Patents by Inventor Roscoe L. Pearce

Roscoe L. Pearce 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: 4808765
    Abstract: There is disclosed a process for treating liquid (liquifiable) and gaseous hydrocarbons to remove substantially all of the acid gases including COS by contacting the hydrocarbon streams with specific aqueous treating agents in a series of sequential specific limit operations and apparatus.
    Type: Grant
    Filed: July 17, 1987
    Date of Patent: February 28, 1989
    Assignee: The Dow Chemical Company
    Inventors: Roscoe L. Pearce, Richard A. Wolcott
  • Patent number: 4690740
    Abstract: Herein is described a technique for maintaining a copper ion in the plus 2 oxidation state, as it is employed as an inhibitor in an alkanolamine gas conditioning absorbent solution to provide corrosion protection of the metals in contact with the alkanolamine solution. The procedure disclosed for maintaining copper in the plus 2 state is to apply an induced or impressed voltage across a point, or several points, in the circulating copper containing solution of the gas conditioning plate for the recovery of CO.sub.2 from flue gas particularly when oxygen is present in the gas being treated.
    Type: Grant
    Filed: March 7, 1986
    Date of Patent: September 1, 1987
    Assignee: The Dow Chemical Company
    Inventors: David C. Cringle, Roscoe L. Pearce, Michael S. DuPart
  • Patent number: 4624839
    Abstract: There is disclosed a procedure for removing copper inhibitor from a circulating fluid which contains the same, which copper may be lost on the cool side of a gas conditioning system by plating out under certain conditions, by contacting a portion of the circulating hot fluid with an activated carbon bed to sorb the copper in excess of the solubility limits within said fluid, regenerating said carbon bed when saturated by contacting said carbon bed with cool circulating fluid, thus returning copper which may have plated out to the circulating fluid in an amount and in an ionic state which will not plate out in the system, the circulating fluid is also treated on the cool side by mechanical filtration, activated carbon sorption and/or ion exchange to remove physical and chemical impurities, contaminates and degradation products.
    Type: Grant
    Filed: February 19, 1985
    Date of Patent: November 25, 1986
    Assignee: The Dow Chemical Company
    Inventors: Richard A. Wolcott, Roscoe L. Pearce, Charles R. Pauley
  • Patent number: 4477419
    Abstract: A method is disclosed for recovering carbon dioxide from gases containing the same as well as oxygen and/or sulfur compounds employing aqueous 5 to 80% alkanolamine solutions. Corrosion of the metals of construction and solvent degradation are minimized by the use of copper ion maintained in solution and continuous removal of ionic iron and solvent degradation products by treating the solvent or a portion of the solvent with a carbon bed, mechanical filter and/or a anion exchange resin.
    Type: Grant
    Filed: March 3, 1983
    Date of Patent: October 16, 1984
    Assignee: The Dow Chemical Company
    Inventors: Roscoe L. Pearce, Richard A. Wolcott, Charles R. Pauley
  • Patent number: 4440731
    Abstract: Corrosion inhibiting compositions for use in aqueous absorbent gas-liquid contacting processes for recovering carbon dioxide (CO.sub.2) from industrial gas and oil combustion and partial combustion process flue gases, particularly employing copper carbonate, in combination with one or more of dihydroxyethylglycine, alkali metal permangenate, alkali metal thiocyanate, nickel or bismuth oxides with or without an alkali metal cartonate. The inhibitors are effective in reducing corrosion of metals in contact with the aqueous absorbent in the absorbent regeneration section of the plant as well as reduce the thermal degradation of the absorbent when high oxygen content combustion gases are treated to recover the CO.sub.2.
    Type: Grant
    Filed: September 8, 1981
    Date of Patent: April 3, 1984
    Assignee: The Dow Chemical Company
    Inventor: Roscoe L. Pearce
  • Patent number: 4431563
    Abstract: The corrosion of ferrous metal surfaces in gas conditioning apparatus is inhibited by using a gas conditioning solution such as aqueous alkanolamines which contain thionitrogen compounds such as metal thiocyanates or thioamides. After recycling the gas conditioning solution for a few days, the solution dissolves sufficient amounts of nickel or cobalt or other metals in the equipment to act as a synergist with the thionitrogen compounds. In the event, the equipment does not contain any soluble synergistic metals, these metals may be added to the gas conditioning solution as soluble metal salts. Examples of useful additive metals are cobalt, nickel, calcium, copper, chromium, zinc, tin, aluminum, and magnesium.
    Type: Grant
    Filed: July 21, 1982
    Date of Patent: February 14, 1984
    Assignee: The Dow Chemical Company
    Inventors: Leroy S. Krawczyk, Charles W. Martin, Roscoe L. Pearce
  • Patent number: 4289738
    Abstract: Sour industrial gases containing carbon dioxide and hydrogen sulfide are treated with amines to remove the CO.sub.2 and H.sub.2 S. The amine absorbent containing or loaded with H.sub.2 S and CO.sub.2 is regenerated and the off-gas containing concentrated amounts of H.sub.2 S and CO.sub.2 is treated in a second amine absorber to produce an amine absorbent loaded with H.sub.2 S. This amine is then regenerated to provide an off-gas containing a high ratio of H.sub.2 S to CO.sub.2 which makes it suitable for use as the feed gas to a sulfur recovery unit such as a Claus plant. The process is automatically controlled so that the concentration of H.sub.2 S in the second amine absorber is built up to and controlled at a desired set point so that the off-gas has the required H.sub.2 S/CO.sub.2 ratio.
    Type: Grant
    Filed: July 22, 1980
    Date of Patent: September 15, 1981
    Assignee: The Dow Chemical Company
    Inventors: Roscoe L. Pearce, Charles W. Martin
  • Patent number: 4112049
    Abstract: Hydrogen sulfide and lower alkyl mercaptans are selectively extracted from a gas stream by contacting the stream with piperazinone or an alkyl substituted piperazinone which may contain a substantial proportion of water. The absorbed sulfur compounds can be regenerated by heating the extraction liquid to about 85.degree.-150.degree. C.
    Type: Grant
    Filed: March 18, 1977
    Date of Patent: September 5, 1978
    Assignee: The Dow Chemical Company
    Inventors: John W. Bozzelli, George D. Shier, Roscoe L. Pearce, Charles W. Martin
  • Patent number: 4071602
    Abstract: A method for selectively separating sulfur oxides from carbon dioxide in an effluent gas stream by contacting the stream with solutions of alkanolamines at from 200.degree.-230.degree. F. At these temperatures the carbon dioxide is not absorbed to any degree by the alkanolamine while the sulfur oxides are quantitatively reacted. The spent alkanolamines are regenerated through the use of a weak base ion exchange resin in a cyclic process.
    Type: Grant
    Filed: November 20, 1975
    Date of Patent: January 31, 1978
    Assignee: The Dow Chemical Company
    Inventor: Roscoe L. Pearce
  • Patent number: 4009083
    Abstract: This invention relates to the low temperature regeneration of liquid desiccants and acid gas absorbing liquid desiccants. Both classes of desiccants can be regenerated to separate water and/or water and acid gases to a satifactory degree under the pressure conditions employed at temperatures substantially below the normal boiling point of the dry desiccant or desiccant-water mixture by countercurrently contacting the desiccant to be regenerated in conventional distillation equipment with the vapors of an easily condensable hydrocarbon or hydrocarbon mixture which is substantially immiscible with the regenerated desiccant at the boiling temperature of the hydrocarbon or hydrocarbon mixture employed as a stripping agent.
    Type: Grant
    Filed: June 23, 1975
    Date of Patent: February 22, 1977
    Assignee: The Dow Chemical Company
    Inventors: George W. Lyon, Roscoe L. Pearce