METHOD FOR TREATING SPENT CAUSTIC STREAMS

摘要

PURPOSE: Provided is a process for treating caustic waste or spent streams containing sulfur compounds with a packed column recycle reactor for the oxidation of the sulfur compounds in the waste stream. CONSTITUTION: A common post-refining sulfur-removal method is caustic washing in which the hydrocarbon streams are contacted with concentrated solutions of caustic soda. The caustic soda reacts with hydrogen sulfide to form sodium sulfide and with mercaptans to form sodium mercaptides. The caustic stream loaded with the above compounds is called spent caustic. A typical spent caustic stream from a refinery contains as much as 10 to 170 g/l of sodium sulfide, 100-1000 ppm of mercaptans and traces of phenols and disulfides.