GB996480A - Improvements relating to the production of gaseous oxides - Google Patents

Abstract

Sulphur dioxide is produced by combustion of sulphur or sulphur-containing compounds with air to yield a burner gas, and recovery of sulphur dioxide by condensation, in a process in which some of the sulphur dioxide in the burner gas is separated from the remainder and returned mixed with air to the burner, the air in the mixture forming part or all of the air for combustion. In Fig. 1 the gases leaving burner 1 pass to condenser 3, and the uncondensed gas passes countercurrent to a stream of chlorosulphonic acid in absorption, column 4. The resulting solution is stripped with dry air in column 7. There may be a difference in temperature or in pressure between columns 4 and 7. In Fig. 3 the gases leaving burner 30 pass to absorption column 33 and the resulting solution reaches stripping column 37 via <PICT:0996480/C1/1> <PICT:0996480/C1/2> <PICT:0996480/C1/3> pressure-reducing valve 36. The mixture of air and sulphur dioxide from the column is recompressed at 38 en route to the condenser 39. In Fig. 4 gases leaving burner 51 pass to absorption column 53 and the resulting solution is flash-vaporized into tank 55. The sulphur dioxide leaving 55 is recompressed at 57 before condensation at 58. The residual solution from tank 55 is stripped in column 60. Specification 796,755 is referred to.