| 摘要 |
A method and composition are disclosed for sweetening, i.e., selectively reducing the levels of H2S and organic sulfides, in gaseous hydrocarbons streams, particularly natural gas streams. A natural gas in a pipe line, at the well head, or at a common collection point from a number of wells, is contacted with a sweetening agent comprising the reaction product of ethylene diamine with 50% uninhibited aqueous formaldehyde. The reaction product is prepared by reacting one part 99% ethylene diamine with two parts 50% aqueous uninhibited formalin at a temperature of about 55-60 DEG C. (higher temperatures may be used if the reaction is carried out under pressure) and is characterized by having a higher flash point, lower toxicity, and a lower freezing point, and better reaction rates, than other sweetening agents currently in use. The sweetening solution is water soluble, free from methanol or other alcohols, does not foam uncontrollably in use, and is free from water insoluble solids which would interfere with the injectability of the solution into a stream of flowing natural gas. The sweetening reaction takes place in-line without the need for a holding tank or reaction vessel. However, the treatment with the sweetening agent may also be carried out in a conventional gas treating tower. The reaction is complete and effective to completely sweeten a sour gas system. |
