JPH01176455A - Carrier composed of inorganic fiber and its production - Google Patents

Abstract

PURPOSE:To enable formation of a fluidized bed at a low flow rate, to get rid of flaking of supported material and to increase a reaction efficiency by constituting a carrier, wherein inorganic fibers are tangled, formed into a ball shape and bonded together. CONSTITUTION:Inorganic fibers cut into required lengths are impregnated with a liquid such as water, alcohol, etc., then aggregates of inorganic fibers are formed by a bonding action of the liquid. These aggregates are turned into small lumps by applying vibrations or impacts and further into balls by being rotated in a rotary granulator while being dried in contact with heated air. The obtained balls are poured into a vessel, wherein the balls are impregnated with a solution or dispersion of a binder such as epoxy type. A carrier composed of the inorganic fibers are produced by drying the binder impregnated balls and curing the binder afterward.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a granular material suitable for use as a carrier for immobilizing microorganisms or oxygen in a bioreactor or as a spawning bed for fish in a fish pond.

[Prior art] In recent years, biological reactions using bioreactors have become widely used in the production of pharmaceuticals and alcohol, as well as in the anaerobic treatment of various industrial and domestic wastewater. The reaction is usually carried out by filling a reaction tank with immobilized microorganisms or immobilized enzyme carriers, or by dispersing and flowing them in the reaction tank and bringing them into contact with the liquid to be treated. I am doing it.

Support materials include agar, copper carrageenan,
Organic materials such as DEAE cellulose, DEAE-Sephadex, acrylamide, polyvinyl alcohol,
Alternatively, inorganic materials such as zeolite, sand, porous ceramics, glass fiber nonwoven fabric, porous glass, stainless steel wool, etc. are used.

Conventionally, the shapes of these carriers include cubes, cylinders, spheres (beads), honeycombs, and the like.

[Problems to be Solved by the Invention] Particularly in the manufacturing process of pharmaceuticals and alcohol, it is necessary to strictly prevent the contamination of so-called miscellaneous bacteria. For this reason, autoclave treatment is usually performed at 130° C. for several hours. However, conventional carriers made of organic materials have the disadvantage that the material deteriorates during the autoclave treatment described above.

Conventional inorganic material carriers have a high specific gravity as a granular carrier when used in a fluidized bed type reaction bed, for example.
Its liquidity is extremely poor. Therefore, in order to maintain a good flow state, the flow rate of the feed liquid must be increased, which is disadvantageous in terms of energy and equipment design. In addition, such a high flow rate also resulted in the inconvenience of cell destruction and outflow of microorganisms or enzymes.

When a carrier made of an inorganic material is used in a fixed bed reaction tank, if the diameter of the carrier is small, clogging is likely to occur.On the other hand, if the diameter of the carrier is large, the total surface area of the carrier will be small and the reaction efficiency will be low. There is an inconvenience that this happens.

[Means for Solving the Problems] The carrier of the present invention is formed by intertwining inorganic fibers to form a spherical shape and bonding the inorganic fibers together with a binder.

In addition, the present invention provides a method for manufacturing such a carrier by impregnating inorganic fibers cut to a required length with a liquid to form an aggregate, forming it into small lumps by vibration or impact, and rotating the small lumps. The present invention provides a method for producing a carrier made of inorganic fibers, which is characterized in that the carrier is heated and dried in a rotary granulator, and then impregnated with a binder liquid and then dried.

Hereinafter, the configuration of the present invention will be explained in more detail.

In the present invention, examples of inorganic fibers include glass fibers, alumina fibers, potassium titanate fibers, carbon fibers, fibrous activated carbon, and silicon carbide fibers, but materials other than these may also be used.

This inorganic fiber has a diameter of 2 to 30 μm and a length of 0.5 μm.
-10 mm, particularly 1-5 mm is preferred. When the diameter of the inorganic fiber is larger than 30 μm, the fiber becomes rigid and becomes difficult to entangle. Therefore, it becomes difficult to form a spherical body, and even if it becomes a spherical body, it becomes weak against mechanical deformation. The diameter of the inorganic fiber is 2μm
If the size is smaller, the price becomes significantly higher. When the inorganic fiber is shorter than 0.5 mm, the inorganic
The entanglement of the fibers is weak, and the strength of the spherical body is low. Furthermore, if the inorganic fibers are longer than 10 mm, they are less likely to get entangled and become spherical.

The inorganic fibers are preferably long fibers cut to the above-mentioned length using a cutter or the like, and specifically chopped strands are exemplified. Further, it is preferable that the inorganic fiber is not treated with a special sizing agent.

As a binder for binding these inorganic fibers together,
Organic binders such as epoxy, acrylic, and vinyl, and inorganic binders such as silica sol and alumina sol are suitable.

This carrier preferably has a diameter of 30 mm or less. This is because if the diameter of the carrier exceeds 30 mm, the distance between the surface and the center of the carrier becomes long, making it difficult for the substance to be reacted to reach the center of the carrier. Note that the lower limit of the diameter of the carrier is not particularly limited, but when the length of the inorganic fiber is about 1 mm, the diameter of the carrier is also about inm.

The carrier of the present invention can be manufactured as follows.

First, an inorganic fiber cut to a required length is impregnated with a liquid such as water or alcohol (water is preferred from the viewpoint of cost, work safety, etc.). At this time, it is preferable to use an excess amount of liquid, to sufficiently impregnate the inorganic fibers with the liquid, and to discard the excess liquid. Further, when CMC (sodium carboxymethyl cellulose) or the like is added to water to make it a viscous liquid, workability is improved.

The inorganic fibers impregnated with the liquid become an aggregate (for example, a lump) of inorganic fibers due to the binding action of the liquid. Therefore, next, vibration or impact is applied to this aggregate to form small lumps. The pellets are then heated and dried in a rotary granulator, for example by contacting them with heated air. Various types of rotary granulators can be used, such as a rotary drum type and a rotary pan type, but since the above-mentioned small granules contain a relatively large amount of liquid, a porous rotary drum such as one made of wire mesh is used. is preferable. In addition, when such a rotating drum is used, by placing the above-mentioned inorganic fiber aggregate in the rotating drum and rotating it, it is possible to apply vibration or impact to the aggregate and form it into small lumps. , drying can continue in the rotating drum.

By rotating in a rotary granulator, the pellets gradually become spherical and resemble pearls.

In this process, the spherical bodies are dried by heating, such as by contacting them with heated air. In addition, when this rotary granulator is of the above-mentioned porous type, it is preferable that only water is drained for a while after the start of rotation, and then the rotary granulator is brought into contact with heated air. When this drying is carried out, the core portion of the spherical body may be dried, or the spherical body may be dried to the extent that only the surface portion thereof is dried.

The spheres thus obtained are then impregnated with a binder. For example, the spheres are impregnated with the binder by transferring the spheres from the rotary granulator described above into a container and injecting a solution or dispersion of the binder into the vessel.

The concentration of the solution or dispersion at this time depends on the type of binder, but it is 2 to 20% by weight, and the binder component (solid content) is 5 to 20% by weight relative to the inorganic fiber. It is preferable to

The spheres impregnated with the binder are then dried and heated to harden the binder and impart the required strength to the spheres. This heating temperature depends on the type of binder, but in the case of ordinary epoxy-based organic binders, the heating temperature is 80 to 13
The temperature is preferably about 0°C, and in the case of inorganic binders such as alumina sol and silica sol, it is preferably about 20 to 300°C.

This heating may be performed, for example, in a heating furnace, or a hot air dryer or the like may be used. Alternatively, the above-mentioned rotary granulator may be used to harden by contacting with heated air. After this hardening treatment, sieving is further performed as necessary to adjust the particle size of the spherical bodies.

Although the wet manufacturing method has been described above, it can also be manufactured by a dry manufacturing method as follows.

That is, first, an inorganic fiber cut into a predetermined length is swung on a pan together with particles having a smaller diameter than the target carrier to form a spherical object, and then the particles pass through, but the A carrier can be produced by passing the spherical particles through a sieve with openings that do not allow them to pass through, selecting the spherical particles, impregnating them with a binder, and drying them.

[Function] Since the carrier of the present invention is substantially composed only of entangled inorganic fibers, its apparent specific gravity is normally extremely small at 0.05 to 0.15 (the porosity is approximately 90 to 0.15). 95%), the carrier of the present invention has excellent fluidity in a fluidized bed reactor, and even when packed in a fixed bed reactor, there is no risk of clogging due to compaction of the carrier. In addition, the reaction tank structure can be made lighter.

Furthermore, when the carrier of the present invention is packed into a fixed bed,
Since the shape is spherical, the filling method is simple and the filling is uniform, so there is little risk of uneven flow of the reaction liquid.

As mentioned above, the carrier of the present invention usually has a porosity of about 9.
Since it is extremely high at 0 to 95%, the reacted liquid can easily diffuse into the interior of the spherical body. Therefore, the reaction is accelerated, and gases such as methane and carbon dioxide generated in the reaction are quickly released from the spherical bodies, so that contact between the immobilized microorganisms or immobilized oxygen and the reacted liquid is not inhibited. . Therefore, it is extremely suitable as a methane bacteria carrier for, for example, anaerobic wastewater treatment.

The elasticity of the carrier of the present invention can be adjusted by adjusting the amount of binder, and the degree of deformation in response to stress can be selected as required. As a result, for example, in a fluidized bed, there is no risk of damage to the carrier or peeling of the immobilized microorganisms or immobilized enzyme due to collisions between the carriers, and in a fixed bed, deformation due to compression can be avoided. In addition, it is used as a spawning bed for fish in fish ponds.
When using the relatively easily deformable spherical bodies having a diameter of ~5 mm, there is no fear that the eggs will peel off due to collisions between the spherical bodies.

[Example] A glass thread was pulled out at high speed from a bushing installed at the bottom of a glass melting tank to form a filament with a diameter of 10 μm, and 2000 filaments were drawn together to form a strand. This strand was cut into a length of 1 mm using a rotary cutter to obtain chopped strands. In this case, the focusing of the glass fibers was done with water. - 2.5 kg of the above chopped strands were placed in a container together with 20 J:l of water and deposited on the bottom of the container by vibration with a vibrator. Next, after discarding the excess Hontsuri 12J2, the eye opening was approximately 1
The sample was loaded into a drum with a diameter of 40 cm and a length of 50 cm made of mm wire mesh. The drum was then rotated at 20 rpm for 10 minutes. Through this operation, the water content is further reduced and the chopped strands have a diameter of about 1
It became a substantially spherical body of ~30 mm. Next, the entire drum was covered with a casing, and heated air at 100° C. was sent into the casing at a rate of 500 IL/min to dry the substantially spherical bodies to the extent that the surface moisture was removed. During this process, the shape of the substantially spherical body gradually approached a true spherical shape. The spheres thus obtained are removed from the drum and
It was immersed in water in which a binder was dispersed. The formulation of the binder is as follows.

EA55 100 parts by weight HC-10100)) EB-143) I TETA 165) 1 water
1200# (Note) The above symbol indicates the following.

EA55: Bisphenol A1 shrimp calolhydrin type epoxy emulsion (solid content 55%) HC-10: Epoxy novolac emulsion (solid content 55%) EB-1: Fatty acid amine emulsion (solid content 45%) TETA Nitriethylenetetramine (solid content 100
%) Thereafter, the spherical bodies were taken out of the water, drained, dried at 80°C, and further heat-cured at 120°C for 10 minutes.

The spherical bodies thus obtained have a diameter of 1 to 30 mm.
The apparent specific gravity is 0.10, and the amount of binder attached is 11% by weight.
, exhibited a porosity of about 95%. This spherical body was suitable as a fluidized bed type reaction tank, a fixed bed type reaction tank, and a spawning bed for fish eggs.

[Effects] As described above, the carrier of the present invention has an apparent low specific gravity and also has the required strength and elasticity.

Therefore, when this carrier is used as a fluidized bed type reactant,
A fluidized bed can be formed at a low flow rate, high reaction efficiency can be obtained without peeling or damage of supported substances, and the power cost for forming the fluidized bed is low.

Furthermore, when the carrier of the present invention is used in a fixed bed type reaction tank,
Coupled with the fact that clogging does not occur and the specific surface area is large, high reaction efficiency can be obtained.

Furthermore, when the carrier of the present invention is used as a spawning bed for fish, its moderate elasticity prevents the eggs from peeling off due to collisions between the carriers and improves the spawning efficiency.

Agent: Patent attorney Tsuyoshi Shigeno

Claims (2)

[Claims] (1) A carrier made of inorganic fibers, in which inorganic fibers are entangled to form a spherical shape, and the inorganic fibers are bonded together with a binder. (2) Inorganic fibers cut to the required length are impregnated with liquid to form aggregates, then formed into small lumps by vibration or impact, and the small lumps are heated and dried in a rotary granulator, and then bonded. 1. A method for producing a carrier made of inorganic fibers, which comprises impregnating a carrier with an agent and then drying the carrier.