Evaluation of Ammonia 'Fixation' Components in Actual Refinery Sour Waters

摘要

High ammonia concentrations (fixed ammonia) in stripped sour waters from petroleum refining are caused by weak organic acids and both weak and strong sulfur acids. The sulfur acids result from oxidation of sulfides present in sour water. Fixed ammonia can be eliminated by adding its molar equivalent of caustic to the top of the stripping column. Caustic addition does not interfere with sulfide removal. Recommended techniques for measuring cyanide and sulfide concentrations in sour waters are inadequate. Ammonia concentration may be overestimated when the recommended procedure is used because ammonia can be generated from organic nitrogen compounds which are present in refinery sour waters.