Patents by Inventor Mark W. Dassel

Mark W. Dassel 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).

  • Publication number: 20010023285
    Abstract: This invention relates to methods and reactor devices for controlling the oxidation of hydrocarbons to dibasic acids, in the presence of a cobalt catalyst and a monobasic acid, such as acetic acid, by treating the catalyst from the reaction mixture, outside the oxidation zone, after the oxidation has taken place at least partially. In one preferred embodiment, the catalyst is reduced to contain, preferably predominantly and more preferably substantially, cobalt ions in valence II, and at least partially precipitated by de-watering and/or thermal treatment. In a different preferred embodiment, the catalyst in the reaction mixture is first oxidized or maintained, preferably predominantly and more preferably substantially, at valence III, the reaction mixture is de-watered, the catalyst is reduced preferably predominantly and more preferably substantially, to valence II, causing precipitation either spontaneously at a predetermined temperature or after further thermal treatment.
    Type: Application
    Filed: April 5, 2001
    Publication date: September 20, 2001
    Inventors: Eustathios Vassiliou, Mark W. Dassel, Ader M. Rostami, Douglas J. Dudgeon, David C. DeCoster
  • Patent number: 6288274
    Abstract: Methods and devices for controlling the reaction rate and/or reactivity of a hydrocarbon to an intermediate oxidation product, such as an acid, within predetermined limits, are disclosed. Control of the reaction rate and/or reactivity within predetermined limits is achieved by monitoring and controlling the oxidant consumption rate. According to the present invention, examples of ways to determine the oxidant consumption rate include, but are not limited to, monitoring the flow rates of incoming and outgoing oxidant, monitoring pressure differentials after temporarily ceasing entry and exit of gases, and monitoring the flow rates of incoming and outgoing gases, and monitoring the rates of incoming and outgoing hydrocarbon.
    Type: Grant
    Filed: February 19, 1999
    Date of Patent: September 11, 2001
    Assignee: RPC Inc.
    Inventors: David C. DeCoster, Eustathios Vassiliou, Mark W. Dassel, Sharon M. Aldrich, Ader M. Rostami
  • Publication number: 20010001649
    Abstract: This invention relates to methods and reactor devices for controlling the oxidation of hydrocarbons to dibasic acids, in the presence of a catalyst and a monobasic acid, by removing the catalyst from the reaction mixture, outside the oxidation zone, after the oxidation has taken place at least partially. Initially, the catalyst is partially precipitated and removed by reducing the water level in the reaction mixture and/or subjecting the reaction mixture to a temperature, at which or over which catalyst precipitates. After the initial partial precipitation of the catalyst, the mother liquor remaining is subjected to a thermal treatment during which at least the major part of the monobasic acid is removed leaving behind molten dibasic acids, in which the remaining catalyst precipitates substantially in its totality, and it is removed. The precipitated catalyst in the two precipitation stages may be recycled in miscellaneous ways.
    Type: Application
    Filed: September 25, 1998
    Publication date: May 24, 2001
    Inventors: DAVID C. DECOSTER, EUSTATHIOS VASSILIOU, MARK W. DASSEL, ADER M. ROSTAMI, DOUGLAS J. DUDGEON
  • Patent number: 6232495
    Abstract: This invention relates to methods and reactor devices for controlling the oxidation of hydrocarbons to dibasic acids, in the presence of a cobalt catalyst and a monobasic acid, such as acetic acid, by treating the catalyst from the reaction mixture, outside the oxidation zone, after the oxidation has taken place at least partially. In one preferred embodiment, the catalyst is reduced to contain, preferably predominantly and more preferably substantially, cobalt ions in valence II, and at least partially precipitated by de-watering and/or thermal treatment. In a different preferred embodiment, the catalyst in the reaction mixture is first oxidized or maintained, preferably predominantly and more preferably substantially, at valence III, the reaction mixture is de-watered, the catalyst is reduced, preferably predominantly and more preferably substantially, to valence II, causing precipitation either spontaneously at a predetermined temperature or after further thermal treatment.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: May 15, 2001
    Assignee: RPC Inc.
    Inventors: Eustathios Vassiliou, Mark W. Dassel, Ader M. Rostami, Douglas J. Dudgeon, David C. DeCoster
  • Patent number: 6218573
    Abstract: This invention relates to methods of controlling the oxidation of cyclohexane to adipic acid in the presence of a monobasic acid solvent, by removing the catalyst from the reaction mixture, outside the reaction zone. Substantially all the unreacted cyclohexane along with at least the majority of the monobasic acid solvent are removed. A substantially non-solvent for the catalyst (first constituent), and water are added into the resulting mixture, in such amounts as to maintain one solids-free single liquid phase. This process is highly facilitated in the presence of considerable amounts of adipic acid. The catalyst may then be extracted with water from the solids-free single liquid phase. A water phase containing dissolved catalyst may also be formed by addition of small amounts of a solvent which is substantially non-solvent for the catalyst and substantially non-solvent for the dibasic acids (second constituent), and/or dropping the temperature.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: April 17, 2001
    Assignee: RPC Inc.
    Inventors: Eustathios Vassiliou, Mark W. Dassel, Ader M. Rostami, Douglas J. Dudgeon, David C. DeCoster
  • Patent number: 6183698
    Abstract: Devices for controlling the reaction rate of a hydrocarbon to an acid or other intermediate oxidation product by pressure drop rate adjustments. The devices incorporate a reaction chamber, different means for monitoring miscellaneous parameters, means for feeding ingredients including gases, means for exiting products and gases, means for stopping the feeding and exiting of gases at predetermined time intervals, means for measuring the pressure drop rate during the period that the feeding and exiting of gases takes effect, and a controller, the function of which is to conduct adjustments in one or more of temperature, feeding rates of hydrocarbon, solvent, catalyst, promoter, and the like until the pressure drop rate and the reaction rate fall within desirable predetermined limits.
    Type: Grant
    Filed: May 12, 1998
    Date of Patent: February 6, 2001
    Assignee: RPC Inc.
    Inventors: Eustathios Vassiliou, Mark W. Dassel, David C. DeCoster, Ader M. Rostami, Sharon M. Aldrich
  • Patent number: 6177053
    Abstract: This invention relates to methods and devices for removing acetic acid from cyclohexane in the direct oxidation of cyclohexane to adipic acid, especially after recycling catalyst which is precipitated by introduction of additional cyclohexane. The removal of acetic acid is preferably conducted by use of rather small amounts of wash-water in one to three stage extractors. A two stage reactor is preferable as being more efficient.
    Type: Grant
    Filed: January 27, 1999
    Date of Patent: January 23, 2001
    Assignee: RPC Inc.
    Inventors: David C. DeCoster, Eustathios Vassiliou, Mark W. Dassel, Ader M. Rostami
  • Patent number: 6143927
    Abstract: This invention relates to methods for controlling the oxidation of hydrocarbons to intermediate oxidation products, such as adipic acid for example, by removing the catalyst from the reaction mixture, outside the reaction zone, after the oxidation has taken place at least partially. The catalyst is at least partially precipitated by reducing the water level in the reaction mixture and subjecting the reaction mixture to a temperature, at which or over which catalyst precipitates.
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: November 7, 2000
    Assignee: RPC Inc.
    Inventors: Mark W. Dassel, Ader M. Rostami, David C. DeCoster, Eustathios Vassiliou
  • Patent number: 6129875
    Abstract: This invention relates to methods for controlling the oxidation of hydrocarbons to dibasic acids, in the presence of a catalyst and a monobasic acid, by removing the catalyst from the reaction mixture, outside the oxidation zone, after the oxidation has taken place at least partially. Initially, the catalyst is partially precipitated and removed by reducing the water level in the reaction mixture and/or subjecting the reaction mixture to a temperature, at which or over which catalyst precipitates. After the initial partial precipitation of the catalyst, the remaining catalyst is subjected to a thermal treatment, during which at least part of the monobasic acid is removed leaving behind molten dibasic acids, in which, at least a major part of the remaining catalyst is precipitated, and it is removed. A minor part of remaining catalyst is removed by methods, which include but are not limited to ion exchange, precipitation with a base or appropriate salt, and electrodialysis.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: October 10, 2000
    Assignee: RPC Inc.
    Inventors: Mark W. Dassel, Ader M. Rostami, Douglas J. Dudgeon, David C. DeCoster, Eustathios Vassiliou
  • Patent number: 6103933
    Abstract: Methods for controlling the oxidation rate of a hydrocarbon to an acid by adjusting addition of a rate-modulator are disclosed. In order to control oxidation rate, the ratio of hydrocarbon to rate modulator is appropriately adjusted. Preferably, this ratio is adjusted continually based on feedback relative to oxidation progress parameters. It may be kept substantially constant at steady state conditions of the oxidation, or it may take a path of predetermined values. The rate-modulator preferably comprises a hydrocarbon oxidation initiator.
    Type: Grant
    Filed: May 21, 1997
    Date of Patent: August 15, 2000
    Assignee: RPC Inc.
    Inventors: David C. DeCoster, Ader M. Rostami, Mark W. Dassel, Eustathios Vassiliou
  • Patent number: 6039902
    Abstract: This invention relates to methods of recycling catalyst in oxidations of hydrocarbons, such as cyclohexane for example, to respective intermediate oxidation products, such as adipic acid for example, by a direct process. The catalyst remains in solution despite removal of water from the composition, since the water removal is controlled at such temperatures and such remaining water levels that prevent catalyst from precipitating. The water removal is preferably conducted before removal of the intermediate oxidation product. Also, preferably, some, and more preferably all steps of the process are conducted in a single liquid phase region.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: March 21, 2000
    Assignee: RPC Inc.
    Inventors: Ader M. Rostami, David C. DeCoster, Eustathios Vassiliou, Mark W. Dassel
  • Patent number: 6037491
    Abstract: This invention relates to methods and devices of preparing acids, such as adipic acid for example, by oxidizing a hydrocarbon, such as cyclohexane for example, with a gas containing an oxidant, preferably oxygen. A respective hydrocarbon is reacted, preferably at a steady state, with a gaseous oxidant to form an acid in a liquid mixture which preferably contains a solvent, a catalyst, water, and an initiator. The ratio of solvent to hydrocarbon may be controlled in a manner to maintain in the reaction zone maximum reaction rate and/or reactivity, or reaction rate and/or reactivity within a desired range, or reaction rate and/or reactivity directed toward a desired range. In addition, the ratio of solvent to hydrocarbon is controlled in a manner to maintain in the reaction zone substantially maximum selectivity and/or yield, or selectivity and/or yield within a desired range, or selectivity and/or yield directed toward a desired range.
    Type: Grant
    Filed: July 25, 1997
    Date of Patent: March 14, 2000
    Assignee: RPC Inc.
    Inventors: Eustathios Vassiliou, Mark W. Dassel, Sharon M. Aldrich, Ader M. Rostami, David C. DeCoster
  • Patent number: 5998572
    Abstract: Methods and devices for controlling the oxidation of a hydrocarbon to an acid by regulating the temperature hold-up time, and conversion in consecutive reaction zones. The temperature in the consecutive reaction zones progressively decreases, while the hold-up time increases. Preferably, the conversion also increases. One of the major advantages of the methods and devices of the present invention is that an outstanding balance between productivity and selectivity/yield of the desired acid may be achieved. In this respect high yields and selectivities may be obtained without sacrificing productivity.
    Type: Grant
    Filed: May 12, 1998
    Date of Patent: December 7, 1999
    Assignee: RPC Inc.
    Inventors: Ader M. Rostami, Mark W. Dassel, Eustathios Vassiliou, David C. DeCoster
  • Patent number: 5980801
    Abstract: Methods for oxidizing a hydrocarbon to an intermediate oxidation product by utilizing an activated initiator. The initiator is activated by partially oxidizing a first mixture of the initiator and a hydrocarbon, which mixture contains a rather large amount of initiator. The first mixture may even be just initiator. The first mixture, after the partial oxidation, is mixed with a second mixture containing hydrocarbon and a smaller amount of initiator. The second mixture may even contain no initiator at all. The oxidation is continued to a desired degree. Preferably, at least one of the two mixtures, and even more preferably both reaction mixtures contain an oxidation catalyst and an acidic solvent.
    Type: Grant
    Filed: June 25, 1998
    Date of Patent: November 9, 1999
    Assignee: Twenty-First Century Research Corporation
    Inventors: Mark W. Dassel, Eustathios Vassiliou, David C. DeCoster, Ader M. Rostami
  • Patent number: 5929277
    Abstract: This invention relates to methods of removing acetic acid from cyclohexane in the direct oxidation of cyclohexane to adipic acid, especially after recycling catalyst which is precipitated by introduction of additional cyclohexane. The removal of acetic acid is preferably conducted by use of rather small amounts of wash-water in one to three stage extractors. A two stage reactor is preferable as being more efficient.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: July 27, 1999
    Assignee: Twenty-First Century Research Corporation
    Inventors: David C. DeCoster, Eustathios Vassiliou, Mark W. Dassel, Ader M. Rostami
  • Patent number: 5908589
    Abstract: This invention relates to methods and reactor devices for controlling the oxidation of hydrocarbons to dibasic acids, in the presence of a catalyst and a monobasic acid, by removing the catalyst from the reaction mixture, outside the oxidation zone, after the oxidation has taken place at least partially. Initially, the catalyst is partially precipitated and removed by reducing the water level in the reaction mixture and/or subjecting the reaction mixture to a temperature, at which or over which catalyst precipitates. After the initial partial precipitation of the catalyst, the mother liquor remaining is subjected to a thermal treatment during which at least the major part of the monobasic acid is removed leaving behind molten dibasic acids, in which the remaining catalyst precipitates substantially in its totality, and it is removed. The precipitated catalyst in the two precipitation stages may be recycled in miscellaneous ways.
    Type: Grant
    Filed: December 8, 1997
    Date of Patent: June 1, 1999
    Assignee: Twenty-First Century Research Corporation
    Inventors: David C. DeCoster, Eustathios Vassiliou, Mark W. Dassel, Ader M. Rostami, Douglas J. Dudgeon
  • Patent number: 5877341
    Abstract: Methods and devices for controlling the reaction rate of a hydrocarbon to an acid or other intermediate oxidation product by pressure drop rate adjustments. The pressure drop rate measurements arc conducted at predetermined time intervals, after stopping the feeding and exiting of gases. The pressure drop at a predetermined time interval is measured or the time it takes for the pressure to drop by a certain degree. Adjustments are then made in one or more temperature, feeding rates of hydrocarbon, solvent, catalyst, promoter, and the like until the pressure drop rate and the reaction rate fall within desirable predetermined limits.
    Type: Grant
    Filed: May 12, 1998
    Date of Patent: March 2, 1999
    Assignee: Twenty-First Century Research Corporation
    Inventors: Eustathios Vassiliou, Mark W. Dassel, David C. DeCoster, Ader M. Rostami, Sharon M. Aldrich
  • Patent number: 5836985
    Abstract: The described method of treatment relates to the field of cardiovascular disease and is a cure for various forms of heart fibrillation. The method consists of sectioning the heart into independent conduction zones such that electrical communication between the zones is terminated. The communication between the zones is then reestablished in such a manner as to restore normal heart rhythm, by way of a pacing mechanism, thereby eliminating the fibrillation.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: November 17, 1998
    Assignee: The Regents of The University of Michigan
    Inventors: Ader M. Rostami, David C. DeCoster, Eustathios Vassiliou, Mark W. Dassel
  • Patent number: 5824819
    Abstract: Methods for oxidizing a hydrocarbon to an intermediate oxidation product by utilizing an activated initiator. The initiator is activated by partially oxidizing a first mixture of the initiator and a hydrocarbon, which mixture contains a rather large amount of initiator. The first mixture may even be just initiator. The first mixture, after the partial oxidation, is mixed with a second mixture containing hydrocarbon and a smaller amount of initiator. The second mixture may even contain no initiator at all. The oxidation is continued to a desired degree. Preferably, at least one of the two mixtures, and even more preferably both reaction mixtures contain an oxidation catalyst and an acidic solvent.
    Type: Grant
    Filed: May 21, 1997
    Date of Patent: October 20, 1998
    Assignee: Twenty-First Century Research Corporation
    Inventors: Mark W. Dassel, Eustathios Vassiliou, David C. DeCoster, Ader M. Rostami
  • Patent number: 5817868
    Abstract: Methods and devices for controlling the oxidation of a hydrocarbon to an acid by regulating the temperature, hold-up time, and conversion in consecutive reaction zones. The temperature in the consecutive reaction zones progressively decreases, while the hold-up time increases. Preferably, the conversion also increases. One of the major advantages of the methods and devices of the present invention is that an outstanding balance between productivity and selectivity/yield of the desired acid may be achieved. In this respect high yields and selectivities may be obtained without sacrificing productivity.
    Type: Grant
    Filed: May 21, 1997
    Date of Patent: October 6, 1998
    Assignee: Twenty-First Century Research Corporation
    Inventors: Ader M. Rostami, Mark W. Dassel, Eustathios Vassiliou, David C. DeCoster