Patents Assigned to Rentech, Inc.
  • Publication number: 20090062108
    Abstract: A method of strengthening a precipitated unsupported iron catalyst by: preparing a precipitated unsupported iron catalyst containing copper and potassium; adding a solution comprising a structural promoter to the previously prepared catalyst; drying the mixture; and calcining the dried catalyst. A method for preparing an iron catalyst, the method comprising: precipitating a catalyst precursor comprising iron phases selected from hydroxides, oxides, and carbonates; adding a promoter to the catalyst precursor to yield a promoted precursor; drying the promoted precursor to yield dried catalyst; and calcining the dried catalyst, wherein the catalyst further comprises copper and potassium. A method of preparing a strengthened precipitated iron catalyst comprising: co-precipitating iron, copper, magnesium, and aluminum; washing the precipitate; alkalizing the precipitate; and drying the precipitate to yield a dried catalyst precursor.
    Type: Application
    Filed: August 26, 2008
    Publication date: March 5, 2009
    Applicant: RENTECH, INC.
    Inventors: Belma Demirel, Charles B. Benham, Dan Fraenkel, Richard A. Bley, Jesse W. Taylor, Sara L. Rolfe, Harold A. Wright
  • Publication number: 20080132588
    Abstract: A gasification plant and methods for producing ammonia, Fischer-Tropsch fuels, electrical power, and/or sulfur from carbon-bearing feedstocks including coal and/or petroleum coke. Methods for production of desired relative amounts of ammonia and Fischer-Tropsch liquid hydrocarbons by adjusting the amount of synthesis gas bypassing the Fischer-Tropsch reactor. The multi-product and integrated plants may be used to reduce the amount of CO2 vented into the atmosphere during the production of these products.
    Type: Application
    Filed: October 18, 2007
    Publication date: June 5, 2008
    Applicant: RENTECH, INC.
    Inventors: Peter S. Pedersen, Dennis L. Yakobson
  • Publication number: 20080038159
    Abstract: 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: Application
    Filed: October 18, 2007
    Publication date: February 14, 2008
    Applicant: RENTECH, INC.
    Inventors: Belma Demirel, Mark Bohn, Charles Benham, James Siebarth, Mark Ibsen
  • Patent number: 7303731
    Abstract: 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: Grant
    Filed: December 7, 2004
    Date of Patent: December 4, 2007
    Assignee: Rentech, Inc.
    Inventors: Belma Demirel, Mark S. Bohn, Charles B. Benham, James E. Siebarth, Mark D. Ibsen
  • Patent number: 7300642
    Abstract: A gasification plant for producing ammonia, Fischer-Tropsch fuels, and electrical power from carbon-bearing feedstocks.
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: November 27, 2007
    Assignee: Rentech, Inc.
    Inventors: Peter S. Pedersen, Dennis L. Yakobson
  • Patent number: 7108835
    Abstract: An arrangement of cooling tubes within a Fischer-Tropsch slurry reactor simplifies removal and reinstallation of cooling tubes for reactor maintenance.
    Type: Grant
    Filed: October 8, 2003
    Date of Patent: September 19, 2006
    Assignee: Rentech, Inc.
    Inventors: William H. Hawthorne, Mark D. Ibsen, Peter S. Pedersen, Mark S. Bohn
  • Patent number: 6976362
    Abstract: A plant for producing Fischer-Tropsch liquids and electrical power with greatly reduced emissions of carbon dioxide to the atmosphere is made up of a syngas generator unit, an air separation unit, a Fischer-Tropsch unit, a CO2 removal unit, and a combined cycle electricity generation unit. Each of Fischer-Tropsch liquids, carbon dioxide, and electrical power can be recoverable under proper economic conditions. Electrical power is recoverable by the use of a gas turbine fueled by predominantly hydrogen and a steam turbine powered by steam generated by cooling exhaust gases from the gas turbine. Sequestration of CO2 and fueling the gas turbine with hydrogen reduces the amount of greenhouse gases emitted to the atmosphere.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: December 20, 2005
    Assignee: Rentech, Inc.
    Inventors: Richard O. Sheppard, Dennis L. Yakobson
  • Patent number: 6838487
    Abstract: 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: Grant
    Filed: December 4, 2003
    Date of Patent: January 4, 2005
    Assignee: Rentech, Inc.
    Inventors: Belma Demirel, Mark S. Bohn, Charles B. Benham, James E. Siebarth, Mark D. Ibsen
  • Patent number: 6809123
    Abstract: A carbon-bearing feedstock is reacted with oxygen and water in a partial oxidation reactor to produce a mixture of hydrogen and carbon monoxide. The hydrogen is removed as a first product and the remaining carbon monoxide is reacted with steam over a bifunctional catalyst to produce higher hydrocarbons and carbon dioxide. The bifunctional catalyst provides water gas shift and Fischer-Tropsch functions.
    Type: Grant
    Filed: August 7, 2002
    Date of Patent: October 26, 2004
    Assignee: Rentech, Inc.
    Inventor: Dennis L. Yakobson
  • Patent number: 6730221
    Abstract: 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: Grant
    Filed: May 29, 2001
    Date of Patent: May 4, 2004
    Assignee: Rentech, Inc.
    Inventors: Mark S. Bohn, James E. Siebarth
  • Patent number: 6712982
    Abstract: 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: Grant
    Filed: April 17, 2003
    Date of Patent: March 30, 2004
    Assignee: Rentech, Inc.
    Inventors: Mark S. Bohn, James E. Siebarth
  • Patent number: 6632846
    Abstract: A plant for manufacturing urea from carbonaceous materials, oxygen from an air separation unit and water, preferably steam, is made up of a syngas generator unit, an air separation unit, Fischer-Tropsch unit, a CO2 removal unit, a hydrogen removal unit, a methanator unit, an ammonia converter unit and a urea synthesizer unit. Each of Fischer-Tropsch liquids, ammonia, hydrogen and urea can be recoverable under proper economic conditions. Electrical power is recoverable by the addition of at least one of a steam turbine and a gas turbine which is/are coupled to an electrical generator.
    Type: Grant
    Filed: September 25, 2001
    Date of Patent: October 14, 2003
    Assignee: Rentech, Inc.
    Inventors: Richard O. Sheppard, Dennis L. Yakobson
  • Patent number: 6627666
    Abstract: A process is described in which the waste gas from the production of acetylene is employed in the Fischer-Tropsch synthesis of hydrocarbon liquids. The process consists of the steps of collecting the waste gas, compressing it to the proper pressure, passing the compressed gas into a reactor containing a Fischer-Tropsch catalyst under the proper conditions of temperature, pressure, and space velocity, and collecting the liquid products thereby formed from the waste gas stream.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: September 30, 2003
    Assignee: Rentech Inc.
    Inventor: Peter S. Pedersen
  • Patent number: 6534552
    Abstract: 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: Grant
    Filed: June 1, 2001
    Date of Patent: March 18, 2003
    Assignee: Rentech, Inc.
    Inventors: Charles B. Benham, Mark S. Bohn, Dennis L. Yakobson
  • Patent number: 6403528
    Abstract: An electron accepting developer useful for producing visible images by reaction with an electron donor in carbonless paper and photo- imaging systems, the developer comprising an acid-treated, water insoluble alkali metal-modified, inorganic oxide or an acid-treated molecular sieve.
    Type: Grant
    Filed: January 10, 2001
    Date of Patent: June 11, 2002
    Assignee: Rentech, Inc.
    Inventors: Dale R. Shackle, Benjamin Chaloner-Gill
  • Patent number: 6306917
    Abstract: 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: Grant
    Filed: August 17, 1999
    Date of Patent: October 23, 2001
    Assignee: Rentech, Inc.
    Inventors: Mark S. Bohn, Charles S. Benham
  • Patent number: 6242167
    Abstract: An electron accepting developer useful for producing visible images by reaction with an electron donor in carbonless paper and photo-imaging systems, the developer comprising an acid-treated, water insoluble alkali metal-modified, inorganic oxide or an acid-treated molecular sieve.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: June 5, 2001
    Assignee: Rentech, Inc.
    Inventors: Dale R. Shackle, Benjamin Chaloner-Gill
  • Patent number: 6083475
    Abstract: The present invention is a simple and reliable method for producing lithiated metal oxides such as those useful as cathode materials in lithium ion electrochemical cells. The method is based on the use of an organic solvent that dissolves both lithium sulfide and elemental sulfur without dissolving the metal oxide or the lithiated product. Lithium sulfide and the metal oxide as a powder are refluxed in the organic solvent under an inert atmosphere. The organic solvent dissolves the lithium sulfide and the dissolved sulfide reduces the metal oxide allowing the intercalation of lithium. At the same time the sulfur that results from the oxidation-reduction reaction is carried away by the solvent thereby promoting the reaction and preventing contamination of the product with sulfur.
    Type: Grant
    Filed: April 2, 1999
    Date of Patent: July 4, 2000
    Assignee: Rentech, Inc.
    Inventors: Dale R. Shackle, Benjamin Chaloner-Gill
  • Patent number: 6068760
    Abstract: Catalyst particles are separated from the wax in a Fischer-Tropsch reactor by feeding a portion of the reactor slurry to a dynamic settler which does not require any pump. As the slurry flows down a pipe in the center of the settler, the slurry flows into the surrounding annular region at the bottom of the settler. The heavier catalyst particles settle down and are removed as the slurry at the bottom of the settler is recycled back to the reactor. The wax rises up in the annular section and this clarified wax is removed by a wax outlet pipe. In an embodiment with an expanded diameter section above the Fischer-Tropsch reactor an additional dynamic settler can be placed inside this section. The Fischer-Tropsch catalyst can be regenerated by purging the catalyst with an inert gas for a period of time and by treating the catalyst with naphtha.
    Type: Grant
    Filed: August 7, 1998
    Date of Patent: May 30, 2000
    Assignee: Rentech, Inc.
    Inventors: Charles B. Benham, Dennis L. Yakobson, Mark S. Bohn
  • Patent number: 6068949
    Abstract: A method for forming a metal ion intercalation compound and the use thereof as the cathode material in an alkali metal battery. In one embodiment, a metal ion intercalation compound is mixed with an electrically conductive material. The metal ion intercalation compound is represented by the formula:M.sub.x T.sub.y A.sub.zwherein M is an alkali metal ion, wherein T is a metal ion capable of existing in more than one stable oxidation state, and wherein A is a multi-element anion with a negative charge greater than 1.
    Type: Grant
    Filed: February 24, 1998
    Date of Patent: May 30, 2000
    Assignee: Rentech, Inc.
    Inventor: Dale R. Shackle