Patents by Inventor Steven H. Christiansen
Steven H. Christiansen 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).
-
Process for the preparation of a stable salt-free iron chelate for use in hydrogen sulfide abatement
Patent number: 5472633Abstract: A stable, salt-free iron chelate for use in aqueous alkaline systems is prepared by contacting iron oxide with an aqueous mixture of from 30 to 45 mole percent trisodium HEDTA and from 55 to 70 mole percent EDTA, heating the mixture to dissolve the iron, and adjusting the pH to from 7 to 10 with base.Type: GrantFiled: October 6, 1992Date of Patent: December 5, 1995Assignee: The Dow Chemical CompanyInventors: Freddie Griffin, Jr., David A. Wilson, Steven H. Christiansen -
Patent number: 5447603Abstract: The invention is an improvement in a process for making cellulosic articles said process involving a separation of cellulosic material from a mixture containing a liquid, metal cations, and cellulosic material. The improvement involves adding to the mixture at least one retaining material which binds at least one metal cation and, in the separation, is retained with the cellulosic material. Suitable retaining agents are either organic or inorganic and include chelate-forming polymers, both synthetic and natural, colloidal suspensions of inorganic compounds, and mixed metal hydroxides. In each case, the metal cations remain in the cellulosic article, e.g. paper, rather going into waste water from which they would otherwise need to be removed.Type: GrantFiled: July 9, 1993Date of Patent: September 5, 1995Assignee: The Dow Chemical CompanyInventors: Robert J. Michalowski, Steven H. Christiansen, R. Keith Frank, Teresa Littleton, Jaime Simon, Walter Vaughn, David A. Wilson
-
Patent number: 5342593Abstract: Sulfur dioxide is removed from a fluid containing SO.sub.2 by employing as an absorbent therefor an aqueous solution of compound represented by Formula I: ##STR1## wherein X is --O--, --NR.sup.1 --, or --N.dbd.; each Y is independently --(CR.sup.2.sub.2)--, --(C.dbd.O)--, --O--, --NR.sup.1 --, --N.dbd., or --C(R.sup.2).dbd.; each R.sup.1 or R.sup.2 is independently hydrogen; an alkyl group; a hydroxyalkyl group; an aldehyde group; a carboxylic acid or salt group; or an alkyl group containing an aldehyde group, a carboxylic acid or salt group, ketone, carboxylic ester, ether, or sulfoxide group; and m is an integer preferably of from 2 to about 4. The absorbent solution preferably can be thermally regenerated by heating to remove SO.sub.2.Type: GrantFiled: August 10, 1992Date of Patent: August 30, 1994Assignee: The Dow Chemical CompanyInventors: Steven H. Christiansen, Dane Chang, David A. Wilson
-
Patent number: 5236678Abstract: Sulfur dioxide is removed from a fluid containing SO.sub.2 by employing as an absorbent for the SO.sub.2 an aqueous solution of a compound represented by Formula I: ##STR1## wherein each Y is independently --(CR.sup.2.sub.2)--or--(CR.sup.2).dbd.and each R.sup.1 or R.sup.2 is independently hydrogen, an alkyl group; an hydroxyalkyl group: an aldehyde group: a carboxylic acid group or salt thereof: an alkyl group containing at least one carboxylic ester, a carboxylic acid or salt thereof, ether, aldehyde, ketone, or sulfoxide group: wherein the compound has at least one carbonyl group. The absorbent solution preferably can be thermally regenerated by heating to remove SO.sub.2.Type: GrantFiled: May 17, 1991Date of Patent: August 17, 1993Assignee: The Dow Chemical CompanyInventors: Dane Chang, Steven H. Christiansen
-
Patent number: 5223181Abstract: Magnesium is separated from magnesium slag containing radioactive thorium and its daughters by solubilizing magnesium from magnesium slurry using carbon dioxide and separating magnesium from magnesium slurry containing thorium and its daughters by filtering. The process concentrates the radioactive thorium and its radioactive daughters from the magnesium slag and reduces the volume of the radioactive waste that requires disposal.Type: GrantFiled: March 27, 1991Date of Patent: June 29, 1993Assignee: The Dow Chemical CompanyInventors: David A. Wilson, Steven H. Christiansen, Jaime Simon, Dana W. Morin
-
Patent number: 5145558Abstract: A composition for alkaline hydrogen peroxide bleaching of mechanical wood pulp which employs a quaternary amine compound, such as (3-chloro-2-hydroxy-propyl) trimethyl ammonium chloride, in the stabilized bleach solution. The brightness of the final paper product made from such bleached pulp shows marked improvement over that in which only chelating agents are employed to improve the brightness according to the known art. The process is useful in both silicate and silicate-free bleach solutions.Type: GrantFiled: February 15, 1991Date of Patent: September 8, 1992Assignee: The Dow Chemical CompanyInventors: Steven H. Christiansen, Teresa Littleton, Robert T. Patton
-
Patent number: 5108723Abstract: A process for removing SO.sub.2 from a fluid containing SO.sub.2 by employing as an absorbent for the SO.sub.2 an admixture of water and a compound represented by Formula I: ##STR1## wherein each R.sup.1, R.sup.2 or R.sup.3 is independently hydrogen; an alkyl group; a carboxylic acid group; a hydroxyalkyl group; an aldehyde group; and alkyl group containing a carboxylic ester, a carboxylic acid or salt, ether, aldehyde, ketone or sulfoxide group; wherein at least one R.sup.1 or R.sup.3 is carboxy methyl group and at least one R.sup.1 or R.sup.3 is hydrogen, preferably at least one R.sup.1 is carboxy methyl and at least one R.sup.3 is hydrogen. The absorbent solution preferably can be thermally regenerated by heating to remove SO.sub.2.Type: GrantFiled: August 16, 1990Date of Patent: April 28, 1992Assignee: The Dow Chemical CompanyInventors: Dane Chang, Steven H. Christiansen, David A. Wilson
-
Patent number: 5098681Abstract: Sulfur dioxide is removed from a fluid containing SO.sub.2 by employing as an absorbent therefor an aqueous solution of compounds represented by Formulas I and II: ##STR1## wherein each R.sup.1 or R.sup.2 is independently hydrogen; an alkyl group; a hydroxyalkyl group; an aldehyde group; a carboxylic acid or salt group; an alkyl group containing at least one carboxylic ester, carboxylic acid or salt, ether, aldehyde, ketone or sulfoxide; and wherein at least one R.sup.1 or R.sup.2 is a carbonyl-containing group, such as an aldehyde group, a carboxylic acid containing group, a carboxyl ester group, or a ketone-containing group; ##STR2## wherein each R.sup.3 is independently hydrogen; an alkyl group; a hydroxyalkyl group; an aldehyde group; a carboxylic acid or salt group; or an alkyl, aryl, or aralkyl group containing at least one carboxylic ester, a carboxylic acid or salt, ether, aldehyde, ketones or sulfoxide group. The absorbent solution preferably can be thermally regenerated by heating to remove SO.sub.Type: GrantFiled: August 16, 1990Date of Patent: March 24, 1992Assignee: The Dow Chemical CompanyInventors: Steven H. Christiansen, Dane Chang, Druce K. Crump
-
Patent number: 5013404Abstract: A process for alkaline hydrogen peroxide bleaching of mechanical wood pulp which employs a quaternary amine compound, such as (3-chloro-2-hydroxypropyl)trimethyl ammonium chloride, in the stabilized bleach solution. The brightness of the final paper product made from such bleached pulp shows marked improvement over that in which only chelating agents are employed to improve the brightness according to the known art. The process is useful in both silicate and silicate-free bleach solutions.Type: GrantFiled: November 15, 1989Date of Patent: May 7, 1991Assignee: The Dow Chemical CompanyInventors: Steven H. Christiansen, Teresa Littleton, Robert T. Patton
-
Patent number: 4980471Abstract: The 2-piperazinones are made by reacting a 1-cyano-1-hydroxyalkane with ethylenediamine or a substituted ethylenediamine in aqueous solution. The process to make the 2-piperazinones suitable as a regenerable sulfur dioxide absorbing medium requires that the cyano compound be present in at least a molar equivalent amount to the diamine and that the resulting 2-piperazinone product be sparged with an inert gas.Type: GrantFiled: October 6, 1989Date of Patent: December 25, 1990Assignee: The Dow Chemical CompanyInventors: Steven H. Christiansen, David A. Wilson, Dane Chang
-
Patent number: 4732650Abstract: Bleaching of wood pulp is improved by the combination of a pretreatment of the pulp with a polyaminocarboxylic acid, e.g. ethylenediaminetetraacetic acid, prior to bleaching with an alkaline aqueous peroxide solution containing a stabilizing amount of an aminophosphonic acid derivative together with a polymer of an unsaturated carboxylic acid or amide or an alkylsulfonic acid substituted amide.Type: GrantFiled: September 15, 1986Date of Patent: March 22, 1988Assignee: The Dow Chemical CompanyInventors: Robert J. Michalowski, Steven H. Christiansen, Jimmy Myers, David A. Wilson
-
Patent number: 4614646Abstract: An aqueous composition containing hydrogen peroxide, or a precursor which will form said peroxide in aqueous solution, is inhibited from decomposition in the presence of small amounts of copper, iron, manganese or other transition metal ions and in the presence of significant amounts of alkaline earth metal ions, e.g. Ca or Mg, by the presence of a combination of inhibitors one being from the group consisting of alkyleneaminephosphonic acids and the other being from the group consisting of polyalkylenepolycarboxylic acids and their analogous amides and sulfonic acid derivatives.Type: GrantFiled: December 24, 1984Date of Patent: September 30, 1986Assignee: The Dow Chemical CompanyInventor: Steven H. Christiansen