GB983391A - Improvements in or relating to the removal of volatile sulphur compounds from gases - Google Patents

Abstract

<PICT:0983391/C4-C5/1> A method of removing volatile sulphur compounds from coal gas which has passed through a benzole scrubbing plant comprises passing some or all of the gas, e.g. via pipe 13, through a scrubber 14 where the gas is desulphurized by a scrubbing medium, passing a portion of the desulpurized gas directly, e.g. via pipe 24, or indirectly, e.g. via the scrubber 14 (see Fig. 5 not shown) to a stripper 17, passing fouled scrubbing medium, e.g. via line 15, to the stripper where the gas from the line 24 removes the sulphur compounds from the scrubbing medium, and returning the stripped medium, e.g. via line 18, to the scrubber 14. The scrubbing medium may be a liquid solvent, e.g. a petroleum or coal tar oil distilling preferably between 220 DEG and 360 DEG C., and an additional stripping gas, e.g. air or two or more of methane, producer, blast furnace, coke oven or coal gas may be delivered to the stripper 17 via lines 30 . . . 32. Heaters 15a, 24a are provided on the inert lines to the stripper 17. In a modification, Fig. 5 (not shown), a particulate solid is used as the scrubbing medium, and the line 24 is connected to the line 18 whereby the desulphurized gas assists in returning the stripped solid to the scrubber 14. Further, the line corresponding to 30 . . . 32 includes a branch connected to the line 15, whereby the additional stripping gas assists in circulating the solid scrubbing medium. A further modification is described in the Provisional Specification in which the line 24 is connected to both line 18 and line 15, the connection to the line 15 described above with respect to Fig. 5 for the additional stripping gas being omitted.