METHOD FOR PREPARING AMINO ACID MIXED SOLID AND APPARATUS FOR PREPARING AMINO ACID MIXED SOLID

Abstract

The present disclosure relates to a method for preparing an amino acid mixed solid, including a first step of preparing an amino acid mixed solution containing an amino acid; a second step of stirring the amino acid mixed solution to form a thin film, and drying and pulverizing the formed thin film to prepare wet granules; and a third step of drying the wet granules to prepare an amino acid mixed solid in a granular formulation, wherein, the second step is conducted for drying the amino acid mixed solution so that a solid concentration in the wet granules is within a granulation concentration range.

Claims

1. A method for preparing an amino acid mixed solid, the method comprising: a first step of preparing an amino acid mixed solution containing an amino acid; a second step of stirring the amino acid mixed solution to form a thin film, and drying and pulverizing the formed thin film to prepare wet granules; and a third step of drying the wet granules to prepare an amino acid mixed solid in a granular formulation, wherein, the second step is conducted for drying the amino acid mixed solution so that a solid concentration in the wet granules is within a granulation concentration range.

2. The method for preparing an amino acid mixed solid of claim 1, further comprising a step of preparing granules using a mixed-type granulator after the second step has been performed and before the third step is performed, wherein at least a portion of the wet granules prepared in the second step is used as a seed for preparing the granules in the mixed-type granulator.

3. The method for preparing an amino acid mixed solid of claim 1, wherein the second step is conducted for controlling the granulation concentration range depending on the kind of amino acids.

4. The method for preparing an amino acid mixed solid of claim 1, wherein the amino acid includes at least one selected from the group consisting of L-threonine, L-tryptophan, L-valine, L-isoleucine, and L-leucine.

5. The method for preparing an amino acid mixed solid of claim 1, wherein the first step includes preparing the amino acid mixed solution by a fermentation method using at least one selected from a microorganism of the genus Brevibacterium, Corynebacterium, Escherichia, Serratia, Erwinia, Enterobacteria, Streptomyces, or Pseudomonas or an artificial mutant thereof.

6. The method for preparing an amino acid mixed solid of claim 1, wherein a linear speed to stir the amino acid mixed solution in the second step is 4 m/s to 17 m/s.

7. The method for preparing an amino acid mixed solid of claim 1, wherein the second step is performed at 0.05 atm to 0.6 atm.

8. The method for preparing an amino acid mixed solid of claim 1, wherein the third step includes a drying process using a fluidized-bed granulator/dryer.

9. The method for preparing an amino acid mixed solid of claim 1, further comprising a process of concentrating the amino acid mixed solution after the first step has been performed and before the second step is performed.

10. An apparatus for preparing an amino acid mixed solid, the apparatus comprising: a fermenter for producing an amino acid mixed solution through a fermentation process; a thin film drying apparatus for drying and pulverizing the amino acid mixed solution supplied from the fermenter to prepare wet granules; and a granule drying apparatus for drying the wet granules to prepare an amino acid mixed solid in a granular formulation, wherein the thin film drying apparatus includes: a stirring unit of the thin film drying apparatus for stirring the amino acid mixed solution to form a thin film provided from the amino acid mixed solution on a thin film drying apparatus inner wall; and a heating unit for heating the thin film drying apparatus inner wall to dry the thin film.

11. The apparatus for preparing an amino acid mixed solid of claim 10, wherein the stirring unit of thin film drying apparatus and the thin film drying apparatus inner wall are isolated by a distance of 5 mm to 15 mm.

12. The apparatus for preparing an amino acid mixed solid of claim 10, wherein the amino acid mixed solution is dried in the thin film drying apparatus so that a solid concentration in the wet granules is within a granulation concentration range, and the granulation concentration range is controlled depending on the kind of amino acids.

13. The apparatus for preparing an amino acid mixed solid of claim 10, further comprising a mixed-type granulator for preparing granules using at least a portion of the wet granules prepared in the thin film drying apparatus as a seed.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0060] FIG. 1 is a flow chart illustrating a method for preparing an amino acid mixed solid according to the present disclosure;

[0061] FIG. 2 is a flow chart illustrating a method for preparing an amino acid mixed solid according to the present disclosure;

[0062] FIG. 3 is a simplified cross-sectional view of a thin film drying apparatus according to the present disclosure; and

[0063] FIGS. 4 and 5 are block diagrams illustrating simplified method and apparatus for preparing an amino acid mixed solid according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0064] Hereinafter, the present disclosure will be described in more detail with reference to Examples. However, the following Examples are only preferred embodiments for illustrating the present disclosure and, therefore, are not intended to limit the scope of the present disclosure thereto. Meanwhile, technical matters not described in the present specification can be sufficiently understood and easily implemented by those skilled in the art of the present disclosure or similar technical fields.

EXAMPLE 1A. PREPARATION OF AMINO ACID MIXED SOLID CONTAINING L-TRYPTOPHAN

[0065] In order to prepare an amino acid mixed solid containing L-tryptophan by the method according to the present disclosure, an L-tryptophan fermentation broth was first recovered from the fermenter.

[0066] The recovered L-tryptophan fermentation broth had a composition of an L-tryptophan concentration of 57 g/L, purity of 67%, and solid content of 8.4%. The recovered L-tryptophan fermentation broth was introduced into a concentration pipe for pilot use (forced circulation type, manufacturer MAHN MIN Machinery Co., Ltd., Korea) and concentrated. The fermentation broth used for concentration was 750 L in total, and concentrated 5 times in accordance with the capacity of the concentration pipe, 150 L/1 time. Concentration was performed under concentration conditions of a pressure of 0.1 atm and a steam pressure of 3 atm until the solid concentration reached 25.5%. Concentration was performed only until the solid concentration reached 25.5% since gelation might occur and fluidity might be lost when the solid concentration was 25.5% or more. The concentration of the recovered concentrate was 178.9 g/L, the purity was 67%, the solid concentration was 25.5%, and the volume was 239 L. Into a thin film drying apparatus, 19.1 L of the recovered concentrate was supplied.

[0067] Wet granules were prepared by performing drying and formulation processes using a thin film drying apparatus (double jacket, horizontal type, manufacturer JANGWOO MACHINERY CO., LTD., Korea). In Example 1A, the operating conditions of the thin film drying apparatus were set to an internal pressure of 0.2 atm, a steam pressure of 3 atm, a knife linear speed of 8 m/s, and a distance of 5 mm between the blades of the stirring unit of the thin film drying apparatus and the inner wall.

[0068] From the thin film drying apparatus, 5.48 kg of wet granules were recovered, and the recovered wet granules had a purity of 67%, solid content of 92%, and an average particle size of about 400 to 700 μm. The wet granules were placed in a fluidized-bed granulator/dryer (manufacturer GR Engineering) and dried. The recovery rate of the amino acid mixed solid recovered from the fluidized-bed granulator/dryer was 97.7%, the recovered amino acid mixed solid weighed 5.04 kg, the purity was 67%, and the solid content was 99%.

Experimental Example 1-1. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Solid Content in Wet Granules Recovered From Thin Film Drying Apparatus

[0069] In order to compare the results of preparation of amino acid mixed solid depending on the solid content in wet granules recovered from the thin film drying apparatus, amino acid mixed solids were prepared while varying the degree of moisture drying.

[0070] In Examples and Comparative Examples used in Experimental Example 1-1, 19.1 L of the same material as the concentrated L-tryptophan fermentation broth used in Example 1A was supplied into a thin film drying apparatus, respectively. The operating conditions of the thin film drying apparatus were maintained the same as in Example 1A, and the introduction speed was adjusted. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0071] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 1 below.

TABLE-US-00001 TABLE 1 Comparative Comparative Division Example 1A Example 1B Example 1C Example 1D Example 1A Example 1B Wet Formation O O O O X X granules of granules Solid 92% 88% 85% 80% 75% 96% content Size 400~700 μm 400~700 μm 500~800 μm 500~800 μm — 200~300 μm Weight 5.48 kg 5.74 kg 5.92 kg 6.30 kg — 5.18 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 5.04 kg 5.05 kg 5.02 kg 5.03 kg 4.88 kg acid Yield 97.7% 98.0% 97.4% 97.5% 94.6% mixed solid

[0072] As a result of the experiment, it was confirmed that granules were not formed when the solid content in wet granules recovered from the thin film drying apparatus was less than 80%, for example, 75% or less. As the solid content in wet granules increased, the formation of granules became more difficult, and an additional formulation process was required. It was confirmed that granules were not formed when the solid content in wet granules was more than 92%, for example, 96% or more.

Experimental Example 1-2. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Stirring Linear Speed of Thin Film Drying Apparatus

[0073] In Examples and Comparative Examples used in Experimental Example 1-2, 19.1 L of the same material as the concentrated L-tryptophan fermentation broth used in Example 1A was supplied into a thin film drying apparatus (JANGWOO MACHINERY CO., LTD., horizontal type TFD), respectively. The stirring speed (linear speed) in the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the stirring speed were maintained the same as in Example 1A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0074] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 2 below.

TABLE-US-00002 TABLE 2 Comparative Comparative Division Example 1A Example 1E Example 1F Example 1G Example 1C Example 1D Linear speed 8 m/s 5 m/s 11 m/s 14 m/s 18 m/s 3 m/s Wet Formation O O O O X X granules of granules Solid 92% 89% 94% 95% 96% — content Size 400~700 μm 400~700 μm 300~600 μm 300~500 μm 200~300 μm — Weight 5.48 kg 5.67 kg 5.33 kg 5.25 kg 5.14 kg — Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 5.04 kg 5.05 kg 4.92 kg 4.89 kg 4.78 kg — acid Yield 97.7% 97.9% 95.5% 94.9% 92.7% — mixed solid

[0075] As a result of the experiment, it was confirmed that as the stirring speed (linear speed) in the thin film drying apparatus increased, the amount of heat that the solids in the amino acid mixed solution can receive increased and the drying rate increased. However, when the linear speed exceeded 17 m/s, the amino acid mixed solution was overdried, the average particle size of wet granules decreased, and there was thus a problem in that the recovery rate decreased due to a significant loss of fine powder to the thin film drying apparatus and the bag filter of the fluidized-bed granulator/dryer. In contrast, at a linear speed of less than 4 m/s, the thin film formation rate decreased inside the thin film drying apparatus, and the load on the stirring unit of the thin film drying apparatus increased during drying and thus stirring was not performed.

Experimental Example 1-3. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Distance Between Stirring Unit of Thin Film Drying Apparatus and Inner Wall in Thin Film Drying Apparatus

[0076] In Examples and Comparative Examples used in Experimental Example 1-3, 19.1 L of the same material as the concentrated L-tryptophan fermentation broth used in Example 1A was supplied into a thin film drying apparatus, respectively. The distance between the blades of the stirring unit of the thin film drying apparatus and the inner wall in the thin film drying apparatus was adjusted, and other operating conditions of the thin film drying apparatus were maintained the same as in Example 1A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0077] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 3 below.

TABLE-US-00003 TABLE 3 Com- parative Example Example Example Division 1A 1H 1E Distance between inner 5 mm 15 mm 25 mm wall and thin film drying apparatus stirring unit blade Wet Formation of O O X granules granules Solid content   92%   87% — Size 400~700 μm 500~900 μm — Weight 5.48 kg 5.81 kg — Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 5.04 kg 5.04 kg — acid Yield 97.7% 97.8% mixed solid

[0078] As a result of the experiment, it was confirmed that as the distance between the blades of the stirring unit of the thin film drying apparatus and the inner wall in the thin film drying apparatus became wider, the amount of the material to be dried increased, which slowed the heat transmission, and thus the drying rate decreased. As can be seen from Comparative Example 1E, when the distance exceeded about 15 mm, the load on the motor of the stirring unit of the thin film drying apparatus was increased by the dried product, thus making the operation impossible.

Experimental Example 1-4. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Pressure Condition in Thin Film Drying Apparatus

[0079] In Examples and Comparative Examples used in Experimental Example 1-4, 19.1 L of the same material as the concentrated L-tryptophan fermentation broth used in Example 1A was supplied into a thin film drying apparatus, respectively. The internal pressure of the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the internal pressure were maintained the same as in Example 1A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0080] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 4 below.

TABLE-US-00004 TABLE 4 Comparative Comparative Division Example 1A Example 11 Example 1F Example 1G Facility Pressure 0.1 atm 0.4 atm 0.6 atm 0.05 atm conditions Steam 47° C. 77° C. 87° C. 34° C. temperature Wet Formation of O O O O granules granules Solid   92%   89%   90%   94% content Size 400~700 μm 400~700 μm 400~700 μm 300~500 μm Weight 5.48 kg 5.68 kg 5.63 kg 5.02 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 5.04 kg 5.05 kg 5.06 kg 4.72 kg acid Yield 97.7% 98.0% 98.2% 91.6% mixed solid

[0081] As a result of the experiment, it was confirmed that more dust was transported to the bag filter and the process yield decreased as the pressure in the thin film drying apparatus became lower but moisture drying was performed at a relatively high temperature and browning due to the high temperature occurred when the pressure in the thin film drying apparatus was high. Specifically, in a case where the pressure in the thin film drying apparatus exceeded about 0.05 atm (Comparative Example 1F), browning was confirmed in the amino acid mixed solid produced. In a case where the pressure in the thin film drying apparatus was less than about 0.6 atm (Comparative Example 1G), it was confirmed that dust was transported to the bag filter of the thin film drying apparatus and thus the process yield decreased to about 91.6%.

Experimental Example 1-5. Preparation of Granules Using Thin Film Drying Apparatus and Mixed-Type Granulator

[0082] Granules were formed using the L-tryptophan concentrate recovered in Example 1A by a thin film drying apparatus and a mixed-type granulator.

[0083] In Example 1J, 18.5 L of 19.1 L of the L-tryptophan concentrate recovered in Example 1A was placed in a thin film drying apparatus (JANGWOO MACHINERY conditions of the thin film drying apparatus were the same as in Example 1A, but the introduction speed of the concentrate was lowered, and the discharged dried product weighed 5.03 kg, and had a purity of 67%, a solid content of 96%, and an average particle size of 200 μm to 300 μm. The discharged dried product was introduced into a mixed-type granulator (Lodige, Mix-Granulator) as a seed, and 0.6 L of the remained L-tryptophan concentrate was introduced into a mixed-type granulator using a metering feed pump (EYELA, RP-2100). Wet granules prepared in the mixed-type granulator weighed 5.68 kg, and had a purity of 67% and a solid content of 88%. The wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 4.98 kg, the recovery rate was 96.6%, the purity was 67% and the solid content was 99%.

[0084] Next, in Comparative Example 1H, 1.6 L of the L-tryptophan concentrate recovered in Example 1A and 9.5 kg of seeds (purity 65%, solid content 99%, average particle size 200 μm to 300 μm) were not introduced into a thin film drying apparatus but were directly introduced into a mixed-type granulator (Lodige, Mix-Granulator) to prepare wet granules. The L-tryptophan concentrate was introduced into the mixed-type granulator using a metering feed pump (EYELA, RP-2100). The wet granules weighed 11.15 kg, and had a purity of 65.1% and a solid content of 88%. The prepared wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 9.79 kg, the recovery rate was 98.8%, the purity was 65.1% and the solid content was 99%.

[0085] Through Example 1J, it was confirmed that a concentrate having a high water content could be prepared into fine granules using a thin film drying apparatus and the fine granules could be used as a seed in a mixed-type granulator.

EXAMPLE 2A. PREPARATION OF AMINO ACID MIXED SOLID CONTAINING L-VALINE

[0086] In order to prepare an amino acid mixed solid containing L-valine by the method according to the present disclosure, the L-valine fermentation broth was first recovered from the fermenter.

[0087] The recovered L-valine fermentation broth had a composition of L-valine concentration of 80 g/L, purity of 80%, and solid content of 9.8%. The recovered L-valine fermentation broth was introduced into a concentration pipe for pilot use (forced circulation type, manufacturer MAHN MIN Machinery Co., Ltd., Korea) and concentrated. The fermentation broth used for concentration was 900 L in total, and concentrated 6 times in accordance with the capacity of the concentration pipe, 150 L/1 time. Concentration was performed under concentration conditions of a pressure of 0.1 atm and a steam pressure of 3 atm until the solid concentration reached 28%. Concentration was performed only until the solid concentration reached 28% since gelation might occur and fluidity might be lost when the solid concentration was 28% or more. The concentration of the recovered concentrate was 237.3 g/L, the purity was 80%, the solid concentration was 28%, and the volume was 303.4 L. Into a thin film drying apparatus, 20.2 L of the recovered concentrate was supplied.

[0088] Drying and formulation processes were performed using a thin film drying apparatus (double jacket, horizontal type, manufacturer JANGWOO MACHINERY CO., LTD., Korea) to prepare wet granules. The operating conditions of the thin film drying apparatus were set to be the same as in Example 1A.

[0089] From the thin film drying apparatus, 6.58 kg of wet granules were recovered, and the recovered wet granules had a purity of 80%, solid content of 90%, and an average particle size of about 400 to 700 μm. The wet granules were placed in a fluidized-bed granulator/dryer (manufacturer GR Engineering) and dried. The recovery rate of the amino acid mixed solid recovered from the fluidized-bed granulator/dryer was 97.7%, the amino acid mixed solid recovered weighed 5.92 kg, the purity was 80%, and the solid content was 99%.

Experimental Example 2-1. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Solid Content in Wet Granules Recovered From Thin Film Drying Apparatus

[0090] In order to compare results of preparation of the amino acid mixed solid depending on the solid content in wet granules recovered from the thin film drying apparatus, amino acid mixed solids were prepared while varying the degree of moisture drying.

[0091] In Examples and Comparative Examples used in Experimental Example 2-1, 20.2 L of the same material as the concentrated L-valine fermentation broth used in Example 2A was supplied into a thin film drying apparatus, respectively. The operating conditions of the thin film drying apparatus were maintained the same as in Example 2A, and the introduction speed was adjusted. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0092] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 5 below.

TABLE-US-00005 TABLE 5 Comparative Comparative Division Example 2A Example 2B Example 2C Example 2A Example 2B Wet Formation O O O X X granules of granules Solid 90% 85% 80% 75% 95% content Size 400~700 μm 400~700 μm 500~800 μm — 200~300 μm Weight 6.58 kg 6.98 kg 7.44 kg — 6.18 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino acid Weight 5.92 kg 5.93 kg 5.96 kg — 5.82 kg mixed solid Yield 97.7% 97.9% 98.3% — 96.0%

[0093] As a result of the experiment, it was confirmed that granules are not formed when the solid content in wet granules recovered from the thin film drying apparatus was less than 80% (Comparative Example 2A). As the solid content in wet granules increased, the formation of granules became more difficult, and an additional formulation process was required. When the solid content in the wet granules was more than 94% (Comparative Example 2B), granules were not formed.

Experimental Example 2-2. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Stirring Linear Speed of Thin Film Drying Apparatus

[0094] In Examples and Comparative Examples used in Experimental Example 2-2, 20.2 L of the same material as the concentrated L-valine fermentation broth used in Example 2A was supplied into a thin film drying apparatus (JANGWOO MACHINERY CO., LTD., horizontal type TFD), respectively. The stirring speed (linear speed) in the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the stirring speed were maintained the same as in Example 2A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0095] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 6 below.

TABLE-US-00006 TABLE 6 Comparative Comparative Division Example 2A Example 2D Example 2E Example 2F Example 2C Example 2D Linear speed 8 m/s 5 m/s 11 m/s 14 m/s 18 m/s 3 m/s Wet Formation O O O O X X granules of granules Solid 90% 87% 92% 94% 96% content Size 400~700 μm 400~700 μm 300~600 μm 300~500 μm 200~300 μm Weight 6.58 kg 6.82 kg 6.43 kg 6.27 kg 6.09 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 5.93 kg 5.91 kg 5.85 kg 5.78 kg 5.93 kg acid Yield 97.9% 97.5% 96.5% 95.4% 97.9% mixed solid

[0096] As a result of the experiment, it was confirmed that as the stirring speed (linear speed) in the thin film drying apparatus increased, the amount of heat that the solids in the amino acid mixed solution can receive increased and the drying rate increased. However, when the linear speed exceeded 17 m/s, the amino acid mixed solution was overdried, the average particle size of wet granules decreased, and there was thus a problem in that the recovery rate decreased due to a significant loss of fine powder to the thin film drying apparatus and the bag filter of the fluidized-bed granulator/dryer. In contrast, at a linear speed of less than 4 m/s, the thin film formation rate decreased inside the thin film drying apparatus, and the load on the stirring unit of the thin film drying apparatus increased during drying and thus stirring was not performed.

Experimental Example 2-3. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Pressure Condition in Thin Film Drying Apparatus

[0097] In Examples and Comparative Examples used in Experimental Example 2-3, 20.2 L of the same material as the concentrated L-valine fermentation broth used in Example 2A was supplied into a thin film drying apparatus, respectively. The internal pressure of the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the internal pressure were maintained the same as in Example 2A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0098] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 7 below.

TABLE-US-00007 TABLE 7 Comparative Comparative Division Example 2A Example 2G Example 2E Example 2F Facility Pressure 0.1 atm 0.4 atm 0.6 atm 0.05 atm conditions Steam 47° C. 77° C. 87° C. 34° C. temperature Wet Formation of O O O O granules granules Solid   90%   88%   86%   97% content Size 400~700 μm 400~700 μm 400~700 μm 200~300 μm Weight 6.58 kg 6.75 kg 6.93 kg 5.75 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 5.92 kg 5.95 kg 5.96 kg kg 5.48 kg acid Yield 97.7% 98.2% 98.4% 90.5% mixed solid

[0099] As a result of the experiment, it was confirmed that more dust was transported to the bag filter and the process yield decreased as the pressure in the thin film drying apparatus became lower but moisture drying was performed at a relatively high temperature and browning due to the high temperature occurred when the pressure in the thin film drying apparatus was high. Specifically, in a case where the pressure in the thin film drying apparatus exceeded about 0.05 atm (Comparative Example 2E), browning was confirmed in the amino acid mixed solid produced. In a case where the pressure in the thin film drying apparatus is less than about 0.6 atm (Comparative Example 2F), it was confirmed that dust passes to the bag filter of the thin film drying apparatus and thus the process yield decreased to about 90.5%.

Experimental Example 2-4. Preparation of Granules Using Thin Film Drying Apparatus and Mixed-Type Granulator

[0100] Granules were formed using the L-valine concentrate recovered in Example 2A by a thin film drying apparatus and a mixed-type granulator.

[0101] In Example 2H, 19.4 L of 20.2 L of the L-valine concentrate recovered in Example 2A was placed in a thin film drying apparatus (JANGWOO MACHINERY CO., LTD., Horizontal type TFD), and drying was performed. The operating conditions of the thin film drying apparatus were the same as in Example 2A, but the introduction speed of the concentrate was lowered, and the discharged dried product weighed 5.93 kg, and had a purity of 80%, a solid content of 95%, and an average particle size of 200 μm to 300 μm. The discharged dried product was introduced into a mixed-type granulator (Lodige, Mix-Granulator) as a seed, and 0.9 L of the remained L-valine concentrate was introduced into a mixed-type granulator using a metering feed pump (EYELA, RP-2100). Wet granules prepared in the mixed-type granulator weighed 6.85 kg, and had a purity of 80% and a solid content of 86%. The wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 5.86 kg, the recovery rate was 96.7%, the purity was 80% and the solid content was 99%.

[0102] Next, in Comparative Example 2G, 1.7 L of the L-valine concentrate recovered in Example 2A and 8.0 kg of seeds (purity 78%, solid content 99%, average particle size 200 μm to 300 μm) were not introduced into a thin film drying apparatus but were directly introduced into a mixed-type granulator (Lodige, Mix-Granulator) to prepare wet granules. The L-valine concentrate was introduced into the mixed-type granulator using a metering feed pump (EYELA, RP-2100). The wet granules weighed 9.75 kg, and had a purity of 78.1% and a solid content of 86%. The prepared wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 8.34 kg, the recovery rate was 98.4%, the purity was 78.1% and the solid content was 99%.

[0103] Through Example 2H, it was confirmed that a concentrate having a high water content can be prepared into fine granules using a thin film drying apparatus and the fine granules can be used as a seed in a mixed-type granulator.

EXAMPLE 3A. PREPARATION OF AMINO ACID MIXED SOLID CONTAINING L-THREONINE

[0104] In order to prepare an amino acid mixed solid containing L-threonine by the method according to the present disclosure, an L-threonine fermentation broth was first recovered from the fermenter.

[0105] The recovered L-threonine fermentation broth had a composition of L-threonine concentration of 155 g/L, purity of 85%, and solid content of 17.7%. The recovered L-threonine fermentation broth was introduced into a concentration pipe for pilot use (forced circulation type, manufacturer MAHN MIN Machinery Co., Ltd., Korea) and concentrated. The fermentation broth used for concentration was 900 L in total, and concentrated 6 times in accordance with the capacity of the concentration pipe, 150 L/1 time. Concentration was performed under concentration conditions of a pressure of 0.1 atm and a steam pressure of 3 atm until the solid concentration reached 60%. Concentration was performed only until the solid concentration reached 60% since gelation might occur and fluidity might be lost when the solid concentration was 60% or more. The concentration of the recovered concentrate was 237.3 g/L, the purity was 85%, the solid concentration was 60%, and the volume was 246.5 L. Into a thin film drying apparatus, 16.4 L of the recovered concentrate was supplied.

[0106] Drying and formulation processes were performed using a thin film drying apparatus (double jacket, horizontal type, manufacturer JANGWOO MACHINERY CO., LTD., Korea) to prepare wet granules. The operating conditions of the thin film drying apparatus were set to be the same as in Example 1A.

[0107] From the thin film drying apparatus, 11.78 kg of wet granules were recovered, and the recovered wet granules had a purity of 85%, solid content of 92%, and an average particle size of about 300 to 600 μm. The wet granules were placed in a fluidized-bed granulator/dryer (manufacturer GR Engineering) and dried. The recovery rate of the amino acid mixed solid recovered from the fluidized-bed granulator/dryer was 97.9%, the recovered amino acid mixed solid weighed 10.82 kg, the purity was 85%, and the solid content was 99%.

Experimental Example 3-1. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Solid Content in Wet Granules Recovered From Thin Film Drying Apparatus

[0108] In order to compare results of preparation of the amino acid mixed solid depending on the solid content in wet granules recovered from the thin film drying apparatus, amino acid mixed solids were prepared while varying the degree of moisture drying.

[0109] In Examples and Comparative Examples used in Experimental Example 3-1, 16.4 L of the same material as the concentrated L-threonine fermentation broth used in Example 3A was supplied into a thin film drying apparatus, respectively. The operating conditions of the thin film drying apparatus were maintained the same as in Example 3A, and the introduction speed was adjusted. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0110] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 8 below.

TABLE-US-00008 TABLE 8 Comparative Comparative Division Example 3A Example 3B Example 3C Example 3A Example 3B Wet Formation O O O X X granules of granules Solid 92% 89% 85% 80% 97% content Size 300~600 μm 300~700 μm 400~700 μm — 200~300 μm Weight 11.76 kg 12.13 kg 12.76 kg — 10.88 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino acid Weight 10.82 kg 10.81 kg 10.84 kg — 10.49 kg mixed solid Yield 97.9% 97.8% 98.1% 95.0%

[0111] As a result of the experiment, it was confirmed that granules were not formed when the solid content in wet granules recovered from the thin film drying apparatus was less than 85% (Comparative Example 3A). As the solid content in wet granules increased, the formation of granules became more difficult, and an additional formulation process was required. When the solid content in the wet granules was more than 96% (Comparative Example 3B), granules were not formed.

Experimental Example 3-2. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Stirring Linear Speed of Thin Film Drying Apparatus

[0112] In Examples and Comparative Examples used in Experimental Example 3-2, 16.4 L of the same material as the concentrated L-threonine fermentation broth used in Example 3A was supplied into a thin film drying apparatus (JANGWOO MACHINERY CO., LTD., horizontal type TFD), respectively. The stirring speed (linear speed) in the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the stirring speed were maintained the same as in Example 3A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0113] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 9 below.

TABLE-US-00009 TABLE 9 Comparative Comparative Division Example 3A Example 3D Example 3E Example 3F Example 3C Example 3D Linear speed 8 m/s 5 m/s 11 m/s 14 m/s 18 m/s 3 m/s Wet Formation O O O O X X granules of granules Solid 92% 90% 94% 96% 97% — content Size 300~600 μm 400~700 μm 300~600 μm 300~400 μm 200~300 μm — Weight 11.76 kg 12.04 kg 11.42 kg 11.10 kg 11.06 kg — Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 10.82 kg 10.81 kg 10.67 kg 10.59 kg 10.55 kg — acid Yield 97.9% 97.8% 96.5% 95.8% 95.4% — mixed solid

[0114] As a result of the experiment, it was confirmed that as the stirring speed (linear speed) in the thin film drying apparatus increased, the amount of heat that the solids in the amino acid mixed solution can receive increased and the drying rate increased. However, when the linear speed exceeded 17 m/s, the amino acid mixed solution was overdried, the average particle size of wet granules decreased, and there was thus a problem in that the recovery rate decreased due to a significant loss of fine powder to the thin film drying apparatus and the bag filter of the fluidized-bed granulator/dryer. In contrast, at a linear speed of less than 4 m/s, the thin film formation rate decreased inside the thin film drying apparatus, and the load on the stirring unit of the thin film drying apparatus increased during drying and thus stirring was not performed.

Experimental Example 3-3. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Pressure Condition in Thin Film Drying Apparatus

[0115] In Examples and Comparative Examples used in Experimental Example 3-3, 16.4 L of the same material as the concentrated L-threonine fermentation broth used in Example 3A was supplied into a thin film drying apparatus, respectively. The internal pressure of the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the internal pressure were maintained the same as in Example 3A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0116] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 10 below.

TABLE-US-00010 TABLE 10 Comparative Comparative Division Example 3A Example 3G Example 3E Example 3F Facility Pressure 0.1 atm 0.4 atm 0.6 atm 0.05 atm conditions Steam 47° C. 77° C. 87° C. 34° C. temperature Wet Formation of O O O O granules granules Solid   92%   90%   89%   97% content Size 300~600 μm 400~700 μm 400~700 μm 200~300 μm Weight 11.76 kg 12.05 kg 12.16 kg 10.37 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 10.82 kg 10.86 kg 10.82 kg 9.94 kg acid Yield 97.9% 98.2% 97.9% 90.0% mixed solid

[0117] As a result of the experiment, it was confirmed that more dust passes to the bag filter and the process yield decreased as the pressure in the thin film drying apparatus became lower but moisture drying was performed at a relatively high temperature and browning due to the high temperature occurred when the pressure in the thin film drying apparatus was high. Specifically, in a case where the pressure in the thin film drying apparatus exceeded about 0.05 atm (Comparative Example 3E), browning was confirmed in the amino acid mixed solid produced. In a case where the pressure in the thin film drying apparatus is less than about 0.6 atm (Comparative Example 3F), it was confirmed that dust was transported to the bag filter of the thin film drying apparatus and thus the process yield decreased to about 90.0%.

Experimental Example 3-4. Preparation of Granules Using Thin Film Drying Apparatus and Mixed-Type Granulator

[0118] Granules were formed using the L-threonine concentrate recovered in Example 3A by a thin film drying apparatus and a mixed-type granulator.

[0119] In Example 3H, 15.8 L of 16.4 L of the L-threonine concentrate recovered in Example 3A was placed in a thin film drying apparatus (JANGWOO MACHINERY CO., LTD., Horizontal type TFD), and drying was performed. The operating conditions of the thin film drying apparatus were the same as in Example 3A, but the introduction speed of the concentrate was lowered, and the discharged dried product weighed 10.51 kg, and had a purity of 85%, a solid content of 96%, and an average particle size of 200 μm to 300 μm. The discharged dried product was introduced into a mixed-type granulator (Lodige, Mix-Granulator) as a seed, and 0.9 L of the remained L-threonine concentrate was introduced into a mixed-type granulator using a metering feed pump (EYELA, RP-2100). Wet granules prepared in the mixed-type granulator weighed 11.46 kg, and had a purity of 85% and a solid content of 93%. The wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 10.64 kg, the recovery rate was 96.3%, the purity was 85% and the solid content was 99%.

[0120] Next, in Comparative Example 3G, 1.4 L of the L-threonine concentrate recovered in Example 3A and 8.4 kg of seeds (purity 82.5%, solid content 99%, average particle size 200 μm to 300 μm) were not introduced into a thin film drying apparatus but were directly introduced into a mixed-type granulator (Lodige, Mix-Granulator) to prepare wet granules. The wet granules weighed 9.88 kg, and had a purity of 82.7% and a solid content of 93%. The L-threonine concentrate was introduced into the mixed-type granulator using a metering feed pump (EYELA, RP-2100). The prepared wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 9.15 kg, the recovery rate was 98.6%, the purity was 82.7% and the solid content was 99%.

[0121] Through Example 3H, it was confirmed that a concentrate having a high water content can be prepared into fine granules using a thin film drying apparatus and the fine granules can be used as a seed in a mixed-type granulator.

EXAMPLE 4A. PREPARATION OF AMINO ACID MIXED SOLID CONTAINING L-ISOLEUCINE

[0122] In order to prepare an amino acid mixed solid containing L-isoleucine by the method according to the present disclosure, an L-isoleucine fermentation broth was first recovered from the fermenter.

[0123] The recovered L-isoleucine fermentation broth had a composition of L-isoleucine concentration of 36 g/L, purity of 58%, and solid content of 6.1%. The recovered L-isoleucine fermentation broth was introduced into a concentration pipe for pilot use (forced circulation type, manufacturer MAHN MIN Machinery Co., Ltd., Korea) and concentrated. The fermentation broth used for concentration was 900 L in total, and concentrated 6 times in accordance with the capacity of the concentration pipe, 150 L/1 time. Concentration was performed under concentration conditions of a pressure of 0.1 atm and a steam pressure of 3 atm until the solid concentration reached 31%. Concentration was performed only until the solid concentration reached 31% since gelation might occur and fluidity might be lost when the solid concentration was 31% or more. The concentration of the recovered concentrate was 180.2 g/L, the purity was 58%, the solid concentration was 31%, and the volume was 162.2 L. Into a thin film drying apparatus, 10.8 L of the recovered concentrate was supplied.

[0124] Drying and formulation processes were performed using a thin film drying apparatus (double jacket, horizontal type, manufacturer JANGWOO MACHINERY CO., LTD., Korea) to prepare wet granules. The operating conditions of the thin film drying apparatus were set to be the same as in Example 1A.

[0125] From the thin film drying apparatus, 4.19 kg of wet granules were recovered, and the recovered wet granules had a purity of 58%, solid content of 88%, and an average particle size of about 400 to 600 μm. The wet granules were placed in a fluidized-bed granulator/dryer (manufacturer GR Engineering) and dried. The recovery rate of the amino acid mixed solid recovered from the fluidized-bed granulator/dryer was 98.3%, the recovered amino acid mixed solid weighed 3.70 kg, the purity was 58%, and the solid content was 99%.

Experimental Example 4-1. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Solid Content in Wet Granules Recovered From Thin Film Drying Apparatus

[0126] In order to compare results of preparation of the amino acid mixed solid depending on the solid content in wet granules recovered from the thin film drying apparatus, amino acid mixed solids were prepared while varying the degree of moisture drying.

[0127] In Examples and Comparative Examples used in Experimental Example 4-1, 10.3 L of the same material as the concentrated L-isoleucine fermentation broth used in Example 34A was supplied into a thin film drying apparatus, respectively. The operating conditions of the thin film drying apparatus were maintained the same as in Example 4A, and the introduction speed was adjusted. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0128] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 11 below.

TABLE-US-00011 TABLE 11 Comparative Comparative Division Example 4A Example 4B Example 4C Example 4A Example 4B Wet Formation O O O X X granules of granules Solid 88% 85% 82% 79% 96% content Size 400~600 μm 400~700 μm 400~700 μm 200~300 μm Weight 4.19 kg 4.33 kg 4.50 kg 3.76 kg Amino acid Weight 3.70 kg 3.68 kg 3.69 kg 3.57 kg mixed solid Yield 98.3% 97.8% 98.1% 95.0%

[0129] As a result of the experiment, it was confirmed that granules were not formed when the solid content in wet granules recovered from the thin film drying apparatus was less than 82% (Comparative Example 4A). As the solid content in wet granules increased, the formation of granules became more difficult, and an additional formulation process was required. When the solid content in the wet granules was more than 94% (Comparative Example 4B), granules were not formed.

Experimental Example 4-2. Comparison Results of Preparation of of Amino Acid Mixed Solid Depending on Stirring Linear Speed of Thin Film Drying Apparatus

[0130] In Examples and Comparative Examples used in Experimental Example 4-2, 10.3 L of the same material as the concentrated L-isoleucine fermentation broth used in Example 4A was supplied into a thin film drying apparatus (JANGWOO MACHINERY CO., LTD., horizontal type TFD), respectively. The stirring speed (linear speed) in the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the stirring speed were maintained the same as in Example 4A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0131] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 12 below.

TABLE-US-00012 TABLE 12 Comparative Comparative Division Example 4A Example 4D Example 4E Example 4F Example 4C Example 4D Linear speed 8 m/s 5 m/s 11 m/s 14 m/s 18 m/s 3 m/s Wet Formation O O O O X X granules of granules Solid 88% 86% 91% 94% 96% — content Size 400~600 μm 400~700 μm 300~500 μm 300~400 μm 200~300 μm — Weight 4.19 kg 4.28 kg 4.02 kg 3.87 kg 3.75 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 3.70 kg 3.68 kg 3.65 kg 3.61 kg 3.57 kg — acid Yield 98.3% 97.9% 97.1% 96.0% 94.8% — mixed solid

[0132] As a result of the experiment, it was confirmed that as the stirring speed (linear speed) in the thin film drying apparatus increased, the amount of heat that the solids in the amino acid mixed solution can receive increased and the drying rate increased. However, when the linear speed exceeded 17 m/s, the amino acid mixed solution was overdried, the average particle size of wet granules decreased, and there was thus a problem in that the recovery rate decreased due to a significant loss of fine powder to the thin film drying apparatus and the bag filter of the fluidized-bed granulator/dryer. In contrast, at a linear speed of less than 4 m/s, the thin film formation rate decreased inside the thin film drying apparatus, and the load on the thin film drying apparatus stirring unit increased during drying and thus stirring was not performed.

Experimental Example 4-3. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Pressure Condition in Thin Film Drying Apparatus

[0133] In Examples and Comparative Examples used in Experimental Example 4-3, 10.3 L of the same material as the concentrated L-isoleucine fermentation broth used in Example 4A was supplied into a thin film drying apparatus, respectively. The internal pressure of the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the internal pressure were maintained the same as in Example 4A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0134] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 13 below.

TABLE-US-00013 TABLE 13 Comparative Comparative Division Example 4A Example 4G Example 4E Example 4F Facility Pressure 0.1 atm 0.4 atm 0.6 atm 0.05 atm condition Steam 47° C. 77° C. 87° C. 34° C. temperature Wet Formation of O O O O granules granules Solid   88%   89%   87%   95.5% content Size 400~600 μm 400~600 μm 400~600 μm 200~300 μm Weight 4.19 kg 4.14 kg 4.23 kg 3.62 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 3.70 kg 3.67 kg 3.69 kg 3.43 kg acid Yield 98.3% 97.6% 98.0% 91.1% mixed solid

[0135] As a result of the experiment, it was confirmed that more dust was transported to the bag filter and the process yield decreased as the pressure in the thin film drying apparatus became lower but moisture drying was performed at a relatively high temperature and browning due to the high temperature occurred when the pressure in the thin film drying apparatus was high. Specifically, in a case where the pressure in the thin film drying apparatus exceeded about 0.05 atm (Comparative Example 4E), browning was confirmed in the amino acid mixed solid produced. In a case where the pressure in the thin film drying apparatus is less than about 0.6 atm (Comparative Example 4F), it was confirmed that dust was transported to the bag filter of the thin film drying apparatus and thus the process yield decreased to about 91.1%.

Experimental Example 4-4. Preparation of Granules Using Thin Film Drying Apparatus and Mixed-Type Granulator

[0136] Granules were formed using the L-isoleucine concentrate recovered in Example 4A by a thin film drying apparatus and a mixed-type granulator.

[0137] In Example 4H, 10.3 L of 10.8 L of the L-isoleucine concentrate recovered in Example 4A was placed in a thin film drying apparatus (JANGWOO MACHINERY conditions of the thin film drying apparatus were the same as in Example 4A, but the introduction speed of the concentrate was lowered, and the discharged dried product weighed 3.64 kg, and had a purity of 58%, a solid content of 95.2%, and an average particle size of 200 μm to 300 μm. The discharged dried product was introduced into a mixed-type granulator (Lodige, Mix-Granulator) as a seed, and 0.5 L of the remained L-isoleucine concentrate was introduced into a mixed-type granulator using a metering feed pump (EYELA, RP-2100). Wet granules prepared in the mixed-type granulator weighed 4.17 kg, and had a purity of 58% and a solid content of 87%. The wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 3.63 kg, the recovery rate was 96.4%, the purity was 58% and the solid content was 99%.

[0138] Next, in Comparative Example 4G, 1.8 L of the L-isoleucine concentrate recovered in Example 4A and 13.1 kg of seeds (purity 56.5%, solid content 99%, average particle size 200 μm to 300 μm) were not introduced into a thin film drying apparatus but were directly introduced into a mixed-type granulator (Lodige, Mix-Granulator) to prepare wet granules. The wet granules weighed 15.13 kg, and had a purity of 56.6% and a solid content of 90%. The L-isoleucine concentrate was introduced into the mixed-type granulator using a metering feed pump (EYELA, RP-2100). The prepared wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 13.59 kg, the recovery rate was 98.8%, the purity was 56.6% and the solid content was 99%.

[0139] Through Example 4H, it was confirmed that a concentrate having a high water content can be prepared into fine granules using a thin film drying apparatus and the fine granules can be used as a seed in a mixed-type granulator.

EXAMPLE 5A. PREPARATION OF AMINO ACID MIXED SOLID CONTAINING L-LEUCINE

[0140] In order to prepare an amino acid mixed solid containing L-leucine by the method according to the present disclosure, an L-leucine fermentation broth was first recovered from the fermenter.

[0141] The recovered L-leucine fermentation broth had a composition of L-leucine concentration of 24 g/L, purity of 46%, and solid content of 5.6%. The recovered L-leucine fermentation broth was introduced into a concentration pipe for pilot use (forced circulation type, manufacturer MAHN MIN Machinery Co., Ltd., Korea) and concentrated. The fermentation broth used for concentration was 900 L in total, and concentrated 6 times in accordance with the capacity of the concentration pipe, 150 L/1 time. Concentration was performed under concentration conditions of a pressure of 0.1 atm and a steam pressure of 3 atm until the solid concentration reached 35%. Concentration was performed only until the solid concentration reached 35% since gelation might occur and fluidity might be lost when the solid concentration was 42% or more. The concentration of the recovered concentrate was 151.0 g/L, the purity was 44%, the solid concentration was 35%, and the volume was 142.2 L. Into a thin film drying apparatus, 10.5 L of the recovered concentrate was supplied.

[0142] Drying and formulation processes were performed using a thin film drying apparatus (double jacket, horizontal type, manufacturer JANGWOO MACHINERY CO., LTD., Korea) to prepare wet granules. The operating conditions of the thin film drying apparatus were set to be the same as in Example 1A.

[0143] From the thin film drying apparatus, 4.12 kg of wet granules were recovered, and the recovered wet granules had a purity of 43%, solid content of 87%, and an average particle size of about 400 to 600 μm. The wet granules were placed in a fluidized-bed granulator/dryer (manufacturer GR Engineering) and dried. The recovery rate of the amino acid mixed solid recovered from the fluidized-bed granulator/dryer was 97.2%, the recovered amino acid mixed solid weighed 3.60 kg, the purity was 43%, and the solid content was 99%.

Experimental Example 5-1. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Solid Content in Wet Granules Recovered From Thin Film Drying Apparatus

[0144] In order to compare results of preparation of the amino acid mixed solid depending on the solid content in wet granules recovered from the thin film drying apparatus, amino acid mixed solids were prepared while varying the degree of moisture drying.

[0145] In Examples and Comparative Examples used in Experimental Example 5-1, 10.0 L of the same material as the concentrated L-leucine fermentation broth used in Example 5A was supplied into a thin film drying apparatus, respectively. The operating conditions of the thin film drying apparatus were maintained the same as in Example 5A, and the introduction speed was adjusted. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0146] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 14 below.

TABLE-US-00014 TABLE 14 Comparative Comparative Division Example 5A Example 5B Example 5C Example 5A Example 5B Wet Formation O O O X X granules of granules Solid 87% 86% 82% 75% 95% content Size 400~600 μm 400~700 μm 400~700 μm 200~300 μm Weight 4.12 kg 4.19 kg 4.50 kg 3.69 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino acid Weight 3.60 kg 3.63 kg 3.69 kg 3.51 kg mixed solid Yield 97.2% 96.4% 98.1% 96.4%

[0147] As a result of the experiment, it was confirmed that granules were not formed when the solid content in wet granules recovered from the thin film drying apparatus was less than 82% (Comparative Example 5A). As the solid content in wet granules increased, the formation of granules became more difficult, and an additional formulation process was required. When the solid content in the wet granules was more than 93% (Comparative Example 2B), granules were not formed.

Experimental Example 5-2. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Stirring Linear Speed of Thin Film Drying Apparatus

[0148] In Examples and Comparative Examples used in Experimental Example 5-2, 10.0 L of the same material as the concentrated L-leucine fermentation broth used in Example 5A was supplied into a thin film drying apparatus (JANGWOO MACHINERY CO., LTD., horizontal type TFD), respectively. The stirring speed (linear speed) in the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the stirring speed were maintained the same as in Example 5A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0149] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 15 below.

TABLE-US-00015 TABLE 15 Comparative Comparative Division Example 5A Example 5D Example 5E Example 5F Example 5C Example 5D Linear speed 8 m/s 5 m/s 11 m/s 14 m/s 18 m/s 3 m/s Wet Formation O O O O X X granules of granules Solid 87% 83% 88% 93% 96% content Size 400~600 μm 400~700 μm 300~500 μm 300~400 μm 200~300 μm Weight 4.12 kg 4.25 kg 4.02 kg 3.87 kg 3.70 kg Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 3.60 kg 3.49 kg 3.45 kg 3.41 kg 3.50 kg — acid Yield 97.2% 97.9% 97.1% 96.0% 94.0% — mixed solid

[0150] As a result of the experiment, it was confirmed that as the stirring speed (linear speed) in the thin film drying apparatus increased, the amount of heat that the solids in the amino acid mixed solution can receive increased and the drying rate increased. However, when the linear speed exceeded 17 m/s, the amino acid mixed solution was overdried, the average particle size of wet granules decreased, and there was thus a problem in that the recovery rate decreased due to a significant loss of fine powder to the thin film drying apparatus and the bag filter of the fluidized-bed granulator/dryer. In contrast, at a linear speed of less than 4 m/s, the thin film formation rate decreased inside the thin film drying apparatus, and the load on the thin film drying apparatus stirring unit increased during drying and thus stirring was not performed.

Experimental Example 5-3. Comparison of Results of Preparation of Amino Acid Mixed Solid Depending on Pressure Condition in Thin Film Drying Apparatus

[0151] In Examples and Comparative Examples used in Experimental Example 5-3, 10.0 L of the same material as the concentrated L-leucine fermentation broth used in Example 5A was supplied into a thin film drying apparatus, respectively. The internal pressure of the thin film drying apparatus was adjusted, and the operating conditions of the thin film drying apparatus except for the internal pressure were maintained the same as in Example 5A. Next, the recovered wet granules were placed in a fluidized-bed granulator/dryer and dried according to Examples and Comparative Examples.

[0152] Experimental results for each condition of Examples and Comparative Examples are as shown in Table 16 below.

TABLE-US-00016 TABLE 16 Comparative Comparative Division Example 5A Example 5G Example 5E Example 5F Facility Pressure 0.1 atm 8 m/s 8 m/s 8 m/s conditions Steam 47° C. 0.4 atm 0.6 atm 0.05 atm temperature Wet Formation of O 77° C. 87° C. 34° C. granules granules Solid   87% O O O content Size 400~600 μm   88%   87%   94% Weight 4.12 kg 400~600 μm 400~600 μm 200~300 μm Wet granules are placed in a laboratory fluidized-bed granulator/dryer and dried (discharged moisture 1%) Amino Weight 3.60 kg 3.46 kg 3.53 kg 3.28 kg acid Yield 97.2% 97.2% 98.0% 93.1% mixed solid

[0153] As a result of the experiment, it was confirmed that more dust passes to the bag filter and the process yield decreased as the pressure in the thin film drying apparatus became lower but moisture drying was performed at a relatively high temperature and browning due to the high temperature occurred when the pressure in the thin film drying apparatus was high. Specifically, in a case where the pressure in the thin film drying apparatus exceeded about 0.05 atm (Comparative Example 5E), browning was confirmed in the amino acid mixed solid produced. In a case where the pressure in the thin film drying apparatus was less than about 0.6 atm (Comparative Example 5F), it was confirmed that dust was transported to the bag filter of the thin film drying apparatus and thus the process yield decreased to about 93.1%.

Experimental Example 5-4. Preparation of Granules Using Thin Film Drying Apparatus and Mixed-Type Granulator

[0154] Granules were formed using the L-leucine concentrate recovered in Example 5A by a thin film drying apparatus and a mixed-type granulator.

[0155] In Example 5H, 10.0 L of 10.5 L of the L-leucine concentrate recovered in Example 5A was placed in a thin film drying apparatus (JANGWOO MACHINERY CO., LTD., Horizontal type TFD), and drying was performed. The operating conditions of the thin film drying apparatus were the same as in Example 5A, but the introduction speed of the concentrate was lowered, and the discharged dried product weighed 3.69 kg, and had a purity of 44%, a solid content of 94.5%, and an average particle size of 200 μm to 300 μm. The discharged dried product was introduced into a mixed-type granulator (Lodige, Mix-Granulator) as a seed, and 0.5 L of the remained L-leucine concentrate was introduced into a mixed-type granulator using a metering feed pump (EYELA, RP-2100). Wet granules prepared in the mixed-type granulator weighed 4.19 kg, and had a purity of 44% and a solid content of 86%. The wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 3.63 kg, the recovery rate was 96.4%, the purity was 43% and the solid content was 99%.

[0156] Next, in Comparative Example 5G, 2.0 L of the L-leucine concentrate recovered in Example 5A and 15.3 kg of seeds (purity 43%, solid content 99%, average particle size 200 μm to 300 μm) were not introduced into a thin film drying apparatus but were directly introduced into a mixed-type granulator (Lodige, Mix-Granulator) to prepare wet granules. The L-leucine concentrate was introduced into the mixed-type granulator using a metering feed pump (EYELA, RP-2100). The wet granules weighed 18.10 kg, and had a purity of 43% and a solid content of 88%. The prepared wet granules were placed in a laboratory fluidized-bed granulator/dryer and dried. The recovered wet granules weighed 16.05 kg, the recovery rate was 98.8%, the purity was 43% and the solid content was 99%.

[0157] Through Example 5H, it was confirmed that a concentrate having a high water content can be prepared into fine granules using a thin film drying apparatus and the fine granules can be used as a seed in a mixed-type granulator.

[0158] Based on the above description, it will be understood by those skilled in the art that the present disclosure may be implemented in a different specific form without changing the technical spirit or essential characteristics thereof. Therefore, it should be understood that the above embodiment is not limitative, but illustrative in all aspects. The scope of the disclosure is defined by the appended claims rather than by the description preceding them, and therefore all changes and modifications that fall within metes and bounds of the claims or equivalents of such metes and bounds are intended to be embraced by the claims.