JPH025154B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a new reaction device for use in industrial fields such as fermentation, pharmaceuticals, food manufacturing, animal and plant cell culture, and wastewater treatment, which produce desired products using microbial reactions and enzymatic reactions. be. [Prior art] There are conventional methods and devices for carrying out decomposition and removal reactions of organic matter in wastewater and nitrification reactions of ammonia nitrogen by storing bacteria that decompose and assimilate organic matter and nitrifying bacteria in a tank. Various methods have been put into practical use, including the sludge method, trickling filter method, honeycomb tube catalytic oxidation device, rotating disk device, and granular media fluidized bed device. The granular media fluidized bed method is attracting attention and research and development is progressing because it has the advantage of being easy to use, and because the granular media is flowing in the tank, problems such as anaerobic formation due to clogging do not occur. ing. This granular media fluidized bed method involves circulating and fluidizing the granular media used for the attachment of microorganisms through an airlift pipe installed in a tank, and supplies dissolved oxygen to the raw water in advance with air or oxygen-enriched gas. ,
There are various methods, such as those that introduce raw water from the bottom of a tank containing granular media to fluidize the granular media, and those that fluidize the media by individually introducing air and raw water from the bottom of the tank that contains granular media. However, with these conventional devices, particles attached to microorganisms overflow into the processing liquid due to agitation by air intake, and as the adhesion of microorganisms progresses, the density of particles gradually decreases. This has disadvantages such as particles with reduced sedimentation speed overflowing out of the tank.For this reason, it is necessary to install an agitator at the top of the tank to forcibly separate the microbial film from the particles, or to prevent particles from flowing out of the tank. Countermeasures have been taken, such as setting up a sedimentation tank to settle and recover the granular media, but these methods are not sufficiently effective, and the addition of new equipment causes a loss of compactness and increases uneconomical performance. It was not enough. In the field of fermentation using microorganisms to synthesize useful substances for foods, medicines, etc., conventionally the mainstream reaction operation was to store floating microorganisms in a tank, but now there is a need to make the reaction more efficient. In order to make it continuous,
In order to maintain a high concentration of microorganisms that can serve as biocatalysts in an incubator, the microorganisms are immobilized and molded using a polymeric material, or granules are used, or the microorganisms are attached to a carrier such as glass beads or a polymeric material. In recent years, methods of carrying out fermentation operations by storing them in a reactor have been studied. Naturally, in these reaction operations, it is necessary to separate microorganism-adhered particles or immobilized microorganisms from the treatment liquid, but to date no effective separation method has been found.
The reality is that we rely on expensive separation methods such as ultrafiltration membranes and centrifugation. [Problems to be Solved by the Invention] The present invention solves these problems of conventional devices, in particular, prevents particulate matter from flowing out of the tank, and makes it possible to maintain the particulate matter in the tank reliably at a low cost. This provides a highly efficient and compact fluidized bed reactor. [Means for Solving the Problems] As a result of various experiments conducted in order to solve the above-mentioned problems, the present invention prevents particles from flowing out into the processing liquid and stabilizes them in the tank. In order to hold the particulate matter and allow the reaction to proceed stably, first, a solid-liquid two-phase part from which gas is separated is formed from the solid-gas-liquid three-phase flow part, and then the solid-liquid two-phase part is separated from the solid-liquid two-phase part. This was done based on the knowledge that it is effective to separate carrier particles, and solid particles to which microorganisms can adhere or polymer substances are used to remove microorganisms in a tank that has a stock solution supply section and an aeration section at the bottom. Alternatively, a fluidized bed reaction tank containing a granular material formed by immobilizing and molding an enzyme, in which a partition wall is provided whose lower end is inclined so that an opening is formed between the tank wall and the tank wall. , and by disposing a baffle plate below the opening substantially parallel to the partition wall, a solid-liquid two-phase part and a solid-gas-liquid three-phase flow part are partitioned, and the solid-liquid two-phase part and the solid-gas-liquid A three-phase flow section is formed into sections, and a processing liquid outlet is provided at the top of the solid-liquid two-phase section, and a separated gas outlet is provided at the top of the solid-gas-liquid three-phase flow section. This is a fluidized bed reactor. An embodiment of the present invention will be described with reference to FIG. 1. The lower part of the fluidized reaction tank 3 is preferably sloped so that the cross-sectional area decreases as it goes downward. A stock solution inflow section 1 and an aeration section 2 are arranged in the tank 3, and in the tank 3 there is provided an immobilized particulate material formed by immobilizing microorganisms or enzymes using solid particles or polymeric substances to which microorganisms can adhere. Item 11 is stored. The solid particles or immobilized particles are kept in a fluid state by the raw solution and air or oxygen-enriched gas flowing from the lower part of the tank 3. The inlets for raw water and air or oxygen-enriched gas may be arranged so that they are introduced individually, as shown in Fig. 1, or they may be arranged so that they are introduced as a multiphase flow in which gas and liquid are mixed in advance. Even if it is done, the method does not matter. When a reaction is to be carried out by attaching microorganisms to the surface, the particulate matter stored in the tank must have physical properties suitable for attachment and fluidization (particle size, density, porosity, surface roughness, etc.). However, the reduction in sedimentation rate when microorganisms are attached, the flow rate of the stock solution, the aeration speed of air or oxygen-enriched gas, the hydraulic retention time of the stock solution, and bed expansion can be selected. In general, sand, sintered material, plastic balls, anthracite, activated carbon,
Lightweight aggregates, glass beads, etc. are selected and used depending on the processing purpose. Further, the amount of filling into the tank is determined in consideration of the aeration rate of liquid passage so that the layer expansion during liquid passage is approximately 2 times the size during sedimentation. When storing granular materials formed by immobilizing microorganisms or enzymes with polymeric substances, etc., it is possible to use those manufactured according to the purpose of the reaction. For example, in the case of industrial wastewater treatment, nitrifying bacteria are immobilized with polyacrylamide or photocrosslinkable resin to carry out the nitrification reaction of ammonia, and lignin-degrading bacteria are immobilized to treat pulp and paper wastewater. In the fermentation field, there are cases where yeast is immobilized to produce alcohol, amino acid fermentation cases, etc.
Alternatively, there are various application cases such as the production of useful medicines by immobilizing genetically engineered E. coli, and the use of granules made by selecting and immobilizing microorganisms or enzymes that can achieve the purpose depending on the purpose. is possible. The introduced stock solution comes into contact with microorganisms or enzymes fluidized in the tank, and passes through the tank in an upward flow while undergoing a biochemical or chemical reaction under aerobic conditions. At the bottom of the tank, solid particles form a stable fluidized bed 9 with relatively little turbulence, but as gas and liquid pass through the layer, solid particles are entrained in the layer from near the layer interface, especially by air bubbles 12. It overflows further upwards. A partition wall 4 is provided at the upper part of the tank, and the partition wall 4 is inclined so that its lower end forms an opening 14 between it and the tank wall.
In addition, a baffle plate 4' is arranged almost parallel to the partition wall to cover the opening, and the particles that overflow along with the air bubbles are led obliquely upward along the baffle plate and are separated from the air bubbles. , the partition wall 4, and the baffle plate 4', and flows into the solid-liquid two-phase flow section 10. Here, the particles are separated from the liquid and flow back to the three-phase flow section 9 through the gap 13 between the baffle plate and the tank wall.
It is effective to provide a rectifying protrusion 8 in this reflux path 13 in order to prevent bubbles from flowing in and smooth the reflux. The processing liquid that has separated the particles into solid and liquid flows out from the processing liquid outlet 5 disposed above the solid-liquid two-phase section, and the bubbles separated by the baffle plate 4' flow out above the solid-gas-liquid three-phase flow section. The gas is discharged to the outside of the tank from a gas discharge port 6 provided in the tank. It is sufficient that the length of the baffle plate 4' is long enough to prevent air bubbles from flowing into the solid-liquid two-phase portion. FIG. 2 shows another embodiment of the present invention, in which the length of the partition wall 7 is shortened and the baffle plate is a plurality of parallel plates 4', 4', etc. as shown in the figure. has the same effect. The tank 3 can be arbitrarily designed and manufactured to provide the same effect, whether it is cylindrical or square. Also, the angles of the partition walls and baffle plates are such that the air bubbles are solid-liquid 2
Any angle may be used as long as it does not flow into the phase, but an angle of about 40° to 60° is preferable. [Example] Figures 1 and 2 of width 50mm x length 450mm x height 4000mm
Using an experimental apparatus having the structure shown in the figure, a comparative experiment was conducted with and without the partition walls 4, 7 and the baffle plate 4'. Experimental conditions Raw water: tap water Gas: air Filled particles: particle size 0.5-0.7mm Sintered filter medium initial filling height 500mm Liquid passing rate: 0.4cm/sec Air flow rate: 0.25cm/sec After 24 hours of continuous operation, the treated water was The amount of spilled particles was measured. Partition walls and baffle plates 4, 4': They were arranged at an angle of 45° at an interval of 50 mm in the upper middle part of the tank. Partition walls and baffle plates 7, 4': Four baffle plates were arranged at an angle of 45° above the middle of the tank and spaced at 30 mm intervals. The experimental results are shown in Table-1.

[Table] As described above, according to the present invention, it is possible to provide an effective fluidized bed reactor that can effectively eliminate the drawbacks of conventional devices with a simple structure.

[Brief explanation of drawings]

1 and 2 are schematic cross-sectional views of the fluidized bed reactor of the present invention, respectively. DESCRIPTION OF SYMBOLS 1... Raw solution inlet, 2... Air diffuser, 3... Fluid reaction tank, 4, 7... Partition wall, 4'... Baffle plate, 5...
...Processing liquid outlet, 6... Gas discharge port, 8... Rectifying projection, 11... Solid particle, 12... Air bubble.

Claims (1)

[Scope of Claims] 1. Solid particles to which microorganisms attach, or granular materials formed by immobilizing microorganisms or enzymes with a polymeric substance, etc., are placed in a tank having a stock solution supply section and an aeration section at the bottom. A fluidized bed reactor is a fluidized bed reactor in which a partition wall is provided in the tank, the lower end of which is inclined such that an opening is formed between the tank wall and the partition wall, which is substantially parallel to the partition wall below the opening. By disposing a baffle plate in the solid-liquid two-phase section and the solid-gas-liquid three-phase flow section, a processing liquid outlet is provided at the top of the solid-liquid two-phase section, and a solid-gas-liquid three-phase flow section is formed. A fluidized bed reactor comprising a separated gas outlet at the top of the reactor. 2. The fluidized bed reactor according to claim 1, wherein the baffle plates are a plurality of parallel plates.