US3909211A
Expired / Lapsed
US
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Coal desulfurization process
Assignee: KVB Inc
•
Filing: 1973-08-31
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Granted: 1975-09-30
•
Expires: 1993-08-31
Abstract
Abstract Coal is desulfurized by heating it in comminuted form in the presence of NO2 and other gases to remove part of the sulfur in the coal. Sulfur still remaining in the coal will be in the form of an inorganic sulfate or sulfite or included in an organic radical, assuming coal has a condensed aromatic ring structure, with two double bonded oxygen atoms attached. This sulfur is for the most part removed by a subsequent additional step of exposing the pre-treated coal to water or to a heated alkali metal hydroxide solution.
Inventors
- 👤 Arthur F Diaz
- 👤 Eugene D Guth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:42
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02; C10L9/06
Claims Analysis
Total Claims: 57
Claim 1
Independent Claim
80 words
A METHOD FOR DESULFURIZING COAL WHICH INCLUDES THE STEPS OF: A. HEATING COAL PARTICLES TO A TEMPERATURE FROM 100* TO 500*F, AND B. SUBJECTING SAID HEATED COAL PARTICLES TO AN OXIDIZING GAS HAVING NO2 AS ONE OF ITS CONSTITUENTS, SAID NO2 SELECTIVELY OXIDIZING SULFUR-CONTAINING COMPOUNDS IN SAID COAL PARTICLES, SAID OTHER CONSTITUENTS OF SAID OXIDIZING GAS BEING SUBSTANTIALLY NON-REACTIVE WITH SAID COAL, WHEREBY OXIDIZED SULFUR-CONTAINING COMPOUNDS AND GASEOUS SULFUR COMPOUNDS ARE FORMED WHICH ARE READILY SEPARABLE FROM SAID COAL PARTICLES.
Claim 2
Independent Claim
80 words
A METHOD FOR DESULFURIZING COAL WHICH INCLUDES THE STEPS OF: A. HEATING COAL PARTICLES TO A TEMPERATURE FROM 100* TO 500*F, AND B. SUBJECTING SAID HEATED COAL PARTICLES TO AN OXIDIZING GAS HAVING NO2 AS ONE OF ITS CONSTITUENTS, SAID NO2 SELECTIVELY OXIDIZING SULFUR-CONTAINING COMPOUNDS IN SAID COAL PARTICLES, SAID OTHER CONSTITUENTS OF SAID OXIDIZING GAS BEING SUBSTANTIALLY NON-REACTIVE WITH SAID COAL, WHEREBY OXIDIZED SULFUR-CONTAINING COMPOUNDS AND GASEOUS SULFUR COMPOUNDS ARE FORMED WHICH ARE READILY SEPARABLE FROM SAID COAL PARTICLES.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said particles of coal have a diameter of no more than one-fourth inch.
Claim 4
Dependent Claim
33 words
The method of claim 1 wherein said reaction takes place at a temperature of 100* to 500*F and a pressure of 1 to 20 atmospheres over a period of 1 to 30 minutes.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein said oxidizing gas includes an inert gas in addition to said NO2, said oxidizing gas being at least 0.25% by volume NO2.
Claim 6
Dependent Claim
39 words
The method of claim 4 wherein said oxidizing gas further includes O2 and NO, said O2 being less than 20% by volume of said oxidizing gas and said No being less than 10% by volume of said oxidizing gas.
Claim 7
Dependent Claim
18 words
The method of claim 5 wherein said O2, said NO and said NO2 exist in approximately equilibrium proportions.
Claim 8
Dependent Claim
11 words
The method of claim 4 wherein said inert gas is nitrogen.
Claim 9
Dependent Claim
39 words
The method of claim 6 wherein said oxidizing gas further includes O2 and NO, said O2 being less than 20% by volume of said oxidizing gas and said NO being less than 10% by volume of said oxidizing gas.
Claim 10
Dependent Claim
18 words
The method of claim 8 wherein said O2, said NO, and said NO2 exist in approximately equilibrium proportions.
Claim 11
Dependent Claim
30 words
The method of claim 1 wherein said particles are oxidized and thereafter further including the step of leaching oxidized sulfur compounds from said particles of coal after said reacting step.
Claim 12
Dependent Claim
12 words
The method of claim 10 wherein said leaching is done by water.
Claim 13
Dependent Claim
17 words
The method of claim 10 wherein said leaching is done by a solution of water and caustic.
Claim 14
Dependent Claim
15 words
The method of claim 10 wherein said oxidizing gas is comprised of an inert gas.
Claim 15
Dependent Claim
34 words
The method of claim 10 wherein said oxidizing reaction takes place at a temperature of 100* to 500*F, at a pressure of 1 to 20 atmospheres, over a period of 1 to 30 minutes.
Claim 16
Independent Claim
94 words
The method of desulfurizing coal containing sulfur in the form of iron pyrites which includes the steps of: a. oxidizing said iron pyrites by reaction with NO2 gas, said coal being in the form of particles no larger than about one-fourth inch in diameter, said oxidation step being of 1 to 30 minutes duration at a temperature of 100* to 500*F and at a pressure of 1 to 20 atmospheres, whereby said iron pyrites are Oxidized to form sulfates and sulfites; and b. leaching said sulfates and sulfites out of said particles of coal.
Claim 17
Independent Claim
94 words
The method of desulfurizing coal containing sulfur in the form of iron pyrites which includes the steps of: a. oxidizing said iron pyrites by reaction with NO2 gas, said coal being in the form of particles no larger than about one-fourth inch in diameter, said oxidation step being of 1 to 30 minutes duration at a temperature of 100* to 500*F and at a pressure of 1 to 20 atmospheres, whereby said iron pyrites are Oxidized to form sulfates and sulfites; and b. leaching said sulfates and sulfites out of said particles of coal.
Claim 18
Dependent Claim
12 words
The method of claim 15 wherein the leaching is done by water.
Claim 19
Independent Claim
97 words
The method of desulfurizing coal containing sulfur in the form of an organic compound which includes the steps of: a. oxidizing said organic sulfur compound by reaction with NO2 gas, said coal being in the form of particles no larger than about one-fourth inch in diameter, said oxidation step being of 1 to 30 minutes in duration, at a temperature of 100* to 500*F and at a pressure of 1 to 20 atmospheres, whereby said organic compounds are oxidized to form sulfates and sulfites; and b. leaching said sulfates and sulfites out of said particles of coal.
Claim 20
Independent Claim
97 words
The method of desulfurizing coal containing sulfur in the form of an organic compound which includes the steps of: a. oxidizing said organic sulfur compound by reaction with NO2 gas, said coal being in the form of particles no larger than about one-fourth inch in diameter, said oxidation step being of 1 to 30 minutes in duration, at a temperature of 100* to 500*F and at a pressure of 1 to 20 atmospheres, whereby said organic compounds are oxidized to form sulfates and sulfites; and b. leaching said sulfates and sulfites out of said particles of coal.
Claim 21
Dependent Claim
12 words
The method of claim 17 wherein said leaching is done by water.
Claim 22
Dependent Claim
17 words
The method of claim 17 wherein said leaching is done by a solution of water and caustic.
Claim 23
Dependent Claim
49 words
The method of claim 17 wherein said oxidation step does not convert all of said organic sulfur compounds to sulfates and sulfites and wherein said leaching is done by a solution of water and caustic, said caustic converting said organic sulfur compounds to sulfates soluble in said caustic solution.
Claim 24
Independent Claim
120 words
The method of desulfurizing coal containing sulfur in the form of an organic compound which includes the steps of: a. oxidizing said organic sulfur compound by reaction with NO2 gas, said coal being in the form of particles no larger than about one-fourth inch in diameter, said oxidation step being of 1 to 30 minutes in duration, at a temperature of 100* to 500*F and at a pressure of 1 to 20 atmospheres; and b. hydrolyzing said oxidized organic sulfur compounds and leaching the products of said hydrolyzation reaction by contacting said coal containing said oxidized organic compounds with a caustic solution, whereby said oxidized organic compounds are converted to sulfates and said sulfates are dissolved in said caustic solution.
Claim 25
Independent Claim
120 words
The method of desulfurizing coal containing sulfur in the form of an organic compound which includes the steps of: a. oxidizing said organic sulfur compound by reaction with NO2 gas, said coal being in the form of particles no larger than about one-fourth inch in diameter, said oxidation step being of 1 to 30 minutes in duration, at a temperature of 100* to 500*F and at a pressure of 1 to 20 atmospheres; and b. hydrolyzing said oxidized organic sulfur compounds and leaching the products of said hydrolyzation reaction by contacting said coal containing said oxidized organic compounds with a caustic solution, whereby said oxidized organic compounds are converted to sulfates and said sulfates are dissolved in said caustic solution.
Claim 26
Independent Claim
129 words
The method of desulfurizing coal and producing sulfuric acid which includes the steps of: a. placing particles of coal having a diameter of no more than one-fourth inch in a reactor vessel, said vessel being maintained at a temperature of 100* to 500*F and a pressure between 1 and 20 atmospheres; b. circulating oxidizing gas through said reactor, said oxidizing gas having NO2 as one of its constituents, said NO2 selectively oxidizing sulfur-containing compounds in said coal particles, said other constituents of said oxidizing gas being substantially non-reactive with said coal; and c. removing gaseous sulfur compounds from said oxidizing gas after it has passed through said reactor by contacting said gas with water whereby said gaseous sulfur compounds are dissolved in said water and sulfuric acid is formed.
Claim 27
Independent Claim
129 words
The method of desulfurizing coal and producing sulfuric acid which includes the steps of: a. placing particles of coal having a diameter of no more than one-fourth inch in a reactor vessel, said vessel being maintained at a temperature of 100* to 500*F and a pressure between 1 and 20 atmospheres; b. circulating oxidizing gas through said reactor, said oxidizing gas having NO2 as one of its constituents, said NO2 selectively oxidizing sulfur-containing compounds in said coal particles, said other constituents of said oxidizing gas being substantially non-reactive with said coal; and c. removing gaseous sulfur compounds from said oxidizing gas after it has passed through said reactor by contacting said gas with water whereby said gaseous sulfur compounds are dissolved in said water and sulfuric acid is formed.
Claim 28
Dependent Claim
13 words
The method of claim 22 wherein said oxidizing gas comprises an inert gas.
Claim 29
Dependent Claim
32 words
The method of claim 22 and further including the step of leaching oxidized sulfur compounds in said coal with a leaching agent after said coal has been reacted with said oxidizing gas.
Claim 30
Dependent Claim
12 words
The method of claim 24 wherein said leaching is done by water.
Claim 31
Dependent Claim
17 words
The method of claim 24 wherein said leaching is done by a solution of water and caustic.
Claim 32
Dependent Claim
10 words
The method of claim 26 wherein said caustic is NaOH.
Claim 33
Dependent Claim
10 words
The method of claim 12 wherein said caustic is NaOH.
Claim 34
Dependent Claim
10 words
The method of claim 19 wherein said caustic is NaOH.
Claim 35
Dependent Claim
31 words
The method of claim 23 and further including the step of leaching oxidized sulfur from said coal with a leaching agent after said coal has been reacted with said oxidizing gas.
Claim 36
Dependent Claim
12 words
The method of claim 30 wherein said leaching is done by water.
Claim 37
Dependent Claim
41 words
The method of claim 30 and further including the step of removing said leached sulfur compounds from said leaching agent by reducing the temperature of said leacHing agent whereby the solubility of said sulfur compounds in said leaching agent is reduced.
Claim 38
Dependent Claim
13 words
The method of claim 32 wherein said oxidizing gas comprises the following gases:
Claim 39
Independent Claim
94 words
The method of desulfurizing coal which includes the steps of: a. heating particles of coal between -14 and +28 mesh size to 200*F; b. flowing a gas mixture comprised of air with 10% NO by volume, thus forming NO2 in situ; said mixture being added through said coal particles at one atomosphere for a period of 3 hours, c. washing said coal particles with water; d. washing said coal particles with a 10% aqueous solution of NaOH; and e. washing said coal particles with water, whereby said sulfur is extracted from said coal particles.
Claim 40
Independent Claim
94 words
The method of desulfurizing coal which includes the steps of: a. heating particles of coal between -14 and +28 mesh size to 200*F; b. flowing a gas mixture comprised of air with 10% NO by volume, thus forming NO2 in situ; said mixture being added through said coal particles at one atomosphere for a period of 3 hours, c. washing said coal particles with water; d. washing said coal particles with a 10% aqueous solution of NaOH; and e. washing said coal particles with water, whereby said sulfur is extracted from said coal particles.
Claim 41
Dependent Claim
23 words
The method of claim 34 with the amount of NO added to said air in the range from 0.25 to 10% by volume.
Claim 42
Dependent Claim
34 words
The method of claim 34 with the usual amount of NO added to said air increased to 10% and the time said gas is passed through said coal particles is reduced to 1.5 hours.
Claim 43
Dependent Claim
20 words
The method of claim 1 wherein said particles of coal has a particle size of from -14 to 28 mesh.
Claim 44
Dependent Claim
24 words
The method of claim 1 wherein said coal particles are contacted with said oxidizing gas for 1 to 4 hours in a batch operation.
Claim 45
Dependent Claim
16 words
The method of claim 38 wherein said oxidizing gas is at least 0.25% by volume NO2.
Claim 46
Dependent Claim
24 words
The method of claim 38 and further including the step of leaching oxidized sulfur compounds from said particles of coal after said oxidizing step.
Claim 47
Independent Claim
148 words
The method of desulfurizing coal and producing salts of sulfuric acid which includes the steps of: a. placing particles of coal having a diameter of no more than one-fourth inch in a reactor vessel, said vessel being maintained at a temperature of 100* to 500* F and a pressure between 1 and 20 atmospheres; b. circulating oxidizing gas through said reactor, said oxidizing gas having NO2 as one of its constituants, said NO2 selectively oxidizing sulfur-containing compounds in said coal particles, said other constituents of said oxidizing gas being substantially non-reactive with said coal; and c. removing gaseous sulfur compounds from said oxidizing gas after it has passed through said reactor by contacting said gas with a compound selected from the group consisting of: NH4OH, alkali metal oxides, alkali metal hydroxides, alkaline metal oxides, and alkaline metal hydroxides, whereby said gaseous sulfur compounds form salts of sulfuric acid.
Claim 48
Independent Claim
148 words
The method of desulfurizing coal and producing salts of sulfuric acid which includes the steps of: a. placing particles of coal having a diameter of no more than one-fourth inch in a reactor vessel, said vessel being maintained at a temperature of 100* to 500* F and a pressure between 1 and 20 atmospheres; b. circulating oxidizing gas through said reactor, said oxidizing gas having NO2 as one of its constituants, said NO2 selectively oxidizing sulfur-containing compounds in said coal particles, said other constituents of said oxidizing gas being substantially non-reactive with said coal; and c. removing gaseous sulfur compounds from said oxidizing gas after it has passed through said reactor by contacting said gas with a compound selected from the group consisting of: NH4OH, alkali metal oxides, alkali metal hydroxides, alkaline metal oxides, and alkaline metal hydroxides, whereby said gaseous sulfur compounds form salts of sulfuric acid.
Claim 49
Dependent Claim
13 words
The method of claim 41, wherein said oxidizing gas comprises an inert gas.
Claim 50
Dependent Claim
28 words
The method of claim 41 and further including the step of leaching oxidized sulfur compounds in said coal after said coal has been reacted with said oxidizing gas.
Claim 51
Dependent Claim
12 words
The method of claim 43, wherein said leaching is done by water.
Claim 52
Dependent Claim
17 words
The method of claim 43, wherein said leaching is done by a solution of water and caustic.
Claim 53
Dependent Claim
10 words
The method of claim 45, wherein said caustic is NaOH.
Claim 54
Dependent Claim
23 words
The method of claim 41, wherein said oxidizing gas is contacted with NH4OH, and said salt of sulfuric acid formed is ammonium sulfate.
Claim 55
Dependent Claim
24 words
The method of claim 41, wherein said oxidizing gas is contacted with calcium oxide, and said salt of sulfuric acid formed is calcium sulfate.
Claim 56
Dependent Claim
24 words
The method of claim 44, wherein said oxidizing gas is contacted with sodium hydroxide, and said salt of sulfuric acid formed is sodium sulfate.
Claim 57
Dependent Claim
24 words
The method of claim 42 and further including the steps of leaching oxidized sulfur compounds from said particles of coal after said reacting step.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |