Patents by Inventor Chong H. Chan

Chong H. Chan 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: 5240568
    Abstract: A process for separating phenol obtained by the decomposition of cumene hydroperoxide from high boiling impurities, includes the following steps:a) feeding phenol rectification bottoms comprising phenol, acetophenone, cumylphenol, alpha-methylstyrene dimers and high boiler residues to a first phenol freeing distillation column A;b) feeding concentrated bottoms with substantially reduced phenol content from column A to a second residue concentration distillation column B;c) withdrawing a stream rich in compounds boiling between phenol and residue, particularly cumylphenol, from said column B from a point below the feed and returning at least a portion of said stream to said column A at a point above the feed;d) recovering overheads from column A comprising at least 95 weight percent phenol; ande) recovering acetophenone-rich overheads from column B comprising at least 70 weight percent acetophenone.
    Type: Grant
    Filed: August 29, 1991
    Date of Patent: August 31, 1993
    Assignee: Allied-Signal Inc.
    Inventors: Chong H. Chan, Lamberto Crescentini, Everett H. Hinton, Jr., Laszlo J. Balint, deceased
  • Patent number: 5131984
    Abstract: The process for rectification of phenol prepared from crude phenol being the product of decomposition of cumene hydroperoxide and having previously been distilled to remove large portions of acetone, cumene and alpha methylstyrene which includes:feeding the column overhead vapors to a condenser, thereby condensing a major portion of the overhead vapors;withdrawing a small portion of the overhead vapors from the condenser while still in a vapor state, the small portion being relatively enriched in lights and laden with light acids;returning the condensate from the condenser to the phenol distillation column as reflux; andwithdrawing product phenol from at least one-theoretical stage below the top of the phenol distillation column, the product phenol having improved clarity when dispersed in water, clarity being at least 93 percent light transmission as measured by an electrophotometer in a water light test.
    Type: Grant
    Filed: September 23, 1991
    Date of Patent: July 21, 1992
    Assignee: Allied-Signal Inc.
    Inventors: Chong H. Chan, William B. Fisher, Joseph D. Shrom
  • Patent number: 4722769
    Abstract: This invention is a process for purifying crude acetone obtained by cleavage of cumene hydroperoxide, said crude acetone containing aldehyde impurities and appreciable amounts of unreacted cumene, by fractionally distilling the acetone in a multiple plate distillation column, said process comprising: continuously feeding crude acetone; continuously feeding a dilute aqueous solution of an alkaline material at a point above the crude acetone feed point; and controlling the temperature profile of the column by adjusting the amount of liquid acetone removed in step (c) to maintain a preselected temperature on a plate in the region between the crude acetone feed point and the alkaline material feed point.
    Type: Grant
    Filed: April 24, 1986
    Date of Patent: February 2, 1988
    Assignee: Allied Corporation
    Inventors: Chong H. Chan, Lamberto Crescentini, Everett H. Hinton, Jr.
  • Patent number: 4276276
    Abstract: An improved process for nitrite production is based on controlled oxidation of nitric oxide in a mixture of nitrogen oxides and oxygen. Oxidized gas is absorbed into an aqueous solution containing a basically reacting ammonium or alkali metal compound to produce nitrite and unabsorbed exit gas. The mole ratio of nitric oxide (NO) to nitrogen dioxide (NO.sub.2) in the unabsorbed exit gas is maintained within a range between 0.8 and 1.2 by either recycling a selected fraction of oxidized gas through the oxidizer or by selectively splitting the inlet stream to the oxidizer. Increased product yield as well as reduced NO.sub.x emissions are achieved as a result.
    Type: Grant
    Filed: March 28, 1980
    Date of Patent: June 30, 1981
    Assignee: Allied Chemical Corporation
    Inventors: James P. Van Hook, Clair E. Hildebrand, Chong H. Chan