MXPA99004530A - Procedure for the preparation of solutions of metioninato of sodium aqueous and use of those solutions for the manufacture of a granul - Google Patents

Abstract

The present invention relates to a process for the preparation of aqueous sodium methioninate solutions with a low content of sodium carbonate from crude hydrolyzed mixtures precipitated in the saponification of 5- (beta-methyl-mercapto ethyl) -hydantoin with 1.1 a 6 equivalents of sodium hydroxide and / or sodium carbonate, by the separation of the sodium carbonate monohydrate by heat and by different procedures are made granules of those solutions

Description

PROCEDURE FOR THE PREPARATION OF SOLUTIONS OF METIONINATO OF SODIUM AQUEOUS AND USE OF THOSE SOLUTIONS FOR THE MANUFACTURE OF A GRANULATE DESCRIPTION OF THE INVENTION: The invention relates to a process for the preparation of aqueous sodium methioninate solutions with a low content of sodium carbonate from the crude precipitated hydrolyzed mixtures in the saponification of 5- (beta-methyl-mercaptoethyl) - hydantoin with 1.1 to 6 equivalents of sodium nidroxide and / or sodium carbonate, by the separation of sodium carbonate monohydrodite from heat and then the manufacture of granulate from these solutions by different procedures. Methionine as well as aqueous solutions of methionine salts, especially sodium methioninate (DE 31 05 009) but also substitution substances such as hydroxy methionine analogues (MHA) are used worldwide as an additive in animal feed for poultry, pigs, and other useful animals and can mainly improve the production of animal protein. According to the requirements, they are preferably applied in fluid or solid form. The sodium methioninate solution found in commerce has a concentration of 40% by weight of methionine REF. 30301 and corresponds in opposition to MHA with respect to biological value to solid methionine, in an equimolar basis comparison. For the preparation of such sodium methioninate solutions, several methods are considered: 1. Dissolution of methionine isolated in caustic soda. 2. alkaline hydrolysis of 5- (beta-methylmercaptoethyl) hydantoin with NaOH and / or Na 2 CO 3 or a mixture of NaOH / Na 2 CO 3 / NaHCO 3. 3. Alkaline hydrolysis of methioninamide The first procedure produces precisely the purest product form, but is more expensive because of the additional step of work compared to the production of solid, and is less economical than the preparation of the same methionine. on the contrary, the second and third procedures establish a more immediate production time of the methionine preparation and, with this, a significant discharge of the solid part of the preparation of the DL-methionine. The preparation of 5- (beta-methylmercaptoethyl) hydantoin is carried out in a known manner by a direct synthesis from the usual starting materials methylmercaptopropionic aldehyde (MMP) and hydrocyanic acid in the presence of ammonia and carbon dioxide. Methioninamide is manufactured in a known manner by hydrolysis of mephionine nitrile, which is again obtained by the direct synthesis of the usual starting materials MMP, hydrocyanic acid or ammonium ammonium cyanide.

The saponification solutions precipitated by process 2 contain large amounts of sodium carbonate, which must be separated. To this end, the hydrolysis mixture in a concentration of 40 to 65% sodium methioninate is concentrated in accordance with DE-0 31 04 997, cooled to room temperature even more deeply and the precipitated sodium carbonate decahydrate is removed. . However, it often precipitates a difficult way to filter. According to US-PS 4 931 987, the procedure is reversed. First leave the sodium carbonate recrystallized and concentrate the solution produced, then. DE-OS-31 05 009 discloses a process in which metansl or ethanol is added before separation. Depending on special requirements may be good for the purpose pursued, use a solid or liquid d supplements of animal feed. The decision for the form of preparation is, among other things dependent on the mixing tools that are available or the special preferences of particular manufacturer. In the preparation of the mixed food, the different feeding media and additional materials are presented as individual components, which are prepared according to their condition, for example by grinding, crumbling, drying or cleaning. When the individual components have the desired condition, the proper mixing process is performed in a suitable mixing apparatus, the individual mixing parts are different according to the size of the apparatus. The essential amino acid methionine is used in the feed supplementation of mixed animals in concentrations of the magnitude of 0.0 to 1.0% by weight. These quantities are added by heavy system or dosage corresponding directly to the mixed feed. DE-OS 31 05 009 discloses aqueous solutions of sodium or potassium methioninate, in their use as additives for food, which has the same effect as methionine, as is solid. By DE 197 07 380 of 15.02.1997 a granulate based on methionine salt is known. It is the task of the invention to indicate a process for preparing poor solutions of sodium carbonate and NaCO, or also free solutions of the above of sodium methioninate, and also the granulates derived therefrom. The object of the invention is a process for the preparation of aqueous sodium methioninate solutions with a minimum content of sodium carbonate and NaHC03 from the saponification of 5- (Beta-methylmercaptoethyl) hydantoin with 1. to 6 equivalents of sodium hydroxide. and / or sodium carbonate, by the precipitation of impurity hydrolysis mixtures, characterized in that, from the raw impure hydrolysis mixture, the water is distilled, preferably in two stages, especially after the addition of more sodium hydroxide, preferably up to excess of 1 mol / liter, in reference to methioninate, until the content of sodium ethioninates is 60 to 90% by weight, and the temperatures of 90 to 140 ° C, especially from 110 to 130 ° C, separating the bicarbonate carbonate from precipitated sodium. As a crystallization process, crystallization by evaporation is particularly suitable. In this way the filtration properties are very favorably influenced by the low viscosity of the solution in the hot state. The filtrate finally has a remaining sodium carbonate content of less than 6% by weight preferably equal to or less than 3.5% by weight, especially equal to or less than 1.5 by weight. The solid generally separated by a centrifuge from a decanter, consisting of about 70% by weight of sodium carbonate and about 15% by weight of methionine, is precipitated according to the invention, at an elevated temperature, against the current state of the technique. Then if cooling at temperatures greater than 120 ° in which s develops hydrolysis, hydantoin is re-introduced. By means of this process, an economically advantageous cyclic process for the production of sodium d-methioninate solution is feasible. If the existing residue of sodium carbonate or hydrogen carbonate is undesirable in the solution, by a corresponding mole addition of free methionine the sodium content is reduced. Methionine can be added in the form of a solution or a suspension. The final concentration of the product is adjusted, if necessary, by the addition of water. By the heat treatment at temperatures from 80 to 200 ° C, especially 130 to 170 ° C, residence time between 0. 1 and 3 hours can the carbonate dissociate by the separation d C02 and form Na-methioninate. For the purpose of removing the C02 from the solution, an inert impulse agent or water vapor is used. As long as water vapor is used as a driving agent, it can be fed both from the outside as well as with suitable apparatuses, for example, evaporative film evaporators from the solution which evaporates. The removal or removal of the C02 can also be assisted by the application of mechanical energy, for example in the form of agitation or by the objective application of technical process apparatus, which especially favor the performance of chemical reactions with an outstanding step d substance of the liquid phase to the gas phase, for this are appropriate: floor columns counter current, columns d body filler, jet or jet devices or columns d blown. In this way, solutions of sodium methioninate are obtained especially stable in storage. Another object of the invention are the granulates capable of sliding or "flowing", produced from free or poor solutions and sodium carbonate by the means indicated. In an advantageous variant, the solution is concentrated under atmospheric pressure or under reduced pressure, so that the removal of water from the solution is carried out favorably by pure evaporation and not by drying. pressures of 20 to 1000 mbar and temperatures between 100 and 160 ° s obtain a pseudo-molten solution able to flow freely This solution then has a remaining water content of about 0.5 to 3% by weight. This pseudo melt then has a solidification temperature of about 4 to 80 ° C. Due to these favorable boundary conditions, the fluidized bed granulation processes are especially suitable for obtaining granules, as they are used in the field of application of the product. . The granulate has a specific weight greater than 650 kg / m preferably greater than 700 kg / m3 at a grain size distribution of 63 to 5000 microns, preferably 300 to 3000 microns, more preferred from 100 to 2400 microns where approximately 90% is presented in a grain size greater than 100 micras. The fraction with a grain size less than 63 miera is generally at a maximum of 2%, preferably 1% l powder fraction according to Dr Groschopp at 1%, preferably less than 0.5%. A granulation process especially suitable for solutions with sodium methioninate contents greater than 65% and weight up to 90% by weight, is carried out in 3 stages, in a granulate generator, in a dryer and in a product cooler. In particular: a) as a granulation, the fluidised bed gantry is especially suitable; b) the drying can be carried out both in the fluidized bed and also, for example, in a vacuum contact dryer; c) for cooling, for example, the fluidised bed, cooling snails or channels or cooling leakage are used. As a drying gas, heated air pre-dried with nitrogen is used, the dew point of the gas is approximately 10 to 40 ° C. The generation of the granulate takes place directly by spraying the highly concentrated product solution in the fluidized bed. As a spraying aggregate, a two-substance nozzle that functions as a pressure nozzle can be used, which is different from the usual technique. Here, the formation of droplets is caused by spontaneous pressure drop in the head of the nozzle, the air around it can advantageously be reduced to a minimum value of 7: 1 to 10: 1 and against the usual procedure (ratio of more). solution: air approximately 2: 1). The air around or in the jacket serves to carry the drops to the fluidized bed. Of special significance for the temperature conduction in the apparatus are the states of the air in relation to the humidity of the product in the fluidized bed. The size of the grain can, in essence, be achieved through the generation of production and the introduction of granules or seeds granulated by tools installed internally in the fluidized bed, for example, end mills or by an external grinding, for example, of the above-ground grain. fluidized bed. The drying step can be directly connected to the granulation in the same device. A separate temperature control must be possible for a suitable drying element both in the drying feed and on the side of the product. The fine grain transported by the drying gas can also be returned to stage d granulation. The temperature in the granulation stage and equally dependent on the humidity of the drying and granulating gas and is in the range of 80 to 120 ° C. In the cooling to 30 to 60 ° C in general you must have security, that the When cooled, it moves mechanically in a dry atmosphere and stays dry, to prevent it from sticking. For this reason, a fluidized-bed cooler, or cooling coil or cooling channels, is considered as a very suitable apparatus. Other suitable mechanical apparatuses can also be used, for example, cooling ducts, dish chillers or snails or cooling coils. These devices have to be covered at least dry gas to prevent the product from adhering. The granulation process by fluidized bed structuring can not only be carried out continuously but also in the case of a bath in only one chamber of a fluidized bed. Here the structured granulation is carried out., drying and cooling in a temporary succession by a corresponding temperature control. Alternatively to the granulation process which has been shown by the granulation of the fluidized bed structure, the existence of dosi substances or flat jet nozzles or a dripping process is offered for generating the granulate. Then the pseudo-melt or the highly concentrated solution with remaining moisture of 0.5 to 10% by weight at temperatures between 70 ° C and preferably 120 and 160 ° is pressed through a well drilled with a fine drill. Due to the axial oscillation of this plate, a particularly unitary drip spectrum can also be achieved with a highly viscous solution. According to the invention, these drops are allowed to solidify in a drop tower in a dry inert gas, for example air or nitrogen. The solidification is carried out more easily elevated temperature, so that simultaneously or a large distance of the water takes place. Then the spheres capture in a fluidized bed and continue drying under the conditions that have been previously painted. The granulated d spheres thus obtained are characterized by a good fluidity capacity, single grain spectrum and dust poverty. Another variant represents the preparation of the granulate by the extrusion of the pseudo-melt of the highly concentrated solution in an extruder with a controlled temperature control. Here you can without any additional substance directly generate an extrudate. According to the matrices used, a granulate of approximately 500 as 5000 microns d diameter was produced. As long as it is convenient and convenient, the product can also be continued drying. To improve the manageability of the manufactured granulate, it is recommended that the methionine salt solutions and the presence of silicate-based flow substances be sprayed and granulated. Hydrophobic hydrophilic silicic acids of pyrogenic nature or produced by precipitation of 5 to 300 m3 / g, preferably silicas dried by dew, belong to them. Finely divided zilites, for example type A or bentonite, are also applicable.

These flow materials can be suspended in the sprayed solution or preferably with the air stream introduced dosed into the installation, where the solution is sprayed and granulated if necessary. The amount of flow substance runs between 0.1 h % by weight, preferably 0.1 to 5% by weight, based on granulated solids. To these flow materials belong the silicate compounds in a natural or, preferably, substances, which are found in the field of foodstuffs, especially fatty acids or their salts, preferably alkaline earth or alkaline salts. The fatty acids include, in particular, stearic acid and palmitic acid or mixtures of fatty acids or their aforementioned salts containing from 16 to 18 carbon atoms. While the non-granulated sodium methioninate, due to its hygroscopic behavior, easily becomes lumpy and loses its ability to flow or run, it is unexpectedly found that this does not happen with the granulates according to the invention, they still remain in poor climatic conditions. to flow and easy to handle. EXAMPLES Example 1: 1000 g of a solution is used, which was obtained by the solution of 200 g of methionine in an equimolar amount of NaOH with the addition of 80 g of Na 2 CO 3 in 666 g of water. This solution is distilled to remove with stirring 600 g of water and the precipitate obtained is separated in a centrifuge of cernid at temperatures higher than 100 ° C. The filtrate contains 71% sodium methioninate and only 1.1% Na2CO3, NaHCO3 calculated as Na2CO3. Example 2 lOOOg of a crude hydrolysis mixture, which was obtained by the saponification of an aqueous solution of 5- (beta-methylmercapto-ethyl) hydantoin with an aqueous Na mole equivalent solution produced as a mixture of NaOH, Na2CO3 to Na2CO3. up to 180 ° with removal of C02 and NH3 from the reaction mixture, containing for example 233 g of Na mitioninate and 84 g of a mixture of Na2CO3 and NaHCO3, calculated as Na2CO3. From this crude hydrolysis mixture, 550 g of water are distilled off, the precipitate formed is separated off at a boiling temperature of 127 ° C or by means of a hot pressure filter. The filtrate contained 60% methioninate -Na and 5.4% of a mixture of Na 2 CO 3, NaHCO 3 calculated as NaCO 3. Example 3 Example 1 was repeated with the difference that the evaporation was carried out in two stages. In the first stage, 350 g of water was distilled off, the suspension was stirred for a certain time in that state, then 200 more of water were distilled. The precipitate was brought back to the boiling temperature of 127 ° by separating on a hot pressure filter. The filtrate contained 62% sodium methioninate only 3.2% Na 2 CO 3 / NaHCO 3; calculated as Na2C03. Example 5 1000 g of a solution are used, as obtained according to Example 3, as filtrate, at a temperature of 8 to 130 ° C in a vortex bed the granulate is dispersed and dried. The drops of the solution are distributed as a thin cap on the extended granulate and dried with 6 Nm3 of N2, where the nitrogen in the used facility was cooled from 95 ° to 58 ° C and the gas dew point rose from 8 ° to 35 ° C. The remaining moisture of the granulate was 6.4%. Example 6 Example 4 was repeated, with the difference that the drying gas before entering the fluidized bed was dehumidified to a dew point of for example -2 ° C. With 15 Nm3 of N2 the granulate had a remaining moisture of only 2.4%.

Claims (15)

1. - Process for the preparation of sodium methioninate solutions with a low content of sodium carbonate from crude hydrolyzed mixtures precipitated by the saponification of 5- (beta-methylmercapto-ethyl) -hydantoin with 1. to 6 equivalents of sodium hydroxide and / or sodium carbonate characterized in that water is distilled from the hydrolyzed mixture, preferably after adding more sodium hydroxide, until the content of sodium methioninate is 60 to 90% by weight and at a temperature of 90 to 140 ° C. Free sodium water is separated as monohydrate and / or bicarbonate.

2. Process according to claim 1, characterized in that the remaining methioninate separated containing sodium carbonate (free of water, monohydrate and / bicarbonate) without cooling, is recycled and returned to the d saponification stage.

3. Method according to claim 1, characterized in that the solution after the separation of sodium monohydrate, free of methionine is put together in an amount that is molar equivalent to the remaining sodium carbonate, the solution is heated to 80 200 ° C if necessary under pressure, and the produced C02 is removed.

4. Method according to claim 3, characterized in that steam for water or an inert gas is used for the removal of C02.

5. - Method according to claim 3 characterized in that, for the removal of CO2, the solution is stirred.

6. - Method according to one or more of the preceding claims, characterized in that the free or poor solution of sodium carbonate is then transformed into a granulate capable of flowing.

7. Process according to claim 6 characterized in that a fluidized lech granulation is used.

8. - Method according to claim, characterized in that the free or poor solution of sodium carbonate is concentrated at temperatures of 100 to 160 ° C and pressures d 10 to 1000 mbar until there is a remaining water content d 0.5 a 3% by weight, and then subjected to fluidized lech granulation.

9. Process according to claim 6, characterized in that the free or poor solution of sodium carbonate is subjected to a granulation of structural fluidized bed.

10. Process according to claim 9, characterized in that a solution with a content greater than 65% by weight up to 95% by weight of sodium methioninate is used.

11. - Procedure according to claims 9 and 10, characterized in that, the process of granulation of realiz entreres stages; a) the production of the granulate b) the drying c) the cooling of the granulate.

12. - Method according to claims 9 to 11, characterized in that the mass ratio of the solution: air (surrounding air or jacket) is between 7: 1 10: 1.

13. Process according to claim 9, characterized in that, sodium methioninate with a content of 0.5 to 10% by weight of remaining moisture, at a temperature of 1 to 160 ° C is pressed through a hole duck co fine perforations and this plate, if necessary, is subjected to axial oscillations, dripping procedure, or sprayed to disperse it and the granulate obtained if necessary, is then dried.

14. Process according to claim 8, characterized in that a solution with a content of 80 to 99, preferably 93 to 99.5% by weight of sodium methionate is extruded and the resulting extrudate is then dried.

15. - Sodium methioninate granulate with a large flow capacity or characterized by the following: a) a density to the agitation greater than 650 kg / m3 b) a grain size distribution of 63 to 5000 microns c) a less dust content from 1% . d) a content of less than 6% by weight sodium carbonate sodium bicarbonate.