JPH0220292B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a packed bed reaction column using a flexible packing material. . More specifically, the present invention relates to a packed bed reactor in which a baffle is inserted in a packed bed filled with a soft filler in a direction perpendicular to the flow direction of the liquid to be treated. In recent years, various methods for producing useful substances using immobilized biocatalysts such as immobilized enzymes or immobilized microorganisms have been studied and are being implemented on an industrial scale. A packed bed type reaction tower is widely used as a reactor for such industrial production. However, most of the immobilized biocatalyst particles packed are soft materials that have inferior mechanical strength compared to ordinary solid catalysts, and these biocatalysts have problems with increasing the size of the reaction tower and operating at high flow rates. As a result, a compaction phenomenon occurs, and as a result, the effective coefficient of the raw catalyst decreases and the reaction rate becomes extremely low, sometimes resulting in a problem that the process becomes impossible. As one method for solving the problems inherent to immobilized biocatalysts, a vertical multitubular reaction tower has been proposed that utilizes the wall effect of the reaction tower to prevent compaction. However, in the reaction tower, it is necessary to measure the pressure loss of each tube in advance and keep it constant, and if the setting is incorrect, a short pass of the liquid to be treated may occur, making it impossible to perform a uniform liquid passage operation. Furthermore, because of the consolidation by self-load, there is a limit to the height of the packed bed, and although it varies depending on the particle size of the flow rate filler during operation, it is usually not possible to use a bed exceeding 2 to 3 m. The present inventors believe that when inserting a buttful into a packed bed filled with a soft filler such as an immobilized biocatalyst in a direction perpendicular to the flow direction of the liquid to be treated, the buttful and the soft filler particles The inventors have discovered that it is possible to prevent the soft filler from being compacted due to friction, and have completed the present invention. Batsuful in the present invention has a circular, oval, triangular, quadrilateral, rhombic, L-shaped, or T-shaped cross-sectional shape.
A rod-like shape, a U-shape, an I-shape, etc., or an elongated body shape is preferable, and a circular, oval, rhombus, etc. shape, in which dead space is less likely to occur below the buffle, is particularly preferable. Alternatively, a hollow buttful may be used. The baffle is provided so as to completely cross the packed bed and span the inside of the reaction column. The arrangement of the baffle may be any of parallel arrangement, staggered arrangement, grid arrangement, etc. Next, embodiments of the reaction tower of the present invention will be described based on the drawings, but the present invention is not limited to such embodiments. FIG. 1 is a schematic plan view of an embodiment of the reaction tower of the present invention, FIG. 2 is a partially cutaway schematic elevational view, and FIG. 3 is a sectional view taken along the line X--X in FIG. 2. A liquid to be treated is introduced into the reaction tower 1 from an inlet 2,
It flows out from outlet 3. Inside the reaction tower, baffles 4 having a circular cross section are inserted at predetermined pitches. The soft filler 5 is filled between baffles in the reaction tower 1 to form a packed bed. As shown in FIG. 3, the arrangement of the baffles 4 in this embodiment is a parallel arrangement. In addition, a staggered arrangement or a lattice arrangement may be used, as shown in FIGS. 4 and 5, respectively. The size of the baffle in the present invention is preferably selected so that the ratio of the total surface area (cm ² ) of the baffle to the reaction tower volume (cm ³ ) (hereinafter, this ratio is referred to as a) is about 0.04 to 0.5. When the value of a is less than about 0.04, the reaction tower is gradually consolidated like a reaction tower without a baffle inserted, and when the value of a is larger than about 0.5, dead space is likely to be formed at the bottom of the buffle, making filling difficult. The horizontal pitch of the full width is the horizontal spacing of the full width.
When L ₁ and the average particle diameter of the soft filler particles are dp, the value of L ₁ /dp is preferably selected to be about 2 to 150, particularly about 5 to 40. When the value of L ₁ /dp is less than about 2, the filling efficiency decreases because the spatial density increases, and when it is greater than 150, the buffing effect decreases. The vertical pitch of Batsuful is approximately 2 when L ₂ is _the vertical spacing of Batsuful.
~190, particularly preferably about 7 to 70. When the value of L ₂ /dp is less than about 2, the spatial density increases, so the filling efficiency decreases, and the
When it is greater than 190, the effect of Batsuful decreases. Although the shape of the reaction tower is not particularly limited, it is preferable to have a cross-sectional shape of either circular or square for ease of manufacture. The height of the packed bed in the reaction tower varies depending on the mechanical strength, particle size, particle shape, etc. of the flexible filler, but it can usually be increased to about 10 m. The reaction column of the present invention can be used not only as a reaction column for enzyme reactions using biocatalysts such as immobilized enzymes and immobilized microorganisms, but also as columns for liquid chromatography and ion exchange. can. Examples of the soft filler used in the present invention include immobilized enzymes and biocatalysts of immobilized microorganisms in which various enzymes and microorganisms are immobilized using soft substances, and flexible fillers for liquid chromatography and ion exchange. Examples include adsorbents. Examples of soft substances include agarose carriers, dextran carriers, cellulose carriers, polyacrylamide carriers, vinyl polymers insoluble in the liquid to be treated, nylon, polystyrene,
Examples include substances commonly used for immobilizing enzymes and microorganisms, such as amino acid copolymers. Examples of the adsorbent include activated adsorbents obtained by chemically modifying the above substances, adsorbents for ion exchange, hydrophobic adsorbents, and adsorbents for affinity chromatography. The reaction column of the present invention can be particularly suitably used for enzymatic reactions using immobilized enzymes or immobilized microorganisms as described above. One of the characteristics of enzymatic reactions is that they can be carried out under mild conditions such as room temperature and normal pressure, but even in enzymatic reactions, there is an exchange of heat during the reaction, although not to the same extent as in normal chemical reactions. . For example, an aspartase reaction using immobilized E. coli is a reaction that generates an exotherm of about 6° C./mol. However, many of the biocatalysts used in enzymatic reactions are sensitive to heat, and therefore, when carrying out reactions over a long period of time, heat exchange is required to keep the temperature inside the reaction tower constant at all times. However, biocatalysts that use soft substances such as immobilized enzymes and immobilized microorganisms have relatively low thermal conductivity, so when using the conventionally widely used double-tube reaction tower, uniform heat exchange is difficult. temperature distribution in the radial direction of the packed bed. Therefore, in order to maintain a uniform temperature throughout the packed bed,
Conventionally, the diameter of the reaction column was made smaller, the temperature during supply of the substrate liquid was lowered according to the calorific value, and a non-isothermal reaction was achieved, or a complex reaction was conducted in which a reaction column and a heat exchanger were combined in series in multiple stages. I had to use a device. However, such reaction towers have limited throughput, complicated operation, and increased equipment costs. In the reaction tower of the present invention, a hollow baffle is used as the baffle inserted in the packed bed, and by passing a cooling medium or a heating medium through the baffle, uniform heat exchange is performed throughout the packed bed. The reaction system can be maintained at a predetermined reaction temperature at all times even in the radial direction of the reaction tower. When performing heat exchange, the size and arrangement pitch of the buffers should be determined by considering the above a and L/dp as conditions for preventing compaction, as well as the calorific value of the reaction, heat transfer area, thermal conductivity of the immobilized biocatalyst, etc. It may be selected appropriately for each reaction. FIG. 6 shows a partially cutaway schematic elevational view of an embodiment of the reaction tower of the present invention using a hollow baffle. The baffle 6 is hollow, and a heating medium or a cooling medium is introduced through an inlet 8 and taken out through an outlet 7.
The battle-full 6 is divided into two stages by a partition wall 9 at the mantle portion. Next, a liquid passage experiment and an enzyme reaction experiment conducted using the reaction tower of the present invention will be shown. Example 1 A square tower with a cross section of 120 mm on a side (height 1500 mm)
mm) is used as a reaction tower, and inside this is an outer diameter of 21 mm,
Staggered arrangement of round bars with a length of 120 mm (horizontal pitch: 38 mm,
48 tubes were inserted with a vertical pitch of 43 mm). This reaction tower was filled with K-carrageenan gel particles (average particle size of gel particles: 1.89 mm, gel concentration: 3.4%) to a height of about 1 m. At this time, a is 0.267cm ² /cm ³ ,
L ₁ /dp was 9.0 and L ₂ /dp was 11.6. A 2% KCl solution was passed through this in a downward flow from the top of the column, and the flow rate (superficial velocity) of the liquid to be treated, pressure loss, and void ratio (=packed bed volume - gel volume / packed bed volume, The relationship between volume (volume = reactor volume - bulk volume) was investigated. The results are shown in Table 1. Comparative Example 1 K-carrageenan gel particles were filled in the same manner as in Example 1 except that Batsuful was not inserted, and 2%
A KCl solution was passed through the chamber to examine the flow rate, pressure drop, and void ratio of the liquid to be treated. The results are shown in Table 1.

[Table] As is clear from Table 1, in Example 1 in which the buttful was inserted, both the pressure loss and the void ratio showed only a very small increase compared to Comparative Example 1. Examples 2 to 10 K-carrageenan gel particles were filled in the same manner as in Example 1, except that bubbles of various shapes were inserted in various arrangements, and a 2% KCl solution was added at a flow rate of 0.7 cm/sec (superficial velocity). The pressure drop and void ratio were examined by passing liquid through the tube.
The results are shown in Table 2. The shape and arrangement of the buffs in each example are shown below. Example 2 Shape: Round bar arrangement with outer diameter of 21 mm: Staggered arrangement with horizontal pitch of 38 mm and vertical pitch of 43 mm (48 rods) a: 0.267 cm ² /cm ³ L ₁ /dp: 9.0 L ₂ /dp: 11.6 Example 3 Shape: Round bar array with outer diameter of 21 mm: Parallel array with horizontal pitch of 38 mm and vertical pitch of 43 mm (42 bars) a: 0.250 cm ² / cm ³ L ₁ / dp: 9.0 L ₂ / dp: 11.6 Example 4 Shape: Outside Arrangement of round bars with _a diameter of 21 mm: Parallel arrangement (16 pieces) with a horizontal pitch of ^{38 mm} and a vertical pitch of ₁₃₅ mm. Circular pipe array: Staggered array with horizontal pitch of 38 mm and vertical pitch of 49 mm (48 pieces) a: 0.125 cm ² / cm ³ L ₁ / dp: 15.3 L ₂ / dp: 21.2 Example 6 Shape: Circular pipe array with outer diameter of 9 mm : Parallel array with horizontal pitch of 38 mm and vertical pitch of 98 mm (18 pieces) a: 0.049 cm ² / cm ³ L ₁ / dp: 15.3 L ₂ / dp: 47.1 Example 7 Shape: Square pipe array of 20 mm on a side: Horizontal pitch of 38 mm , parallel array with a vertical pitch of 142 mm (16 pipes) a: 0.113 cm ² / cm ³ L _{1 /} dp: 9.5 L ₂ / dp: 64.5 Example 8 Shape: Rhombic pipe array with a side of 20 mm: horizontal pitch 38 mm, vertical pitch 115 mm Parallel array (16 pieces) a: 0.118 cm ² / cm ³ L ₁ / dp: 5.1 L _{2 /} dp: 45.4 Example 9 Shape: 18 mm x 3 mm plate array: Each plate horizontally with a horizontal pitch of 38 mm and a vertical pitch of 125
Parallel array in mm (16 pieces) a: 0.065 cm ² / cm ³ L ₁ / dp: 10.5 L _{2 /} dp: 64.6 Example 10 Shape: 18 mm x 3 mm plate array: Each plate is arranged vertically with a horizontal pitch of 38 mm and a vertical pitch of 38 mm. Pituchi 125
Parallel arrangement in mm (16 pieces) a: 0.065cm ² /cm ³ L ₁ /dp: 18.5 L ₂ /dp: 56.6

[Table] As is clear from Table 2, when the buffle is inserted, the pressure loss can be suppressed to 23 to 40% of that when the buffle is not inserted (Comparative Example 1). Example 11 A square tower with a cross section of 260 mm on a side (height 700 mm)
Reaction tower A has 96 circular pipes with an outer diameter of 20 mm arranged in a staggered arrangement (horizontal pitch: 40 mm, vertical pitch: 34.6 mm), a rectangular reaction tower with a cross section of 200 x 260 mm (height
Reaction tower B has 10 circular pipes with an outer diameter of 34 mm and a length of 200 mm in a staggered arrangement (horizontal pitch: 120 mm, vertical pitch: 104 mm) in a rectangular tower with an outer diameter of 700 mm, and a pipe with an outer diameter of 60 mm in reaction tower B. K- was added to each reaction column C using the carrageenan gel method.
Immobilized E. coli particles (average particle size 5.56 mm) with E. coli immobilized on carrageenan particles (Genyugel WG)
Filled with 2% KCl solution at a flow rate (superficial velocity) of 0.03
The solution was passed at a rate of cm/sec for 10 consecutive days. As a result, almost no compaction occurred in any of the reaction towers, and continuous liquid flow treatment was possible. The filling heights of reaction towers A, B, and C are 0.56 m, 0.56 m, and 0.56 m, respectively, and a,
L ₁ /dp and L ₂ /dp are each 0.41 in reaction column A.
cm ² /cm ³ , 3.6 and 2.6, respectively 0.07 in reaction column B
cm ² /cm ³ , 15.5 and 12.6, respectively in reaction column C.
They were 0.13cm ² /cm ³ , 10.8 and 7.9. Example 12 A rectangular square tower with a cross section of 640 mm x 780 mm (height
The same immobilized E. coli as used in Example 11 was placed in a reaction tower in which 96 circular pipes with an outer diameter of 60 mm were arranged in a staggered manner (horizontal pitch: 120 mm, vertical pitch: 104 mm).
(Apparent filling volume) Filled (a=0.15cm ² /cm ³ ,
L ₁ /dp = 10.8, L ₂ /dp = 7.9). Add to this ammonia fumarate solution (initial concentration 1.22M, PH
8.5) was passed at a rate of 360/hour to perform an aspartase reaction. 34°C hot water is constantly passed through the pipe, and the substrate liquid is kept at 37°C.
After preheating to ℃, the solution was passed through. Table 3 shows the temperature of the effluent, the number of days of operation until breakthrough, and the total amount of L-aspartic acid produced in the effluent. Comparative Example 2 Aspartase reaction was carried out in the same manner as in Example 12, except that a reaction tower without a buffer was used, and L-aspartic acid was obtained. The results are shown in Table 3.

[Table] As shown in Table 3, when the Batsuful is inserted and heat exchange is performed by it, the temperature of the effluent is almost constant, the number of breakthrough days is doubled, and the amount of L-aspartic acid per unit biocatalyst is increased. The production amount can be significantly increased. Example 13 Instead of immobilized E. coli, immobilized Brevibacterium flavum particles (average particle size 5.56
mm) using (a=0.15cm ² /cm ³ , L ₁ /dp=10.8,
L ₂ /dp=7.9), flow rate (superficial velocity) using sodium fumarate solution (initial concentration 1M, PH7.0) as the substrate liquid.
L-malic acid was produced in the same manner as in Example 12, except that the solution was passed at a rate of 120/hour and the fumarase reaction was carried out. Table 4 shows the temperature of the effluent, the number of days of operation until breakthrough, and the total amount of L-phosphoric acid produced in the effluent. Incidentally, during the operation, the reaction temperature was raised to 50°C, but even in that case, the temperature distribution in the axial direction remained uniform. Comparative Example 3 A fumarase reaction was carried out in the same manner as in Example 13, except that a reaction tower without a buffer was used, and L-malic acid was obtained. The results are shown in Table 4.

[Table] As shown in Table 4, when a buffer is inserted and heat exchange is performed thereby, the temperature of the effluent remains almost constant, and the production amount of L-malic acid can be greatly increased. Example 14 The procedure was carried out in the same manner as in Example 13, except that immobilized Brevibacterium ammoniagenes in which Brevibacterium ammoniagenes was immobilized on K-carrageenan particles was used instead of Brevibacterium flavum (a = 0.15). cm ² /cm ³ , L ₁ /dp=10.8,
L ₂ /dp=7.9), L- using sodium fumarate solution
produced malic acid. Table 5 shows the temperature of the effluent, the number of operating days until breakthrough, and the total amount of L-malic acid produced in the effluent. Comparative Example 4 L-malic acid was obtained by passing liquid in the same manner as in Example 14, except that a reaction tower without a buffer was used. The results are shown in Table 5.

[Table] Example 15 Immobilized amino acylase was immobilized on Diaion HPA-25 (ion exchange resin manufactured by Mitsubishi Chemical Industries, Ltd.) by an adsorption method in the same reaction tower as that used in Example 1. Acylase was filled to a height of about 1 m (a = 0.267 cm ² /cm ³ , L ₁ /dp = 40.0,
_L2 /dp=51.8). When a 0.38M acetyl-DL-phelalanine solution was passed through this reaction column at a superficial velocity of 0.11 cm/sec and the pressure drop was measured, it was found to be 42.5 cm-H ₂ O/m-
It was hot in bed. On the other hand, when a similar liquid flow test was conducted in a reaction tower without a buffer inserted, the pressure loss was
It was large, 50cm-H ₂ O/m-bed. Example 16 In the same reaction tower as used in Example 1,
DEAE-Sephadex A-25 (dextran gel manufactured by Pharmacia) was filled to a height of about 1 m (a = 0.267 cm ² /cm ³ , L ₁ /dp = 141, L ₂ /
dp=183). When water was passed through this reaction tower at a superficial velocity of 0.083 cm/sec and the pressure drop was examined, it was found that 455 cm-H ₂ O/
It was on m-bed. On the other hand, when a similar liquid passage test was conducted using a reaction tower without a buffer inserted, the pressure loss was as large as 888 cm-H ₂ O/m-bed.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of an embodiment of the reaction column of the present invention, FIG. 2 is a partially cutaway schematic elevational view of the embodiment of FIG. 1, and FIG. 3 is taken along the line X-X of FIG. The cross-sectional view and FIGS. 4 and 5 are a schematic vertical cross-sectional view and a schematic plan view, respectively, of an embodiment of the baffle arrangement in the present invention,
FIG. 6 is a partially cutaway schematic elevational view of another embodiment of the reaction column of the present invention. (Main symbols in the drawing), 1: reaction tower, 4, 6: buffer, 5: soft filler, 7: heat exchange medium outlet, 8: heat exchange medium inlet.

Claims (1)

[Scope of Claims] 1. A packed bed type reaction tower in which a baffle is inserted in a packed bed filled with a soft filler in a direction perpendicular to the flow direction of the liquid to be treated. 2. The baffle according to claim 1, wherein the buttful is a bar-shaped or elongated buttful whose cross-sectional shape is circular, elliptical, triangular, square, rhombus, L-shape, T-shape, U-shape, or I-shape. reaction tower. 3. The reaction tower according to claim 1 or 2, wherein the buffer is a hollow body. 4. The reaction tower according to claim 3, wherein the hollow part of the baffle constitutes a passage for a cooling medium or a heating medium. 5. The reaction column according to claim 1, 2, 3, or 4, wherein the flexible packing material is an immobilized enzyme. 6. The reaction column according to claim 1, 2, 3, or 4, wherein the flexible filler is an immobilized microorganism. 7 Claims 1 and 2, wherein the soft filler is an adsorbent for liquid chromatography.
The reaction column according to item 3 or 4. 8. The reaction column according to claim 6, wherein the immobilized microorganism is an immobilized E. coli for producing L-aspartic acid. 9. The reaction column according to claim 6, wherein the immobilized microorganism is immobilized Brevibacterium flavum or immobilized Brevibacterium ammoniagenes for L-malic acid production.