| 摘要 |
is catalytically oxidised by feeding a hot gas mixt. of SO2 and O2 through a number of catalyst stages to form SO3. Commercial O2 is fed downstream of the catalyst in the first stage into the gas mixt., and also into the last stage upstream of the catalyst. Downstream of the catalyst in each stage, the gas mixt. is cooled by a separate coolant. The gas is pure O2; gas contg. min. 90 vol.% O2; or air enriched with O2. The gas mixt. leaving the last stage is pref. fed into H2SO4 to obtain acid with a desired concn.; and 10-25 moles O2 are pref. added per 100 pts. wt. H2SO4 obtd. per unit of time. The initial hot gas mixt. is pref. obtd. from a sulphur burner, and contains min. 8 vol.% SO2. The conversion to SO3 is min. 98 wt.%. Pref. process, a simple absorption plant is used; and up to 50 wt.% of the catalyst is removed in the first stage and replaced by a non-catalyst. Used for mfr. of SO3 and H2SO4 with increased efficiency and output. |
