JP2011156475A - Carbon dioxide reduction system by subterranean isolation of algae fixing discharged co2 - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely reduce CO<SB>2</SB>by collecting and isolating algae having absorbed CO<SB>2</SB>. <P>SOLUTION: The algae 3 are stored in a reactor tank 2, CO<SB>2</SB>from a thermal power plant 1 is supplied to the algae 3, which are irradiated with the sunlight to perform photosynthesis. The algae 3 having absorbed CO<SB>2</SB>by the photosynthesis is isolated into an underground cavity 6 to isolate CO<SB>2</SB>. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a system for reducing CO ₂ by collecting and sequestering algae with fixed exhaust CO ₂ .

In recent years, global warming has been regarded as a problem, and a specific policy for suppressing an increase in the concentration of CO _{2 in} the atmosphere, which is a major cause of global warming, has been demanded. In order to suppress an increase in the concentration of CO ₂ , various considerations have been made such as CO ₂ emission regulation, emission credit trading, CO ₂ collection, storage, and sequestration. Conventionally, by supplying CO ₂ to algae, techniques for immobilizing CO ₂ algae have been proposed (e.g., see Patent Document 1).

In Patent Document 1, supplying the CO ₂ in algae, by irradiating sunlight, algae utilize the incorporation of CO ₂ by the photosynthesis, it is immobilized CO ₂ algae. As a result, for example, CO ₂ generated in large quantities at a thermal power plant or the like is absorbed and fixed to prevent global warming. In addition, algae in which CO ₂ is fixed is reused or discarded as a fertilizer, feed, soil improvement material, for example.

However, reuse of algae for fertilizers means that algae are decomposed, and fixed CO ₂ is released to the atmosphere. Eventually, as shown in FIG. 5, after the CO ₂ from the CO ₂ source to absorb fixed with algae, CO ₂ algae is decomposed by reuse of the algae is open to the atmosphere, the CO ₂ Kamata Algae Only CO ₂ circulates, such as being absorbed by The same is true when algae are disposed of by incineration.

Thus, the technique of absorbing and fixing CO ₂ using algae and reusing the algae cannot suppress global warming by suppressing the emission of CO ₂ .

In addition, there is a concept of carbon balance in which a target value for suppression is specifically determined and executed for the absolute amount of emissions such as environmentally hazardous substances centering on CO ₂ . For example, target values are set and executed in all areas of the product life cycle, from product development / production to logistics, recycling, and disposal.

Such a concept reduces the CO ₂ emitted in the process such as production, but does not consider reducing the already emitted CO ₂ .

JP 10-314546 A

The present invention has been made in view of the above situation, by isolating and collecting the algae incorporating CO _2, geological sequestration algae fixing the CO ₂ emissions that can reduce the CO ₂ reliably The purpose is to provide a carbon dioxide reduction system.

A first mode for achieving the above object is the isolation means for collecting the algae that have absorbed carbon dioxide discharged into the atmosphere by photosynthesis and isolating the algae by sending the algae to the ground. carbon dioxide reduction system according to geological sequestration algae fixing the discharge CO _2, characterized in that it comprises a certain.

In the first aspect, by photosynthesis algae absorbs CO _2, since the algae are isolated in the ground together with the CO ₂ absorbed, CO ₂ without releasing CO ₂ absorbed by the algae into the atmosphere Can be isolated directly. This realizes a reduction in CO _2.

  Underground is a general term for land and submarine substratum, and includes existing holes such as wells that have withered water and holes that have been excavated for oil field development.

According to a second aspect of the present invention, in the carbon dioxide reduction system by underground sequestration of algae with fixed exhaust CO ₂ described in the first aspect, the algae are stored in a reaction tank, and the reaction bath is in the reduction of carbon dioxide system according geosequestration algae fixing the discharge CO _2, characterized in that light in the pooled the algae is configured to be irradiated.

In the second aspect, the algae cultured in the reaction tank can be used to absorb and sequester CO ₂ in the atmosphere to reduce CO ₂ .

A third aspect of the present invention is the reduction of carbon dioxide system according geosequestration algae fixing the discharge CO ₂ to the first aspect, the algae, characterized in that inhabiting lakes in the carbon dioxide reduction system according to geological sequestration fixed algae emission CO ₂ to.

In the third aspect, CO ₂ in the atmosphere can be sequestered using algae that inhabit the lake, and CO ₂ can be reduced. In particular, when targeting abnormally generated algae, the algae can be collected to improve water quality.

According to a fourth aspect of the present invention, in the carbon dioxide reduction system according to any one of the first to third aspects, the carbon dioxide reduction system by sequestration of algae with fixed exhaust CO ₂ supplies carbon dioxide to the algae. in the carbon dioxide reduction system according to geological sequestration algae fixing the discharge CO _2, characterized in that it comprises a carbon supply means.

In the fourth aspect, more CO ₂ can be absorbed by the algae. This aspect is suitable for use in combination with a facility that emits a large amount of CO ₂ such as a thermal power plant.

According to a fifth aspect of the present invention, in the carbon dioxide reduction system according to any one of the first to fourth aspects, the carbon dioxide reduction system by sequestration of algae with fixed exhaust CO ₂ is used to promote the growth of the algae. in the carbon dioxide reduction system according to geological sequestration algae fixing the discharge CO _2, characterized in that it comprises a fertilizing unit.

In the fifth aspect, the algae production can be increased by the fertilizer application means, the absorption of CO ₂ can be promoted, and the sequestered CO ₂ can be increased.

A sixth aspect of the present invention, in the first to fifth carbon reduction system according to geological sequestration algae fixing the discharge CO ₂ as described in any one of the aspects of, ground which the algae are sent prospecting It is a carbon dioxide reduction system by underground sequestration of algae with fixed exhaust CO ₂ characterized by being a well or a waste oil well.

In the sixth aspect, it is possible to isolate the algae that has absorbed CO ₂ in the exploratory wells or waste oil wells, it is possible to isolate the CO ₂ to an existing deep underground site, holes for isolating the CO ₂ It is not necessary to excavate a new one.

A seventh aspect of the present invention, in the first to fifth carbon reduction system according to geological sequestration algae fixing the discharge CO ₂ as described in any one of the aspects of, ground which the algae are sent submarine It is a carbon dioxide reduction system by underground sequestration of algae with fixed exhaust CO ₂ characterized by being an underlayer.

In the seventh aspect, the plankton that has absorbed CO ₂ can be isolated in the submarine underlayer, and the technology of CCS (CO ₂ submarine storage) can be applied.

CO ₂ reduction system according to collecting and isolating the algae of the present invention, it is possible to reliably reduce the CO ₂ by collecting and isolating the algae has absorbed CO _2.

It is a schematic diagram of a carbon dioxide reduction system according to geological sequestration fixed algae emission CO ₂ according to an embodiment of the present invention. It is a schematic diagram of a carbon dioxide reduction system according to geological sequestration fixed algae emission CO ₂ that inhabit lakes. It is a schematic block diagram of the carbon dioxide reduction system in the case of actively cultivating algae. It is a schematic block diagram of the carbon dioxide reduction system which has a fertilizer means which accelerates | stimulates culture | cultivation of algae. It is a conceptual diagram of the carbon dioxide reduction system which concerns on a prior art.

Based on FIG 1, illustrating a CO ₂ reduction system according to geological sequestration fixed algae exhaust CO _2. FIG. 1 shows a schematic configuration for explaining a carbon dioxide reduction system by underground sequestration of algae with fixed exhaust CO _{2 according} to an embodiment of the present invention. The carbon dioxide reduction system according to the present embodiment is provided on the site of a thermal power plant that is an example of a CO ₂ generation source (carbon dioxide supply means), and CO ₂ (exhaust CO ₂ ) discharged from the thermal power plant or the like. ₂ ) is absorbed and sequestered.

As shown in the figure, a reaction tank 2 is provided outside the thermal power plant 1. The reaction tank 2 is a container whose upper surface is opened, and the algae 3 are stored in the inside together with water. The reaction tank 2 is connected to a CO ₂ discharge part (not shown) of the thermal power plant 1 via a pipe 4, and the CO ₂ discharged from the thermal power plant 1 is stored in the reaction tank 2. The algae 3 are supplied.

The algae 3 stored in the reaction tank 2 are supplied with CO ₂ discharged from the thermal power plant 1. The reaction tank 2 has a lid formed of a member that transmits sunlight, such as glass, although not shown in particular, so that only CO ₂ discharged from the thermal power plant 1 is supplied into the reaction tank 2. It has become. Since sunlight is irradiated inside the reaction tank 2 arranged outdoors, photosynthesis is performed. By this photosynthesis, CO ₂ discharged from the thermal power plant 1 is absorbed by the algae 3. Naturally, CO ₂ in the atmosphere is also absorbed by the algae 3 in the vicinity of the water surface of the reaction tank 2.

CO ₂ dissolves more in water than in air. Therefore, CO ₂ can be absorbed more efficiently than when plants other than algae 3 are used. In addition, as algae 3, it is preferable to use a thing with a finer size. This is because if it is fine, the contact area with water becomes larger, so that CO ₂ can be efficiently absorbed. Examples of the microalgae include cyanobacteria (Microkistis, Anabena, Anabenopsis), and green algae (Chlorella, Squidamo, Chlamydomonas). Any algae may be used, but among them, it is preferable to select one having a high ability to fix CO ₂ .

On the other hand, the reaction tank 2 is connected to the cavity 6 through an isolating means (pump 5), and the algae 3 in the reaction tank 2 is pumped up by the pump 5 and introduced into the cavity 6. . That is, the algae 3, CO ₂ is sent to the left isolation means in a state of being absorbed underground are collected on site by (pump 5) (cavity 6), with CO ₂ algae 3 absorbed Isolated in the cavity 6.

The “underground” as used herein refers to a place where the algae 3 in which CO ₂ has been absorbed is not decomposed without being exposed to the atmosphere, or even if it is decomposed, it does not come out on the ground. Specific examples of the underground may be a cavity 6 newly excavated to isolate the algae 3 (see FIG. 1), an oil field gap (waste oil well) after the fuel is taken out, or an oil field For example, voids (test wells) etc. after performing the test digging. In particular, when an oil field gap or the like is applied, CO ₂ can be sequestered in the ground using the existing ground gap. In addition, in places close to the coastal area such as the thermal power plant 1, the algae 3 may be isolated to the seabed underlayer through a pipeline disposed on the seabed.

  As the pump 5, for example, an eccentric rotor is rotated inside a stator whose cross-sectional shape continuously changes in the axial direction, and a Mono pump or a screw-like screw that pumps a slurry-like conveyed product in the axial direction is rotated. Thus, a screw pump or the like that transfers the slurry-like transported material in the axial direction can be applied. When the algae 3 is in the form of a slurry, it is preferable to use these Mono pumps or screw pumps. Although not particularly illustrated, a filtering device or the like may be provided to separate water, and only the algae 3 may be pumped into the cavity 6.

In the CO ₂ reduction system described above, the algae 3 are photosynthesized in the reaction tank 2 to absorb CO ₂ , and the algae 3 are isolated together with the absorbed CO ₂ in the cavity 6, so that the CO ₂ absorbed by the algae 3 is absorbed. CO ₂ can be directly sequestered without releasing it into the atmosphere. For this reason, it becomes possible to collect and sequester the algae 3 that have absorbed CO ₂ from the thermal power plant 1 and to reliably reduce CO ₂ .

In particular, CO ₂ is not isolated directly into the underground cavity 6 but is fixed to the algae 3, and the algae 3 is isolated in the cavity 6. If CO ₂ is isolated directly into the cavity 6, CO ₂ is a gas, and therefore, there is a risk of leaking to the ground via a gap in the ground.

However, in the present invention, since CO ₂ is isolated by the algae 3, there is no possibility of such a leak, so that the state where CO ₂ is isolated in the cavity 6 can be stably maintained. Further, since there is no possibility of CO ₂ leakage, the cavity 6 may be present at a shallow depth. Therefore, it can be realized at a lower cost than providing a deep cavity.

Since CO ₂ reduction by algae according to the prior art is to decompose algae (see FIG. 5), CO ₂ was released to the atmosphere, and CO ₂ reduction was not effective. However, in the carbon dioxide reduction system according to the present invention, since the algae 3 to which CO ₂ is fixed is isolated as described above, it is possible to make the CO ₂ reduction effective and practical. .

Another embodiment of the CO ₂ reduction system will be described with reference to FIG. FIG. 2 shows a schematic configuration for explaining a carbon dioxide reduction system by underground sequestration of algae with fixed CO ₂ inhabiting lakes. In addition, the same code | symbol is attached | subjected to the thing same as what was shown in FIG. 1, and the overlapping description is abbreviate | omitted.

In the carbon dioxide reduction system described above, the CO ₂ discharged from the thermal power plant 1 is directly fixed to the algae 3, but the CO ₂ discharged to the atmosphere is indirectly fixed to the algae 3. Also good. Such a carbon dioxide reduction system is illustrated.

  As shown in the drawing, the lake 7 is inhabited with abnormally generated algae 3 such as so-called blue powder. A pump 5 that collects the algae 3 is disposed in the vicinity of the lake 7. The algae 3 collected by the pump 5 is put into the cavity 6 through the filtration device 8. The filtration device 8 is a device that separates water and algae 3. The water separated by the filtering device 8 is returned to the lake 7 so that the lake 7 does not dry up.

Then, the algae 3 separated by the filtering device 8 is sent to the cavity 6 while the CO ₂ is absorbed, as in the CO ₂ reduction system shown in FIG. 1, and the algae 3 is absorbed by the absorbed CO _2. At the same time, the cavity 6 is isolated. For this reason, it is possible to directly sequester CO ₂ without releasing a large amount of CO ₂ absorbed by the abnormally generated algae 3 into the atmosphere.

In other words, the carbon dioxide reduction system according to the present embodiment uses the occurrence of an abnormality in the algae 3 as an opportunity to isolate CO ₂ , and absorbs the algae 3 to eliminate the state called blue powder and improve the water quality of the lake 7. And CO ₂ can be reduced at the same time.

In the embodiment described above, the algae 3 are used to absorb and sequester CO ₂ that is inevitably generated by the implementation of a business such as power generation in the thermal power plant 1 or the like. Abnormally generated algae 3 was absorbed and sequestered for water quality improvement and CO ₂ reduction. However, the carbon dioxide reduction system of the present invention may be one that actively cultures the algae 3 in order to absorb and sequester CO ₂ in the atmosphere.

  3 and 4 show a schematic configuration of the carbon dioxide reduction system when the algae 3 are actively cultured.

As shown in FIG. 3, the carbon dioxide reduction system according to this embodiment is configured as a CO ₂ absorption plant including a culture tank 2 </ _b > A, a pump, and a cavity 6. Specifically, the culture tank 2A is a container having an open upper surface, and is arranged so that sunlight is irradiated to the inside thereof. The culture tank 2A is provided in the vicinity of the cavity 6 provided by excavating the ground, and the algae 3 of the culture tank 2A is introduced into the cavity 6 by the pump 5.

In such a culture tank 2A, CO _{2 in} the atmosphere is taken into the culture tank 2A and irradiated with sunlight, so that the algae 3 are photosynthesised. By this photosynthesis, CO ₂ in the atmosphere is absorbed by the algae 3. The algae 3, similar to the CO ₂ reduction system shown in FIG. 1, algae 3 is sent to the left cavity 6 in a state in which CO ₂ has been absorbed, algae 3 into the cavity 6 with CO ₂ absorbed Isolated. For this reason, CO ₂ can be directly isolated without releasing CO ₂ in the atmosphere to the atmosphere.

  In addition, after collecting and isolating the algae 3 from the culture tank 2A, the algae 3 is newly supplied into the culture tank 2A or left until the algae 3 increases to a certain amount. Fertilizer means may be provided so as to actively culture the algae 3.

  As shown in FIG. 4, in order to promote the culture of the algae 3, fertilizing means 9 for fertilizing the environment inhabited by the algae 3 is used. The fertilizer application means 9 spreads iron (iron compound) in the culture tank 2A. By the application of iron by the fertilizing means 9, the iron content in the culture tank 2A can be supplemented, and the environment inhabited by the algae 3 can be fertilized to grow the algae 3. In addition to iron, nitric acid, ammonia (nitrogen compound), and phosphoric acid can be added to increase the algae 3.

The present invention can be used in the industrial field of systems that reduce CO ₂ by collecting and sequestering algae.

DESCRIPTION OF SYMBOLS 1 Thermal power plant 2 Reaction tank 2A Culture tank 3 Algae 4 Piping 5 Pump (isolation means)
6 Cavity (underground)
7 Lakes 8 Filtration equipment 9 Fertilizer means

Claims (7)

The exhausted CO ₂ is fixed by collecting the algae that have absorbed carbon dioxide discharged into the atmosphere by photosynthesis and isolating the algae by sending the algae into the ground. Carbon dioxide reduction system by underground sequestration of algae. In the carbon dioxide reduction system by underground sequestration of algae with fixed exhaust CO _{2 according} to claim 1,
The algae are stored in a reaction tank,
The reaction vessel is stored carbon dioxide reduction system according to geological sequestration fixed algae emission CO ₂ to light to the algae, characterized in that it is configured to be irradiated. In the carbon dioxide reduction system by underground sequestration of algae with fixed exhaust CO _{2 according} to claim 1,
The algae, carbon dioxide reduction system according to geological sequestration algae fixing the discharge CO _2, characterized in that in which inhabit lakes. In the carbon dioxide reduction system by underground sequestration of the algae in which the exhausted CO ₂ is fixed according to any one of claims 1 to 3,
A carbon dioxide reduction system by ground sequestration of algae with fixed exhaust CO ₂ , comprising carbon dioxide supply means for supplying carbon dioxide to the algae. In the carbon dioxide reduction system according to geological sequestration algae fixing the CO ₂ emissions to any one of claims 1 to 4,
A carbon dioxide reduction system by sequestration of algae with fixed exhaust CO ₂ , comprising fertilizer means for promoting the growth of the algae. In the carbon dioxide reduction system by underground sequestration of algae to which the exhausted CO ₂ is fixed according to any one of claims 1 to 5,
A carbon dioxide reduction system by sequestration of algae with fixed exhaust CO ₂ characterized in that the ground to which the algae is sent is a test well or a waste oil well. In the carbon dioxide reduction system by underground sequestration of algae to which the exhausted CO ₂ is fixed according to any one of claims 1 to 5,
Carbon dioxide reduction system according to geological sequestration algae fixing the discharge CO _2, characterized in that the ground in which the algae are sent is sub-seabed layers.

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