US 4,058,976 A · Method and apparatus for removal of last traces of soluble ash and elements from solvent refined coal

Abstract

Solvent refined coal is treated with liquid water at a temperature of about 500.degree.-550.degree. F in a closed cylindrical vessel under the saturation pressure 665-1030 psig of water at that temperature and under gentle agitation to insure low shear liquid-solid contact for about 1/2 to 2 hours. Surprisingly, the soluble ash, generally sodium or potassium salts, is leached out to bring the sodium content down from 50-60 parts per million to a value of less than 1 part per million which makes the product very suitable as a feed for direct firing in a gas turbine. In addition the total ash content is reduced from a value of approximately 0.1% to a value less than 0.05% which means that in addition to reducing the quantity of sodium and potassium, there are other constituents of the ash which also have been removed.

Claims7

Dependent claims

Apparatus for the removal of the last traces of sodium and potassium salts and other soluble ash from solvent refined coal at a power generation site comprising:

a. crushing and feeding means for feeding finely divided solvent refined coal and water in the form of a slurry into an initial mixing and dearating chamber;
b. proportioning means to control the proportion of water to solvent refined coal;
c. an initial mixing and deaerating chamber for receiving the controlled proportions of solvent refined coal and water;
d. mixing means for stirring;
e. steam supply and proportioning means to properly control the amount of steam and thereby to achieve heating of the mixture to the steam-water saturation temperature at a chamber internal pressure of about 1 atmosphere;
f. second feeding means for feeding the coal slurry into a pressure tight vessel;
g. a pressure-tight vessel into which the aforementioned second feeding means discharges the coal slurry;
and,
h. heating means to heat the contents of said pressure-tight vessel and maintain the contents thereof at a temperature of about 500.degree. to 600.degree. F and at the corresponding water-steam saturation pressure for a time ranging from approximately 1/2 to 2 hours.

6 more elements

Apparatus for the removal of the last traces of sodium and potassium salts and other soluble ash from solvent refined coal at the solvent refined coal refining process plant comprising:

a. means for supplying a liquid solvent refined coal stream from a solvent refined coal refining process with the solvent refined coal stream under pressure of the order of 1200 to 1500 psi and at a temperature of 500.degree. - 600.degree. F;
b. water injecting means for injecting wash water into the liquid solvent refined coal stream in proportion to the rate of flow of solvent refined coal with the proportion of wash water added being of the order of 10 to 20% of the weight flow of the solvent refined coal;
c. means for delivering the liquid solvent refined coal stream thus treated to an agitated extraction vessel for obtaining low shear liquid-liquid contact between the solvent refined coal and the water while at the same time minimizing the development of emulsions;
and
d. separation means for separating the washed solvent refined coal from at least a portion of the wash water injected by said water injecting means.

2 more elements

Dependencies are inferred from the claim text.

Method and apparatus for removal of last traces of soluble ash and elements from solvent refined coal

Life of this patent

Method and apparatus for removal of last traces of soluble ash and elements from solvent refined coal

Life of this patent

Abstract

Claims7