METHOD AND APPARATUS FOR REMOVING REDUCED SULPHUR COMPOUNDS FROM VAPOURS AND/OR GAS STREAMS

摘要

A process and apparatus are provided for the removal, by absorption and oxidation, of objectionably odoriferous inorganic sulphur compounds from gaseous mixtures thereof. The process includes the first step of prescrubbing the gaseous mixture by: passing the gaseous mixture upwardly in intimate gas/ liquid contact in a contact zone with downwardly flowing alkaline liquid scrubbing medium; recirculating partially spent liquid scrubbing medium; and sparging a pool of the partially spent liquid scrubbing medium with air; and the second step of scrubbing the prescrubbed gaseous mixture by: passing the prescrubbed gaseous mixture upwardly in intimate gas/liquid contact in a contact zone with downwardly flowing liquid scrubbing medium comprising an aqueous, neutral-to-alkaline solution of sodium, potassium or calcium hypochlorite having a concentration of available chlorine of between 10mg/1 to 60,000 mg/l; and recirculating partially spent liquid scrubbing medium comprising hypochlorite solution. The apparatus includes a first or upper countercurrent gas/liquid scrubbing section and second or lower countercurrent gas/liquid scrubbing section, each section including external recirculation legs provided with make-up liquid inlet lines. The process and apparatus thus uses the convenient technique of wet scrubbing that produces low enough residual concentration of sulphur compounds essentially to eliminate the odor problems.