| abstract |
PROBLEM TO BE SOLVED: To produce an oxygen-containing compound containing a dihydric phenol directly from coal at low cost and high yield without passing through coal tar. A high value-added oxygenated compound is obtained and converted to a high calorie modified coal or a coal-water-oil slurry. SOLUTION: In a reaction step 26, low-grade coal 20 is used for 10 to 4 times. Thermal decomposition in water in a subcritical or supercritical state having a pressure of 0 MPa and a temperature of 200 to 550 ° C. gives a decomposition product. Next, in a separation step 36, a water-soluble substance and a residue 28 and a water-insoluble oil component 29 are separated from the decomposition product, and then in a water-soluble substance recovery step 37, catechol, resorcin, hydroquinone or a mixture thereof containing 2 An oxygen-containing compound 27 mainly containing a polyhydric phenol is recovered. The obtained residue and the water-insoluble oil are converted into a modified coal 32 or a coal-water-oil slurry 34. |