Solvent separation method

Abstract

A method for separating solvent-containing water, which is generated in the process for producing an ashless coal, into a solvent and water readily without using any adsorbent or the like (a solvent separation method). The solvent separation method comprises: a solvent-containing water supply step of supplying the solvent-containing water into a pressure vessel for solvent separation purposes; and a temperature retention step of retaining the temperature of the solvent-containing water that has been supplied into the pressure vessel for solvent separation purposes at a predetermined temperature (e.g., 100 to 180 DEG C. inclusive). In the pressure vessel for solvent separation purposes, water in the liquid form moves downward and the solvent moves upward due to the difference between the density of water and the density of the solvent at the predetermined temperature. In this manner, the solvent-containing water can be separated into the solvent and water.

1 . A solvent separation method for separating solvent-containing water, which is generated in the process for producing an ashless coal, into a solvent and water, the method comprising:
 an extraction step of extracting a solvent-soluble coal component by heating a slurry obtained by mixing a coal and the solvent;   a separation step of separating a solution containing the solvent-soluble coal component from the slurry obtained in the extraction step; and   an ashless coal acquisition step of obtaining an ashless coal by vaporizing and separating the solvent from the solution separated in the separation step,   wherein a solvent-containing water supply step of supplying the solvent-containing water into a pressure vessel for solvent separation purposes and   a temperature retention step of retaining the temperature of the solvent-containing water that has been supplied into the pressure vessel for solvent separation purposes at a predetermined temperature are included; and   the solvent-containing water is separated into the solvent and water by moving water in the liquid form downward and moving the solvent upward in the pressure vessel for solvent separation purposes due to the difference between the density of water and the density of the solvent at the predetermined temperature.   
     
     
         2 . The solvent separation method according to  claim 1 , wherein
 in the temperature retention step, the temperature of the solvent-containing water is retained at the predetermined temperature and the solvent-containing water is allowed to stand.   
     
     
         3 . The solvent separation method according to  claim 1 , wherein
 in the temperature retention step, the temperature of the solvent-containing water in the pressure vessel for solvent separation purposes is retained at a temperature of 100 to 180 DEG C. inclusive.   
     
     
         4 . The solvent separation method according to  claim 1 , wherein
 the pressure in the pressure vessel for solvent separation purposes is specified to be a pressure higher than the saturated vapor pressure of water.   
     
     
         5 . The solvent separation method according to  claim 1 , wherein
 an inert gas is filled in the pressure vessel for solvent separation purposes.   
     
     
         6 . The solvent separation method according to  claim 1 , wherein
 the solvent-containing water, which is generated in the extraction step in the process for producing an ashless coal, is supplied to the pressure vessel for solvent separation purposes.   
     
     
         7 . The solvent separation method according to  claim 2 , wherein
 in the temperature retention step, the temperature of the solvent-containing water in the pressure vessel for solvent separation purposes is retained at a temperature of 100 to 180 DEG C. inclusive.   
     
     
         8 . The solvent separation method according to  claim 2 , wherein
 the pressure in the pressure vessel for solvent separation purposes is specified to be a pressure higher than the saturated vapor pressure of water.   
     
     
         9 . The solvent separation method according to  claim 2 , wherein
 an inert gas is filled in the pressure vessel for solvent separation purposes.   
     
     
         10 . The solvent separation method according to  claim 2 , wherein
 the solvent-containing water, which is generated in the extraction step in the process for producing an ashless coal, is supplied to the pressure vessel for solvent separation purposes.