Patents by Inventor Steven A. Heffernen

Steven A. Heffernen 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: 5356603
    Abstract: This invention is a method for producing hydrocyanic acid by using an element which comprises a foraminous structure fabricated from a material consisting essentially of a metal selected from the group consisting of platinum, rhodium, palladium and alloys of mixtures thereof characterized by (a) a novel configuration whereby the initial product of the formula: curve the flat ratio (C/F) multiplied by mesh size (N) and wire diameter (d.sub.w), for said element is greater than at least about 0.08 and (b) where, for a given methane and ammonia throughput, the conversion efficiency is a function of the curve to flat ratio (C/F), wire diameter (d.sub.w) and mesh size (N) combination and conversion efficiency is improved by increasing the mesh size (N) for a given wire diameter, increasing the wire diameter (d.sub.w) for a given mesh size, and increasing the curve to flat ratio (C/F) to a ratio of above 1.0. Preferably the initial product of the formula is greater than 0.
    Type: Grant
    Filed: January 26, 1993
    Date of Patent: October 18, 1994
    Assignee: Johnson Matthey Inc.
    Inventors: William A. Hochella, Steven A. Heffernen
  • Patent number: 5278124
    Abstract: This invention is a catalytic element for use in the catalytic oxidation of ammonia. The element comprises a foraminous structure fabricated from a material consisting essentially of a metal selected from the group consisting of platinum, rhodium, palladium and alloys of mixtures thereof characterized by (a) a novel configuration whereby the initial product of the formula: curve to the flat ratio (C/F) multiplied by mesh count in inches (N) and wire diameter (d.sub.W), for said element is at least about 0.08 and (b) where, for a given hydrogen throughput, the conversion efficiency is a function of the curve to flat ratio (C/F), wire diameter (d.sub.W) and mesh count (N) combination and conversion efficiency is improved by increasing the mesh count (N) for a given wire diameter, increasing the wire diameter (d.sub.W) for a given mesh count, and increasing the curve to flat ratio (C/F) to a ratio of above 1.0. Preferably the initial product of the formula is greater than 0.2, more preferably 0.
    Type: Grant
    Filed: July 23, 1992
    Date of Patent: January 11, 1994
    Assignee: Johnson Matthey, Inc.
    Inventors: William A. Hochella, Steven A. Heffernen
  • Patent number: 5160722
    Abstract: This invention is a catalytic element for use in the catalytic oxidation of ammonia. The element comprises a foraminous structure fabricated from a material consisting essentially of a metal selected from the group consisting of platinum, rhodium, palladium and alloys of mixtures thereof characterized by (a) a novel configuration whereby the initial product of the formula: curve the flat ratio (C/F) multiplied by mesh count in inches (N) and wire diameter (d.sub.w), for said element is greater than at least about 0.08 and (b) where, for a given hydrogen throughput, the conversion efficiency is a function of the curve to flat ratio (C/F), wire diameter (d.sub.w) and mesh count (N) combination and conversion efficiency is improved by increasing the mesh count (N) for a given wire diameter, increasing the wire diameter (d.sub.w) for a given mesh count, and increasing the curve to flat ratio (C/F) to a ratio of above 1.0. Preferably the initial product of the formula is greater than 0.2, more preferably 0.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: November 3, 1992
    Assignee: Johnson Matthey, Inc.
    Inventors: William A. Hochella, Steven A. Heffernen
  • Patent number: 5122185
    Abstract: This invention is a method for the recovery of precious metal selected from the group consisting of platinum and rhodium lost from a platinum-containing catalyst during ammonia oxidation processes at a temperature above 850.degree. C. which comprises bringing said lost precious metal into contact with a foraminate element fabricated from a material consisting essentially of palladium, by itself, or palladium and a minor amount of another metal selected from the group consisting of other platinum group metals, Ni, Au, Mn, Mg, Cr, C, B, Cu and alloys of mixtures thereof characterized by (a) a novel configuration whereby the initial product of the formula: curve to flat ratio (C/F) multiplied by mesh size (N) and wire diameter (d.sub.w), for the element is greater than at least about 0.9 and (b) where, for a given nitrogen throughput, the weight recovery efficiency is a function of the curve to flat ratio (C/F), wire diameter (d.sub.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: June 16, 1992
    Assignee: Johnson Matthey Inc.
    Inventors: William A. Hochella, Steven A. Heffernen