OP-II-3

PP-II-51CATALYTIC REVERSE-PROCESS FOR SO 2 OXIDATION:MODELLING OF THE NEW FLOW SHEETSZagoruiko A.N.Boreskov Institute of Catalysis SB RAS, Novosibirsk, RussiaE-mail: zagor@catalysis.ruUtilization of sulfur dioxide in the waste gases of non-ferrous smelters is atraditionally important environmental protection problem. Usually this problem issolved by catalytic oxidation of SO 2 to SO 3 with following production of sulfuric acid.The reverse-process of sulfur dioxide oxidation, characterized with high efficiency,low capital costs and low energy consumption [1] has found a wide application in thisarea during last decades. Reverse-process has demonstrated a unique operationstability in case of oscillations of significant gas flow rate and temperature, typical forsmelter off-gases, but improvement of operation stability and efficiency undersignificant oscillations of SO 2 inlet concentration and increased SO 2 inlet content(above 3-4% vol.) is still a problem.V1In1V4С1Inlet gasС2С3HEX1Gas to SO3absorptionHEX2V3Fig. 1. Flow sheet of theprocess for gases with stronglyvariable SO 2 concentrationV – switching valves,In – beds of inert material,С – catalyst beds,HEX – heat exchangersIn2V2The new flow-sheet of the reverse-process is proposed for resolution of thisproblem (Fig.1). In this process the reversals of the gas flow are performed only inthe beds of inert heat-regenerating material, while the flow direction in the catalystbeds is kept constant [2]. Such approach provides lower maximum temperature inthe catalyst bed [3], giving the way both to reduce equilibrium limitations and thusincrease SO 2 conversion and to improve process stability. According to simulation426