Polysulfide measurement methods using colormetric techniques
AssigneeAmerican Air Liquide, Inc.
InventorsV.S. Meenakshi Sundaram, Daniel Duarte, Malik Haouchine
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Abstract
Methods of converting a sulfide in a composition to polysulfide are described, one method comprising the steps of exposing the composition to conditions and for a time sufficient to cause conversion of at least a portion of the sulfide, to polysulfide to form a modified composition; and controlling the conversion to polysulfide by measuring a color parameter of the modified composition.
Claims28
A method of converting a sulfide in a composition to polysulfide, the method comprising the steps of:
- a) exposing the composition to conditions and for a time sufficient to cause conversion of at least a portion of the sulfide to polysulfide, thus forming a modified composition;
- and
- b) controlling the conversion to polysulfide by measuring a color parameter of the modified composition.
A method of combining a fluid comprising oxygen with a composition comprising sulfide during production of polysulfide in the composition, the method comprising the steps of:
- a) combining the composition with the fluid comprising oxygen under conditions sufficient for oxygen in the fluid comprising oxygen to contact at least some of the sulfide, thus forming a modified composition, and maintaining said contact for a time sufficient to cause conversion of a portion of at least some of the sulfide to polysulfide in said modified composition;
- and
- b) controlling the combining of said composition with said fluid comprising oxygen by measuring a color parameter of said modified composition.
A method of controlling conversion of sodium sulfide to sodium polysulfide in a white liquor oxidation process, the method comprising:
- a) combining white liquor with a fluid comprising oxygen under conditions sufficient for oxygen in the fluid comprising oxygen to contact at least some sodium sulfide in the white liquor, thus forming a partially oxidized white liquor, and maintaining the contact for a time sufficient to cause conversion of a portion of the sodium sulfide, but not all of the sodium sulfide, to sodium polysulfide in the partially oxidized white liquor;
- and
- b) controlling the combining of the white liquor with the oxygen-containing fluid by measuring a color parameter of the partially oxidized white liquor and controlling the conversion to sodium polysulfide versus thiosulfate produced by controlling one or more parameters during said contact selected from the group consisting of temperature, flow rate of said white liquor, flow rate of said fluid comprising oxygen, concentration of oxygen in a container where said contact is taking place, mixing of said white liquor and said fluid comprising oxygen, catalyst concentration, total pressure of the partially oxidized white liquor, and combinations thereof.
A method of converting a polysulfide in a composition to sulfide, the method comprising the steps of:
- a) exposing the composition to conditions and for a time sufficient to cause conversion of at least a portion of the polysulfide to sulfide, thus forming a modified composition;
- and
- b) controlling the conversion to sulfide by measuring a color parameter of the modified composition.
Dependencies are inferred from the claim text.