Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acids and salts thereof
Patent
1995-05-23
1997-09-30
Shippen, Michael L.
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acids and salts thereof
562575, C07C32100
Patent
active
056727453
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process, which may preferably be performed continuously, suitable for the large-scale industrial production of aqueous alkali metal or alkaline earth metal methioninate solutions which may be used directly, for example as feed additives, or for the isolation of amino acid or salts thereof suitable for use as feed additives. The process is suitable in particular for the production of methioninate solution. Methionine and aqueous solutions of methionine salts, in particular of sodium methioninate (DE 31 05 009 C), together with substitutes such as methionine hydroxy analogue (MHA) are used world-wide as feed additives for rearing poultry, pigs and other agro-economic animals and are mainly useful for the production of animal proteins. It is particularly in view of the increasing world population and increasing problems of food supply that methionine, being one of the essential amino acids in the animal growth process, and its various forms are of special importance and so too, consequently, is the more economic production thereof. Depending upon requirements, the products are preferably used in solid or liquid form.
Commercially available sodium methioninate solution has a concentration of 40 wt. % of methionine and, unlike the substitute, MHA, it has equivalent biological value to solid methionine, measured on an equimolar basis. There are three main methods available for the production of such sodium methioninate solutions:
Although this method produces the purest form of the product, it is more expensive than production of the solid form due to the additional processing stage and is thus less economical than the production of methionine itself. or NaOH/Ca(OH).sub.2 mixtures for which it is necessary to use approximately 2-3 hydroxy equivalents to avoid the production of unwanted by-products.
When Ca(OH).sub.2 is used, while the excess saponification agent may be removed in the form of calcium carbonate (DE 31 05 006 C), it must however be disposed of as virtually unusable waste salt or returned to the hydroxide form, in which it may be reused but which requires expensive steps such as calcining and quenching. On the other hand, when sodium hydroxide solution is used alone, the excess must either be removed in the form of the sodium carbonate produced (DE 31 04 997 A) or it must be removed as sodium sulphate which is formed after neutralisation of the sodium carbonate with sulphuric acid (EP 253 740). Salt formation and the expensive salt removal process as well as the risk of undesirable residues being left behind in the product solution constitute the disadvantages of this method.
As is known, for example from EP 0 228 938, this may be performed with approximately stoichiometric quantities of hydroxide without giving rise to excessive by-product formation. This constitutes an important advantage in comparison with method 2.
Methionine amide may be prepared in a known manner by hydrolysing methionine nitrile, which may in turn be obtained by direct synthesis from the customary starting materials, methylmercaptopropionaldehyde (MMP), hydrocyanic acid or ammonium cyanide, and ammonia.
The method of acid-catalysed nitrile hydrolysis cannot be used as it inevitably leads to the formation of neutral salt, while alkaline nitrile hydrolysis is preferably performed with the addition of catalytically active carbonyl compounds, in particular ketones (Houben-Weyl, Methoden der Organischen Chemie, enlarged supplementary volumes to the 4th edition, volume E5, pages 535 et seq., and the literature cited therein).
As considerable expense and losses are entailed in isolating methionine cleanly and subsequently hydrolysing it to NaMet with NaOH as described, for example, in patent EP 228 938, such a process is uneconomic.
In the other example stated in the same patent, MMP-cyanohydrin is first prepared in the customary manner from MMP and HCN in a 500 ml pressure vessel, and the MMP-cyanohydrin is then converted into methionine nitrile by the introduction of condensed NH.sub.3. After rel
REFERENCES:
patent: 4243814 (1981-01-01), Pascal
patent: 4459423 (1984-07-01), Doya
patent: 4677224 (1987-06-01), Commeyras
patent: 4851576 (1989-07-01), Commeyras
patent: 4960932 (1990-10-01), Gillonnier
Hasseberg Hans-Albrecht
Huthmacher Klaus
Petsch Heinrich
Rautenberg Stephan
Weigel Horst
Degussa - Aktiengesellschaft
Shippen Michael L.
LandOfFree
Method for the continuous preparation of methionine or methionin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for the continuous preparation of methionine or methionin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for the continuous preparation of methionine or methionin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2257862