Patents by Inventor Motasimur R. Khan

Motasimur R. Khan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5534040
    Abstract: A process for upgrading plastic material containing inorganic filler or reinforcement material for use as feedstock in a partial oxidation gas generator for the production of raw synthesis gas, fuel gas, or reducing gas. The plastic material is granulated and partially liquefied by heating in a closed autoclave at a temperature in the range of about 400.degree. F. to 495.degree. F. and a pressure in the range of about 150 psig to 750 psig while the plastic material is in contact with a pumpable hydrocarbonaceous liquid solvent. A pumpable slurry is thereby produced comprising solubilized plastic, unsolubilized plastic, hydrocarbonaceous liquid solvent, separated inorganic material and unseparated inorganic material. After removing the separated inorganic material, the remainder of the slurry is then reacted by partial oxidation to produce said raw synthesis gas, fuel gas or reducing gas.
    Type: Grant
    Filed: March 31, 1995
    Date of Patent: July 9, 1996
    Assignee: Texaco Inc.
    Inventors: Motasimur R. Khan, Christine C. Albert, Stephen J. DeCanio
  • Patent number: 5498827
    Abstract: A process for upgrading plastic material containing inorganic filler or reinforcement material for use as feedstock in partial oxidation gas generator for the production of raw synthesis gas, fuel gas, or reducing gas. The plastic material is granulated and mixed with water to produce the plastic sludge. The plastic sludge is preheated at a temperature in the range of about 350.degree. F. to 475.degree. F. in the absence of air in a closed system. The preheated plastic sludge is then hydrothermally treated at a temperature in the range of about 450.degree. F. to 650.degree. F. at a pressure in the range of about 100 to 1200 psig and above the vapor pressure of water at that temperature. The hydrothermally treated plastic sludge is cooled, degassed, and mixed with ground solid carbonaceous fuel, e.g., coal and water, to produce a pumpable aqueous slurry having a solids content in the range of about 40 to 60 wt. %.
    Type: Grant
    Filed: October 4, 1993
    Date of Patent: March 12, 1996
    Assignee: Texaco Inc.
    Inventors: Motasimur R. Khan, Christine C. Albert, Stephen J. DeCanio
  • Patent number: 5445659
    Abstract: A process for converting scrap plastic material into a high quality transportation fuel. The plastic material is granulated and mixed with granulated solid carbonaceous fuel e.g. coal and liquid hydrocarbonaceous solvent e.g. waste motor oil to produce a plastic-containing sludge. The plastic-containing sludge is liquefied in a closed autoclave while in contact with hydrogen gas. A pumpable slurry from the autoclave is heated and fractionated in a fractionation zone to produce a hydrocarbonaceous distillate which may be used for transportation fuel. A bottoms stream from the fractionation zone comprising liquid hydrocarbonaceous material and inorganic material is reacted by partial oxidation to produce nontoxic slag and raw synthesis gas, fuel gas or reducing gas which may be purified in a gas purification zone.
    Type: Grant
    Filed: October 4, 1993
    Date of Patent: August 29, 1995
    Assignee: Texaco Inc.
    Inventors: Motasimur R. Khan, Christine C. Albert, Stephen J. DeCanio
  • Patent number: 5423894
    Abstract: Pumpable aqueous slurries of low rank coal e.g. subbituminous coal and lignite having a comparatively high solids content are made by keeping the particles of coal in contact with a non-oxidizing gas e.g. nitrogen and/or CO.sub.2 thereby maintaining a hydrophobic surface on the particles of coal while they are ground and dried, contacted with an aqueous slurry of liquid hydrocarbonaceous fuel which is absorbed and which coats the particles of coal, and then dried. The dried coated particles of low rank coal are mixed with water to produce a pumpable slurry having a solids content in the range of about 50 to 60 wt. %. In one embodiment, at least a portion of the water needed to produce said pumpable slurry is derived by cooling and condensing out water from the non-oxidizing gas that was used to dry the low rank coal. In still another embodiment, the dewatered non-oxidizing gas is introduced into the combustor of a gas turbine to moderate the temperature and thereby reduce the formation of NO.sub.x gases.
    Type: Grant
    Filed: May 3, 1993
    Date of Patent: June 13, 1995
    Assignee: Texaco Inc.
    Inventors: Edward T. Child, William L. Lafferty, Jr., Motasimur R. Khan
  • Patent number: 5356540
    Abstract: A pumpable aqueous slurry of sewage sludge as produced by the steps of (1) dewatering sewage sludge to produce an aqueous slurry having a solids content of about 10 to 25 wt. %; (2) pretreating said aqueous slurry of sewage sludge to improve its slurrying characteristics by one or a combination of (a) heating, (b) hydrothermal treatment, and (c) heating, mixing and shearing; and (3) mixing the following materials together at a temperature in the range of about ambient to 400.degree. F. to produce a pumpable aqueous slurry having a solids content in the range of about 30 to 65 wt. %: (a) pretreated aqueous slurry of sewage sludge; (b) a nonionic water soluble alkoxylated alkylphenol additive; and (c) sewage sludge-containing material and/or solid carbonaceous fuel-containing material to increase the solids loading.
    Type: Grant
    Filed: May 20, 1991
    Date of Patent: October 18, 1994
    Assignee: Texaco Inc.
    Inventors: Motasimur R. Khan, Christine C. Albert
  • Patent number: 5292442
    Abstract: A process for disposing of sanitary sewage sludge by producing a pumpable slurry of sewage sludge with or without solid carbonaceous fuel and burning said slurry as fuel in a partial oxidation gas generator, furnace, or boiler. The aqueous slurry of sewage sludge is concentrated by removing water by means of a conventional belt filter press, centrifuge, or hydroclone. The dewatered slurry of sewage sludge is heated by direct contact with steam while air and organic vapors are simultaneously removed, to reduce the pressure in the system; hydrothermally treated in two steps with indirect and direct heat exchange with steam; dewatered by flash evaporation and centrifuging; and burned with or without admixture with solid carbonaceous fuel in a partial oxidation gasifier, furnace, boiler, or incinerator to produce synthesis gas or a hot raw effluent gas stream. In a preferred embodiment, the effluent gas stream is cleaned and purified and non-contaminating ash and slag are separated.
    Type: Grant
    Filed: October 1, 1992
    Date of Patent: March 8, 1994
    Assignee: Texaco Inc.
    Inventors: Motasimur R. Khan, Harvey D. Schindler, Christine C. Albert, Stephan J. DeCanio
  • Patent number: 5273556
    Abstract: A process for disposing of sewage sludge by heating and shearing an aqueous mixture of sewage sludge in a tubular-shaped processing means containing a plurality of rotating agitators to produce a pumpable aqueous slurry of sewage sludge. The aqueous slurry of sewage sludge is mixed with solid carbonaceous fuel or an aqueous slurry of solid carbonaceous fuel to produce a pumpable aqueous slurry of sewage sludge and solid carbonaceous fuel. The aqueous slurry of sewage sludge and solid carbonaceous fuel is heated in a first steam jacketed rotary disc mixing-heating means. Alternately, first and second hoppers are filled with said heated aqueous slurry of sewage sludge and solid carbonaceous fuel and cycled between a second steam jacketed rotary disc mixing-heating means; wherein while one hopper is being filled the contents in the other hopper are being dewatered. The thickened pumpable slurry is burned in a partial oxidation gasifier, furnace, boiler, or incinerator to produce a hot effluent gas steam.
    Type: Grant
    Filed: March 30, 1992
    Date of Patent: December 28, 1993
    Assignee: Texaco Inc.
    Inventors: Matthew A. McMahon, Ronald J. McKeon, Robert F. Heyl, Motasimur R. Khan, Kenneth W. McKenzie, Enrique F. Depaz
  • Patent number: 5266085
    Abstract: A process for disposing of sewage sludge comprising the steps of, (1) dewatering the sewage sludge to produce an aqueous slurry of sewage sludge having a solids content of about 10 to 30 wt. %; (2) simultaneously heating and shearing said dewatered sewage sludge at about 150.degree. F. to 210.degree. F. in the absence of air for 0.5 seconds to 60 minutes while being continuously passed through a tubular-shaped processing means containing a plurality of rotating agitators, thereby producing a pumpable slurry having a viscosity of less than about 2000 centipoise; (3) dewatering the sewage sludge if necessary; (4) mixing at a temperature in the range of about ambient to 180.degree. F. in a ribbon or in-line static mixer the slurry of sewage sludge from (2) and/or (3) with a supplemental solid carbonaceous fuel e.g. coal and/or petroleum-coke to produce a pumpable aqueous slurry of sewage sludge and supplemental fuel having a solids content in the range of about 50 to 60 wt.
    Type: Grant
    Filed: November 23, 1992
    Date of Patent: November 30, 1993
    Assignee: Texaco Inc.
    Inventors: Matthew A. McMahon, Motasimur R. Khan, Robert F. Heyl, Ronald J. McKeon, Kenneth W. McKenzie
  • Patent number: 5264009
    Abstract: A process for disposing of sanitary sewage sludge by producing a pumpable slurry of sewage sludge with or without solid carbonaceous fuel and burning said slurry as fuel in a partial oxidation gas generator, furnace, or boiler. The aqueous slurry of sewage sludge is concentrated by removing water by means of a conventional belt filter press, centrifuge, or hydroclone. The dewatered slurry of sewage sludge is preheated and sheared; hydrothermally treated; and its solids content increased. A chelating agent, for example an aminopolycarboxylic acid or a hydrocarboxylic acid is mixed with the aqueous slurry of sewage sludge during the preheating and shearing step and/or the step for increasing its solids content. By means of the subject process, the viscosity of the slurry of sewage sludge with or without solid carbonaceous fuel is reduced and coagulation is suppressed.
    Type: Grant
    Filed: September 1, 1992
    Date of Patent: November 23, 1993
    Assignee: Texaco Inc.
    Inventor: Motasimur R. Khan
  • Patent number: 5234468
    Abstract: A process for disposing of sewage sludge comprising the steps of, (1) dewatering the sewage sludge to produce amorphous sewage sludge having a solids content of about 28 to 50 wt. %; (2) heating said amorphous sewage sludge at about 150.degree. F. to 510.degree. F. in the absence of air for 3 seconds to 60 minutes and mildly shearing the sewage sludge, thereby producing a pumpable feed slurry of sewage sludge having a viscosity in the range of about 400 to 1500 centipoise and a higher heating value in the range of about 5000 to 9500 BTU/LB; and (3) burning said pumpable slurry from (2) in a partial oxidation gasifier, furnace, boiler, or incinerator to produce an effluent gas stream. In one embodiment, the effluent gas stream is cleaned and purified and non-contaminating fly-ash and slag are separated. The fly-ash may be mixed with the sewage sludge in the process to facilitate separation of water during pressing and to encapsulate the non-combustible materials in the sewage sludge.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: August 10, 1993
    Assignee: Texaco Inc.
    Inventor: Motasimur R. Khan
  • Patent number: 5234469
    Abstract: A process for disposing of sewage sludge comprising the steps of, (1) dewatering the sewage sludge to produce an aqueous slurry of sewage sludge having a solids content of about 10 to 50 wt. %; (2) heating and mildly shearing said dewatered sewage sludge at about 150.degree. F. to 210.degree. F. in the absence of air for 3 seconds to 60 minutes by a rotor/mixer at a speed of about 15 to 1000 r.p.m., thereby producing a pumpable slurry having a viscosity of less than about 2500 centipoise; (3) mixing at a temperature in the range of about ambient to 200.degree. F. the slurry of sewage sludge from (2) with a supplemental fuel to produce a pumpable slurry of sewage sludge and supplemental fuel having a solids content in the range of about 50 to 65 wt. % and a higher heating value in the range of about 6,000 to 18,000 BTU/LB; and (4) burning said pumpable slurry from (3) in a partial oxidation gasifier, furnace, boiler, or incinerator to produce an effluent gas stream.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: August 10, 1993
    Assignee: Texaco Inc.
    Inventors: Motasimur R. Khan, Matthew A. McMahon, Christine C. Albert, Ronald J. McKeon, Stephen J. DeCanio
  • Patent number: 5217625
    Abstract: A process for disposing of sanitary sewage sludge by producing a pumpable slurry of sewage sludge with or without solid carbonaceous fuel and burning said slurry as fuel in a partial oxidation gas generator, furnace, or boiler. First, an aqueous slurry of sewage sludge is concentrated to produce sewage sludge cake. The sewage sludge cake is preheated and sheared while in contact with sulfuric or sulfurous acid to produce a pumpable acidified aqueous slurry of sewage sludge having a pH of about 1 to 5. After two-stage hydrothermal treatment with neutralization of the sewage sludge after the second hydrothermal stage, the solids content of the pumpable aqueous slurry of sewage sludge is increased. By means of the subject process, the viscosity of the slurry of sewage sludge with or without solid carbonaceous fuel is reduced and coagulation is suppressed.
    Type: Grant
    Filed: October 2, 1992
    Date of Patent: June 8, 1993
    Assignee: Texaco Inc.
    Inventors: Motasimur R. Khan, Matthew A. McMahon, Ronald J. McKeon
  • Patent number: 5211724
    Abstract: An improved process for the low-cost disposal of noxious sewage sludge in a safe way without polluting the environment. In the process, sewage sludge having a solids content of about 0.5 to 20 wt.% is concentrated by pressing in a belt filter press, optionally followed by pressing in a high intensity press. It was unexpectedly found that the morphology of the resulting dewatered sewage sludge is changed by such mechanical treatment so that slurries with higher concentrations of solids are achieved. The dewatered sewage sludge is heated, flash evaporated and/or centrifuged, and mixed with a supplemental fuel e.g., liquid hydrocarbonaceous and/or solid carbonaceous fuel to produce a pumpable fuel slurry having a total solids content in the range of about 50 to 70 wt.% and comprising about 10 to 40 wt.% dewatered sewage sludge and having a higher heating value in the range of about 5,000 to 14,000 BTU/Lb.
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: May 18, 1993
    Assignee: Texaco, Inc.
    Inventors: Motasimur R. Khan, Ronald J. McKeon
  • Patent number: 5211723
    Abstract: This invention relates to a novel pumpable sewage sludge fuel and process for burning it. An aqueous slurry of sewage sludge is dewatered and dried to a solids content in the range of about 50 to 99 wt. % in a drying zone in the absence of free-oxygen containing gas but while in contact with a gaseous material selected from the group consisting of N.sub.2, CO.sub.2, H.sub.2, CO, and mixtures thereof. The dried sewage sludge is mixed with a supplementary fuel from the group consisting of solid carbonaceous fuel, liquid hydrocarbonaceous fuel, mixtures thereof, and optionally with water to produce a pumpable slurry fuel feedstream having a solids content in the range of about 50 to 65 wt. % and a higher heating value of at least about 6,000 Btu/lb. The slurry fuel feedstream may be burned in a partial oxidation gasifier, furnace, boiler, or incinerator.
    Type: Grant
    Filed: September 19, 1991
    Date of Patent: May 18, 1993
    Assignee: Texaco Inc.
    Inventor: Motasimur R. Khan
  • Patent number: 5188739
    Abstract: A process for disposing of sanitary sewage sludge by producing a pumpable slurry of sewage sludge and solid carbonaceous fuel e.g. coal, petroleum coke, rubber. The slurry is burned as a fuel in a partial oxidation gas generator, furnace, or boiler. In the process, an aqueous slurry of sewage sludge is concentrated by removing water by means of a conventional belt filter press or presses. The dewatered slurry of sewage sludge is hydrothermally treated and cooled and depressurized. The viscosity of the slurry of sewage sludge is reduced to less than about 2000 centipoise by shearing. The sheared sewage sludge is then ground together with a solid carbonaceous fuel to produce a pumpable slurry which is burned with a free-oxygen containing gas in a partial oxidation gasifier, furnace, boiler, or incinerator to produce a hot raw effluent gas stream. In a preferred embodiment, the effluent gas stream is cleaned and purified and non-contaminating ash and slag are separated.
    Type: Grant
    Filed: December 2, 1991
    Date of Patent: February 23, 1993
    Assignee: Texaco Inc.
    Inventors: Motasimur R. Khan, Richard B. Zang, Christine C. Albert
  • Patent number: 5188741
    Abstract: A process for treating sanitary sewage sludge to achieve increased solids, decreased viscosity, and a reduction of pathogens. The aqueous slurry of sewage sludge having a solids content in the range of about 3 to 35 wt. % is simultaneously conveyed and preheated, mascerated, heated in an heat exchanger, hydrothermally treated in a closed vessel under a blanket of nitrogen at about 500.degree. F. and a pressure of about 750 psig and above the vapor pressure of water at that temperature, dewatered and cooled in a first multi-step flash evaporation zone where the pressure is dropped in three steps from about 750 psig to about 50 psig and then in a second flash evaporation zone the pressure is dropped to about 25 psig, cooling and condensing the vapor from said first and second flash evaporation zones, and removing a dewatered pumpable slurry of sewage sludge product having a solids content in the range of about 5 to 50 wt. % and a reduced amount of pathogens.
    Type: Grant
    Filed: April 1, 1992
    Date of Patent: February 23, 1993
    Assignee: Texaco Inc.
    Inventors: Richard B. Zang, Motasimur R. Khan
  • Patent number: 5188740
    Abstract: A process for disposing of sanitary sewage sludge by producing a pumpable slurry of sewage sludge and low grade solid carbonaceous fuel and burning said slurry as fuel in a partial oxidation gas generator, furnace, or boiler. The aqueous slurry of sewage sludge is concentrated by removing water by means of a conventional belt filter press or presses. Prior to and/or immediately after said concentrating step particles of low grade solid carbonaceous fuel e.g. lignitic coal, peat, wood and cellulose-containing materials are mixed with the slurry of sewage sludge. The dewatered slurry of sewage sludge and low grade solid carbonaceous fuel is hydrothermally treated in three stages and excess water is separated by flash evaporization and/or centrifuging.
    Type: Grant
    Filed: December 2, 1991
    Date of Patent: February 23, 1993
    Assignee: Texaco Inc.
    Inventor: Motasimur R. Khan