Patents by Inventor Mark S. Bohn
Mark S. Bohn 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).
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Patent number: 8431081Abstract: Solvent extraction is used to remove wax and contaminants from an iron-based Fischer-Tropsch catalyst in a natural circulation continuous-flow system. The wax-free catalyst is then subjected to controlled oxidation to convert the iron to its initial oxidized state, Fe2O3. Reactivation of the oxide catalyst precursor is carried out by addition of synthesis gas.Type: GrantFiled: May 10, 2011Date of Patent: April 30, 2013Assignee: Rentech, Inc.Inventors: Belma Demirel, Mark S. Bohn, Charles B. Benham, James E. Siebarth, Mark D. Ibsen
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Publication number: 20110211996Abstract: Solvent extraction is used to remove wax and contaminants from an iron-based Fischer-Tropsch catalyst in a natural circulation continuous-flow system. The wax-free catalyst is then subjected to controlled oxidation to convert the iron to its initial oxidized state, Fe2O3. Reactivation of the oxide catalyst precursor is carried out by addition of synthesis gas.Type: ApplicationFiled: May 10, 2011Publication date: September 1, 2011Inventors: Belma Demirel, Mark S. Bohn, Charles B. Benham, James E. Siebarth, Mark D. Ibsen
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Patent number: 7964156Abstract: Solvent extraction is used to remove wax and contaminants from an iron-based Fischer-Tropsch catalyst in a natural circulation continuous-flow system. The wax-free catalyst is then subjected to controlled oxidation to convert the iron to its initial oxidized state, Fe203. Reactivation of the oxide catalyst precursor is carried out by addition of synthesis gas.Type: GrantFiled: October 18, 2007Date of Patent: June 21, 2011Assignee: Rentech, Inc.Inventors: Belma Demirel, Mark S. Bohn, Charles B. Benham, James E. Siebarth, Mark D. Ibsen
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Patent number: 7683006Abstract: A method for transforming at least a part of the catalyst precursor hematite into x-carbide (Fe5C2) and ??-carbide (FeC2.2) without a large amount of fines generation. This method slows the transformation of the hematite to iron carbides by reducing the partial pressure of the synthesis gas by inert gas dilution. The activation time is about three to about five hours.Type: GrantFiled: March 27, 2009Date of Patent: March 23, 2010Assignee: Rentech, Inc.Inventors: Dennis L. Yakobson, Elijah C. Philipp, Mark S. Bohn
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Publication number: 20090227448Abstract: A method for transforming at least a part of the catalyst precursor hematite into x-carbide (Fe5C2) and ??-carbide (FeC2.2) without a large amount of fines generation. This method slows the transformation of the hematite to iron carbides by reducing the partial pressure of the synthesis gas by inert gas dilution. The activation time is about three to about five hours.Type: ApplicationFiled: March 27, 2009Publication date: September 10, 2009Applicant: RENTECH, INC.Inventors: Dennis L. Yakobson, Elijah C. Philipp, Mark S. Bohn
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Patent number: 7544719Abstract: A method for transforming at least a part of the catalyst precursor hematite into ?-carbide (Fe5C2) and ??-carbide (FeC2.2) without a large amount of fines generation. This method slows the transformation of the hematite to iron carbides by reducing the partial pressure of the synthesis gas by inert gas dilution. The activation time is about three to about five hours.Type: GrantFiled: July 12, 2006Date of Patent: June 9, 2009Assignee: Rentech, Inc.Inventors: Dennis L. Yakobson, Elijah C. Philipp, Mark S. Bohn
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Publication number: 20080015266Abstract: A method for transforming at least a part of the catalyst precursor hematite into ?-carbide (Fe5C2) and ??-carbide (FeC2.2) without a large amount of fines generation. This method slows the transformation of the hematite to iron carbides by reducing the partial pressure of the synthesis gas by inert gas dilution. The activation time is about three to about five hours.Type: ApplicationFiled: July 12, 2006Publication date: January 17, 2008Inventors: Dennis L. Yakobson, Elijah C. Philipp, Mark S. Bohn
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Patent number: 7303731Abstract: Solvent extraction is used to remove wax and contaminants from an iron-based Fischer-Tropsch catalyst in a natural circulation continuous-flow system. The wax-free catalyst is then subjected to controlled oxidation to convert the iron to its initial oxidized state, Fe2O3. Reactivation of the oxide catalyst precursor is carried out by addition of synthesis gas.Type: GrantFiled: December 7, 2004Date of Patent: December 4, 2007Assignee: Rentech, Inc.Inventors: Belma Demirel, Mark S. Bohn, Charles B. Benham, James E. Siebarth, Mark D. Ibsen
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Patent number: 7108835Abstract: An arrangement of cooling tubes within a Fischer-Tropsch slurry reactor simplifies removal and reinstallation of cooling tubes for reactor maintenance.Type: GrantFiled: October 8, 2003Date of Patent: September 19, 2006Assignee: Rentech, Inc.Inventors: William H. Hawthorne, Mark D. Ibsen, Peter S. Pedersen, Mark S. Bohn
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Patent number: 6838487Abstract: Solvent extraction is used to remove wax and contaminants from an iron-based Fischer-Tropsch catalyst in a natural circulation continuous-flow system. The wax-free catalyst is then subjected to controlled oxidation to convert the iron to its initial oxidized state, Fe2O3. Reactivation of the oxide catalyst precursor is carried out by addition of synthesis gas.Type: GrantFiled: December 4, 2003Date of Patent: January 4, 2005Assignee: Rentech, Inc.Inventors: Belma Demirel, Mark S. Bohn, Charles B. Benham, James E. Siebarth, Mark D. Ibsen
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Patent number: 6739136Abstract: A combustion system for a hybrid solar receiver comprises a pre-mixer which combines air and fuel to form an air-fuel mixture. The mixture is introduced tangentially into a cooling jacket. A burner plenum is fluidically connected to the cooling jacket such that the burner plenum and the cooling jacket are arranged in thermal contact with one another. The air-fuel mixture flows through the cooling jacket cooling the burner plenum to reduce pre-ignition of the air-fuel mixture in the burner plenum. A combustion chamber is operatively associated with and open to the burner plenum to receive the air-fuel mixture from the burner plenum. An igniter is operatively positioned in the combustion chamber to combust the air-fuel mixture, releasing heat. A recuperator is operatively associated with the burner plenum and the combustion chamber and pre-heats the air-fuel mixture in the burner plenum with heat from the combustion chamber.Type: GrantFiled: November 22, 2002Date of Patent: May 25, 2004Assignee: Midwest Research InstituteInventors: Mark S. Mehos, Kenneth M. Anselmo, James B. Moreno, Charles E. Andraka, K. Scott Rawlinson, John Corey, Mark S. Bohn
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Patent number: 6730221Abstract: Catalyst particles are separated from the wax in a reactor slurry reactor by feeding a portion of the slurry to a dynamic settler. Heavier catalyst particles settle and are removed as the slurry at the bottom of the settler is recycled back to the reactor. Clarified wax is removed at the top of the settler. A multi-channel baffle prevents turbulence, improving retention of the desired heavier catalyst particles.Type: GrantFiled: May 29, 2001Date of Patent: May 4, 2004Assignee: Rentech, Inc.Inventors: Mark S. Bohn, James E. Siebarth
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Patent number: 6712982Abstract: Catalyst particles are separated from the wax in a reactor slurry reactor by feeding a portion of the slurry to a dynamic settler. Heavier catalyst particles settle and are removed as the slurry at the bottom of the settler is recycled back to the reactor. Clarified wax is removed at the top of the settler. A multi-channel baffle prevents turbulence, improving retention of the desired heavier catalyst particles.Type: GrantFiled: April 17, 2003Date of Patent: March 30, 2004Assignee: Rentech, Inc.Inventors: Mark S. Bohn, James E. Siebarth
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Publication number: 20030205516Abstract: Catalyst particles are separated from the wax in a reactor slurry reactor by feeding a portion of the slurry to a dynamic settler. Heavier catalyst particles settle and are removed as the slurry at the bottom of the settler is recycled back to the reactor. Clarified wax is removed at the top of the settler. A multi-channel baffle prevents turbulence, improving retention of the desired heavier catalyst particles.Type: ApplicationFiled: April 17, 2003Publication date: November 6, 2003Inventors: Mark S. Bohn, James E. Siebarth
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Publication number: 20030136398Abstract: A combustion system for a hybrid solar receiver comprises a pre-mixer which combines air and fuel to form an air-fuel mixture. The mixture is introduced tangentially into a cooling jacket. A burner plenum is fluidically connected to the cooling jacket such that the burner plenum and the cooling jacket are arranged in thermal contact with one another. The air-fuel mixture flows through the cooling jacket cooling the burner plenum to reduce pre-ignition of the air-fuel mixture in the burner plenum. A combustion chamber is operatively associated with and open to the burner plenum to receive the air-fuel mixture from the burner plenum. An igniter is operatively positioned in the combustion chamber to combust the air-fuel mixture, releasing heat. A recuperator is operatively associated with the burner plenum and the combustion chamber and pre-heats the air-fuel mixture in the burner plenum with heat from the combustion chamber.Type: ApplicationFiled: November 22, 2002Publication date: July 24, 2003Inventors: Mark S. Mehos, Kenneth M. Anselmo, James B. Moreno, Charles E. Andraka, K. Scott Rawlinson, John Corey, Mark S. Bohn
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Patent number: 6534552Abstract: Increased hydrocarbon yields from natural gas and reduced oxygen consumption improvements are obtained by recycling hydrogen to a Fischer-Tropsch reactor, which can have a catalyst exhibiting either a low water gas shift activity such as cobalt, or a high water gas shift activity such as iron. At least a portion of the remaining tail gas, either before or after the hydrogen has been removed, is recycled to the inlet of the synthesis gas production reactor.Type: GrantFiled: June 1, 2001Date of Patent: March 18, 2003Assignee: Rentech, Inc.Inventors: Charles B. Benham, Mark S. Bohn, Dennis L. Yakobson
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Publication number: 20020179506Abstract: Catalyst particles are separated from the wax in a reactor slurry reactor by feeding a portion of the slurry to a dynamic settler. Heavier catalyst particles settle and are removed as the slurry at the bottom of the settler is recycled back to the reactor. Clarified wax is removed at the top of the settler. A multi-channel baffle prevents turbulence, improving retention of the desired heavier catalyst particles.Type: ApplicationFiled: May 29, 2001Publication date: December 5, 2002Inventors: Mark S. Bohn, James E. Siebarth
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Patent number: 6487859Abstract: A hybrid high-temperature solar receiver is provided which comprises a solar heat-pipe-receiver including a front dome having a solar absorber surface for receiving concentrated solar energy, a heat pipe wick, a rear dome, a sidewall joining the front and the rear dome, and a vapor and a return liquid tube connecting to an engine, and a fossil fuel fired combustion system in radial integration with the sidewall for simultaneous operation with the solar heat pipe receiver, the combustion system comprising an air and fuel pre-mixer, an outer cooling jacket for tangentially introducing and cooling the mixture, a recuperator for preheating the mixture, a burner plenum having an inner and an outer wall, a porous cylindrical metal matrix burner firing radially inward facing a sodium vapor sink, the mixture ignited downstream of the matrix forming combustion products, an exhaust plenum, a fossil-fuel heat-input surface having an outer surface covered with a pin-fin array, the combustion products flowing through theType: GrantFiled: July 31, 2001Date of Patent: December 3, 2002Assignee: Midwest Research InstituteInventors: Mark S. Mehos, Kenneth M. Anselmo, James B. Moreno, Charles E. Andraka, K. Scott Rawlinson, John Corey, Mark S. Bohn
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Publication number: 20020120017Abstract: Apparatus and processes for producing power, liquid hydrocarbons and carbon dioxide from heavy feedstocks, using a partial oxidation reactor to produce a synthesis gas, a Fischer-Tropsch reactor to convert the synthesis gas to hydrocarbon products and tail gases containing hydrogen and carbon dioxide, and a combined cycle plant to produce power from steam generated by recovering heat from the reactors and from combustible tail gases. By varying operating conditions and utilizing hydrogen for recycle to the Fischer-Tropsch reactor and/or hydrocracking wax products to produce lighter hydrocarbons, the process can selectively maximize the production of power, hydrocarbons or carbon dioxide. In preferred embodiments, the Fischer-Tropsch reactor can be a slurry reactor and can employ an iron-based catalyst.Type: ApplicationFiled: September 25, 2001Publication date: August 29, 2002Inventors: Mark S. Bohn, Charles B. Benham
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Publication number: 20020059798Abstract: A hybrid high-temperature solar receiver is provided which comprises a solar heat-pipe-receiver including a front dome having a solar absorber surface for receiving concentrated solar energy, a heat pipe wick, a rear dome, a sidewall joining the front and the rear dome, and a vapor and a return liquid tube connecting to an engine, and a fossil fuel fired combustion system in radial integration with the sidewall for simultaneous operation with the solar heat pipe receiver, the combustion system comprising an air and fuel pre-mixer, an outer cooling jacket for tangentially introducing and cooling the mixture, a recuperator for preheating the mixture, a burner plenum having an inner and an outer wall, a porous cylindrical metal matrix burner firing radially inward facing a sodium vapor sink, the mixture ignited downstream of the matrix forming combustion products, an exhaust plenum, a fossil-fuel heat-input surface having an outer surface covered with a pin-fin array, the combustion products flowing through theType: ApplicationFiled: July 31, 2001Publication date: May 23, 2002Inventors: Mark S. Mehos, Kenneth M. Anselmo, James B. Moreno, Charles E. Andraka, K. Scott Rawlinson, John Corey, Mark S. Bohn