JPS62183848A - Stirring type packed bed reactor - Google Patents

Abstract

PURPOSE:To enhance reaction efficiency by preventing channeling, in an upward flow type packed bed immobilized biocatalyst reactor, by respectively independently stirring the central part and outer peripheral part of the packed bed in a vertical column. CONSTITUTION:The substrate supplied from an inlet 16 passes through a pipe 17 to remove air bubbles in the substrate and reaches an immobilized biocatalyst packed part 13 from a packed bed support net 20 to be reacted by an immobilized biocatalyst (a). Herein, by stirring the immobilized biocatalyst (a) at a low speed by rotating blades 2, 3, no channeling is generated even in large caliber reactor and the biocatalyst is efficiently contacted with the substrate to enhance reaction efficiency. Subsequently, a formed reaction product passes through a biocatalyst outflow preventing net 21 to reach the next process. The biocatalyst floated while accompanied by air bubbles is separated under stirring by a scraping blade 22 and air bubbles are exhausted from an outlet 23 and the biocatalyst is returned to a packed bed part.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a stirred packed bed reactor.

(Prior Art) In recent years, there has been much research and development regarding the establishment of production technology using immobilized biocatalysts, and the reactors used therein are wide-ranging, including packed bed types, fluidized bed types, stirred tank types, and models.

(Problems to be Solved by the Invention) Conventionally, packed bed reactors do not have strong stirring, so even fragile immobilized biocatalysts are not destroyed.

Furthermore, since there is little back-mixing of liquids, there is an advantage that even reactions where product inhibition occurs can be carried out with high efficiency.

There are upward and downward flow methods for passing liquid into the reactor, but downward flow is more effective in terms of preventing backflow and efficiently reacting with plug flow.

However, in a downward flow, if the substrate tends to adhere to the immobilized biocatalyst, or if such substances coexist in the solution containing the substrate, the pressure loss increases over time.

In addition, although the pressure loss is small in the upward flow, a phenomenon in which the flow concentrates in the easily flowing portion of the packed bed, that is, channeling occurs, and the reaction efficiency decreases.

In particular, this tendency becomes more pronounced as the diameter of the reactor increases.

(Means for Solving the Problems) Therefore, the technical problem of the present invention is to provide an upflow type packed bed type immobilized biocatalyst that can improve the contact between the immobilized biocatalyst and the substrate and increase the reaction efficiency. The purpose of the present invention is to scale a catalyst reactor, and the technical means of the present invention to solve this technical problem is to fill the center and outer periphery of a packed bed in a vertical column packed with an immobilized biocatalyst. A stirring blade that is independently driven at a low speed is installed, and a substrate inlet is provided at the bottom of the vertical column, and the substrate that is continuously supplied from the lower substrate inlet and the packed immobilized biocatalyst are mixed. The reaction is brought into contact by the stirring action of the stirring blade.

(Effects of the Invention) The present invention employs a system in which a stirring blade is installed in the packed bed portion of the reactor and is rotated at a low speed to stir the immobilized biocatalyst. No axial flow occurs due to this stirring. Since the packed bed is always moving in the circumferential direction, channeling can be prevented and reaction efficiency can be improved.

(Example) The embodiments shown in the drawings will be described below.

The outer periphery of the vertical column main body is constituted by a temperature-maintaining jacket (1), and (la) and (lb) are the hot water inlet and outlet.

The inside of the main body constitutes an immobilized biocatalyst filling part (13), in which central stirring H (2) and outer peripheral stirring H (3) are formed in multiple stages, and central stirring blades (2) are formed in multiple stages. ) is the axis (4)
The outer stirring blade (3) is attached to the frame (5).

The shaft (4) is directly driven by the motor (6) and is connected to the frame (
5) is driven by the motor (7);
) drives the pulley (9) from the pulley (8) via the belt, and the pipe (
1o), and the frame (5) is driven by the pipe (10).

The lower end of the illustrated shaft (4) is supported by a knife jigs (11) provided in the center of the frame (5).
1) is supported by support needles (12) located at the bottom of the vertical column.

The lower conical part (14) of the vertical column is also formed with a jacket (15), (15a) (15b
) are the hot water inlet and outlet.

Further, (16) is a substrate inlet formed in the conical part (14).

Furthermore, a bubble removal pipe (17) is formed in the conical part (14), and this is connected to a bubble discharge pipe (19), so that bubbles can be discharged by opening the cutout cock (18).

At the center of the bubble removal pipe (17) is the support needle (1).
2) is upright.

At the boundary between the immobilized biocatalyst filling part (13) and the conical part (14), there is a conical network (20) for supporting the immobilized biocatalyst packed layer.

In the illustrated example, the tip of the support needle (12) is supported by the center of the net (2o).

An immobilized biocatalyst outflow prevention net (21) is stretched over the upper cylinder (24) of the vertical column body, and there is a scraping blade (22) for air bubble separation that rotates along this net, and the frame (
5) is attached to the drive pipe (1o).

(23) is a living organism outlet in a hemispherical part (25) formed following the cylindrical part (24).

This reactor has the immobilized biocatalyst filling section (13) as described above.
, a conical net for supporting the packed bed of immobilized biocatalyst (20), a central stirring blade (2) installed in multiple stages to stir the packed bed in the center, and an outer peripheral stirring blade installed in multiple stages to stir the outer periphery. (3), Exhaust pipe (19) for air bubbles remaining on the bottom surface of the net (20), Jacket for temperature maintenance) (1), Motors (6) and (7) for rotating each stirring blade, Immobilized biocatalyst Scraping to separate air bubbles adhering to the outflow prevention net (21) and the immobilized biocatalyst that floats and accumulates on its underside! It consists of (22).

Next, to explain the action according to the flow of the substrate, the substrate heated to the reaction temperature releases dissolved gas, which becomes bubbles and collects at the top of the packed bed support net (20) at the bottom of the reactor.

The air bubbles pass through the pipe (17) and the discharge pipe (19).
It is discharged from there by a metering pump (not shown).

The substrate from which air bubbles have been removed passes from the packed bed support net (20) to the immobilized biocatalyst filling section (13), and the immobilized biocatalyst (
Reacted by a).

Here, the immobilized biocatalyst is attached to a blade (2) rotating at low speed (
3).

In addition, these wings (2) (attached to the center and outer periphery)
3) are usually adjusted and rotated so that the speeds of their tips are the same.

In this way, by stirring the packed bed with a stirring blade, channeling does not occur even in a reactor with a large diameter, and the immobilized biocatalyst and substrate come into contact with each other efficiently, improving reaction efficiency.

The reactants generated by passing through the packed bed pass through a net for preventing outflow of the immobilized biocatalyst and reach the next step.

Then, the immobilized biocatalyst that floats together with the reactants along with fine bubbles reaches the lower surface of the immobilized biocatalyst outflow prevention net (21) and accumulates thereon. The blade (22) scrapes off this accumulated layer.
By stirring at low speed, fine air bubbles are separated from the immobilized biocatalyst, and the IM for preventing the immobilized biocatalyst from flowing out is separated.
(21) and is discharged from the outlet (23).

The immobilized biocatalyst separated from the bubbles is removed by a propeller-type scraping blade (
22) to smoothly immobilize the biocatalyst packed bed part (1
Returned to 3).

According to the embodiment, the air bubbles accumulated on the lower surface of the packed bed support net (20) can be continuously or intermittently discharged by the air bubble removing pipe (17) attached to the lower surface of the net (20). Unbalanced flow of the substrate due to stagnation can be prevented, and reaction efficiency can be improved.

Furthermore, in a practical-scale reactor, unless the diameter of the reactor is increased, problems such as (1) large pressure drop and (2) crushing of the immobilized biocatalyst at the bottom of the reactor will occur.

Therefore, the diameter of the reactor must necessarily be increased.

When a packed bed is stirred by one uniaxial stirrer in such a large-diameter reactor, the stirring speed differs greatly between the center of the stirring blade and its tip. However, as in the embodiment, a plurality of independent stirrers may be installed and each stirrer may be rotated at different rotational speeds so that the circumferential speeds thereof are equal.

By this method, even in a large-diameter reactor, the stirring state is made uniform, channeling is prevented, and the reaction efficiency is improved.

In addition, each stirrer may be installed so that it can rotate in forward and reverse directions.

In addition, when the gas dissolved in the substrate solution kept at a low temperature is heated to the reaction temperature, it becomes bubbles and the filling support t
It stays on the bottom surface of PW4 (20). Therefore, the flow in that part is blocked and a biased flow occurs before reaching the packed bed (13).
It may also cause channeling within the packed bed.

Therefore, the packed bed support net (20) is formed into a conical shape, and air bubbles are collected at the top of the net and can be discharged to the outside of the yarn via a pipe (17) by a metering pump.

Further, fine air bubbles may reach the inside of the packed bed and adhere to the immobilized biocatalyst.

In this way, the immobilized biocatalyst with air bubbles increases its buoyancy,
It floats up to the rope part (21) for preventing outflow of the immobilized biocatalyst.

For this reason, the immobilized biocatalyst is deposited on the underside of the net.
Therefore, a rotating stirring blade (22) is installed so as to be in contact with the bottom surface of the screen, and by rotating this blade at a low speed, the air bubbles and the immobilized biocatalyst can be separated, and the separated immobilized biocatalyst is sink.

This is because the stirring blade (22) rotates in the direction of downward flow as described above.

Since there is no accumulation of immobilized biocatalyst on the bottom surface of the screen, no increase in pressure loss occurs within the reactor.

A specific experimental example will be described below.

Experiment 1> The immobilized protease was covalently immobilized on alumina (density 3.5 g/cIi1) with a diameter of 0.7 mφ, and the created immobilized protease was placed in a stirred packed bed reactor (160 mφ), and 10% casein was added from the bottom. A reaction was carried out by passing a molten solution (ζ50°C) at SV:1O. Here, SV is 5 pace Veloci
ty (space velocity). In this case, the rotation speed of the stirrer that stirs the packed bed section is at the center (blade diameter 70 m).
3 Orpm, and the outer circumference (blade diameter 1506)
The speed was set to 14 rpm so that the circumferential speeds were almost the same.

Further, the gas dissolved in the 10% casein solution became bubbles and remained at the top of the lower surface of the packed bed support network, so these were removed using a metering pump via a vibrator. In this way, by stirring the packed bed at low speed using a dual-type stirrer while removing air bubbles that remain at the top of the bottom surface of the packed bed support network, channeling does not occur, and no backflow occurs due to stirring. I was able to react.

The decomposition rate in this case was about 93 to 97%, assuming that the decomposition rate in the downward flow method, which has the highest reaction efficiency, was 100%.

In addition, it was 70 to 85% in an upward flow type packed bed reactor in which the packed bed was not stirred.

Alumina has a heavy density of 3.5 g/cd, so fine bubbles were attached to it, and no bubbles were observed floating to the bottom surface of the immobilized biocatalyst outflow prevention net. therefore,
In this case, it was found that it was not necessary to install a scraping blade.

Experimental Example 2 β-galactosidase originating from Aspergillus oryzae immobilized on phenol-formalin resin was placed in the stirred packed bed reactor shown in Experimental Example 1, and 12% reduced skim milk (45% ℃) was passed at 5V=14. The rotation speed of the stirrer is 1Orpm at the center.
In addition, the outer circumferential speed was set to 4.6 rpm so that the circumferential speeds were almost the same. As in Experimental Example 1, since it was prepared by reduction, it contained a large amount of air bubbles, which gathered and remained at the top of the lower surface of the packed bed support network. Therefore, it was removed almost continuously using a metering pump via a vibrator.

Further, this resin had a light density of 1.1 g/cj, and therefore the immobilized β-galactosidase with fine bubbles attached thereto floated to the bottom surface of the immobilized biocatalyst outflow prevention mesh. When these immobilized β-galactosidase were agitated using a scraper for separating air bubbles, the air bubbles were separated, and these immobilized enzymes settled into the packed bed part due to the downward flow generated by the blades and their own weight.

When the reaction was carried out under the above conditions, the decomposition rate was 1.1 times that of the case without stirring, which was close to the decomposition rate when the liquid was passed in a downward flow.

In any case, the present invention improves the upward flow phenomenon in conventional packed bed reactors, and improves reaction efficiency by stirring the packed bed using stirring blades rotating at low speed. It is something.

[Brief explanation of drawings]

The drawing is a sectional view showing the reactor of the present invention. (1) ... Jacket (2) (3) ... Stirring blade (13) ... Immobilized biocatalyst filling part (16) ...
- Substrate inlet (17)...Bubble removal vibe (20)...Conical net for supporting the packed bed of immobilized biocatalyst (21)...Net for preventing outflow of the immobilized biocatalyst (2
2) Scraping blade for bubble separation (23) Product outlet

Claims (1)

[Claims] Stirring blades that are independently driven at low speed are installed at the center and outer periphery of the packed bed in a vertical column filled with an immobilized biocatalyst, and a substrate inlet is provided at the bottom of the vertical column. A stirred packed bed reactor characterized in that a substrate continuously supplied from a substrate inlet and the filled immobilized biocatalyst are brought into contact with each other by the stirring action of the stirring blade to cause a reaction.