Patent application number | Description | Published |
20100015037 | REACTION VESSEL AND PROCESS FOR ITS USE - The invention relates to a reaction vessel in which hydrogen sulphide is prepared from sulphur and hydrogen, wherein the reaction vessel consists partly or entirely of a material which is resistant to the reaction mixture, its compounds or elements and retains its resistance even at high temperatures. | 01-21-2010 |
20120165573 | PROCESS FOR PREPARING METHYLMERCAPTOPROPIONALDEHYDE - A process for preparing methylmercaptopropionaldehyde in a single reaction unit, is provided. According to the preferred embodiment, the process comprises, simultaneously contacting a gaseous mixture comprising acrolein with a liquid mixture comprising methylmercaptopropionaldehyde, methyl mercaptan, a catalyst and methylmercaptopropionaldehyde methyl thiohemiacetal in the reactive absorber; absorbing the acrolein from the gaseous mixture into the liquid mixture; reacting the absorbed acrolein with the methyl mercaptan or the methylmercaptopropionaldehyde methyl thiohemiacetal to obtain methylmercapto-propionaldehyde; removing gaseous impurities and by-products from the liquid mixture; and separating the obtained methylmercaptopropionaldehyde product from the reactive absorber, directing a portion of the separated product to storage or further processing and recycling the remaining portion to the reactive absorber; wherein the methyl mercaptan optionally comprises dimethyl sulfide or dimethyl ether. | 06-28-2012 |
20120215021 | STORAGE-STABLE 2-HYDROXY-4-(METHYLTHIO)BUTYRONITRILE - A storage stable mixture containing 86 to 97% by weight of 2-hydroxy-4-methylthiobutyronitrile, 2 to 14% by weight of water, 0.05 to 0.5% by weight of HCN and having a pH of 1 to 4, measured using a pH electrode at 23° C. is provided. A method to produce the storage stable mixture and its use in manufacture of DL-methionine or 2-hydroxy-4-methylthiobutyric acid is also provided. | 08-23-2012 |
20120215022 | METHOD FOR THE PRODUCTION OF 2-HYDROXY-4-(METHYLTHIO)BUTYRONITRILE FROM 3-(METHYLTHIO)PROPANAL AND HYDROGEN CYANIDE - A method for the production of 2-hydroxy-4-(methylthio)butyronitrile having good storage stability in a multi-zone reactor, is provided. 3-methylmercaptopropionaldehyde is reacted with hydrogen cyanide in the presence of a base as catalyst in a main reaction zone of the multizone reactor to form a reaction mixture comprising the 2-hydroxy-4-(methylthio)butyronitrile, unreacted 3-methylmercaptopropionaldehyde, the catalyst and residual amounts of gaseous hydrogen cyanide. The residual gaseous hydrogen cyanide is removed from the main reaction zone to an absorption and post-reaction zone of the reactor which comprises a mixture of 3-methylmercaptopropionaldehyde and the catalyst; and the gaseous hydrogen cyanide is further reacted with the 3-methylmercaptopropionaldehyde in the absorption and post reaction zone. A molar ratio of hydrogen cyanide to 3-(methylthio)propanal in the main reaction zone is from 0.98 to 1.03. | 08-23-2012 |
20130231501 | METHOD OF PRODUCTION OF A METHIONINE SALT - A reaction system suitable for production of a methionine salt contains a reactive rectification column containing a weir having a height of 100 mm or more. | 09-05-2013 |
20130245318 | METHOD FOR THE CONVERSION OF METHYLMERCAPTOPROPIONALDEHYDE FORMED FROM CRUDE ACROLEIN AND CRUDE METHYL MERCAPTAN - A reactive rectification column suitable for the production of 2-hydroxy-4-methylmercaptobutyric acid and/or methionine contains a weir having a height of 100 mm or more. | 09-19-2013 |
20140051890 | PROCESS FOR PREPARING METHYLMERCAPTOPROPIONALDEHYDE - A process for preparing methylmercaptopropionaldehyde in a single reaction unit, is provided. According to the preferred embodiment, the process comprises, simultaneously contacting a gaseous mixture comprising acrolein with a liquid mixture comprising methylmercaptopropionaldehyde, methyl mercaptan, a catalyst and methylmercaptopropionaldehyde methyl thiohemiacetal in the reactive absorber; absorbing the acrolein from the gaseous mixture into the liquid mixture; reacting the absorbed acrolein with the methyl mercaptan or the methylmercaptopropionaldehyde methyl thiohemiacetal to obtain methylmercapto-propionaldehyde; removing gaseous impurities and by-products from the liquid mixture; and separating the obtained methylmercaptopropionaldehyde product from the reactive absorber, directing a portion of the separated product to storage or further processing and recycling the remaining portion to the reactive absorber; wherein the methyl mercaptan optionally comprises dimethyl sulfide or dimethyl ether. | 02-20-2014 |
20140213819 | METHOD FOR THE PRODUCTION OF 2-HYDROXY-4-(METHYLTHIO)BUTYRONITRILE FROM 3-(METHYLTHIO)PROPANAL AND HYDROGEN CYANIDE - A method for the production of 2-hydroxy-4-(methylthio)butyronitrile having good storage stability in a multi-zone reactor, is provided. 3-methylmercaptopropionaldehyde is reacted with hydrogen cyanide in the presence of a base as catalyst in a main reaction zone of the multizone reactor to form a reaction mixture comprising the 2-hydroxy-4-(methylthio)butyronitrile, unreacted 3-methylmercaptopropionaldehyde, the catalyst and residual amounts of gaseous hydrogen cyanide. The residual gaseous hydrogen cyanide is removed from the main reaction zone to an absorption and post-reaction zone of the reactor which comprises a mixture of 3-methylmercaptopropionaldehyde and the catalyst; and the gaseous hydrogen cyanide is further reacted with the 3-methylmercaptopropionaldehyde in the absorption and post reaction zone. A molar ratio of hydrogen cyanide to 3-(methylthio)propanal in the main reaction zone is from 0.98 to 1.03. | 07-31-2014 |
20150051421 | PROCESS FOR THE PREPARATION OF METHIONINE - The invention relates to a process for the preparation of D,L-methionine, in which carbon dioxide is fed to an aqueous potassium methioninate solution obtained by hydrolysis of 5-(2-methylmercaptoethyl)hydantoin, in order to precipitate out crude methionine, which is separated off and purified, where, for the purposes of purification, an aqueous solution of the separated-off crude methionine is prepared and subjected to a recrystallization, characterized in that the solution from which the recrystallization takes place contains potassium ions and also a crystallization additive, where the crystallization additive is a nonionic or anionic surfactant, or a mixture of different nonionic or anionic surfactants, and that the recrystallization takes place by introducing a 60 to 110° C.-hot methionine solution into a 35 to 80° C.-warm methionine suspension, the temperature of which is lower than that of the introduced solution, the temperature of the methionine suspension being maintained between 35 and 80° C. during the addition. | 02-19-2015 |