摘要:
The present invention is relative to a method of producing dry thioctic acid in which a raw material in which concentrated thioctic acid is present is treated with liquid or supercritical CO.sub.2, thus yielding thioctic acid with low residual solvent contents in a simple industrial method.
摘要:
Lithium phosphate catalysts for the rearrangement of alkene oxides to the corresponding alkenols are prepared as overcoats on inert carriers. The catalysts are prepared for example by overcoating the inert carrier with the lithium phosphate in the presence of moisture.
摘要:
A process for the preparation of methionine or a salt of methionine by reaction of the components 3-methylmercaptopropionaldhyde, hydrogen cyanide, ammonia and carbon dioxide or components from which the above-mentioned components can be prepared, optionally in the presence of water, to 5-(2-methylmercaptoethyl)-hydantoin and further reaction thereof to methionine or the salt thereof, characterised in that the reaction of the components is initiated by means of at least one premixture in such a way that a first mixture is formed containing at least the predominant proportion (at least 5/10) of the 3-methylmercaptopropionaldeyde and at least 1/10 of the hydrogen cyanide component or corresponding quantities of components from which these components can be prepared, and less than 5/10 of one of the components ammonia, carbon dioxide or of the components from which ammonia or carbon dioxide can be prepared, and in that this first mixture is combined with the other component(s) for the reactive conversion to 5-(2-methylmercaptoethyl)-hydantoin, wherein this (these) latter component(s) may be premixed in one or more other mixtures.
摘要:
There is provided a process for the work-up of this material having the formula ##STR1## because of its poor crystallizability has heretofore been available only with large yield losses. The yield losses are due to the fact that the crystals of this compound are associated with large amounts of residual solvent material which gives rise to complex and expensive drying procedures. In accordance with the present invention the crude LPE is dried by means of fluid or supercritical carbon dioxide which maces it possible to reduce drying times from the previous range of about 124 hours to about 10 hours for the same amount of product and thus produce a dry LPE which has smaller amounts of residual solvent, as well as smaller by-products than that obtained by conventional drying.
摘要:
A method of producing 3,5,5-trimethylcyclohexa-3-ene-1-one (.beta.-isophorone) by isomerization of 3,5,5-trimethylcyclohexa-2-ene-1-one (.alpha.-isophorone) in a liquid phase in the presence of a homogeneous or heterogeneous catalyst in which a mixture with a relatively low concentration of .beta.-isophorone is drawn off from the reaction container and the .beta.-isophorone isolated by vacuum distillation. .beta.-isophorone is an important synthetic structural element for the production of carotinoids, vitamins and pharmaceutical products.
摘要:
A process for the preparation of methionine or a salt of methionine by reaction of the components 3-methylmercaptopropionaldhyde, hydrogen cyanide, ammonia and carbon dioxide or components from which the above-mentioned components can be prepared, optionally in the presence of water, to 5-(2-methylmercaptoethyl)-hydantoin and further reaction thereof to methionine or the salt thereof, characterised in that the reaction of the components is initiated by means of at least one premixture in such a way that a first mixture is formed containing at least the predominant proportion (at least 5/10) of the 3-methylmercaptopropionaldeyde and at least 1/10 of the hydrogen cyanide component or corresponding quantities of components from which these components can be prepared, and less than 5/10 of one of the components ammonia, carbon dioxide or of the components from which ammonia or carbon dioxide can be prepared, and in that this first mixture is combined with the other component(s) for the reactive conversion to 5-(2-methylmercaptoethyl)-hydantoin, wherein this (these) latter component(s) may be premixed in one or more other mixtures.
摘要:
To supplement feeds and industrially produced mixed feeds with L-lysine, there are used aqueous L-lysine solutions having a L-lysine content between 30 and 80 weight percent, preferably between 50 and 70 weight percent. In comparison with crystallized L-lysine, they are clearly more stable and in equimolar amounts show the same L-lysine activity as the known forms presently offered.
摘要:
The calcium salts of mono-hydroxymethyl lysine and bis(hydroxymethyl) lysine are prepared by reacting lysine and formaldehyde in water containing calcium ions at a pH of at least 8 and at most 12.5. The compounds are useful as fodder for ruminants.