# US 9,752,088 B2 · Ashless coal production method

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- Number: US 9,752,088 B2
- Document ID: US9752088B2
- Status: Granted
- Kind: B2
- Application number: 15/022,116
- Filed: 2014-10-08
- Published: 2016-08-11
- Granted: 2017-09-05
- Earliest claimed: 2013-10-09
- Assignees: Kobe Steel, Ltd.
- Applicants: Kobe Steel, Ltd.
- Inventors: Koji Sakai; Noriyuki Okuyama; Shigeru Kinoshita; Takuya Yoshida
- Web page: https://patentgrep.com/patent/US9752088B2

## CPC

- C10L 5/04: Raw material {of mineral origin} to be used; Pretreatment thereof {(pretreatment of fuels of non-mineral origin C10L5/40)}
- C10L 5/00: Solid fuels (produced by solidifying fluid fuels C10L7/00; peat briquettes C10F7/06)
- C10L 9/00: Treating solid fuels to improve their combustion
- C10L 9/02: by chemical means
- C10L 2290/544: Extraction for separating fractions, components or impurities during preparation or upgrading of a fuel
- 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 method for producing an ashless coal includes an extraction step, a separation step and an ashless coal acquirement step. In the extraction step, a slurry obtained by mixing a coal with a solvent is heated and thereby a solvent-soluble component of the coal is extracted. In the separation step, the slurry is separated into a solution of the solvent-soluble component of the coal and a solid content-concentrated liquid. In the ashless coal acquirement step, an ashless coal is obtained by evaporating and separating the solvent from the solution. The solvent is a mixture of a dissolution medium and a coal extraction accelerator added thereto. The solvent contains a bicyclic aromatic compound that is liquid at ordinary temperature. The coal extraction accelerator containing no nitrogen has two benzene rings and has at least one cyclic structure having no double bond.

## Claims

### Claim 1

A method for producing an ashless coal, the method comprising:
heating a slurry obtained by mixing a coal with a solvent and thereby extracting a component of the coal that is soluble in the solvent;
separating a slurry obtained by the extracting into a solution in which the component of the coal that is soluble in the solvent is dissolved, and a solid content-concentrated liquid in which a component of the coal that is insoluble in the solvent have been concentrated; and
obtaining the ashless coal by evaporating and separating the solvent from the solution separated in the separation,
wherein the solvent is a mixture obtained by adding an acenaphthene as a coal extraction accelerator to a dissolution medium comprising 1-methylnaphthalene as a main component,
wherein a concentration in percentage by weight of the coal extraction accelerator in the solvent is 40 wt % or less.

### Claim 2 (depends on 1)

The method for producing an ashless coal according to claim 1, wherein the solvent evaporated and separated in the obtaining ashless coal is circulated and used as the solvent for the extraction.

### Claim 3 (depends on 1)

The method for producing an ashless coal according to claim 1, wherein a heating temperature of the slurry in the extracting is from 300 to 420° C.

### Claim 4 (depends on 3)

The method for producing an ashless coal according to claim 3, wherein a heating temperature of the slurry in the extracting is from 360 to 400° C.

### Claim 5 (depends on 1)

The method for producing an ashless coal according to claim 1, wherein a pressure of the extracting in an extraction vessel is from 1.0 to 2.0 MPa.

### Claim 6 (depends on 3)

The method for producing an ashless coal according to claim 3, wherein a temperature is from 300 to 380° C. and a pressure is from 1.0 to 3.0 MPa in the separating.