摘要:
It is known to isolate MHA from a reaction mixture obtained by the addition of hydrocyanic acid (HCN) to methyl mercaptopropionic aldehyde (MMP) and the hydrolysis of the methyl mercapto propionic aldehyde cyanohydrine (MMP-CH) obtained thereby with sulphuric acid, in which the reaction mixture is brought into contact with a substantially non-water-miscible organic solvent, in order to form an extraction solution having the solvent and MHA transferred from the reaction mixture, and the MHA is obtained as an extract from this extraction solution by concentration. The simplest and most economical process of the invention concerning the processing of the reaction product which facilitates the production of a highly concentrated product with an extremely low dimer, oligomer and by-product content, is characterised in that the concentration is conducted in such a way that the remaining extract contains less than 4 wt % and preferably less than 2 wt % of water. Animal feed supplement, mixtures for supplementing animal feed, e.g. with methionine or ammonium-MHA.
摘要:
A process is provided for the recovery of sulfuric acid from NH.sub.4 HSO.sub.4 and (NH.sub.4).sub.2 SO.sub.4 salts produced from the sulfuric acid hydrolysis of methylmercaptopropionaldehyde (MMP) cyanohydrin to produce 2-hydroxy-4-methylthiobutyric acid (MHA), which can be used as an additive in animal feed. The sulfate salts are combusted in a furnace to produce sulfur dioxide; the sulfur dioxide is contacted with an aqueous solution containing sulfuric acid and hydrogen peroxide, where the sulfur dioxide is converted into sulfuric acid. The product sulfuric acid is recovered.
摘要:
A method for the isolation of 2-hydroxy-4-methylthiobutyric acid (MHA), wherein MHA is isolated from a reaction mixture obtained by addition of hydrogen cyanide (HCN) to methylmercaptopropionaldehyde (MMP) and hydrolysis by sulphuric acid of the methylmercaptopropionaldehyde cyanohydrin (MMP-CH) thus obtained. The reaction mixture is brought into contact in a liquid/liquid extraction system with an organic solvent substantially immiscible with water, in order to form an extraction solution which contains the solvent and the MHA transferred out of the reaction mixture. By bringing the salt content of the reaction mixture, prior to the liquid/liquid extraction, to a concentration of about >50 wt. % (wt./wt.), preferably >55 wt. %, referred to the sum of the inorganic constituents of the reaction mixture, the coordinated use of energy in the total system is improved, the evaporation of strongly corrosive solutions is avoided, the efficiency of the hydrolysis step is increased and the distribution coefficients during the extraction are improved. The MHA is isolated as the extract from this extraction solution by evaporation, and may be used as animal feed supplement.
摘要:
A method for obtaining 2-hydroxy-4-methylthiobutyric acid (methionine-hydroxy analog, MHA) in primarily free form which is stable in storage by distilling a product solution containing MHA and by producing MHA product mixtures with improved storage stability from such a distillate. The distillate can be produced directly starting from MHA raw products from any MHA production process, which can optionally also contain solvent or water. The starting material may also be a commercial MHA product.
摘要:
The invention relates to a device for carrying out exothermal chemical reactions wherein a gas phase is guided across a fixed bed and allowed to react. Said device comprises a housing and an exchangeable unit wherein the reaction takes place.
摘要:
A device for carrying out exothermal chemical reactions wherein a gas phase is guided across a fixed bed and allowed to react, comprising a housing and an exchangeable unit wherein the reaction takes place.
摘要:
The invention relates to a method for the separation of methyl mercaptan from reaction gas mixtures obtained by means of the catalytic conversion of H2S with methanol, by means of converting the methyl mercaptan into MMP in the presence of the byproducts with acrolein, and separating the same.