Patents by Inventor Mark Julian Roberts

Mark Julian Roberts 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: 20210348850
    Abstract: A coil-wound heat exchanger with mixed refrigerant shell side cooling that is adapted to reduce radial temperature maldistribution by providing tube sheets at one end of a warm bundle that are each connected to tube sheets in a single circumferential zone and are in fluid flow communication with a control valve. Tube sheets at the other end of the warm bundle are each connected to tube sheets in a single radial section and in multiple circumferential zones. A temperature sensor is provided in each circumferential zone. When a temperature difference is detected, one or more of the control valves is adjusted to reduce the temperature difference.
    Type: Application
    Filed: May 5, 2020
    Publication date: November 11, 2021
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Mark Julian Roberts, Justin David Bukowski, Annemarie Ott Weist
  • Publication number: 20210285721
    Abstract: A method and system for liquefying a natural gas feed stream and removing nitrogen therefrom.
    Type: Application
    Filed: March 13, 2020
    Publication date: September 16, 2021
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Sylvain Vovard, Justin David Bukowski, Fei Chen, Mark Julian Roberts
  • Publication number: 20210231366
    Abstract: Systems and methods are described for increasing capacity and efficiency of a nitrogen refrigerant boil-off gas recovery system for a natural gas storage tank. Boil-off gas is condensed against two-phase nitrogen in a condensing heat exchanger having an inner vessel through which the boil-off gas flows and an outer vessel through which the two phase nitrogen flows. Logic controls maintain storage tank pressure and power consumption within preferred levels by adjusting the pressure of the two-phase nitrogen in the heat exchanger. Additional logic controls maintain the temperature difference between the nitrogen streams entering into and returning from the cold end of a second heat exchanger by controlling the position of an expansion valve on the return circuit.
    Type: Application
    Filed: January 23, 2020
    Publication date: July 29, 2021
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Mark Julian Roberts, Fei Chen
  • Patent number: 10982898
    Abstract: Described herein are methods and systems for the liquefaction of natural gas to produce a LNG product. The methods and systems use an apparatus for separating a flash gas from a liquefied natural gas (LNG) stream to produce a LNG product and recovering refrigeration from the flash gas. The apparatus includes a shell casing enclosing a heat exchange zone comprising a coil wound heat exchanger, and a separation zone. The heat exchange zone is located above and in fluid communication with the separation zone. Flash gas is separated from the LNG product in the separation zone and flows upwards from the separation zone into the heat exchange zone where refrigeration is recovered from the separated flash gas.
    Type: Grant
    Filed: May 11, 2018
    Date of Patent: April 20, 2021
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Fei Chen, Christopher Michael Ott, Annemarie Ott Weist, Mark Julian Roberts
  • Patent number: 10866022
    Abstract: Described herein are methods and systems for the liquefaction of a natural gas stream using a refrigerant comprising methane or a mixture of methane and nitrogen. The methods and systems use a refrigeration circuit and cycle that employs one or more turbo-expanders to expand one or more streams of gaseous refrigerant to provide one or more streams of at least predominantly gaseous refrigerant that are used to provide refrigeration for liquefying and/or precooling the natural gas, and a J-T valve to expand down to a lower pressure a stream of liquid or two-phase refrigerant to provide a vaporizing stream of refrigerant that provides refrigeration for sub-cooling.
    Type: Grant
    Filed: April 27, 2018
    Date of Patent: December 15, 2020
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Gowri Krishnamurthy, Mark Julian Roberts
  • Patent number: 10852059
    Abstract: Systems and methods described for increasing capacity and efficiency of natural gas liquefaction processes having a mixed refrigerant precooling system with multiple pressure levels comprising cooling the compressed mixed refrigerant stream and separating the cooled compressed mixed refrigerant stream into a vapor and liquid portion. The liquid portion provides refrigeration duty to a first precooling heat exchanger. The vapor portion is further compressed, cooled, and condensed, and used to provide refrigeration duty to a second precooling heat exchanger. A flash gas separated from the liquefied natural gas is warmed and combined with the natural gas feed stream.
    Type: Grant
    Filed: September 28, 2017
    Date of Patent: December 1, 2020
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Gowri Krishnamurthy, Mark Julian Roberts, Adam Adrian Brostow
  • Patent number: 10788260
    Abstract: Described herein is a method of removing refrigerant from a natural gas liquefaction system in which vaporized mixed refrigerant is withdrawn from the closed-loop refrigeration circuit and introduced into a distillation column so as to be separated into an overhead vapor enriched in methane and a bottoms liquid enriched in heavier components. Overhead vapor is withdrawn from the distillation column to form a methane enriched stream that is removed from the liquefaction system, and bottoms liquid is reintroduced from the distillation column into the closed-loop refrigeration circuit. Also described are methods of altering the rate of production in a natural gas liquefaction system in which refrigerant is removed as described above, and a natural gas liquefaction systems in which such methods can be carried out.
    Type: Grant
    Filed: August 8, 2017
    Date of Patent: September 29, 2020
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Brian Keith Johnston, Gowri Krishnamurthy, Mark Julian Roberts
  • Patent number: 10788261
    Abstract: Described herein are methods and systems for the liquefaction of a natural gas feed stream using a refrigerant comprising methane. The methods and systems use a refrigeration circuit and cycle that employs two or more turbo-expanders to expand two or more streams of gaseous refrigerant down to different pressures to provide cold streams of at least predominantly gaseous refrigerant at different pressures that are used to provide refrigeration for precooling and liquefying the natural gas. The resulting liquefied natural gas stream is then flashed to produce an LNG product and a flash gas, the flash gas being recycled to the natural gas feed stream.
    Type: Grant
    Filed: April 27, 2018
    Date of Patent: September 29, 2020
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Gowri Krishnamurthy, Mark Julian Roberts
  • Patent number: 10767922
    Abstract: A method and apparatus for liquefying a natural gas feed stream and removing nitrogen therefrom to produce a nitrogen-depleted LNG product, in which a natural gas feed stream is fed into the warm end of a main heat exchanger, cooled and at least partially liquefied, withdrawn from an intermediate location of the main heat exchanger and separated to form a nitrogen-enriched natural gas vapor stream and a nitrogen-depleted natural gas liquid stream, the liquid and vapor streams being reintroduced into an intermediate location of the main heat exchanger and further cooled in parallel to form a first LNG stream and a first at least partially liquefied nitrogen-enriched natural gas stream, respectively.
    Type: Grant
    Filed: June 19, 2017
    Date of Patent: September 8, 2020
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Fei Chen, Yang Liu, Gowri Krishnamurthy, Christopher Michael Ott, Mark Julian Roberts
  • Patent number: 10753676
    Abstract: Systems and methods described for increasing capacity and efficiency of natural gas liquefaction processes having a mixed refrigerant precooling system with multiple pressure levels comprising cooling the compressed mixed refrigerant stream and separating the cooled compressed mixed refrigerant stream into a vapor and liquid portion. The liquid portion provides refrigeration duty to a first precooling heat exchanger. The vapor portion is further compressed, cooled, and condensed, and used to provide refrigeration duty to a second precooling heat exchanger. A flash gas separated from the liquefied natural gas is warmed and combined with the natural gas feed stream.
    Type: Grant
    Filed: September 28, 2017
    Date of Patent: August 25, 2020
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Gowri Krishnamurthy, Mark Julian Roberts, Adam Adrian Brostow
  • Publication number: 20200217585
    Abstract: A system and method for increasing the efficiency of natural gas liquefaction processes by using a hybrid cooling system and method. More specifically, a system and method for converting a transcritical precooling refrigeration process to a subcritical process. In one embodiment, the refrigerant is cooled to sub-critical temperature using an economizer. In another embodiment, the refrigerant is cooled to a sub-critical temperature using an auxiliary heat exchanger. Optionally, the economizer or auxiliary heat exchanger can be bypassed when ambient temperatures are sufficiently low to cool the refrigerant to a sub-critical temperature. In another embodiment, the refrigerant is isentropically expanded.
    Type: Application
    Filed: March 23, 2020
    Publication date: July 9, 2020
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Gowri Krishnamurthy, Mark Julian Roberts
  • Publication number: 20200200471
    Abstract: A liquefaction system is capable of sequentially or simultaneously liquefying multiple feed streams of hydrocarbons having different normal bubble points with minimal flash. The liquefying heat exchanger has separate circuits for handling multiple feed streams. The feed stream with the lowest normal boiling point is sub-cooled sufficiently to suppress most of the flash. Feed streams with relatively high normal boiling points are cooled to substantially the same temperature, then blended with bypass streams to maintain each product near its normal bubble point. The system can also liquefy one stream at a time by using a dedicated circuit or by allocating the same feed to multiple circuits.
    Type: Application
    Filed: March 2, 2020
    Publication date: June 25, 2020
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Laurent Marc Brussol, David Joseph Holzer, Sylvain Vovard, Russell Shnitser, Adam Adrian Brostow, Mark Julian Roberts
  • Patent number: 10663220
    Abstract: Systems and methods described for increasing capacity and efficiency of natural gas liquefaction processes having a mixed refrigerant precooling system with multiple pressure levels comprising cooling the compressed mixed refrigerant stream and separating the cooled compressed mixed refrigerant stream into a vapor and liquid portion. The liquid portion provides refrigeration duty to a first precooling heat exchanger. The vapor portion is further compressed, cooled, and condensed, and used to provide refrigeration duty to a second precooling heat exchanger. Optionally additional precooling heat exchangers, and/or phase separators may be used.
    Type: Grant
    Filed: October 7, 2016
    Date of Patent: May 26, 2020
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Gowri Krishnamurthy, Mark Julian Roberts
  • Patent number: 10619917
    Abstract: A liquefaction system is capable of sequentially or simultaneously liquefying multiple feed streams of hydrocarbons having different normal bubble points with minimal flash. The liquefying heat exchanger has separate circuits for handling multiple feed streams. The feed stream with the lowest normal boiling point is sub-cooled sufficiently to suppress most of the flash. Feed streams with relatively high normal boiling points are cooled to substantially the same temperature, then blended with bypass streams to maintain each product near its normal bubble point. The system can also liquefy one stream at a time by using a dedicated circuit or by allocating the same feed to multiple circuits.
    Type: Grant
    Filed: September 13, 2017
    Date of Patent: April 14, 2020
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Laurent Marc Brussol, David Joseph Holzer, Sylvain Vovard, Russell Shnitser, Adam Adrian Brostow, Mark Julian Roberts
  • Publication number: 20200056836
    Abstract: A natural gas liquefaction method and system having integrated nitrogen removal. Recycled LNG gas is cooled in a separate and parallel circuit from the natural gas stream in the main heat exchanger. Cooled recycled gas and natural gas streams are directed to a nitrogen rectifier column after the warm bundle. The recycle stream is introduced to the rectifier column above the natural gas stream and at least one separation stage is located in the rectifier column between the recycle stream inlet and the natural gas inlet. The bottom stream from the rectifier column is directed to a cold bundle of the main heat exchanger where it is subcooled.
    Type: Application
    Filed: August 14, 2018
    Publication date: February 20, 2020
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Mark Julian Roberts, Fei Chen, Christopher Michael Ott, Annemarie Ott Weist
  • Patent number: 10544986
    Abstract: A system and method is provided for increasing the capacity and efficiency of natural gas liquefaction processes by debottlenecking the refrigerant compression system. A secondary compression circuit comprising at least one double flow compressor is provided in parallel fluid flow communication with at least a portion of a primary compression circuit.
    Type: Grant
    Filed: March 29, 2017
    Date of Patent: January 28, 2020
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Joseph Gerard Wehrman, Gowri Krishnamurthy, Mark Julian Roberts
  • Publication number: 20190346203
    Abstract: Described herein are methods and systems for the liquefaction of natural gas to produce a LNG product. The methods and systems use an apparatus for separating a flash gas from a liquefied natural gas (LNG) stream to produce a LNG product and recovering refrigeration from the flash gas. The apparatus includes a shell casing enclosing a heat exchange zone comprising a coil wound heat exchanger, and a separation zone. The heat exchange zone is located above and in fluid communication with the separation zone. Flash gas is separated from the LNG product in the separation zone and flows upwards from the separation zone into the heat exchange zone where refrigeration is recovered from the separated flash gas.
    Type: Application
    Filed: May 11, 2018
    Publication date: November 14, 2019
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Fei Chen, Christopher Michael Ott, Annemarie Ott Weist, Mark Julian Roberts
  • Publication number: 20190331414
    Abstract: Described herein are methods and systems for the liquefaction of a natural gas feed stream using a refrigerant comprising methane. The methods and systems use a refrigeration circuit and cycle that employs two or more turbo-expanders to expand two or more streams of gaseous refrigerant down to different pressures to provide cold streams of at least predominantly gaseous refrigerant at different pressures that are used to provide refrigeration for precooling and liquefying the natural gas. The resulting liquefied natural gas stream is then flashed to produce an LNG product and a flash gas, the flash gas being recycled to the natural gas feed stream.
    Type: Application
    Filed: April 27, 2018
    Publication date: October 31, 2019
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Gowri Krishnamurthy, Mark Julian Roberts
  • Publication number: 20190331413
    Abstract: Described herein are methods and systems for the liquefaction of a natural gas stream using a refrigerant comprising methane or a mixture of methane and nitrogen. The methods and systems use a refrigeration circuit and cycle that employs one or more turbo-expanders to expand one or more streams of gaseous refrigerant to provide one or more streams of at least predominantly gaseous refrigerant that are used to provide refrigeration for liquefying and/or precooling the natural gas, and a J-T valve to expand down to a lower pressure a stream of liquid or two-phase refrigerant to provide a vaporizing stream of refrigerant that provides refrigeration for sub-cooling.
    Type: Application
    Filed: April 27, 2018
    Publication date: October 31, 2019
    Applicant: Air Products and Chemicals, Inc.
    Inventors: Gowri Krishnamurthy, Mark Julian Roberts
  • Patent number: 10393429
    Abstract: A method for controlling the flow of natural gas and refrigerant in the main heat exchanger of a natural gas liquefaction facility. The method provides for the automated control of a flow rate of a natural gas feed stream through a heat exchanger based on one or more process variables and set points. The flow rate of refrigerant streams through the heat exchanger is controlled by different process variables and set points, and is controlled independently of the flow rate of the natural gas feed stream.
    Type: Grant
    Filed: April 6, 2016
    Date of Patent: August 27, 2019
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Fei Chen, Brian Keith Johnston, Mark Julian Roberts