Removal of hydrogen sulphide from gaseous effluents - by automatically controlled Claus process

摘要

H2S is removed from gaseous effluents, e.g. from sulphide ore roasting or another H2S source by the Claus process comprising withdrawing from the chimney a part of H2S through a duct to an oven, where it is burnt with air to SO2, which is returned to the chimney via another duct; the two streams are mixed together in mixer, where SO2 reacts with the remaining H2S at 150-200 degrees C; the resulting molten sulphur is collected in a container. The process is controlled, by withdrawing a sample of the purified gas mixt. passing it through a pressure regulator and dividing into two streams. One stream is passed through a washer where SO2 is removed, and then into a coulometric titrating apparatus where the H2S cntent is determined. The second stream is passed through a washer where H2S is removed (e.g. with Bi2O3 in H2SO4 soln.) and then into a coulometric titrating apparatus where the SO2 content is determined (the washing and titrating procedures and apparatus can be of any conventional type). Signals from the titrating apparatuses are passed to a regulator, which controls the supply of air to an oven by means of a servo-motor. An additional oven can be placed above the sampling point to burn any remaining H2S with additional air supply.