Patents by Inventor Tan J. Chen

Tan J. Chen 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).

  • Feed pretreatment for pervaporation process
    Patent number: 5416259
    Abstract: The pervaporative treatment of hydrocarbon feeds which have been exposed to air or oxygen and which contain mixtures of aromatic and non-aromatic hydrocarbons to selectively separate the feed into an aromatics rich stream and a non-aromatics rich stream is improved by the step of pretreating the hydrocarbon feed over an adsorbent such as attapulgite clay.
    Type: Grant
    Filed: September 21, 1993
    Date of Patent: May 16, 1995
    Assignee: Exxon Research & Engineering Co.
    Inventors: Charles P. Darnell, Tan J. Chen, Enrique F. Juarez
  • Pervaporation process employing permeate recycle
    Patent number: 5288712
    Abstract: The selectivity of a membrane pervaporation aromatics/non-aromatics separation process is unexpectedly improved by the recycle of permeate to the separation process for co-processing with fresh feed. The selectivity obtained is greater than that achieved by processing either the feed or a recycle permeate stream by itself.
    Type: Grant
    Filed: October 7, 1992
    Date of Patent: February 22, 1994
    Assignee: Exxon Research & Engineering Co.
    Inventor: Tan J. Chen
  • Recovery of alcohols from n-paraffins by pervaporation
    Patent number: 5230801
    Abstract: The present invention is a process for the recovery of normal alcohols, especially C.sub.1 -C.sub.20 n-alcohols, preferably n-C.sub.4 -C.sub.14 alcohols, most preferably n-C.sub.6 -C.sub.11 alcohols from n-paraffins by means of pervaporation through a membrane. The alcohols/paraffin feed mixture may be that produced in the Fischer-Tropsch synthesis process wherein mixtures of CO and H.sub.2 are reacted to produce paraffin waxes and a minor but still valuable amount of alcohols.
    Type: Grant
    Filed: November 2, 1992
    Date of Patent: July 27, 1993
    Assignee: Exxon Research and Engineering Company
    Inventors: Charles P. Darnell, Russell J. Koveal, Tan J. Chen, W. S. Winston Ho
  • Control of oxygen level in feed for improved aromatics/non-aromatics pervaporation (OP-3602)
    Patent number: 5095171
    Abstract: The separation of aromatic hydrocarbons from mixtures of aromatic and non-aromatic hydrocarbon feeds under pervaporation conditions, is improved by the control of the amount of oxygen present in the feed. The amount of oxygen in the feed, such as heavy cat naphtha or other cracked feed, should be less than 30 wppm, preferably less than 10 wppm. The oxygen level in the feed can be controlled by the addition of small amount of oxygen scavenger into the feed. Hindered phenols are representative of useful oxygen scavengers.
    Type: Grant
    Filed: April 8, 1991
    Date of Patent: March 10, 1992
    Assignee: Exxon Research and Engineering Company
    Inventors: Joseph L. Feimer, Tan J. Chen