摘要:
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.
摘要:
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.
摘要:
A method to produce D,L-Methionine from 2-hydroxy-4-(methylthio)butyronitrile by reaction with ammonia, optionally in the presence of carbon dioxide, is provided. The 2-hydroxy-4-(methylthio)butyronitrile is obtained by reaction of 3-methylmercapto-propionaldehyde with hydrogen cyanide in the presence of a base as catalyst in a main reaction zone of a multizone reactor. 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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A method to produce D,L-Methionine from 2-hydroxy-4-(methylthio)butyronitrile by reaction with ammonia, optionally in the presence of carbon dioxide, is provided. The 2-hydroxy-4-(methylthio)butyronitrile is obtained by reaction of 3-methylmercaptopropionaldehyde with hydrogen cyanide in the presence of a base as catalyst in a main reaction zone of a multizone reactor. 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.
摘要:
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.
摘要:
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.