flow reversal SO, converter is presented for relatively concentrated gases with the catalyst bed divided into three stages and inter-stage quenching. Based upon modeling and simulation, the typical operation mode, effects of the quenching ratio, the flow cycle duration, and the catalyst activity have been investigated. Comparison with the inter-stage heat removal converter has also been done. Simulation for a commercialized converter is given, too. The calculated results show the new converter is very effective for the tested cases.