Patents by Inventor Dennis A. Duncan

Dennis A. Duncan 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: 6383455
    Abstract: A cracking furnace within the firebox of which is located a ceramic structure presenting opposing wall surfaces which thereby define a slot-like passageway through which hydrocarbons may be fed through the firebox of the furnace. This ceramic structure is capable of service under much greater heat loads and temperatures than are metallic reaction lines as have heretofore been used, allowing for a greater firebox temperature which in turn produces an even more rapid cracking of saturated hydrocarbon into ethylene at millisecond residence times within the firebox limits.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: May 7, 2002
    Assignee: Stone & Webster Engineering Corp.
    Inventors: Dennis A. Duncan, Joseph M. Gondolfe
  • Patent number: 6312652
    Abstract: A furnace construction for cracking of saturated hydrocarbon feed stocks to olefinic product mixtures, wherein the reaction lines of such furnace are fabricated of a ceramic refractory feed inlet pipe coaxially located with a ceramic refractory tube to define an annular space there between which in part is located without and within the radiant heating firebox volume of such furnace, this to provide for a zone wherein hot cracked olefin product gas is quenched in temperature in such annular space outside of such firebox and a cracking zone within the firebox within which hydrocarbon feed is cracked to an olefin containing product gas composition. The ceramic refractory material construction permits of such pipe-tube reaction line structure to be exposed to a much greater heat/temperature content of which the firebox is capable than reaction lines of metallic construction.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: November 6, 2001
    Assignee: Stone & Webster Engineering Corp.
    Inventor: Dennis A. Duncan
  • Patent number: 5976355
    Abstract: A process for producing liquid fuels from heavy hydrocarbons such as residual oil in which the cracking temperatures are in the range of 800.degree. F. to 1200.degree. F., and the residence times are between 0.05 seconds and 0.50 seconds.
    Type: Grant
    Filed: December 14, 1995
    Date of Patent: November 2, 1999
    Assignee: Stone & Webster Engineering Corp.
    Inventors: Axel R. Johnson, Robert J. Gartside, Joseph L. Ross, Dennis A. Duncan
  • Patent number: 4663019
    Abstract: A process for producing olefins and gasoline from residual oil by thermally cracking a side cut fraction from a fractionation tower, quenching the cracked product with residual oil, producing coke from a portion of the quenched product and using a portion of the coke to provide reaction heat for the thermal cracking.
    Type: Grant
    Filed: March 9, 1984
    Date of Patent: May 5, 1987
    Assignee: Stone & Webster Engineering Corp.
    Inventors: Robert J. Gartside, Axel R. Johnson, Joseph L. Ross, Dennis A. Duncan
  • Patent number: 4585544
    Abstract: A process for pretreating residual oil by thermal regenerative vaporizing and pretreatment at short residence times and catalytically cracking the pretreated effluent from the thermal regenerative pretreatment process.
    Type: Grant
    Filed: March 9, 1984
    Date of Patent: April 29, 1986
    Assignee: Stone & Webster Engineering Corporation
    Inventors: Robert J. Gartside, Axel R. Johnson, Joseph L. Ross, Dennis A. Duncan, Edwin J. Bassler
  • Patent number: 4585543
    Abstract: A system is provided for recovering hydrocarbons from hydrocarbon-containing solids such as oil shale, tar sands or coal. The process includes preheating finely divided solids prior to introduction to a low residence time tubular reactor where a portion of the hydrocarbon is removed from the solids. The solids are then separated from the hydrocarbon product, stripped of residual hydrocarbons then transferred to a gasifier to burn the remaining entrapped hydrocarbon to serve as the heat source for the process.
    Type: Grant
    Filed: March 9, 1984
    Date of Patent: April 29, 1986
    Assignee: Stone & Webster Engineering Corp.
    Inventors: Dennis A. Duncan, Herman Woebeke
  • Patent number: 4234408
    Abstract: Solid carbonaceous material is hydrocracked to provide aliphatic and aromatic hydrocarbons for use as gaseous and liquid fuels or chemical feed stock. Particulate carbonaceous material such as coal in slurry with recycled product oil is preheated in liquid state to a temperature of 600.degree.-1200.degree. F. in the presence of hydrogen gas. The product oil acts as a sorbing agent for the agglomerating bitumins to minimize caking within the process. In the hydrocracking reactor, the slurry of oil and carbonaceous particles is heated within a tubular passageway to vaporize the oil and form a gas-solid mixture which is further heated to a hydropyrolysis temperature in excess of 1200.degree. F. The gas-solid mixture is quenched by contact with additional oil to condense normally liquid hydrocarbons for separation from the gases. A fraction of the hydrocarbon liquid product is recycled for quenching and slurrying with the carbonaceous feed.
    Type: Grant
    Filed: April 13, 1979
    Date of Patent: November 18, 1980
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Dennis A. Duncan
  • Patent number: 4234407
    Abstract: Solid, carbonaceous material is cracked in the presence of hydrogen or other reducing gas to provide aliphatic and aromatic hydrocarbons of lower molecular weight for gaseous and liquid fuels. The carbonaceous material, such as coal, is entrained as finely divided particles in a flow of reducing gas and preheated to near the decomposition temperature of the high molecular weight polymers. Within the reactor, small quantities of oxygen containing gas are injected at a plurality of discrete points to burn corresponding amounts of the hydrogen or other fuel and elevate the mixture to high temperatures sufficient to decompose the high molecular weight, carbonaceous solids. Turbulent mixing at each injection point rapidly quenches the material to a more moderate bulk temperature. Additional quenching after the final injection point can be performed by direct contact with quench gas or oil.
    Type: Grant
    Filed: February 26, 1979
    Date of Patent: November 18, 1980
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Dennis A. Duncan, Justin L. Beeson, R. Donald Oberle, Henry A. Dirksen
  • Patent number: 4225414
    Abstract: A process is disclosed for hydrocracking coal or other carbonaceous material to produce various aromatic hydrocarbons including benzene, toluene, xylene, ethylbenzene, phenol and cresols in variable relative concentrations while maintaining a near constant maximum temperature. Variations in relative aromatic concentrations are achieved by changing the kinetic severity of the hydrocracking reaction by altering the temperature profile up to and quenching from the final hydrocracking temperature. The relative concentration of benzene to the alkyl and hydroxyl aromatics is increased by imposing increased kinetic severity above that corresponding to constant heating rate followed by immediate quenching at about the same rate to below the temperature at which dehydroxylation and dealkylation reactions appreciably occur.
    Type: Grant
    Filed: February 26, 1979
    Date of Patent: September 30, 1980
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Dennis A. Duncan
  • Patent number: 4209490
    Abstract: A bench scale hydrocarbon reactor simulator accurately simulating full scale reactor coking conditions wherein the rate of coking may be measured by maintaining constant temperature of the reactor simulator exit gas by a temperature responsive circuit varying power supplied to a heater, the increase in power to the heater being proportional to deposition of coke on the heater sheath.
    Type: Grant
    Filed: August 28, 1978
    Date of Patent: June 24, 1980
    Assignee: Institute of Gas Technology
    Inventors: Dennis A. Duncan, Henry A. Dirksen