JPS6221769A - Manufacture of porous ceramic structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a porous porcelain structure that can be used as a bioreactor, a material, a sound absorbing material, a heat insulating material, an aeration pipe, or the like.

(Prior art) There are various methods for immobilizing microorganisms, enzymes, etc., such as carrier binding method, cross-linking method, entrapping method, and composite method. Can be divided.

The lattice type is a method in which enzymes are wrapped in a lattice of glue, and ceramic porous bodies are increasingly being used as a holder for %r glucos because ceramic has advantages such as chemical resistance and microbial inactivity.

(Problem to be solved by the invention) However, in the conventional technology, the strength of the glue is insufficient,
Alternatively, enzymes, microbial cells, etc. may leak out due to insufficient glue retention in the ceramic porous body, resulting in problems such as product contamination, decreased yield, and increased manufacturing costs.

ζNext means for solving the problem) The present invention was made as a result of intensive studies to solve the above problem, and involves forming fibrous crystals of silicon nitride in porous porcelain. Based on the idea of This method succeeded in forming crystals in the form of crystals, overcoming the problems of the prior art. .

(Function) According to the present invention, since the pores of the porous porcelain are filled with the desired active silicon nitride fibrous crystals (whiskers), the glue is firmly fixed in the pores by the fibers. This makes it possible to significantly reduce the amount of microbial enzymes, etc. that leak out.

Example 1 Silicon powder (reagent 1st grade 200 mesh, pass)...300
Ii Tertiary butyl alcohol...2401n
tHydroxyglobil cellulose (RPC-8L manufactured by Nippon Soda)...Pour 3I or more into an alumina porcelain pot mill with an internal volume of 11 (15 mφ9
9. (Using 1 kg of S-group alumina coccule)) Pulverize and mix for 72 hours. The thus obtained t-slurry was transferred to a beaker, and alumina porous porcelain (average pore diameter 70 μm,
Porosity 62 cm, size 50 x 80 W x 5 V
m) Soak.

The beaker is placed in a vacuum deaerator to remove the air inside the porous body, and then returned to atmospheric pressure to allow the slurry to permeate into the pores.

The product thus obtained was heated at a temperature of 1380°C in a mixed gas atmosphere of 60 volumes of nitrogen gas and 40 volumes of hydrogen gas.
Bake for 1 hour.9. The fired products are shown in Figures 1 to 3 (
As shown in the microscopic copper photo), the inside of the pores is filled with fine silicon nitride fibers. (4fJ tQQ10×2o
o, Xr*o, x2oob) Therefore, the glue is firmly fixed in the pores by the fibers, and the outflow of microorganisms, enzymes, etc. can be greatly reduced.

Example 2 A honeycomb was formed using spinel (yrght2o4) material, and enzyme immobilization and fermentation tests were performed.

(1) Molding and firing of honeycomb structure The above was dissolved and mixed in a kneader for 1 hour to form a 4-stroke.

This is set in a simple extrusion molding machine (manual type), cooled to -15°C below zero with dry ice, extruded into an N2 kerosene tank, and frozen.

The dimensions of the honeycomb molded body are length 10 as shown in Figure 4.
0m, diameter 50'1mm, pinch 3m, wall thickness 0,5
It is m.

The two frozen molded bodies are placed in a freeze dryer and dried for 6 hours.

The dried product is fired in an electric furnace at a temperature of 1680°C for 2 hours.

The fired body is a porous body with a porosity of 60 cm and an average pore diameter of 30 μm.

The dimensions are unchanged from the time of molding.

(2) Silicon impregnation and baking treatment Using the same silicon slurry and impregnation method as in Example 1,
One side of the fired product was treated and baked under the same conditions.This product has a similar structure with silicon nitride fibers formed in the pores.

(3) Enzyme immobilization The above ingredients are mixed and heated to 80°C to dissolve, and then allowed to cool.

Separately, a sake yeast suspension 15- is prepared and mixed with the carrageenan solution.

Two types of honeycombs are immersed in this mixed solution, vacuum degassed to remove air, and then the pressure is returned to atmospheric pressure to impregnate the pores with the solution.

On the other hand, prepare 2000 fnt of 1.51 KC2 solution,
The honeycomb is soaked in this solution to completely glue the impregnating solution.

The thus obtained 9 yeast-immobilized dal (il-1500-) was poured into a culture solution and cultured at 30°C for 5 days.

In this way, honeycomb-shaped immobilized yeast glue is obtained.

(4) Alcohol fermentation test A fermentation test was carried out using a fermentation apparatus as shown in FIG. 5, in which 300 di of a fermentation liquid mainly containing glucose was poured.

The outline of the apparatus is shown in FIG. 5, in which a honeycomb structure 1 is installed in a housing 2. A condenser 3 is attached to the upper part of the device 2, and cooling water is allowed to flow in all directions of the arrows. Further, the device 2 is connected by an arm ignition so that the fermentation solution is circulated from the upper side to the lower end, and a heat exchanger 4 connected to a constant temperature water tank 5 and a circulation bonder 6 are sequentially provided in the middle. The lower part of the device 2 is also connected to an air cylinder 7°7. In addition, the upward flow rate of the fermentation liquid in the device 2 is set to 5~-, and the flow rate in the pipe is 430o/FnI.
This is n.

The results of a fermentation test using this equipment are shown in Figure 6.

According to this, the product according to the present invention can obtain a high alcohol concentration in a short period of time, whereas the product treated as a comparative example has a lower alcohol production rate. However, in the case of the one according to the present invention, no blockage was observed in the honeycomb cells, but in the case of the comparative example, it was observed that the immobilized pores were peeled off from the pores and partially blocked the honeycomb cells. .

In carrying out the present invention, the material of the porous porcelain is not limited to the above-mentioned alumina, and titania, silica, norphea, etc. may also be selected as appropriate.

Effects of the Invention According to the present invention, fibrous crystals of silicon nitride can be generated in the pores of porous porcelain by an extremely simple method, and the manufactured product can be produced in the pores of porous porcelain. The remarkable increase in surface area of fibrous crystals compared to the surface area and lattice defects of fibrous crystals provides a porous carrier with excellent adsorption and binding properties, and the carrier itself Dimensional stability ratio, stability against bacteria, stability against changes and chemical attack of solutions, thermal stability, high temperature combustion of the enzyme after deterioration, making it fully reusable, activity of the immobilized nine enzymes Excellent long-term stability
It is capable of demonstrating L-friend performance.

In addition to enzymes, it can be used to separate and purify microorganisms, biochemical substances, and immobilize microorganisms, and can also be used in a wide range of fields such as reaction tubes, 7 materials, sound absorbing materials, heat insulation materials, and aeration pipes. Needless to say, it can be used.

[Brief explanation of drawings]

Figures 1 to 3 are microscopic photographs of the fc product obtained according to the present invention, Figure 4 is a perspective view of the dimensions of the honeycomb structure used in the test, and Figure 5 is a simplified explanation of the alcohol fermentation test equipment. Figure 6 is a graph of the fermentation test results. DESCRIPTION OF SYMBOLS 1... Honeycomb structure, 2... Device, 3... Condenser, 4... Heat exchanger, 5... Constant temperature water tank, 6...
...Circulation pump, 7...Air pump

Claims (1)

[Claims] A porous porcelain structure characterized in that fibrous crystals of silicon nitride are formed in the pores by filling the pores of porous porcelain with silicon powder and firing in a hydrogen and nitrogen mixed gas atmosphere. manufacturing method.