Patents Assigned to T-Thermal Inc.
  • Production of sulfur from sulfur dioxide obtained from flue gas
    Patent number: 4837001
    Abstract: This invention is a regenerable process for producing elemental sulfur from SO.sub.2 initially contained in a dilute gas source by: (1) absorbing the SO.sub.2 in a concentrated Na.sub.2 SO.sub.3 solution to convert most of the Na.sub.2 SO.sub.3 to Na.sub.2 S.sub.2 O.sub.5 ; (2) separating one third of the absorbed SO.sub.2 ; (3) reacting the residual mixture with solid NaHCO.sub.3 to form gaseous carbon dioxide used in a subsequent step and a slurry composed of solid Na.sub.2 SO.sub.3 suspended in a Na.sub.2 SO.sub.3 solution; (4) separating solid Na.sub.2 SO.sub.3 from the solution which is recycled to (1) above; (5) reducing solid Na.sub.2 SO.sub.3 to Na.sub.2 S; (6) reacting the Na.sub.2 S with H.sub.2 O and CO.sub.2 to form solid NaHCO.sub.3 which is recycled to (3) above and gaseous H.sub.2 S; (6) reacting gaseous H.sub.2 S with SO.sub.2 separated in (2) above to form water and elemental sulfur.
    Type: Grant
    Filed: February 27, 1987
    Date of Patent: June 6, 1989
    Assignee: T-Thermal, Inc.
    Inventor: Ralph Miller
  • Method for recycling NO in a system producing ferric sulfate
    Patent number: 4818514
    Abstract: The present invention provides a method of using air to reclaim and recycle potentially contaminating NO in a system producing ferric sulfate solution from the oxidation of ferrous sulfate and sulfuric acid in the presence of NO and oxygen. The present invention economically avoids a potentially wasteful and hazardous production of NO containing gas.
    Type: Grant
    Filed: September 15, 1987
    Date of Patent: April 4, 1989
    Assignee: T-Thermal, Inc.
    Inventor: Ralph Miller
  • Simultaneous separation and conversion to sulfur of H.sub.2 S
    Patent number: 4693881
    Abstract: This invention is a regenerable process for converting H.sub.2 S to S by (1) reacting the H.sub.2 S with Fe.sub.2 (SO.sub.4).sub.3 to form S, FeSO.sub.4 and H.sub.2 SO.sub.4 ; (2) separating the S; oxidizing the FeSO.sub.4 and H.sub.2 SO.sub.4 with a gas containing oxygen in the presence of NO to form H.sub.2 O, Fe.sub.2 (SO.sub.4).sub.3 and a gas with a depleted oxygen content, separating the gas from the Fe.sub.2 (SO.sub.4).sub.3 and recycling the Fe.sub.2 (SO.sub.4).sub.3 to the S formation reaction.
    Type: Grant
    Filed: July 17, 1985
    Date of Patent: September 15, 1987
    Assignee: T-Thermal, Inc.
    Inventor: Ralph Miller
  • Conversion of oxides of nitrogen to nitrogen for pollution abatement
    Patent number: 4663135
    Abstract: A process for removing oxides of nitrogen from a gas in which the molar ratio of NO to NO.sub.2 is greater than 1. Sufficient NO is oxidized by the reaction NO+2HNO.sub.3 =H.sub.2 O+3NO.sub.2 by a solution whose HNO.sub.3 concentration is maintained above about 20% to form a gas whose molar ratio of NO to NO.sub.2 is close to 1. Substantially equivalent amounts of NO and NO.sub.2 are absorbed by a solution whose pH is maintained below about 2 containing HNO.sub.3 and dissolved NH.sub.3. The absorbed oxides of nitrogen react with the dissolved NH.sub.3 at a temperature above about 50.degree. C. to form elemental nitrogen and water. The process can be carried out in several steps or in substantially one step.
    Type: Grant
    Filed: December 23, 1985
    Date of Patent: May 5, 1987
    Assignee: T-Thermal Inc.
    Inventor: Ralph Miller