JP2516154B2 - Method and apparatus for producing microbiological energy and useful substances - Google Patents

Abstract

PURPOSE:To produce energy and a useful substance having a multipurpose and complex function by steadily supplying hydrogen and carbon dioxide gas required by hydrogen-assimilating methane-producing bacteria from endogeneous and exogeneous sources. CONSTITUTION:Energy and a useful substance are produced by a thicrobiological process. For example, hydrogen 4 is generated by electrolysis 3 of water by the use of solar energy 1, the generated hydrogen 4 is supplied together with carbon dioxide gas 8 to a culture system 7 for hydrogen-assimilating methane- producing bacteria and the produced methane 9 is burned 10 to yield energy and the carbon dioxide gas 8 to be supplied to the culture system 7. At least a part 13 of the proliferated bacterial cells of the hydrogen-assimilating methane- producing bacteria is purified to produce a useful substance such as a corrinoid 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing energy and useful substances by a hydrogen-assimilating chemoautotrophic bacterium, and in particular, hydrogen required for biosynthesis by a hydrogen-assimilating chemoautotrophic bacterium. The present invention relates to a microbiological treatment technique which can be obtained by electrolyzing water and which also remarkably contributes to elimination of global environmental pollution caused by the production of carbon dioxide.

[0002]

2. Description of the Related Art So-called hydrogen-utilizing chemoautotrophic bacteria are
A useful substance can be produced by growing hydrogen gas as the only electron donor and carbon dioxide as the only carbon source. Therefore, by utilizing hydrogen-utilizing chemoautotrophic bacteria that produce various valuable substances, from the viewpoint of stability, it is possible to supply hydrogen on-site stably, if possible, to prevent global warming. There was a strong demand for the practical application of a new material production technology that fixes carbon dioxide, which is the main cause of, and does not release it to the atmosphere, and that can also contribute to the improvement of the global environment. Conventionally, substance production by effectively utilizing the function of hydrogen-utilizing chemoautotrophic bacteria has been performed at a research level, but the number of cases is relatively small.

[0003] Although there are some pioneering research about the industrial use of the bacterium group, the supply of hydrogen is not only unstable, there is also a problem with the steady supply technology for culture Li actor, these All of these are either left in the middle of the research or are discontinued. For example, a recent excellent research, Daicel Chemical Industries, Ltd. by the acetoacetate Corynebacterium Ujjii (Acetobacterium w
Although there is a study on production of acetic acid from hydrogen and carbon dioxide by Oodii ), this study has not been put to practical use because the prospect of stable supply of hydrogen and cost cannot be predicted .

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As mentioned above,
At present, research on substance production by effectively utilizing the function of hydrogen-assimilating chemoautotrophic bacteria, or technology on chemoautotrophic bacteria capable of producing substances at the same time as energy production by assimilating hydrogen and carbon dioxide Although research has been conducted, these studies have been suspended at the research stage due to the stability of the supply of hydrogen required as a substrate and the unsteadiness of the supply to the reactor, and there is no prospect of industrialization.

The present invention provides a method capable of innovative energy production and material production based on a completely new idea that overcomes the drawbacks of the prior art, and provides a multifunctional and versatile material production process. The purpose is to More specifically, the present invention provides a technique capable of stably supplying hydrogen, and also self-sufficient carbon dioxide gas required by the bacterium in the system, and if necessary, a combustion furnace of a thermal power plant or a business site outside the system. An object of the present invention is to provide a method and a device for producing a corrinoid substance , which is a versatile energy and useful substance by introducing carbon dioxide gas discharged from the substance . In addition, corrinoid
Substance is a general term for compounds with choline nucleus, vitamin B
Cyanocobalamin, 5,6-dimethy, known as ₁₂
Rubens imidazolyl cyanocobamide and other bioactive substances
And related substances.

[0006]

In order to solve the above-mentioned object, the present invention reasonably combines the electrolysis technology of water with electric energy and the respective functions of hydrogen-utilizing chemoautotrophic bacteria, It is intended to provide a novel energy and corinoid substance production method and production device based on a new idea in which functions are combined and multifunctional. That is, the present invention electrolyzes water to generate hydrogen, supplies the produced hydrogen and carbon dioxide to a hydrogen-assimilating methanogen, cultures the same, and burns methane discharged therefrom to generate energy. In addition to the above, carbon dioxide gas generated by combustion of methane is supplied to the culture of the hydrogen-utilizing methanogen, and at least a part of the grown bacterial cells of the hydrogen-utilizing methanogen is purified to produce a corrinoid substance. And a method for producing a microbiological energy and corrinoid substance.

Further, according to the present invention, a hydrogen generator for electrolyzing water to generate hydrogen, a means for introducing the generated hydrogen and carbon dioxide, and a means for discharging the generated methane are provided inside. A reactor capable of culturing methanogens,
Extract excess hydrogen-utilizing methanogen from the reactor.
Cell separation means for taking out and purifying corinoid substances
And a combustor for burning methane discharged from the reactor, and a means for circulating carbon dioxide gas discharged by the combustion in the reactor. In the present invention described above, it is preferable to use a solar cell that utilizes solar energy, which is a clean and permanent energy source, for electrolysis of water.

That is, according to the present invention, hydrogen can be used as an electron donor and can be propagated using inorganic carbon in carbon dioxide as a carbon source, as well as methane as an energy substance and a corrinoid substance as a physiologically active substance. A chemoautotrophic bacterium capable of biosynthesis is inoculated into a culture reactor, while the hydrogen required by the bacterium is secured by solar energy → solar cell → electrolysis of water, which is then cultivated by the chemoautotrophic bacterium. The most preferred embodiment is to continuously and stably introduce the bacterium into the reactor and culture the bacterium in a large amount to produce an energy substance and a corrinoid substance. However, the electrolysis according to the present invention does not prevent the electrolysis from being performed by other power supply means including power purchase.

As a technique for generating hydrogen from water,
Although there is catalytic photolysis of water (for example, Japanese Patent Laid-Open No. 4-295001), it is still far from practical use in terms of efficiency.
In addition, a technique of generating CH ₃ OH + H ₂ O → CO ₂ + 3H ₂ + energy from methanol and water or causing water to act on coke requires a large-scale facility and has a problem of by-product substances.

Furthermore, in the present invention, the electron donor hydrogen, methane productivity of chemical autotrophic bacteria carbon dioxide can be grown as a carbon source, i.e. methanolate Agrobacterium (Methanobacterium) genus, meta knob Levi Citrobacter (Methanobrevibact
er ), methanomicrobium ( Methanomi)
crobium) genus, Methanococcus (Methano
Coccus ) and other hydrogen-utilizing methane-producing chemoautotrophic bacteria are used to inoculate a culture reactor and perform large-scale cultivation to produce energy substances, namely methane, and useful substances, ie, corrinoids. In addition, the carbon dioxide gas required by the bacterium as a carbon source is the carbon dioxide gas generated as a result of using the methane produced by the bacterium itself as an energy source together with the carbon dioxide gas generated from the combustion furnace of a thermal power plant or a business site. Can be supplied. In this way, it is an environment-friendly technology that does not release carbon dioxide gas outside the system.

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a process chart showing an embodiment of the present invention. FIG.
In particular, a specific one or more species of chemoautotrophic bacteria belonging to the hydrogen-utilizing methanogens are selected and cultured separately, and a culture reactor 7 ( In the following, abbreviated as reactor). On the other hand, the solar energy 1 is converted into electric energy by the solar cell 2, and the electric energy is used to electrolyze 3 water.

Of the oxygen and hydrogen obtained in this step, oxygen 5 is used as an oxidant, an O ₃ raw material, breeding oxygen, etc. mainly for multipurpose outside the system, but the generated hydrogen is used for the air supply pipe 4. After passing through the sterilizing filter 6 and passing through the sterilizing filter 6 to remove foreign bacteria, it is introduced into the reactor 7 and used as an electron donor of the chemoautotrophic bacterium of the present invention.
The methane 9 produced by the biosynthesis of methane-producing chemoautotrophic bacteria inoculated into the reactor 7 is burned 10, and the heat and the like are recovered by a recovery device and used for multiple purposes as an energy source. During the combustion of methane 10, oxygen 5 generated in the electrolysis process of the water may be introduced and acted.

Carbon dioxide produced as a result of combustion 11
By being returned and circulated in the reactor 7, a part of carbon dioxide gas and hydrogen necessary for growth are provided as substrate components. The carbon dioxide gas to be supplemented is supplied from the outside of the system 12, and the other essential components are supplied from the medium 17, so that the carbon dioxide gas grows smoothly without delay. Further, H ₂ O generated by combustion of methane can be returned to the electrolysis step 3 and used.

The biological reaction in which a hydrogen-utilizing methane-fermenting bacterium produces methane gas using hydrogen and carbon dioxide as substrates is as follows. CO ₂ + 4H ₂ → CH ₄ + 2H ₂ O The carbon dioxide gas required by methane-producing chemoautotrophic bacteria is insufficient only with the combustion gas 11 of methane, and therefore, for example, an external combustion furnace of a thermal power plant or a business site It is also possible to employ a method in which the exhaust gas 12 from the gas is passed through the sterilization filter 6 and then complementarily introduced into the reactor 7. By applying this type of method, the present invention can significantly contribute to the improvement and conservation of the global environment. The surplus bacterial cells 13 grown in the reactor 7 are periodically and quantitatively drawn out of the reactor 7, and a corrinoid substance is separated by appropriately using a known method . In particular, it is the most preferable embodiment that the corrinoid substance 14 is extracted and separated, purified, and provided for medicinal purposes.

[0015]

The method for producing microbiological energy and corinoid substances by the hydrogen-utilizing chemoautotrophic bacterium of the present invention is as follows: by selecting a methane-producing chemoautotrophic bacterium as the bacterium, Methane, which is an energy substance, is biosynthesized by the supplied hydrogen and carbon dioxide, and the extremely valuable corinoid-based substance, for example , a typical example of which is currently dependent on the import of almost 100% from the inside of the cells. Vitamin B ₁₂ which is a substance
And its related compounds adenosyl cobalamin and methyl
This is an excellent new biological production process that can be provided for medicinal purposes by accumulating useful substances such as cobalamin and other coenzymes in high concentrations, and extracting and purifying this from bacterial cells.

The method of the present invention generated hydrogen very stably by electrolyzing hydrogen, and made it possible to constantly supply hydrogen to the culture reactor of chemoautotrophic bacteria without quantitative fluctuation. Regarding the supply of electric power, it is preferable to install a condenser having an appropriate capacity in order to buffer the instability due to solar energy, which is the optimum mode for carrying out the present invention, at night or in rainy weather. Also, a path for purchasing electricity may be provided. Further, it is needless to say that wind power, wave power, temperature difference, geothermal, magnetic fluid and any other type can be applied as the auxiliary power source.

On the other hand, carbon dioxide gas as a carbon source of chemoautotrophic bacteria is sterilized from carbon dioxide gas produced when methane biosynthesized by hydrogen-utilizing methanogens is burned as an energy source. By constantly supplying to the culture reactor, it is possible to suppress the release of carbon dioxide gas to the outside of the system and promote smooth growth of the bacterium. The carbon dioxide generation / supply line uses CH ₄ generated by the bacterium → oxidative combustion →
CO ₂ → reactor → CH ₄ path is controlled so that the release to the outside of the system is suppressed as much as possible, and a device that does not release carbon dioxide by maintaining an appropriate supply amount, a so-called closed system is configured, which can significantly contribute to global environmental conservation. .

Further, according to the present invention, it is possible to select carbon dioxide gas discharged from combustion furnaces of various workplaces containing a large amount of carbon dioxide gas as a carbon source of the bacterium. It is a new microbiological production technology that can also help to resolve the problem. INDUSTRIAL APPLICABILITY The present invention is a process for effectively utilizing solar energy as a total system to produce energetic substances and corinoid substances, and further achieve efficient internal circulation of substances to reduce CO ₂ load to the outside of the system. This is an epoch-making technology that suppresses this as much as possible. Therefore, in the future,
There is no doubt that this type of process will evolve. We also believe that the adoption of this material production process will definitely contribute to the improvement of the global environment, especially the elimination of global warming.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Example 1 The following test was performed according to the process chart shown in FIG. First, Methanobacterium Agrobacterium Forumi deer arm corrinoids as hydrogen-utilizing the methanogens that accumulated in the cells (M
ethanobacterium formi ci cu
m, ATCC 33274). The bacterium is used as medium A
TCC 1045 (see Table 1 for medium composition) was separately used to carry out expansion culture, and this was used as an inoculum in a culture reactor of 100 m.
1 inoculation.

[0020]

[Table 1]

An additional 900 ml of the medium ATCC 1045 was added to make the total culture volume in the culture reactor 1 liter, and the acclimation was started at a low load of 50 ml / day of the medium at the beginning. From the first week after the start of operation, the feed rate was fixed at 100 ml / day (retention time: 10 days),
When the bacterial cell concentration reached 10000 mg / l (10 g / l), the surplus bacterial cells were quantitatively extracted to maintain the bacterial cell concentration in the reactor at a constant value. The bacterial cell mixture was drawn out of the reactor in an amount equal to the supply amount, separated by a UF membrane and returned to the reactor.

On the other hand, the hydrogen to be supplied to the culture reactor is
As described above, solar energy is converted into electric energy by a solar cell, and water (20
% Sodium hydroxide solution) is electrolyzed to maintain the life of about 10 g of methane-fermenting bacteria present in the culture reactor, and about 12 hydrogen required for growth.
Mol / day (about 24 g H ₂ / day, 270 liters / day,
Actually, because there was a margin in the solar cell, twice the required amount was supplied).
Mol (140 g CO ₂ /day...65 liters /
Day). This was the proportion of _{H 2 / CO 2 = 4/} 1.

Since unused hydrogen and carbon dioxide still remain in the mixed gas of hydrogen and carbon dioxide which is discharged after being used by methanogens in the reactor, a blower installed outside the reactor. 50 liters of exhaust gas due to
Circulates in the tank to increase the gas utilization rate. In order to generate 23 to 25 g / day of hydrogen required by hydrogen-utilizing methanogens, a required electricity amount of about 3 F (Faraday) and a current intensity of about 28 A (Ampere) are required. About 5
It becomes 60W (watt).

[0024] were used in this practical test, the ability of the solar cell using single-crystalline silica and modules, maximum output 100
W / M ² × 10M ² = 1KW, optimum operating voltage is about 20V
olt, the optimum operating current was about 3 A, and the conversion efficiency of solar energy was about 16%, so a lead battery with a storage capacity of 10 times the load was installed after the solar cell, and a booster. Was installed to increase the voltage to 100 Volt, and then the water was electrolyzed. From the above, it can be said that the use of this solar cell has supplied the reactor with double the amount of hydrogen required by 10 g of hydrogen-utilizing methanogens, 24 g / day.

Regarding the carbon dioxide gas to be supplied, as described above, in the present invention, the methane gas biosynthesized by the methanogen is used as an energy source, and the carbon dioxide gas produced as a result is sterilized and harmed. Although air is supplied to the reactor, in the present embodiment, commercially available carbon dioxide gas (purity 99.9%) was purchased and supplied from a cylinder. The supply amount of carbon dioxide gas to the reactor after the verification test reaches the steady state is as described above.

The corrinoid in the surplus cells was extracted by a conventional method, and the corrinoid solution was treated with an ion exchange resin ( Ambe).
rlite XAD-2 ) was adsorbed on a column, and then eluted with methanol to purify it, and the total amount of corrinoid was calculated by an absorptiometer as a dicyano type. that's all,
Operated for 3 months with the detailed experimental equipment and conditions,
Table 2 summarizes the range of various experimental data obtained within one month after the entire system reached a steady state.

[0027]

[Table 2]

Through the above-described demonstration experiment, hydrogen obtained by converting solar energy into electric energy by a solar cell and electrolyzing water by this energy is stable against hydrogen-utilizing methanogens, It was confirmed that it is possible to reliably produce methane, which is an energy substance, and corrinoid, which is a useful substance, by continuously and constantly supplying (at the same time, carbon dioxide gas). Incidentally, Methanobacterium Agrobacterium Forumi deer beam used in this example (Methanobacterium
to obtain substantially the same results also formi ci cum) other than hydrogen-utilizing methanogens.

[0029]

According to the present invention, as described in detail, the invention is based on an idea of a completely different dimension from the prior art, and has the following effects. (1) Solar energy → Solar cells → Hydrogen can be reliably and stably obtained by electrolysis of water, and by continuously and constantly supplying this to hydrogen-utilizing methanogens, energy can be obtained. It is possible to reliably produce methane, which is a substance, and high-value-added corrinoids with remarkable pharmacological effects. Further, by burning methane, energy such as heat energy can be generated.

(2) Comparison of the cost of hydrogen obtained by electrolysis of solar energy → solar cell → water with the cost of hydrogen obtained by the conventional technique on the basis of the purity of 99.99% is about 1/4 cheaper. It is an undeniable fact that solar cells will spread widely in the near future from the viewpoints of global environmental problems, energy conservation, and resource conservation, and the energy and corrinoid substance production technology according to the present invention is a process with extremely high economic effect. I will not say anything.

(3) Since the present invention circulates carbon dioxide gas, which is a substrate of methanogens, in the system and does not discharge it out of the system, it can remarkably contribute to the elimination of global warming. (4) The present invention, unlike the prior art, without generating intractable excess sludge, high value-added growth intracellularly Conversely coli
Accumulates a large amount of oid substances. The residue obtained by extracting this useful substance can be further recycled as feed or fertilizer, so that the present invention can be expected to have a remarkable economic effect.

[Brief description of drawings]

FIG. 1 is a process chart showing an embodiment of the present invention.

[Explanation of symbols]

1: Solar energy, 2: Solar cell, 3: Electrolysis of water, 4: Hydrogen gas pipe, 5: Oxygen, 6: Disinfection filter, 7: Reactor, 8: Return circulation circuit, 9: Methane, 1
0: combustion, 11: CO ₂ , 12: external CO ₂ , 13: surplus cells, 14: corinoid, 15: heat storage device, 16: inoculum, 17: medium, 18: discharge, B: blower

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location (C12P 5/02 (C12P 5/02 C12R 1:01) C12R 1:01) (C12P 17/18 (C12P 17/18 B C12R 1:01) C12R 1:01)

Claims (2)

(57) [Claims] 1. Electrolysis of water to generate hydrogen, the generated hydrogen and carbon dioxide gas are supplied to a hydrogen-assimilating methanogen and cultured, and methane discharged from the bacterium is burned to generate energy. Along with obtaining, supply carbon dioxide gas generated by combustion of methane to the culture of the hydrogen-utilizing methanogen,
A method for producing a microbiological energy and a useful substance, which comprises purifying at least a part of cells of the hydrogen-utilizing methanogen that has grown to obtain a corrinoid substance. 2. A hydrogen-utilizing methanogen is provided inside a hydrogen generator for electrolyzing water to generate hydrogen, and a means for introducing the generated hydrogen and carbon dioxide gas and a means for discharging the generated methane. a reactor capable of culture, remaining from the reactor
Extract the surplus hydrogen-utilizing methanogens, corinoid
Microbial organisms characterized by having a microbial cell separation means for subjecting to substance purification, a combustor for burning methane discharged from the reactor, and a means for circulating carbon dioxide gas discharged by combustion to the reactor Production equipment.