Patents by Inventor Mark A. W. Stewart

Mark A. W. Stewart 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: 11643377
    Abstract: A method for processing a chemical stream includes contacting a feed stream with a catalyst in a reactor portion of a reactor system that includes a reactor portion and a catalyst processing portion. The catalyst includes platinum, gallium, or both and contacting the feed stream with the catalyst causes a reaction which forms an effluent stream. The method includes separating the effluent stream from the catalyst, passing the catalyst to the catalyst processing portion, and processing the catalyst in the catalyst processing portion. Processing the catalyst includes passing the catalyst to a combustor, combusting a supplemental fuel in the combustor to heat the catalyst, treating the heated catalyst with an oxygen-containing gas to produce a reactivated catalyst, and passing the reactivated catalyst from the catalyst processing portion to the reactor portion. The supplemental fuel may include a molar ratio of hydrogen to other combustible fuels of at least 1:1.
    Type: Grant
    Filed: July 8, 2022
    Date of Patent: May 9, 2023
    Assignee: Dow Global Technologies LLC
    Inventors: Matthew T. Pretz, Mark W. Stewart, Lin Luo, Hangyao Wang
  • Publication number: 20220340505
    Abstract: A method for processing a chemical stream includes contacting a feed stream with a catalyst in a reactor portion of a reactor system that includes a reactor portion and a catalyst processing portion. The catalyst includes platinum, gallium, or both and contacting the feed stream with the catalyst causes a reaction which forms an effluent stream. The method includes separating the effluent stream from the catalyst, passing the catalyst to the catalyst processing portion, and processing the catalyst in the catalyst processing portion. Processing the catalyst includes passing the catalyst to a combustor, combusting a supplemental fuel in the combustor to heat the catalyst, treating the heated catalyst with an oxygen-containing gas to produce a reactivated catalyst, and passing the reactivated catalyst from the catalyst processing portion to the reactor portion. The supplemental fuel may include a molar ratio of hydrogen to other combustible fuels of at least 1:1.
    Type: Application
    Filed: July 8, 2022
    Publication date: October 27, 2022
    Applicant: Dow Global Technologies LLC
    Inventors: Matthew T. Pretz, Mark W. Stewart, Lin Luo, Hangyao Wang
  • Patent number: 11414363
    Abstract: A method for processing a chemical stream includes contacting a feed stream with a catalyst in a reactor portion of a reactor system that includes a reactor portion and a catalyst processing portion. The catalyst includes platinum, gallium, or both and contacting the feed stream with the catalyst causes a reaction which forms an effluent stream. The method includes separating the effluent stream from the catalyst, passing the catalyst to the catalyst processing portion, and processing the catalyst in the catalyst processing portion. Processing the catalyst includes passing the catalyst to a combustor, combusting a supplemental fuel in the combustor to heat the catalyst, treating the heated catalyst with an oxygen-containing gas to produce a reactivated catalyst, and passing the reactivated catalyst from the catalyst processing portion to the reactor portion. The supplemental fuel may include a molar ratio of hydrogen to other combustible fuels of at least 1:1.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: August 16, 2022
    Assignee: Dow Global Technologies LLC
    Inventors: Matthew T. Pretz, Mark W. Stewart, Lin Luo, Hangyao Wang
  • Publication number: 20210261482
    Abstract: A method for processing a chemical stream includes contacting a feed stream with a catalyst in a reactor portion of a reactor system that includes a reactor portion and a catalyst processing portion. The catalyst includes platinum, gallium, or both and contacting the feed stream with the catalyst causes a reaction which forms an effluent stream. The method includes separating the effluent stream from the catalyst, passing the catalyst to the catalyst processing portion, and processing the catalyst in the catalyst processing portion. Processing the catalyst includes passing the catalyst to a combustor, combusting a supplemental fuel in the combustor to heat the catalyst, treating the heated catalyst with an oxygen-containing gas to produce a reactivated catalyst, and passing the reactivated catalyst from the catalyst processing portion to the reactor portion. The supplemental fuel may include a molar ratio of hydrogen to other combustible fuels of at least 1:1.
    Type: Application
    Filed: June 26, 2019
    Publication date: August 26, 2021
    Applicant: Dow Global Technologies LLC
    Inventors: Matthew T. Pretz, Mark W. Stewart, Lin Luo, Hangyao Wang
  • Patent number: 10589242
    Abstract: According to one or more embodiments, a fluid catalytic reactor may include a riser, a lower reactor portion, a transition portion, and a flow director. The riser may include a cross-sectional area, and the lower reactor portion may include a cross-sectional area. The transition portion may attach the riser to the lower reactor portion. The cross-sectional area of the riser may be less than the cross-sectional area of the lower reactor portion such that the transition portion is tapered inward from the lower reactor portion to the riser. The flow director may be positioned at least within an interior region of the transition portion. The flow director may include a body which affects the velocity profile of fluids moving from the lower reactor portion to the riser.
    Type: Grant
    Filed: October 25, 2017
    Date of Patent: March 17, 2020
    Assignee: Dow Global Technologies LLC
    Inventors: Matthew T. Pretz, Mark W. Stewart, Ben J. Freireich, Madhusudhan Kodam, Brien A. Stears
  • Patent number: 10392319
    Abstract: Manage sulfur present as sulfur or a sulfur compound in a hydrocarbon feedstream while effecting dehydrogenation of hydrocarbon(s) (e.g. propane) contained in the hydrocarbon feedstream to its/their corresponding olefin (e.g. propylene where the hydrocarbon is propane) without subjecting the feedstream to desulfurization before it contacts a fluidizable dehydrogenation catalyst that is both a desulfurant and a dehydrogenation catalyst and comprises gallium and platinum on an alumina or alumina-silica catalyst support with optional alkali or alkaline earth metal such as potassium. Contact with such a catalyst yields a desulfurized crude olefin product that corresponds to the hydrocarbon and has a reduced amount of sulfur or sulfur compounds relative to the sulfur or sulfur compounds present in the hydrocarbon feedstream prior to contact with the catalyst.
    Type: Grant
    Filed: December 3, 2014
    Date of Patent: August 27, 2019
    Assignee: Dow Global Technologies LLC
    Inventors: Matthew T. Pretz, Lin Luo, Brien A. Stears, Mark W. Stewart
  • Publication number: 20190255498
    Abstract: According to one or more embodiments, a fluid catalytic reactor may include a riser, a lower reactor portion, a transition portion, and a flow director. The riser may include a cross-sectional area, and the lower reactor portion may include a cross-sectional area. The transition portion may attach the riser to the lower reactor portion. The cross-sectional area of the riser may be less than the cross-sectional area of the lower reactor portion such that the transition portion is tapered inward from the lower reactor portion to the riser. The flow director may be positioned at least within an interior region of the transition portion. The flow director may include a body which affects the velocity profile of fluids moving from the lower reactor portion to the riser.
    Type: Application
    Filed: October 25, 2017
    Publication date: August 22, 2019
    Applicant: Dow Global Technologies LLC
    Inventors: Matthew T. Pretz, Mark W. Stewart, Ben J. Freireich, Madhusudhan Kodam, Brien A. Stears
  • Patent number: 10065905
    Abstract: Increase propane dehydrogenation activity of a partially deactivated dehydrogenation catalyst by heating the partially deactivated catalyst to a temperature of at least 660° C., conditioning the heated catalyst in an oxygen-containing atmosphere and, optionally, stripping molecular oxygen from the conditioned catalyst.
    Type: Grant
    Filed: October 31, 2017
    Date of Patent: September 4, 2018
    Assignee: Dow Global Technologies LLC
    Inventors: Matthew Pretz, Lin Luo, Susan Domke, Howard W. Clark, Richard A. Pierce, Andrzej M. Malek, Mark W. Stewart, Brien A. Stears, Albert E. Schweizer, Jr., Guido Capone, Duncan P. Coffey, Isa K. Mbaraka
  • Publication number: 20180057422
    Abstract: Increase propane dehydrogenation activity of a partially deactivated dehydrogenation catalyst by heating the partially deactivated catalyst to a temperature of at least 660° C., conditioning the heated catalyst in an oxygen-containing atmosphere and, optionally, stripping molecular oxygen from the conditioned catalyst.
    Type: Application
    Filed: October 31, 2017
    Publication date: March 1, 2018
    Inventors: Matthew Pretz, Lin Luo, Susan Domke, Howard W. Clark, Richard A. Pierce, Andrzej M. Malek, Mark W. Stewart, Brien A. Stears, Albert E. Schweizer, JR., Guido Capone, Duncan P. Coffey, Isa K. Mbaraka
  • Patent number: 9834496
    Abstract: Increase propane dehydrogenation activity of a partially deactivated dehydrogenation catalyst by heating the partially deactivated catalyst to a temperature of at least 660° C., conditioning the heated catalyst in an oxygen-containing atmosphere and, optionally, stripping molecular oxygen from the conditioned catalyst.
    Type: Grant
    Filed: July 11, 2012
    Date of Patent: December 5, 2017
    Assignee: Dow Global Technologies LLC
    Inventors: Matthew Pretz, Lin Luo, Susan Domke, Howard W. Clark, Richard A. Pierce, Andrzej M. Malek, Mark W. Stewart, Brien A. Stears, Albert E. Schweizer, Jr., Guido Capone, Duncan P. Coffey, Isa K. Mbaraka
  • Patent number: 9725382
    Abstract: An improved catalytic dehydrogenation process which process comprises contacting an alkane or alkyl aromatic feedstream with a dehydrogenation catalyst under catalytic conditions in an up-flow fluidized reactor, wherein the fluidized reactor comprises one or more reactors, which catalytic conditions include a temperature within a range of from 500 to 800° C., a weight hourly space velocity within a range of from 0.1 to 1000, a gas residence time within a range of from 0.1 to 10 seconds, and, subsequent to the fluidized reactor, effecting separation of entrained catalyst from reactor effluent by use of a cyclonic separation system, wherein the improvement comprises interposing a cooling means between an up-flow fluidized reactor and the cyclonic separation system to substantially halt thermal reactions, thereby effectively increasing overall molar selectivity to alkene product is provided.
    Type: Grant
    Filed: October 14, 2014
    Date of Patent: August 8, 2017
    Assignee: Dow Global Technologies LLC
    Inventors: Matthew T. Pretz, Mark W. Stewart
  • Patent number: 9687765
    Abstract: An improved process and an improved apparatus for minimizing attrition of catalyst particles, especially propane dehydrogenation catalyst particles, entrained in a combined flow of such particles and an entraining gas in a catalyst recovery means during separation of such particles from the entraining gas, by use of a pre-treatment step in which the combined flow is at a rate between 7.6 and 15.2 meters per second are provided.
    Type: Grant
    Filed: October 14, 2013
    Date of Patent: June 27, 2017
    Assignee: Dow Global Technologies LLC
    Inventors: Matthew Pretz, Mark W. Stewart, Don F. Shaw, Brien A. Stears, Madhusudhan M. Kodam, Ben Freireich
  • Patent number: 9643898
    Abstract: Effect adiabatic, catalytic alkanol (alcohol) dehydration using two or more sequential dehydration catalyst beds each of which has disposed therein a different catalyst and, preferably, eliminating heating and heating apparatus disposed between each sequential pair of dehydration catalyst beds.
    Type: Grant
    Filed: November 17, 2014
    Date of Patent: May 9, 2017
    Assignee: Dow Global Technologies LLC
    Inventors: Derrick W. Flick, Mark W. Stewart
  • Publication number: 20160289144
    Abstract: Manage sulfur present as sulfur or a sulfur compound in a hydrocarbon feedstream while effecting dehydrogenation of hydrocarbon(s) (e.g. propane) contained in the hydrocarbon feedstream to its/their corresponding olefin (e.g. propylene where the hydrocarbon is propane) without subjecting the feedstream to desulfurization before it contacts a fluidizable dehydrogenation catalyst that is both a desulfurant and a dehydrogenation catalyst and comprises gallium and platinum on an alumina or alumina-silica catalyst support with optional alkaline or alkaline earth metal such as potassium. Contact with such a catalyst yields a desulfurized crude olefin product that corresponds to the hydrocarbon and has a reduced amount of sulfur or sulfur compounds relative to the sulfur or sulfur compounds present in the hydrocarbon feedstream prior to contact with the catalyst.
    Type: Application
    Filed: December 3, 2014
    Publication date: October 6, 2016
    Inventors: Matthew T. Pretz, Lin Luo, Brien A. Stears, Mark W. Stewart
  • Publication number: 20160272559
    Abstract: An improved catalytic dehydrogenation process which process comprises contacting an alkane or alkyl aromatic feedstream with a dehydrogenation catalyst under catalytic conditions in an up-flow fluidized reactor, wherein the fluidized reactor comprises one or more reactors, which catalytic conditions include a temperature within a range of from 500 to 800° C., a weight hourly space velocity within a range of from 0.1 to 1000, a gas residence time within a range of from 0.1 to 10 seconds, and, subsequent to the fluidized reactor, effecting separation of entrained catalyst from reactor effluent by use of a cyclonic separation system, wherein the improvement comprises interposing a cooling means between an up-flow fluidized reactor and the cyclonic separation system to substantially halt thermal reactions, thereby effectively increasing overall molar selectivity to alkene product is provided.
    Type: Application
    Filed: October 14, 2014
    Publication date: September 22, 2016
    Inventors: Matthew T. Pretz, Mark W. Stewart
  • Publication number: 20160244383
    Abstract: Effect adiabatic, catalytic alkanol (alcohol) dehydration using two or more sequential dehydration catalyst beds each of which has disposed therein a different catalyst and, preferably, eliminating heating and heating apparatus disposed between each sequential pair of dehydration catalyst beds.
    Type: Application
    Filed: November 17, 2014
    Publication date: August 25, 2016
    Inventors: Derrick W. Flick, Mark W. Stewart
  • Publication number: 20150298037
    Abstract: An improved process and an improved apparatus for minimizing attrition of catalyst particles, especially propane dehydrogenation catalyst particles, entrained in a combined flow of such particles and an entraining gas in a catalyst recovery means during separation of such particles from the entraining gas, by use of a pre-treatment step in which the combined flow is at a rate between 7.6 and 15.2 meters per second are provided.
    Type: Application
    Filed: October 14, 2013
    Publication date: October 22, 2015
    Inventors: Matthew Pretz, Mark W. Stewart, Don F. Shaw, Brien A. Stears, Madhusudhan M. Kodam, Ben Freireich
  • Publication number: 20140200385
    Abstract: Increase propane dehydrogenation activity of a partially deactivated dehydrogenation catalyst by heating the partially deactivated catalyst to a temperature of at least 660° C, conditioning the heated catalyst in an oxygen-containing atmosphere and, optionally, stripping molecular oxygen from the conditioned catalyst.
    Type: Application
    Filed: July 11, 2012
    Publication date: July 17, 2014
    Applicant: DOW GLOBAL TECHNOLOGIES LLC
    Inventors: Matthew T. Pretz, LIn Luo, Susan Domke, Howard W. Clark, Richard A. Pierce, Andrzej M. Malek, Mark W. Stewart, Brien A. Stears, Albert E. Schweizer, JR., Guido Capore, Duncan P. Coffey, Isa K. Mbaraka
  • Publication number: 20080034760
    Abstract: Disclosed are a method and device for a refrigerant-based thermal energy storage and cooling system with isolated external melt cooling. The disclosed embodiments provide a refrigerant-based ice storage system with increased reliability, lower cost components, and reduced power consumption compared to a single phase system such as a glycol system.
    Type: Application
    Filed: August 10, 2007
    Publication date: February 14, 2008
    Applicant: ICE ENERGY, INC.
    Inventors: Ramachandran Narayanamurthy, Mark W. Stewart, Robert R. Willis
  • Patent number: 7324452
    Abstract: A system for managing data transmission from a number of queues employs a regular credit count and a history credit count for each queue. Generally, the regular credit count is used in arbitration. The count is decreased when data is transmitted from the queue and increased at given intervals if the queue is facing no transmission-blocking backpressure. The history credit count is increased in lieu of the regular credit count when transmission from the queue is blocked. Thus, the history credit count keeps track of potential transmission opportunities that would be lost due to the blocking of transmission from the queue. The history credit counts are periodically polled instead of the regular credit counts to give each queue an opportunity to catch up in its use of transmission opportunities.
    Type: Grant
    Filed: January 14, 2002
    Date of Patent: January 29, 2008
    Assignee: Fujitsu Limited
    Inventors: Hong Xu, Mark A. W. Stewart