Patents by Inventor H. Alex Yoon

H. Alex Yoon 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: 20090045100
    Abstract: This invention relates to a multi-stage process for hydroprocessing gas oils. Preferably, each stage possesses at least one hydrocracking zone. The second stage and any subsequent stages possess an environment having a low heteroatom content. Light products, such as naphtha, kerosene and diesel, may be recycled from fractionation (along with light products from other sources) to the second stage (or a subsequent stage) in order to produce a larger yield of lighter products, such as gas and naphtha. Pressure in the zone or zones subsequent to the initial zone is from 500 to 1000 psig lower than the pressure in the initial zone, in order to provide cost savings and minimize overcracking.
    Type: Application
    Filed: October 23, 2008
    Publication date: February 19, 2009
    Applicant: Chevron U.S.A. Inc.
    Inventors: H. Alex Yoon, Jay B. Parekh, Arthur J. Dahlberg
  • Publication number: 20080283444
    Abstract: This invention relates to a multi-stage process for hydroprocessing gas oils. Preferably, each stage possesses at least one hydrocracking zone. The second stage and any subsequent stages possess an environment having a low heteroatom content. Light products, such as naphtha, kerosene and diesel, may be recycled from fractionation (along with light products from other sources) to the second stage (or a subsequent stage) in order to produce a larger yield of lighter products, such as gas and naphtha. Pressure, in the zone or zones subsequent to the initial zone is from 500 to 1000 psig lower than the pressure in the initial zone, in order to provide cost savings and minimize overcracking.
    Type: Application
    Filed: June 12, 2008
    Publication date: November 20, 2008
    Applicant: CHEVRON U.S.A. INC.
    Inventors: H. Alex Yoon, Jay Parekh, Arthur J. Dahlberg
  • Publication number: 20030221990
    Abstract: This invention relates to a multi-stage process for hydroprocessing gas oils. Preferably, each stage possesses at least one hydrocracking zone. The second stage and any subsequent stages possess an environment having a low heteroatom content. Light products, such as naphtha, kerosene and diesel, may be recycled from fractionation (along with light products from other sources) to the second stage (or a subsequent stage) in order to produce a larger yield of lighter products, such as gas and naphtha. Subsequent zones are maintained at a lower pressure than that of the first zone, thereby reducing operating expenses.
    Type: Application
    Filed: June 4, 2002
    Publication date: December 4, 2003
    Inventors: H. Alex Yoon, Jay Parekh, Arthur J. Dahlberg