# US 5,350,431 A · Process for chemical desulfurization of coal

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- Number: US 5,350,431 A
- Document ID: US5350431A
- Status: Granted
- Kind: A
- Application number: 08/051,159
- Filed: 1993-04-22
- Granted: 1994-09-27
- Earliest claimed: 1992-05-11
- Assignees: Idemitsu Kosan Co., Ltd.
- Inventors: Toru Yamashita
- Web page: https://patentgrep.com/patent/US5350431A

## CPC

- C10L 9/00: Treating solid fuels to improve their combustion
- C10L: FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS

## Abstract

A process for chemical desulfurization of coal, in which coal is brought into contact with a desulfurizing agent after or while the coal is irradiated with ultraviolet light, thereby to give remarkably high desulfurization ratios and remarkably high yields of low sulfur coal.

## Claims

### Claim 1

A process for chemical desulfurization of coal, which comprises bringing coal into contact with a desulfurizing agent after or while the coal is irradiated with ultraviolet light for 1 minute to 10 hours.

### Claim 2 (depends on 1)

A process according to claim 1, wherein the coal is at least one member selected from the group consisting of peat, lignite, brown coal, bituminous coal and anthracite.

### Claim 3 (depends on 1)

A process according to claim 1, wherein the coal contains an aromatic sulfur compound.

### Claim 4 (depends on 1)

A process according to claim 1, wherein the coal to be subjected to the chemical desulfurization is preliminarily crushed.

### Claim 5 (depends on 1)

A process according to claim 1, wherein the coal has a particle diameter of 10 mm or less.

### Claim 6 (depends on 1)

A process according to claim 1, wherein the coal is irradiated with ultraviolet light from a high-pressure mercury lamp or an ultrahigh-pressure mercury lamp.

### Claim 7 (depends on 6)

A process according to claim 6, wherein the coal is irradiated with ultraviolet light having a wavelength of 200 nm.

### Claim 8 (depends on 1)

A process according to claim 1, wherein the coal is irradiated with ultraviolet light for 1 to 2 hours.

### Claim 9 (depends on 1)

A process according to claim 1, wherein the desulfurizing agent is an alkali compound or an aqueous solution thereof.

### Claim 10 (depends on 9)

A process according to claim 9, wherein the alkali compound is selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate and calcium carbonate.

### Claim 11 (depends on 1)

A process according to claim 1, wherein the desulfurizing agent is an oxidizing agent.

### Claim 12 (depends on 11)

A process according to claim 11, wherein the oxidizing agent is selected from the group consisting of potassium permanganate, sodium hypochlorite, hydrogen peroxide and chlorine water.

### Claim 13 (depends on 1)

A process according to claim 1, wherein the desulfurizing agent is a metal chloride.

### Claim 14 (depends on 13)

A process according to claim 13, wherein the metal chloride is CaCl.sub.2 or FeCl.sub.3.

### Claim 15 (depends on 1)

A process according to claim 1, wherein the desulfurizing agent is used in an amount of 5 to 300% as a solid content based on the amount of the coal.

### Claim 16 (depends on 1)

A process according to claim 1, wherein the chemical desulfurization is carried out at a temperature of 0.degree. to 450.degree. C. at a pressure of atmospheric pressure to 50 kg/cm.sup.2 for 30 seconds to 48 hours.

### Claim 17 (depends on 1)

A process according to claim 1, wherein the desulfurized coal is washed with an acid and dried.

### Claim 18 (depends on 2)

The process according to claim 2, wherein the coal contains 0.3 to 10% sulfur; and the coal has a particle diameter of 5 mm or less.

### Claim 19 (depends on 18)

The process according to claim 18, wherein the coal is irradiated with ultraviolet light having a wavelength of 200 to 229 nm for 1 to 2 hours; the chemical desulfurization is carried out at a temperature of 0.degree. to 450.degree. C., at a pressure of atmospheric pressure to 50 kg/cm.sup.2 for 30 seconds to 48 hours with a desulfurizing agent selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, calcium carbonate, potassium permanganate, sodium hypochlorite, hydrogen peroxide, CaCl.sub.2 and FeCl.sub.2.