Methods for sweetening hydrocarbons

Abstract

Sour natural gas, containing H.sub.2 S and organic sulfide contaminants, is contacted with a sweetening composition comprising an aqueous solution of a substantially equimolar mixture of OCl and HO.sub.2. (preferably NaOCl and NaOOH) for a time sufficient to oxidize the sulfides to an odorless form. The solution has a pH of 9.0-10.5, an oxidation normality of 0.001-0.1. The solution may be produced by mixing Cl.sub.2 into a dilute aqueous solution of NaOH at about pH 10.5 until the pH reaches a level of about 9.5-10.5, or produced electrochemically in a diaphragm cell having a bipolar electrode in the same compartment as the anode, collecting the effluent gas from the cell and absorbing said effluent gas into a dilute aqueous solution of NaOH at about pH 9.5-10.5. The treatment may be run as an adjunct to a metal chelate redox treatment to improve the oxidation by the redox catalyst and to improve the catalyst regeneration. The treatment may be run in batch, in a scrubbing tower, or in-line in a flowing gas stream with solids removal provided.

Dependencies are inferred from the claim text.