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US 4,505,776 AGranted
Composition and method for treating flue gas and methanol containing effluents
AssigneeWescam Services Inc.
InventorFrancis E. Murray
Life of this patent
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AssigneeWescam Services Inc.
InventorFrancis E. Murray
Estimating the term…
A composition is provided which comprises an aqueous alkaline solution of a metal salt and black liquor, the metal salt being selected from the group consisting of iron, chromium, cobalt and nickel salts. This composition is useful in a process described for absorption of hydrogen sulfide from flue gas, followed by subsequent oxidation of dissolved sulfide to thiosulfate, if desired. The presence of the metal ions and black liquor synergistically catalyzes the overall reaction of absorption of hydrogen sulfide, followed by oxidation of the sulfide. Preferably, prior to scrubbing to remove hydrogen sulfide with the solution, the flue gas is first cooled to near its dew point, and then scrubbed with water to remove particulates. Additionally, the effluent flue gas from the absorption step is usefully scrubbed with water to recover heat, following which it is used to scrub condensates from a kraft pulp mill. The metal salt in the solution is preferably an iron salt at a concentration of about 0.002 M., the black liquor concentration being preferably about 1% to 5% by volume of the solution, and the pH being usefully about 9.0 to 9.5.
A composition comprising an aqueous alkaline solution of a metal salt and black liquor, the metal salt being selected from the group consisting of iron, chromium, cobalt, and nickel salts, with the concentration of black liquor being 1 to 10% by volume, and the amount of metal salt and black liquor in solution being sufficient to synergistically increase absorption of hydrogen sulfide by said solution.
A composition comprising an aqueous alkaline solution of a metal salt and black liquor, the metal salt being selected from the group consisting of iron, chromium, cobalt, and nickel salts, with the concentration of black liquor being 1 to 10% by volume, and the amount of metal salt and black liquor in solution being sufficient to synergistically catalyze the overall reaction of absorption of hydrogen sulfide by said solution, followed by oxidation of sulfide therein by oxygen to thiosulfate.
A method of purifying flue gas comprising scrubbing the flue gas with an aqueous alkaline solution of a metal salt and black liquor to absorb hydrogen sulfide, the metal salt being selected from the group consisting of iron, chromium, cobalt, and nickel salts, with the concentration of black liquor being 1 to 10% by volume, and the amount of metal salt and black liquor in solution being sufficient to synergistically increase absorption of hydrogen sulfide by the solution.
A method of oxidizing sulfide in an alkaline solution comprising exposing the solution to oxygen in the presence of black liquor dissolved in the solution, the black liquor concentration being 1 to 10% by volume.
A method of purifying flue gas comprising:
A method of purifying flue gas and condensates from a kraft pulp mill, comprising:
A method of purifying flue gas and condensates from a kraft pulp mill, comprising:
A method of purifying flue gas and condensates from a kraft pulp mill comprising:
Dependencies are inferred from the claim text.