GB444327A - Improvements in the recovery of hydrogen sulphide from gases - Google Patents

Abstract

In recovering hydrogen sulphide from gases containing it in addition to carbon dioxide while employing alkaline absorption liquids, the absorption liquid is brought into contact with the gas in a finely divided, preferably atomized, form and the time of contact of the absorption liquid with the gas is kept below five seconds and preferably at about one second or less, the hydrogen sulphide being recovered by heating the resulting liquor. By working in this manner practically only hydrogen sulphide is removed from the gas. Suitable absorption liquids include aqueous solutions of soda, potash, borates, phosphates, metaborates or arsenites, solutions of organic bases such as ethanolamine, ethylene diamine, ethanol diamines, ethylene triamines or like polyamines, or alkylated or hydroxyalkylated derivatives of these bases or solutions of the salts of weak organic acids such as taurine or alanine. The known atomizing nozzles, disintegrators, Theisen washers, Feld washers or Ströder washers may be employed for the fine subdivision of the washing liquids. Preferably, the washing temperature is kept low and the concentration of the washing liquid as high as possible. When it is desired that the small quantity of carbon dioxide absorbed should not be present in the regenerated hydrogen sulphide, the regeneration may be effected in two stages, the first stage being carried out at a temperature somewhat below the boiling-point, the gas thus escaping, which is practically pure hydrogen sulphide, being collected separately while in the second stage the liquid is heated to boiling whereby the remainder of the hydrogen sulphide with some carbon dioxide is driven off. Examples are given. Specification 391,780 is referred to.