Regeneration of solvent in H2S removal from gases

摘要

A process of removing hydrogen sulfide from a gas stream in which the hydrogen sulfide is dissolved in an absorption zone by a solvent having a good solvent power for hydrogen sulfide and a much greater solvent power for sulfur dioxide. The resultant solution is divided into a major stream and a minor stream. The major stream is contacted with a small excess of sulfur dioxide over that required for reaction with hydrogen sulfide. Most of this solution is recycled to the absorption zone. The minor stream withdrawn from the absorption zone is mixed with the solution formed in the reaction zone which is not recycled, the proportion being such that there remains a small excess of hydrogen sulfide in solution. This solution is then stripped of hydrogen sulfide. By this means only a small fraction of the solution has to be stripped. Preferred solvents are those which promote the reaction of hydrogen sulfide with sulfur dioxide.