Method for producing ash-free coal

Patent metadata

Field	Value
Publication number	US-10035967-B2
Application number	US-201414782693-A
Country	US
Kind code	B2
Filing date	Apr 15, 2014
Priority date	Apr 16, 2013
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

A method for producing an ashless coal which includes a slurry preparation step, an extraction step, a separation step, an ashless coal acquirement step, and a by-product acquirement step. The separation step is conducted under the state of being pressurized to a pressure equal to or higher than a vapor pressure of the solvent. In the by-product acquirement step, the solvent is evaporated and separated from the solid content-concentrated slurry by spraying the solid content-concentrated slurry into a flash tank in which a pressure is set to lower than a saturation pressure of the solid content-concentrated slurry from a spray nozzle while maintaining a pressure of the solid content-concentrated slurry in a nozzle orifice of the spray nozzle at a level equal to or higher than the vapor pressure of the solvent.

First claim

The invention claimed is:

1. A method for producing an ashless coal, comprising:
mixing a coal with a solvent to prepare a slurry;
heating the slurry to extract a coal component soluble in the solvent;
separating the slurry, after the heating, into a solution in which the coal component soluble in the solvent is dissolved and a solid content-concentrated slurry in which a coal component insoluble in the solvent is concentrated under pressure equal to or higher than a vapor pressure of the solvent;
evaporating and separating the solvent from the solution which has been separated to yield an ashless coal;
evaporating and separating the solvent from the solid content-concentrated slurry which has been separated by spraying the solid content-concentrated slurry into a flash tank in which a pressure is set to lower than a saturation pressure of the solid content-concentrated slurry from a spray nozzle while maintaining a pressure of the solid content-concentrated slurry in a nozzle orifice of the spray nozzle at a level equal to or higher than the vapor pressure of the solvent to yield a by-product coal;
introducing into the flash tank to substitute solvent vapor with inert gas in the flash tank, and
contacting the by-product coal with the inert gas.

2. The method of claim 1 , wherein the evaporating and separating is performed in the presence of an inert gas.

3. The method of claim 1 , wherein the coal is mixed with the solvent in an amount of 10 to 50 wt % on a dried coal basis.

4. The method of claim 1 , wherein the coal is mixed with the solvent in an amount of 20 to 35 wt % on a dried coal basis.

5. The method of claim 1 , wherein the slurry is heated to a temperate of from 300 to 420° C.

6. The method of claim 1 , wherein the slurry is heated to a temperate of from 360 to 400° C.

Assignees

• Kobe Steel Ltd

Inventors

• Yoshida Takuya
• Okuyama Noriyuki
• Kinoshita Shigeru
• Sakai Koji

Classifications

• C10L2290/48

  Expanders, e.g. throttles or flash tanks · CPC title

• C10L9/10 Primary

  by using additives · CPC title

• C10L2290/06

  Heat exchange, direct or indirect · CPC title

• C10L2290/52

  Hoppers · CPC title

• C10L2290/24

  Mixing, stirring of fuel components · CPC title