Patents by Inventor Dennis A. Ruest
Dennis A. Ruest 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).
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Patent number: 6548701Abstract: A process for the continuous preparation of 3-(methylthio)propanal. A liquid reaction medium is contacted with a gaseous acrolein feed stream in a gas/liquid contact zone. The reaction medium contains 3-(methylthio)propanal, methyl mercaptan and a catalyst for the reaction between methyl mercaptan and acrolein. The gaseous acrolein feed stream comprises acrolein vapor and non-condensable gas. Acrolein is transferred from the acrolein feed stream to the reaction medium and reacts with methyl mercaptan in that medium to produce a liquid reaction product containing 3-(methylthio)propanal. The non-condensable gas is separated from the liquid reaction product. The reaction product is divided into a product fraction and a circulating fraction, and the circulating fraction is recycled to the gas/liquid contact zone.Type: GrantFiled: October 5, 2001Date of Patent: April 15, 2003Assignee: Novus International, Inc.Inventors: Yung C. Hsu, Dennis A. Ruest
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Publication number: 20020173677Abstract: A process for the continuous preparation of 3-(methylthio)propanal. A liquid reaction medium is contacted with a gaseous acrolein feed stream in a gas/liquid contact zone. The reaction medium contains 3-(methylthio)propanal, methyl mercaptan and a catalyst for the reaction between methyl mercaptan and acrolein. The gaseous acrolein feed stream comprises acrolein vapor and non-condensable gas. Acrolein is transferred from the acrolein feed stream to the reaction medium and reacts with methyl mercaptan in that medium to produce a liquid reaction product containing 3-(methylthio)propanal. The non-condensable gas is separated from the liquid reaction product. The reaction product is divided into a product fraction and a circulating fraction, and the circulating fraction is recycled to the gas/liquid contact zone.Type: ApplicationFiled: October 5, 2001Publication date: November 21, 2002Applicant: Novus International, Inc.Inventors: Yung C. Hsu, Dennis A. Ruest
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Patent number: 6320076Abstract: A process for the continuous preparation of 3-(methylthio)propanal. A liquid reaction medium is contacted with a gaseous acrolein feed stream in a gas/liquid contact zone. The reaction medium contains 3-(methylthio)propanal, methyl mercaptan and a catalyst for the reaction between methyl mercaptan and acrolein. The gaseous acrolein feed stream comprises acrolein vapor and non-condensable gas. Acrolein is transferred from the acrolein feed stream to the reaction medium and reacts with methyl mercaptan in that medium to produce a liquid reaction product containing 3-(methylthio)propanal. The non-condensable gas is separated from the liquid reaction product. The reaction product is divided into a product fraction and a circulating fraction, and the circulating fraction is recycled to the gas/liquid contact zone.Type: GrantFiled: December 22, 1999Date of Patent: November 20, 2001Assignee: Novus International, Inc.Inventors: Yung C. Hsu, Dennis A. Ruest
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Patent number: 6031138Abstract: A process for the continuous preparation of 3-(methylthio)propanal. A liquid reaction medium is contacted with a gaseous acrolein feed stream in a gas/liquid contact zone. The reaction medium contains 3-(methylthio)propanal, methyl mercaptan and a catalyst for the reaction between methyl mercaptan and acrolein. The gaseous acrolein feed stream comprises acrolein vapor and non-condensable gas. Acrolein is transferred from the acrolein feed stream to the reaction medium and reacts with methyl mercaptan in that medium to produce a liquid reaction product containing 3-(methylthio)propanal. The non-condensable gas is separated from the liquid reaction product. The reaction product is divided into a product fraction and a circulating fraction, and the circulating fraction is recycled to the gas/liquid contact zone.Type: GrantFiled: June 22, 1998Date of Patent: February 29, 2000Assignee: Novus International, Inc.Inventors: Yung C. Hsu, Dennis A. Ruest
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Patent number: 5925794Abstract: A process for the continuous preparation of 3-(methylthio)propanal. A liquid reaction medium is contacted with a gaseous acrolein feed stream in a gas/liquid contact zone. The reaction medium contains 3-(methylthio)propanal, methyl mercaptan and a catalyst for the reaction between methyl mercaptan and acrolein. The gaseous acrolein feed stream comprises acrolein vapor and non-condensable gas. Acrolein is transferred from the acrolein feed stream to the reaction medium and reacts with methyl mercaptan in that medium to produce a liquid reaction product containing 3-(methylthio)propanal. The non-condensable gas is separated from the liquid reaction product. The reaction product is divided into a product fraction and a circulating fraction, and the circulating fraction is recycled to the gas/liquid contact zone.Type: GrantFiled: June 20, 1996Date of Patent: July 20, 1999Assignee: Novus International, Inc.Inventors: Yung C. Hsu, Dennis A. Ruest
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Patent number: 5744647Abstract: A process for the continuous preparation of 3-(methylthio)propanal. A liquid reaction medium is contacted with a gaseous acrolein feed stream in a gas/liquid contact zone. The reaction medium contains 3-(methylthio)propanal, methyl mercaptan and a catalyst for the reaction between methyl mercaptan and acrolein. The gaseous acrolein feed stream comprises acrolein vapor and non-condensable gas. Acrolein is transferred from the acrolein feed stream to the reaction medium and reacts with methyl mercaptan in that medium to produce a liquid reaction product containing 3-(methylthio)propanal. The non-condensable gas is separated from the liquid reaction product. The reaction product is divided into a product fraction and a circulating fraction, and the circulating fraction is recycled to the gas/liquid contact zone.Type: GrantFiled: July 11, 1996Date of Patent: April 28, 1998Assignee: Novus International, Inc.Inventors: Yung C. Hsu, Dennis A. Ruest
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Patent number: 5637766Abstract: A process for the continuous preparation of 3-(methylthio)propanal. A liquid reaction medium is contacted with a gaseous acrolein feed stream in a gas/liquid contact zone. The reaction medium contains 3-(methylthio)propanal, methyl mercaptan and a catalyst for the reaction between methyl mercaptan and acrolein. The gaseous acrolein feed stream comprises acrolein vapor and non-condensable gas. Acrolein is transferred from the acrolein feed stream to the reaction medium and reacts with methyl mercaptan in that medium to produce a liquid reaction product containing 3-(methylthio)propanal. The non-condensable gas is separated from the liquid reaction product. The reaction product is divided into a product fraction and a circulating fraction, and the circulating fraction is recycled to the gas/liquid contact zone.Type: GrantFiled: November 13, 1995Date of Patent: June 10, 1997Assignee: Novus International, Inc.Inventors: Yung C. Hsu, Dennis A. Ruest
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Patent number: 5352837Abstract: A process for the continuous preparation of 3-(methylthio)propanal. A liquid reaction medium is contacted with a gaseous acrolein feed stream in a gas/liquid contact zone. The reaction medium contains 3-(methylthio)propanal, methyl mercaptan and a catalyst for the reaction between methyl mercaptan and acrolein. The gaseous acrolein feed stream comprises acrolein vapor and non-condensable gas. Acrolein is transferred from the acrolein feed stream to the reaction medium and reacts with methyl mercaptan in that medium to produce a liquid reaction product containing 3-(methylthio)propanal. The non-condensable gas is separated from the liquid reaction product. The reaction product is divided into a product fraction and a circulating fraction, and the circulating fraction is recycled to the gas/liquid contact zone.Type: GrantFiled: June 8, 1993Date of Patent: October 4, 1994Assignee: Novus International, Inc.Inventors: Yung C. Hsu, Dennis A. Ruest
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Patent number: 4883911Abstract: A process for the preparation of alkylthioalkanoate salts by reaction of an alkali metal alkylmercaptide with a lactone in the presence of an aprotic polar organic solvent. Preferably, the alkali metal mercaptide is prepared by reaction of an alkylmercaptan and an alkali metal phenate.Type: GrantFiled: October 6, 1988Date of Patent: November 28, 1989Assignee: Monsanto CompanyInventor: Dennis A. Ruest
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Patent number: 4777289Abstract: A process for the preparation of alkylthioalkanoate salts by reaction of an alkali metal alkylmercaptide with a lactone in the presence of an aprotic polar organic solvent. Preferably, the alkali metal mercaptide is prepared by reaction of an alkylmercaptan and an alkali metal phenate.Type: GrantFiled: May 8, 1986Date of Patent: October 11, 1988Assignee: Monsanto CompanyInventor: Dennis A. Ruest
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Patent number: 4524077Abstract: A process for the preparation of 2-hydroxy-4-methylthiobutyric acid having improved color, odor and lower viscosity. 2-hydroxy-4-methylthiobutyric acid which is also known as 2-hydroxy-4-(methylthio) butanoic acid, is hydrolyzed with sulfuric acid having an initial strength of between about 50% by weight and about 70% by weight on an organic-free basis, thereby producing an intermediate aqueous hydrolysis product solution containing 2-hydroxy-4-methylthiobutyramide. The 2-hydroxy-4-methylthiobutyramide is hydrolyzed with sulfuric acid having a strength of between about 30% by weight and about 50% by weight on an organic-free basis to produce an aqueous hydrolyzate containing 2-hydroxy-4-methylthiobutyric acid. The hydrolyzate solution is contacted with a substantially water-immiscible organic solvent in a liquid-liquid extraction system to produce an extract comprising the solvent and 2-hydroxy-4-methylthiobutyric acid transferred from the hydrolyzate. The acid product is then recovered from the extract.Type: GrantFiled: November 14, 1983Date of Patent: June 18, 1985Assignee: Monsanto CompanyInventors: Dennis A. Ruest, Masaharu Takano, Lawrence R. Wolf
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Patent number: 4080376Abstract: Novel imide carboxylates, O-carboxylates thereof, and amide carboxylates are useful as intermediates for preparation of sequestrant compounds.Type: GrantFiled: April 19, 1976Date of Patent: March 21, 1978Assignee: Monsanto CompanyInventors: Chung Y. Shen, Roger L. Kidwell, Dennis A. Ruest
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Patent number: 4059579Abstract: Novel imide carboxylates, O-carboxylates thereof, and amide carboxylates are useful as intermediates for preparation of sequestrant compounds.Type: GrantFiled: October 10, 1974Date of Patent: November 22, 1977Assignee: Monsanto CompanyInventors: Dennis A. Ruest, Roger L. Kidwell, Chung Y. Shen
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Patent number: 3935257Abstract: Compounds represented by the formula ##EQU1## wherein M is alkali metal and acids thereof are useful intermediates for preparation of sequestrant compounds represented by the formula ##EQU2## and acids thereof.Type: GrantFiled: March 18, 1974Date of Patent: January 27, 1976Assignee: Monsanto CompanyInventors: Dennis A. Ruest, C. Y. Shen, John L. Mason