Patents by Inventor Catherine T. Sigal

Catherine T. Sigal 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).

  • ZSM-5 zeolites having uniformly large crystals
    Patent number: 4908342
    Abstract: There is provided an improvement for making large crystallite ZSM-5 zeolites by a method comprising forming the zeolite in a medium containing a combination of tetramethylammonium and tetrapropylammonium cations. The improvement involves the addition of sodium chloride to the aqueous reaction medium to increase the uniformity of crystallite size and to increase the mean crystallite size. Also provided are catalysts comprising these ZSM-5 crystallites and processes for converting organic compounds with these catalysts.
    Type: Grant
    Filed: March 3, 1987
    Date of Patent: March 13, 1990
    Assignee: Mobil Oil Corporation
    Inventors: John P. McWilliams, Catherine T. Sigal
  • Abatement of NO.sub.x in exhaust gases
    Patent number: 4778665
    Abstract: Abatement of nitrogen oxides in an industrial exhaust gas is effected by reduction of the nitrogen oxides with ammonia in the presence of a catalyst comprising a porous crystalline siliceous solid such as a ZSM-5 type zeolite. Fast responses to changes of NO.sub.x load is achieved with a zeolite of low to moderate acid activity. The catalyst may be virgin catalyst, aged catalyst previously used for the conversion of a hydrocarbon or an organic compound, or artifically aged catalyst.
    Type: Grant
    Filed: February 6, 1987
    Date of Patent: October 18, 1988
    Assignee: Mobil Oil Corporation
    Inventors: Sowmithri Krishnamurthy, John P. McWilliams, David A. Pappal, Catherine T. Sigal, Thomas R. Kiliany, Jr.
  • Guard bed catalyst for organic chloride removal from hydrocarbon feed
    Patent number: 4721824
    Abstract: A method is provided for removing trace amounts of organic chlorides from feedstocks by passing the feedstock in contact with a guard bed catalyst comprising shaped particles formed by extruding a mixture of magnesium oxide and a binder inert to the feedstock. The process has particular importance in removing organic chlorides from toluene feedstocks prior to contacting toluene with a disproportionation or alkylation catalyst comprising magnesium-ZSM-5.
    Type: Grant
    Filed: March 12, 1987
    Date of Patent: January 26, 1988
    Assignee: Mobil Oil Corporation
    Inventors: John P. McWilliams, Margaret I. Nemet-Mavrodin, Catherine T. Sigal, Robert C. Wilson, Jr.