Process for treating and regenerating spent caustic
AssigneeStone & Webster Engineering Corp.
InventorStephen Z. Masoomain
Life of this patent
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Abstract
The present invention relates to a process for treating and regenerating a spent caustic solution at ambient temperatures which includes oxidizing the spent caustic stream with an air/ozone gas mixture, followed by irradiating the oxidized spent caustic stream with a broad range of ultraviolet radiation and finally filtering the spent caustic solution.
Claims7
A process for treating a spent caustic solution derived from washing hydrocarbon process effluents comprising sulfides and other inorganic sulfur acid salts at ambient temperatures comprising;
- (a) removing residual dispersed oil from the spent caustic solution before oxidizing the spent caustic solution;
- (b) oxidizing the spent caustic solution in a reactor vessel with an air and ozone gas mixture;
- (c) radiating the ozidized spent caustic solution with ultraviolet radiation;
- (d) filtering the oxidized and radiated spent caustic solution;
- and
- (e) discharging the treated spent caustic solution.
A process for regenerating a spent caustic stream which consists essentially of:
- (a) removing residual dispersed oil from the spent caustic stream;
- (b) oxidizing the deoiled spent caustic stream at temperatures in the range of from 80.degree. F.-120.degree. F., with an air/ozone gas mixture in a reactor vessel;
- (c) radiating the oxidized spent caustic stream with ultraviolet radiation having a wavelength in the range of from 185 nm to 300 nm by flowing the oxidized spent caustic through an annulus between an outer metal sleeve and a quartz sleeve enclosing an ultraviolet light source;
- (d) filtering the radiated spent caustic stream through a ten micron filter to provide a permeate;
- (e) filtering the permeate of the ten micron filter through a plurality of serially connected nanofiltration banks to remove ionic species and produce a nanofiltration permeate;
- and
- (f) returning the nanofiltration permeate for recycling the caustic stream.
Dependencies are inferred from the claim text.