Method and apparatus for transporting coal as a coal/liquid carbon dioxide slurry
AssigneeArthur D. Little, Inc.
InventorChakra J. Santhanam
Life of this patent
Estimating the term…
Abstract
Method and apparatus for transporting coal in finely divided form in a coal/liquid slurry. Liquid carbon dioxide, which can be formed by burning coal at the coal source point and liquefying the resulting gaseous carbon dioxide, serves as the slurry liquid. The slurry is pumped through a slurry pipeline to the coal use point under conditions of temperature and pressure to maintain the carbon dioxide in liquefied form. Subsequent to deslurrying, the coal-free carbon dioxide can be liquefied and returned through a liquid pipeline to the coal source point for reuse. The use of liquid carbon dioxide as a slurry medium is also applicable to transporting other finely divided solids such as ores and the like.
Claims41
A method for transporting coal from a coal source point to a coal use point, comprising the steps of
- (a) slurrying coal in finely divided form with liquid carbon dioxide to form a stable coal/liquid carbon dioxide slurry at said coal source point;
- (b) pumping said slurry through a pipeline to said coal use point;
- and
- (c) deslurrying said coal/liquid carbon dioxide slurry at said coal use point to separate said coal and said liquid carbon dioxide and to provide said coal in condition for burning and coal-free carbon dioxide, said deslurrying comprising adibatically expanding said slurry to reduce the pressure to that level at which essentially all of said carbon dioxide is vaporized out of said slurry;
- and prior to said expanding, introducing into said slurry sufficient heat to provide that lost in said expanding, whereby no appreciable amount of said carbon dioxide is solidified.
A method for transporting coal from a coal source point to a coal use point, comprising the steps of
- (a) forming liquid carbon dioxide at said coal source point by burning coal in an excess of air to form combustion gases containing carbon dioxide, purifying said combustion gases to provide essentially pure carbon dioxide gas, and liquefying said carbon dioxide gas;
- (b) slurrying coal in finely divided form with said liquid carbon dioxide to form a coal/liquid carbon dioxide slurry at said coal source point;
- (c) pumping said slurry through a pipeline to said coal use point;
- and
- (d) deslurrying said coal/liquid carbon dioxide slurry at said coal use point to separate said coal and said liquid carbon dioxide and to provide said coal in condition for burning and coal-free carbon dioxide.
A method for transporting coal from a coal source point to a coal use point, comprising the steps of
- (a) forming liquid carbon dioxide at said coal source point by burning coal in an excess of air to form combustion gases containing carbon dioxide, purifying said combustion gases to provide essentially pure carbon dioxide gas, and liquefying said carbon dioxide gas;
- (b) forming with said liquid carbon dioxide a coal/liquid carbon dioxide slurry in which said coal is in finely divided particulate form having a size range between about 40.mu. and about 300.mu. and a size distribution optimized with respect to the viscosity of said liquid carbon dioxide to stabilize said slurry, and in which said coal makes up from about 60% to about 80% by total weight of said slurry;
- and
- (c) pumping said slurry through a pipeline to said coal use point.
apparatus for transporting coal in finely divided form from a coal source point to a coal use point, comprising in combination
- (a) means at a coal source point to form liquid carbon dioxide comprising combustion means to burn coal thereby to form gaseous carbon dioxide;
- means to purify said gaseous carbon dioxide;
- and means to liquefy the purified gaseous carbon dioxide;
- (b) slurry forming means at said coal source point to form a coal/liquid carbon dioxide slurry;
- (c) deslurrying means at a coal use point to deslurry said coal/liquid carbon dioxide slurry to provide coal for combustion and essentially coal-free carbon dioxide;
- and
- (d) slurry pipeline means connecting said slurry forming means and said deslurrying means arranged to carry said coal/liquid carbon dioxide slurry under conditions of temperature and pressure to maintain essentially all of said carbon dioxide in liquid form.
Dependencies are inferred from the claim text.