JP3165966B2 - Crystallization method of anhydrous fructose - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention relates to the production of crystalline fructose. More specifically, the present invention provides a method for producing crystalline fructose on a large scale, with high production rates and high yields, using a crystallizer having optimal heat and mass transfer properties.

[0002]

The present invention relates to an improved method for crystallizing anhydrous fructose crystals from an aqueous solution. An economical method for producing crystalline fructose on a large scale and in high yield is disclosed herein. Crystalline fructose is generally obtained by seeding a supersaturated fructose solution to induce crystal growth. However, due to the solubility and stability of fructose and the high viscosity of the fructose solution, it is often uncertain to maintain optimal conditions to ensure economical production of pure crystalline material.

[0003] Fructose is well soluble in water, and aqueous solutions are extremely viscous. High fructose heat of crystallization,
Large amounts of heat due to the heat of mixing and additional cooling of the crystal mass must be removed during fructose crystallization. Furthermore, since fructose has a very narrow metastable region, the temperature difference between the solution and the cooling surface must be very small, which makes crystallization very difficult.

[0004] To overcome this difficulty, some conventional methods involve using an organic solvent and crystallizing fructose from an aqueous solution. For example, Finnish Patent Application No. 862025 describes a continuous fructose crystallization process using an organic solvent. However,
The viscosity of the fructose solution leads to a reduction in the production rate, so that even when the crystal mass is pumped from a vertical crystallizer, the yield is only about 40% and the production rate is about 0.17 t /
m ³ / d. The production rate (t / m ³ / d) is defined as the production rate (metric ton) of crystals per total volume (cubic meter) of the crystallizer.

[0005] Crystallization from organic or aqueous solvent mixtures is also described in Stanley EP 015617. However, the use of organic solvents creates problems for large-scale crystallization. These are unsuitable because they have a fire and the solvent is toxic and small amounts of residue remaining in the crystalline material will render the crystalline material unsuitable for use in foods Including the fact that

Various methods have been developed that do not use organic solvents in the fructose crystallization operation, but these methods are often economically disadvantageous due to the high viscosity and instability of the supersaturated fructose solution. UK Patent Application No. 2172288A teaches a process for continuous crystallization of fructose from an aqueous solution. The syrup is quickly mixed with the seed crystals and placed on a surface until a cake is formed, and then ground into free flowing granules. Although this method solves the problem of continuous handling of viscous solutions, the particulate amorphous contains all the impurities that were in the supplied syrup. In addition, other grinding and drying steps significantly increase operating costs. Similar costs are incurred using the method described in U.S. Pat. No. 4,199,373, where the syrup is seeded with crystalline fructose and left in a mold or container, after which the crystalline material is recovered. , Dried and ground.

Various patents describe methods that allow fructose to selectively crystallize from aqueous solutions. Japanese Application No. 118200 describes two towers, one for granulation and one for crystallization. The feed from the first column containing 33-50% fructose syrup is mixed with the massecuite (crystal-containing) overflow from the second column. The resulting mixture is cooled as it moves downward in a laminar flow. The crystalline fructose is then obtained by centrifugation. Although this method does not require the additional drying and grinding steps of other crystallization methods, it requires low vertical laminar flow and heat transfer, resulting in low production rates and limited scale-up capacity. You.

[0008] One useful procedure for the crystallization of fructose from aqueous solutions is described in US Patent 3,926,062. The patent describes a method in which a supersaturated solution is seeded and then allowed to evaporate and / or cool under normal stirring while maintaining a specified range of concentrations and temperatures. By continuously concentrating the mother liquor, this method can be used to produce fructose crystals in multiple stages. Although suggestions have been made that only cooling can be used, it is not considered to be as advantageous as the operation using continuous evaporation, since the mother liquor must be concentrated again at the start of each batch. Although such operations are useful for the production of small batches of crystalline fructose, they cannot be used in industrial scale production due to heat transfer constraints and lack of proper mixing and supersaturation control.

According to US Pat. No. 3,883,365, large fructose crystals are obtained from an aqueous solution in a two-stage batch process, which comprises adjusting the pH of the solution and slowly cooling the crystal mass to seed the crystals. In this case, a supersaturated solution that is optimal for crystal formation is generated. Due to the long crystallization time of the operation, a pH adjustment must be made and the production rate of the process is only about 0.25 t /
m ³ / d.

[0010]

Although all of the above processes have been successfully used in the production of crystalline fructose, high levels of aqueous solutions can be obtained without resorting to expensive operating steps including evaporation, drying and milling. It was previously thought that it was not possible to produce crystalline fructose on a large scale with yield, high productivity (production rate) and good purity. It is an object of the present invention to provide a cost effective method for producing fructose crystals on a large scale and with high productivity in high yield.

Another object of the present invention is to provide a method for crystallization of fructose which does not use an organic solvent and does not require pH adjustment.

It is another object of the present invention to provide a crystallizer with optimal heat transfer and mixing capabilities for large scale production of high purity fructose crystals.

Other objects will become apparent from the following description of the present invention.

[0014]

Few crystals of anhydrous fructose by crystalline fructose either added to the fructose solution, or to seed the naturally formed in the solution to provide summary nucleation sites SUMMARY OF THE INVENTION The invention Is disclosed herein. In a multi-stage crystallization operation, all but the first stage are seeded with the crystal mass from the previous crystallization and the crystasl foot which is the mother liquor (under white). The resulting mixture is mixed with slow cooling to carefully maintain the temperature and saturation for anhydrous crystallization.

In the production of fructose crystals, low supersaturation and small temperature differences should be maintained. In a preferred embodiment, the temperature difference between the solution and the means used to cool the solution is less than about 6 ° C and fructose, which is supersaturated, but less than 1.25 supersaturated, preferably 1. It has a supersaturation between 1 and 1.2. Such conditions may be heat transfer equipment or at least 5
It can be adjusted very easily in a crystallizer provided with a heat transfer surface of at least m ² / m ³ . If such a crystallizer is used, the crystallizer is not tilted by more than 45 degrees and is arranged for effective mixing and optimally at a distance of less than 300 mm, and At least 5 degrees along the cooling plate.

In this embodiment, the mixing blade is located between the cooling surfaces and within 30 mm of the cooling surface. Preferably, the speed of the mixing blade is at least about 50 mm / sec during the crystallization operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG . 1 is a front view showing a part of a fructose crystallization apparatus according to the present invention, FIG. 2 is a side view showing a part of a crystallization apparatus, and FIG. FIG. 4 is a partially enlarged front view of the crystallizer shown in FIG. 2, and FIG. 4 is a partially cutaway front view of another embodiment of the fructose crystallization apparatus according to the present invention.

[0018] DETAILED DESCRIPTION A. of invention Operation Generally, improved fructose crystallization from aqueous solutions by allowing effective heat transfer within small temperature differences and by using a horizontal cylindrical crystallizer to perform good mixing of the crystal mass Has now been found by the present invention. Although not intended to be a limitation on the present invention, to provide a mechanical equilibrium between crystalline anhydrous fructose and dissolved fructose such that the growth of the crystal structure is slow enough to avoid incorporation of water molecules. It is contemplated that the parameters described herein will be employed.

The crystallization is carried out by adding an appropriate amount of seeds to the saturated or supersaturated fructose solution or by allowing the solution to form spontaneously, and then whitening according to the gradient determined during the crystallization. This is done by cooling. An appropriate amount of crystal foot is seeded from the second stage to the final crystallization stage in a multi-stage crystallization operation. The appropriate amount of seed crystals to add (M _s ) depends on their size (d _s ), their length (m), the amount of final crystals (M), and the desired crystal size (D) as follows: Depends on: M _S (ton) = (d _S / D) ³ × M (ton)

[0020] The fructose mass is mixed simultaneously, allowing for optimal heat transfer and maximum crystal growth rate within the mass. The crystallization operation is a batch operation but can also be carried out semi-continuously by interconnecting several similar crystallizers. The two-stage method is advantageous when large crystal size products are desired. Cooling program is dependent on the quality of syrup which is supplied, but the production rate by the improved method is typically a 0.5-0.8t / m ³ / d, and the cooling time is typically Is 15-30 hours.

A crystallization yield of 65% of the dry material can be reached at the end of the crystallization. The collection and drying of the crystals are performed by a conventional method. If the yield is very high, the bubbles may be mixed with the crystal mass at no more than 20% before separating the crystals from the mother liquor and reducing the viscosity. This facilitates centrifugation. The product size is typically 0.4-0.6 mm and the purity is higher than 99.5%.

B. By using the crystallizer crystallizer, supersaturated state and optimal cooling, mixing and crystalline mass transfer can be achieved in a large-scale manner. For large-scale production of fructose, the size of the crystallizer is optimally about 30 m ³ .

The figure shows a crystallizer that is horizontal or typically at a tilt angle of 5 degrees, but less than 45 degrees, to ensure effective axial mixing and discharge of the system. The heat transfer surface in the crystallizer should be at least 5 m ² / m ³ , preferably 10 m ² / m ³ or more, so that the temperature difference between the fructose mass and the cooling plate is such that the cooling rate is 4 ° C./m Even in the case of time, it is about 6.0 ° C. or less.

According to the embodiment shown in FIGS. 1 to 3 in which a multi-stage crystallization region is present, cooling water flows into the cooling jacket 3 through the water inlet 8 and the space within the crystallizer is less than 300 mm. When the cooling plate 2 is circulated, effective heat transfer is obtained. The cooling water passes through the cooling plate and discharges through a water outlet 9 located at the end of the crystallizer opposite the water inlet.

A motor 6 mounted on a support 7 has a shaft 4 provided with a sealing member 5 at an entry point into the crystallization apparatus.
Drive. An intense mixing blade 1 extends from a shaft in the crystallizer. The mixing blade is arranged between the cooling plates 2 such that the distance between the blade and the plate is less than 30 mm to ensure proper mixing of the mother liquor near the crystal surface. The rotational speed of the mixer is such that the speed at the end of the mixing blade is typically 130 m at any point in the crystallization.
m / sec, but should not be less than 50 mm / sec. At high supersaturation, small mixing efficiencies were found to be insufficient to maintain high crystal growth rates, and too much mixing was found to spontaneously result in crystal formation.

The fructose syrup (mother liquor) to be crystallized enters the crystallizer through the inlet 10. Horizontal flow in the crystallizer is provided by a small open area in the cooling plate at least 5 degrees along the crystallizer. The white under solution containing the solution is removed from the crystallizer through outlet 11 where it is centrifuged and the crystalline material is collected.

FIG. 4 shows another embodiment of the present invention, but the crystallization apparatus may have only two crystallization regions. Such a crystallizer uses the same general components as the crystallizer shown in FIGS. 1 to 3, but the effective heat transfer is through the cooling water jacket 3 'and in the center of the device. Through a single cooling plate 2 'extending upward. Similarly, only two mixing blades 1 'are required for mixing the crystallization mixture. The motor (not shown), the sealing member 5 'and the shaft 4' are the same parts as those in FIG.

C. During the entire crystallization operation, the temperature difference between the fructose mass and the cooling member is kept below about 6.0 ° C., and the supersaturation is below 1.25, preferably between 1.1 and 1.2. Held between. A sufficient heat transfer zone and mixing efficiency keep the temperature difference between the fructose mass and the cooling plate sufficiently small, despite the very short crystallization time. The supersaturation that determines the cooling rate is calculated during crystallization as follows: Y = 10000 × (Ct−Cml) /） Ct × (1
00-Cml)｝ Qml = 100 × (QF-Y) / (100-Y) Cml = F (Qml, Tm) S = Cml × (100-Cml ′) / {Cml ′ ×
(100−Cml)｝ Y = crystal yield,% of dry matter Ct = total dry matter concentration,% w / w Cml = measured mother liquor concentration,% w / w Qml = mother liquor purity,% w of dry matter / W Cml ′ = saturated concentration of mother liquor,% w / w F = experimentally determined solubility function Tm = temperature of crystal mass, ° C. S = supersaturation

The mother liquor concentration and temperature are measured, for example, by a refractometer on the line and a suitable thermometer. The total dry matter concentration of the crystal mass and the purity of the supplied liquid are obtained by laboratory analysis. The solubility of fructose in water is a function of purity and temperature and is obtained experimentally.

The aqueous feed solution contains glucose as a major impurity and contains more than 90% by weight fructose, based on the total weight of dry solids. In order to obtain a corresponding yield when the final temperature of the cooling is about 25 ° C., the dry solids concentration of the mass must be above 90% by weight. No pH adjustment of the feed syrup is required due to the short crystallization time, but the optimum pH range of the feed syrup is 4.5-5.
5, which minimizes fructose degradation.

Careful supersaturation adjustment combined with effective heat transfer and effective mixing results in maximum crystal growth rates without spontaneous crystal formation throughout the entire crystallization operation. The yields of 0.5-0.8 t / m ³ / d achieved in the main crystallization by this improved method are substantially higher than the yields obtained using the most advantageous methods presented hitherto.

In a preferred embodiment, the fructose solution is evaporated to a concentration of at least about 90% (w / w) dry solids and is led to the crystallizer after adjusting to the seeding temperature. During this crystallization step, seeding is done and the cooling program is determined as described above. Following this stage, a portion of the mass is removed leaving a crystalline "foot" that acts as a seed in the next major crystallization. further,
The concentrated feed is added and the cooling program is repeated once more as set above. After the main crystallization, the crystals are separated from the other mother liquors by centrifugation and then dried.

[0033] In another embodiment, the crystal foot is used in another crystallizer filled with additional syrup.

[0034]

EXAMPLES Example 1-5 Crystallization Parameters Both preliminary and main crystallization experiments were performed on a 6 liter pilot crystallizer shown in FIG. 2 equipped with a cooling water jacket and an effective mixer. . The crystallizer was connected to a programmable thermostat Mgw Lauda RKP 20. The crystallizer length was 18 cm and the diameter was 21 cm. The crystallizer had a heat transfer area of 42 m ² / m ³ and was slightly inclined.

The crystallizer consisted of two crystallization zones, 8 cm in width, and two mixing blades were placed between the two zones. The distance between the mixing blade and the cooling plate was about 1.5 cm. During the test, the rotation speed of the mixer was 11 rpm and the speed at the end of the mixing blade was 130 mm / sec.

The supplied syrup is obtained from a factory plant, which consists of 95.5% fructose, 1.0% dextrose, 2.2% oligosaccharides and the balance which is mainly salts as analyzed by HPLC. This syrup with low crystallization properties was chosen to show the effectiveness of the present invention. The pH of the supplied syrup was 4.1, and it was adjusted to about 5.0 in all examples except Example 4.

As a seed crystal, a commercially available fructose crystal was subjected to a frisch crusher 14.702 type (Fritsh pulverissette type 1).
4.702). PMT-PA
As analyzed by the MAS particle measurement and analysis system, the average grain size of the seed was about 0.03 mm and 90% of the crystals were between 0.02-0.08 mm. The crystallization parameters of the examples are summarized in Table 1 and the results are listed in Table 2. Table 1 Crystallization parameters Example 1 Example 2 Example 3 Spare Main Spare Main Spare Main ──────────────────────────── a 91.0 92.6 90.9 92.0 91.3 93.3 b 8.1 8.2 8.1 7.9 8.2 8.6 c 0.014 17.7 0.038 14.2 0.038 9.7 d 56.5 57.0 56.0 57.0 57.0 57.0 e 35.5 28.0 36.0 28.0 40.0 28.0 f 24 21 26 24 24 15 g 5.0 5.1 5.0 Table 1 (continued) Example 4 Example 5 Spare Main Spare Main ─────────────────── a 91.3 91.8 91.0 92.2 b 8.1 8.4 8.2 8.8 c 0.038 10.8 0.038 10.3 d 56.0 56.5 56.0 57.0 e 37.0 24.5 37.0 25.0 f 24 20 24 30 g 4.1 4.9 a: concentration of crystal mass,% w / w b: amount of crystal mass, kg c: amount of seed crystal or crystal foot,% w / w of dry substance d: crystal Initial temperature of crystallization, ° C e: Final temperature of crystallization, ° C f: Crystallization time, hg: pH of supplied syrup

In Example 1, the fructose solution was first adjusted to pH 5.0 with a 5% w / w NaHCO ₃ solution. The supplied syrup was evaporated to 91.0% w / w and 8.1 kg of it was transferred to a crystallizer at a temperature of 56.5 ° C. Once the crystallizer was filled, the syrup was seeded with 0.014% seed and the pre-crystallization cooling program was started. The concentration of the mother liquor was measured with a laboratory refractometer and the mass was cooled to 35.5 ° C. so that the calculated supersaturation was 1.25 or less. The crystallization time is 24
In time, and the yield was 44.3% at the end of the crystallization.

When pre-crystallization is complete, a portion of the crystal mass is withdrawn and the remainder is left in the crystallizer so that the crystal foot, which determines the crystal size of the product, is 17.7 early in the main crystallization. %was. The crystallizer was charged with an evaporative feed syrup that was mixed with the crystal foot, resulting in a gradual rise in temperature to 57 ° C. and an increase in dry matter concentration to 92.6%. When the crystallizer is full, start the cooling program. The mass was cooled to 28 ° C. so that supersaturation was kept below 1.25. Main crystallization time is 21
It was time.

After the main crystallization, the crystals are separated from the mother liquor,
Then, it was washed with a laboratory centrifuge HettichRoto Silenta 2. Centrifuge basket diameter is 21cm
And the amount of wash water was 1.5-2.5% based on the weight of the crystal mass. The crystals were dried in a laboratory fluid dryer.

At the end of the crystallization, the yield of crystals was 56.
6% and the purity of the crystals was 99% of dry matter. The average particle size of the product was 0.49 mm and the standard deviation from the average particle size was 47% as determined by sieving analysis.

In the other examples, the same operation as in Example 1 was performed. Variables measured during the experiment as described in 6 to no Table 2. The time from the beginning of cooling in the main crystallization, the temperature of the cooling water, the concentration of the mother liquor and the degree of supersaturation are described. In each case, the concentration was measured with a laboratory refractometer. The temperature difference between the cooling water and the crystal mass was less than 1.0 ° C. Example 1 Table 2 Variables in test operation 1 ──────────────────────────── Time Pre-crystallization time Main crystallization Temperature Concentration s Temperature Concentration sh ° C w / w%-h ° C w / w%-──────────────────────────── 0.0 56.5 91.0 1.16 0.0 57.0 91.2 1.15 12.9 52.2 90.5 1.23 0.5 57.0 91.1 1.15 14.1 51.1 90.2 1.23 11.3 50.5 88.5 1.03 15.6 49.7 89.6 1.20 12.5 50.0 88.3 1.02 16.6 48.8 89.4 1.20 14.3 46.9 88.1 1.08 17.5 48.0 89.2 1.20 15.9 44.3 87.7 1.11 18.5 47.0 88.7 1.16 23.0 28.0 84.5 20.3 42.9 88.3 1.23 24.9 35.5 84.9 1.05 ──────────────────────────── Example 2 Table 3 Variables in test operation 2 ──── ──────────────────────── time Pre-crystallization time Main crystallization temperature concentration s temperature concentration sh ° C w / w%-h ° C w / w % − ─── ───────────────────────── 0.0 56.0 90.9 1.17 0.0 57.0 90.8 1.11 0.5 56.0 90.9 1.17 0.5 57.0 90.4 1.06 4.1 54.0 90.9 1.24 1.6 56.2 90.3 1.07 10.7 54.1 90.2 1.14 2.5 55.5 90.0 1.05 22.0 42.9 87.7 1.16 (42.7 28.0 83.2 1.02) 23.5 39.8 87.0 1.15 24.5 37.8 86.4 1.14 26.0 36.0 85.6 1.10 26.8 36.0 85.2 1.07 ───────────────── ─────────── Example 3 Table 4 Variables in test operation 3 ──────────────────────────── Time Pre-crystallization time Main crystallization temperature concentration s temperature concentration sh ° C w / w%-h ° C w / w%-─────────────────────── ───── 0.0 57.0 91.3 1.21 11.2 41.0 87.2 1.12 3.6 56.5 91.1 1.18 12.5 37.0 86.0 1.09 18.0 49.3 88.9 1.12 13.0 35.4 85.7 1.09 19.2 48.0 88.9 1.15 14.6 30.7 84.8 1.10 20.1 46.9 88.5 1.14 15.5 28.2 84.5 1.13 21.4 44.7 87.6 1.10 22.7 42.3 86.9 1.08 24.1 39.9 86.5 1.10 ──────────────────────────── Example 4 Table 5 Variables in test operation 4 ────── ────────────────────── time Pre-crystallization time Main crystallization temperature concentration s temperature concentration sh ℃ w / w% − h ℃ w / w% − ──────────────────────────── 0.0 56.0 91.3 1.23 14.6 39.6 86.8 1.13 0.5 56.3 91.0 1.17 15.5 37.7 86.2 1.12 3.2 55.8 90.0 1.19 16.5 35.5 85.7 1.12 20.5 45.1 87.4 1.07 17.5 32.8 85.2 1.12 21.9 42.4 86.9 1.01 18.5 29.9 85.1 1.18 23.2 39.7 86.6 1.11 19.5 27.0 84.5 1.17 24.5 37.2 85.7 1.09 20.0 24.5 83.8 1.16 ──────────────── { Example 5 Table 6 Variables in Test Operation 5} Time Pre-crystallization time Main crystallization temperature Concentration s Temperature Concentration sh ° C w / w%-h ° C w / w%-──────────────────────────── 0.0 56.0 91.0 1.18 0.0 57.0 90.5 1.07 0.8 55.9 90.8 1.17 14.5 39.8 87.0 1.14 18.8 47.1 87.9 1.07 15.4 38.0 86.0 1.08 22.1 41.9 86.8 1.09 16.4 35.6 85.4 1.08 22.8 40.5 86.4 1.08 18.1 30.7 84.6 1.10 23.9 38.2 85.9 1.08 18.8 28.9 84.3 1.11 24.5 37.0 85.7 1.09 20.0 25.3 83.7 1.12 ──────────────────────────── Table 7 results of the test operation in example 1-5 ─────── ───────────────────── Example 1 Example 2 Example 3 Spare Main Spare Main Spare Main ────────────── Ａ a 44.3 56.6 40.5 57.5 38.8 62.8 b − − 60.6 c 0.17 0.49 0.16 0.62 0.16 0.66 d 47 31 27 e 99 99.5 99.9 f 0.52 0.75 0.46 0.70 0.48 0.90 ─── ───────── ─────────────── Table 7 (Continued) ─────────────────── Example 4 Example 5 Preliminary main spare main ─ ────────────────── a 42.6 54.5 40.9 57.8 b 56.2 57.1 c 0.13 0.35 0.13 0.37 d 59 57 e − − f 0.52 0.71 0.50 0.78 ──────── ───────────a: crystal yield after completion of pre-crystallization and crystal yield before centrifugation in main crystallization,% w / w b: crystal yield of product,% w / w c: average product size, mm d: standard deviation from average product size,% e: product purity,% w / w of dry matter f: production rate, t / m ³ / day The average product size and standard deviation were determined by sieving analysis at the end of the pre-crystallization using a laboratory microscope.

[Brief description of the drawings]

FIG. 1 is a front view showing a cutaway part of a fructose crystallization apparatus according to the present invention.

FIG. 2 is a side view showing a part of the crystallization apparatus cut away.

FIG. 3 is a partially enlarged view of the crystallizer shown in FIG.

FIG. 4 is a partially cutaway front view showing another embodiment of the fructose crystallization apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1 'Mixing blade 2, 2' Cooling plate 3, 3 'Cooling jacket 4, 4' Shaft 5, 5 'Seal member 6 Motor 7 Support stand 8 Water inlet 9 Water outlet 10 Inflow 11 Outlet

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-268695 (JP, A) JP-A-50-105842 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C13K 11/00 C13G 1/00 B01D 9/00-9/02

Claims (12)

(57) [Claims] 1. The following steps: a) preparing an aqueous solution containing at least about 90% dry substance, wherein the fructose content of the dry substance is at least about 90% by weight; b) converting the aqueous solution at a temperature of 50-60 ° C Seeding, and c) Supersaturation of the aqueous solution with respect to saturated fructose is about 1.
25, and the temperature difference between the hottest and coldest parts of the aqueous solution is less than about 6 ° C.
Cooling the crystal mass formed at a controlled rate and by continuous mixing, wherein the cooling is performed in a crystallizer having a heat transfer surface of 5 m ² / m ³ or more, and 40 ° C or less
Done so that the lower final temperature is achieved within 30 hours
That the crystallization process of anhydrous fructose from water consisting of. 2. The method according to claim 1, wherein the crystals formed are centrifuged and dried. 3. The method of claim 1, wherein the bubbles are mixed into the crystal mass at a volume of less than 20% of the volume of the crystal mass before centrifugation. 4. The method of claim 1, wherein the supersaturation is between about 1.1 and 1.2. 5. The crystallizer is horizontal or tilted no more than about 45 degrees, and comprises a mixing blade and a cooling plate, wherein the cooling plate is about 3 inches between each plate.
2. The method of claim 1, wherein the cooling plate has an open area at least about 5 degrees along the cooling device at a spacing of no more than 00 mm. 6. The distance between the mixing blade and the cooling member is 30.
The method according to claim 5, wherein the mixing blade is installed between the cooling members so as to be less than or equal to mm. 7. The method of claim 5, wherein the speed of the mixing blade tip is such that the speed of the tip of the mixing blade at all points of crystallization is greater than or equal to about 50 mm / sec. 8. The method according to claim 5, wherein the heat transfer surface of the cooling device is 10 m ² / m ³ . 9. A heat transfer surface of 5 m ² / m ³ or more, and a temperature difference between the warmest part and the coldest part of the aqueous solution is about 1
0 ℃ comprising means for mixing such that less, wherein
Crystallizer suitable for production at high production rates of crystalline fructose according to the method of claim 1, wherein. 10. The cooling device is horizontal or about 4
The mixer comprises a mixer and a cooling plate, which are inclined at less than 5 degrees and are located in the crystallizer, the cooling plates being arranged at intervals of less than about 300 mm and at least 5 degrees along the crystallizer. The crystallizer according to claim 9, wherein the crystallizer has an opening area of: 11. The crystallizer according to claim 10, wherein the mixer comprises a blade provided between the cooling plates, and a distance between the blade and the cooling plate is 30 mm or less. 12. The crystallizer according to claim 10, wherein the speed of the blade is at least about 50 mm / sec at all points of crystallization.