Patents Assigned to The Pittsburg & Midway Coal Mining Co.
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Patent number: 4457826Abstract: A process for preventing the formation of deleterious coke deposits on the walls of coal liquefaction reactor vessels involves passing hydrogen and a feed slurry comprising feed coal and recycle liquid solvent to a coal liquefaction reaction zone while imparting a critical mixing energy of at least 3500 ergs per cubic centimeter of reaction zone volume per second to the reacting slurry.Type: GrantFiled: January 26, 1982Date of Patent: July 3, 1984Assignee: The Pittsburg & Midway Coal Mining Co.Inventors: Norman L. Carr, Michael E. Prudich, William E. King, Jr., William G. Moon
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Patent number: 4424108Abstract: Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest.Type: GrantFiled: January 8, 1982Date of Patent: January 3, 1984Assignee: The Pittsburg & Midway Coal Mining Co.Inventors: Walter A. Braunlin, Alan Gorski, Leo J. Jaehnig, Clifford J. Moskal, Joseph D. Naylor, Krishnia Parimi, John V. Ward
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Patent number: 4422927Abstract: Polymer precursor materials are vaporized without polymerization or are removed from a raw naphtha fraction by passing the raw naphtha to a vaporization zone (24) and vaporizing the naphtha in the presence of a wash oil while stripping with hot hydrogen to prevent polymer deposits in the equipment.Type: GrantFiled: January 25, 1982Date of Patent: December 27, 1983Assignee: The Pittsburg & Midway Coal Mining Co.Inventors: Dennis C. Kowalczyk, Bruce A. Bricklemyer, Joseph J. Svoboda
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Patent number: 4377464Abstract: A C.sub.5 -900.degree. F. (C.sub.5 -482.degree. C.) liquid yield greater than 50 weight percent MAF feed coal is obtained in a coal liquefaction process wherein a selected combination of higher hydrogen partial pressure, longer slurry residence time and increased recycle ash content of the feed slurry are controlled within defined ranges.Type: GrantFiled: September 3, 1981Date of Patent: March 22, 1983Assignee: The Pittsburg & Midway Coal Mining Co.Inventors: Norman L. Carr, William G. Moon, Michael E. Prudich
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Patent number: 4364818Abstract: Pyrite addition to a coal liquefaction process (22, 26) is controlled (118) in inverse proportion to the calcium content of the feed coal to maximize the C.sub.5 --900.degree. F. (482.degree. C.) liquid yield per unit weight of pyrite added (110). The pyrite addition is controlled in this manner so as to minimize the amount of pyrite used and thus reduce pyrite contribution to the slurry pumping load and disposal problems connected with pyrite produced slag.Type: GrantFiled: July 15, 1981Date of Patent: December 21, 1982Assignee: The Pittsburg & Midway Coal Mining Co.Inventors: Bruce K. Schmid, James E. Junkin
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Patent number: 4364817Abstract: The relative ratio of heavy distillate to light distillate produced in a coal liquefaction process is continuously controlled by automatically and continuously controlling the ratio of heavy distillate to light distillate in a liquid solvent used to form the feed slurry to the coal liquefaction zone, and varying the weight ratio of heavy distillate to light distillate in the liquid solvent inversely with respect to the desired weight ratio of heavy distillate to light distillate in the distillate fuel oil product. The concentration of light distillate and heavy distillate in the liquid solvent is controlled by recycling predetermined amounts of light distillate and heavy distillate for admixture with feed coal to the process in accordance with the foregoing relationships.Type: GrantFiled: March 4, 1981Date of Patent: December 21, 1982Assignee: The Pittsburg & Midway Coal Mining Co.Inventors: Raymond P. Anderson, David K. Schmalzer, Charles H. Wright
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Patent number: 4356078Abstract: A continuous process for blending coal with a water immiscible liquid produces a uniform, pumpable slurry. Pulverized raw feed coal and preferably a coal derived, water immiscible liquid are continuously fed to a blending zone (12 and 18) in which coal particles and liquid are intimately admixed and advanced in substantially plug flow to form a first slurry. The first slurry is withdrawn from the blending zone (12 and 18) and fed to a mixing zone (24) where it is mixed with a hot slurry to form the pumpable slurry. A portion of the pumpable slurry is continuously recycled to the blending zone (12 and 18) for mixing with the feed coal.Type: GrantFiled: September 8, 1980Date of Patent: October 26, 1982Assignee: The Pittsburg & Midway Coal Mining Co.Inventors: Leonard J. Heavin, Edward E. King, Dennis L. Milliron
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Patent number: 4330388Abstract: Normally solid dissolved coal product and a distillate liquid product are produced by continuously passing a feed slurry comprising raw feed coal and a recycle solvent oil and/or slurry together with hydrogen to a preheating-reaction zone (26, alone, or 26 together with 42), the hydrogen pressure in the preheating-reaction zone being at least 1500 psig (105 kg/cm.sup.2), reacting the slurry in the preheating-reaction zone (26, or 26 with 42) at a temperature in the range of between about 455.degree. and about 500.degree. C. to dissolve the coal to form normally liquid coal and normally solid dissolved coal. A total slurry residence time is maintained in the reaction zone ranging from a finite value from about 0 to about 0.2 hour, and reaction effluent is continuously and directly contacted with a quenching fluid (40, 68) to substantially immediately reduce the temperature of the reaction effluent to below 425.degree. C.Type: GrantFiled: September 9, 1980Date of Patent: May 18, 1982Assignee: The Pittsburg & Midway Coal Mining Co.Inventors: Raymond P. Anderson, David K. Schmalzer, Charles H. Wright
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Patent number: 4328088Abstract: Normally solid dissolved coal product and a distillate liquid product are produced by continuously passing a feed slurry comprising raw feed coal and a recycle solvent oil and/or slurry together with hydrogen to a preheating-reaction zone (26, alone, or 26 together with 42), the hydrogen pressure in the preheating-reaction zone being at least 1500 psig (105 kg/cm.sup.2), reacting the slurry in the preheating-reaction zone (26, or 26 with 42) at a temperature in the range of between about 455.degree. and about 500.degree. C. to dissolve the coal to form normally liquid coal and normally solid dissolved coal. A total slurry residence time is maintained in the reaction zone ranging from a finite value from about 0 to about 0.2 hour, and reaction effluent is continuously and directly contacted with a quenching fluid (40, 68) to substantially immediately reduce the temperature of the reaction effluent to below 425.degree. C.Type: GrantFiled: September 9, 1980Date of Patent: May 4, 1982Assignee: The Pittsburg & Midway Coal Mining Co.Inventors: Raymond P. Anderson, David K. Schmalzer, Charles H. Wright