KR20170098011A

KR20170098011A - A floating culture system for mass cultivation of microalgae

Info

Publication number: KR20170098011A
Application number: KR1020160019856A
Authority: KR
Inventors: 이철균; 박한울; 임상민; 이종찬; 김필한; 정대우; 정인재
Original assignee: 인하대학교 산학협력단
Priority date: 2016-02-19
Filing date: 2016-02-19
Publication date: 2017-08-29

Abstract

The present invention relates to a floating culture system for the mass cultivation of microalgae, which comprises the following: a culture vessel surrounded by a microalgae culture medium containing photosynthetic microorganisms to be cultured and a barrier for partitioning environmental water; a floating means making the culture vessel to float above the water surface while fixing the same; and a shape-retaining support retaining the original shape of the culture vessel while being located at the lower end of the culture vessel. According to one embodiment of the present invention, the system having a structure for promoting the mixture of microalgae culture liquid is provided to realize the effect of microbial mass culture.

Description

Description of the Related Art [0002] A floating culture system for mass culture of microalgae {

The present invention relates to a subtype incubator for microbial mass culture.

The generation of carbon dioxide from the use of fossil fuels is causing global warming, and it is necessary to develop biofuels as sustainable green fuels for the era when fossil fuels are depleted. Among biofuels, biodiesel is widely used as a raw material for diesel engines, which is an internal combustion engine, and is a fuel that is attracting attention as an environmentally friendly fuel. However, fatty acid glycerol esters, fatty acids or lipids derived from plants and animals are used as raw materials for production, but since the lipids are mostly food resources, there is a risk that the mass production of biodiesel may cause food depletion problems. Therefore, it is necessary to develop the production resources of lipids for biodiesel production without causing food problems. Microalgae in geological production resources are expected to be a source of future biodiesel because they have excellent ability to produce organic materials, especially lipids, by using photosynthesis using sunlight, carbon dioxide and water. In order to produce biofuels using microalgae-derived lipids, a method different from conventional microalgae production methods must be considered. The method of producing biofuel from microalgae by operating an existing expensive bioreactor is inadequate in view of economical efficiency, and it is not easy to expand or manufacture the scale of the unit reactor on land, It is impossible to enlarge the scale with a reduction of light energy. Therefore, in order to realize the production of biofuels derived from microalgae and to secure economical efficiency, researches have been made to produce microalgae in a large space of a desert or ocean in an inexpensive reactor material such as a plastic material for mass culture. In this regard, Korean Patent No. 1484576 discloses a photobioreactor having a partition wall for promoting the flow of a microalgae culture solution in a marine photobioreactor.

However, in the case of the prior art, since the upper surface and the lower surface of the photobioreactor must be bonded to form a barrier rib, it is not applicable to an open type incubator, and since the durability of the culture container is weakened by thermal bonding for forming barrier ribs, It is not easy to expand the scale of the bioreactor.

It is an object of the present invention to provide a subtype incubator for mass culture of microalgae, which can be used in a large scale, open, closed type photobioreactor, for solving various problems including the above problems. However, these problems are exemplary and do not limit the scope of the present invention.

According to one aspect of the present invention, there is provided a culture container comprising: a culture vessel surrounded by a microalgae culture medium containing a photosynthetic microorganism to be cultured and a flexible barrier for partitioning environmental water; Lifting means for lifting the culture vessel above the water surface while fixing it; And a shape-retaining support for allowing the original shape of the culture vessel to be maintained at the lower end of the culture vessel, is provided for a micro-algae incubator for massive microalgae culture.

According to one embodiment of the present invention as described above, a microcavity large-scale culture effect can be realized by using an incubator having a structure for promoting the mixing of the microalgae culture solution. Of course, the scope of the present invention is not limited by these effects.

1 is a conceptual diagram showing a microalgae culture liquid leaching phenomenon due to algae generated from the outside of a general microalgae incubator 110 in which the shape-retaining support 140 is not installed.
FIG. 2 is a conceptual diagram showing that the micro-algae incubator 100 for mass culture of microalgae of the present invention is provided with the shape-retaining support 140 to prevent the migration of microalgae culture liquid by algae.
FIG. 3 is a view showing a state in which a chain support 142 is installed at the lower end of a micro-algae incubator 100 for mass culturing microalgae of the present invention.
FIG. 4 is a view showing a state in which a rope support 145 is installed at the lower end of a subtype microalgae incubator 100 for mass culture of microalgae of the present invention.
5 is a photograph showing the migration of the microalgae culture liquid of the microalgae incubator 100 without the shape-retaining support 140. FIG. 5A is a photograph showing the microalgal culture liquid of the microalgae incubator 100, This is a photograph showing the prevention of leaning (B).
FIG. 6 is a graph showing the results of analysis of culture solution mixing efficiency according to presence or absence of the shape-retaining support 140 of the micro-algae incubator 100 for mass culture of microalgae of the present invention.

Definition of Terms:

As used herein, the term "microalgae" refers to phytoplankton inhabiting the ocean, and plankton, such as cochlearinism, which often causes red tides, is also a microalgae. Microalgae, which focuses on marine bioenergy research, is a species of microalgae that is rich in lipids, that is, oil. The size is about 10 microns (micron, one millionth of a meter) and about one tenth the thickness of the hair.

As used herein, the term "photosynthetic microorganism" refers to algae, red algae, and blue algae capable of photosynthesis, including, for example, Chlorella, Chlamydomonas , Haematococous , Botryococcus ), may be a three or four etc. death mousse (Scenedesmus), Spirulina (Spirulina), tetra-cell Miss (Tetraselmis), two flying it Ella (Dunaliella), but is not limited to such. At this time, the above microalgae can produce carotenoids, microbial cells, pycobiliproteins, lipids, carbohydrates, unsaturated fatty acids and proteins in a culture container.

The term " environmental water " as used herein refers to water in the space where the inventive photobioreactor is introduced and cultivation is performed, and includes water, fresh water, and water, Water may also be included.

DETAILED DESCRIPTION OF THE INVENTION [

In the subtype microalgae incubator, the environmental water may be seawater, fresh water or water, and the floatation means may be a pontoon, a plastic pail, a styrofoam, a buoy, a pipe or a piece of wood.

The flexible barrier may be an impermeable polymer film, a semi-permeable membrane or a mesh material, and the shape-retaining support may be linear or rod-shaped, and the linear shape-retaining support may be a chain or rope have.

In the subtype microalgae incubator, the flow may be a tidal current, an oceanic current or a wave, and the culture vessel may be an open culture vessel with an open top.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, It is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thickness and size of each layer are exaggerated for convenience and clarity of explanation.

It is to be understood that throughout the specification, when an element such as a film, region or substrate is referred to as being "on", "connected to", "laminated" or "coupled to" another element, It will be appreciated that elements may be directly "on", "connected", "laminated" or "coupled" to another element, or there may be other elements intervening therebetween. On the other hand, when one element is referred to as being "directly on", "directly connected", or "directly coupled" to another element, it is interpreted that there are no other components intervening therebetween do. A uniform code refers to a uniform element. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers and / or portions, these members, components, regions, layers and / It is obvious that no. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

Also, relative terms such as "top" or "above" and "under" or "below" can be used herein to describe the relationship of certain elements to other elements as illustrated in the Figures. Relative terms are intended to include different orientations of the device by adding weight to the orientation depicted in the Figures. For example, in the figures the elements are turned over so that the elements depicted as being on the top surface of the other elements are oriented on the bottom surface of the other elements. Thus, the example "top" may include both "under" and "top" directions depending on the particular orientation of the figure. If the elements are oriented in different directions (rotated 90 degrees with respect to the other direction), the relative descriptions used herein can be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing ideal embodiments of the present invention. In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention should not be construed as limited to the particular shapes of the regions shown herein, but should include, for example, changes in shape resulting from manufacturing.

FIG. 1 is a conceptual diagram illustrating a general microalgae incubator 110 in which a shape-retaining support 140 is not installed, and illustrating the migration of the microalgae culture solution 120 by algae generated from the outside. As shown in the figure, since the conventional microalgae incubator 110 does not have a support capable of maintaining its original shape, it is cultured by the algae 150 generated in the water during the process of culturing the microalgae after being installed on the water surface The shape of the culture container 130 is deformed due to the force applied to one surface of the container 130 and thus the microalgae culture liquid 120 is not mixed evenly and is squeezed to one side. The entire area of the incubator is not used for the microalgae cultivation due to the migration of the microalgae culture solution 120 and the microalgae cultured in the lower part of the microalgae incubator 110 where the depth of the culture container 130 is deep, The microalgae culture liquid 120 can not be smoothly mixed with the sunlight and the productivity of the microalgae incubator 110 per unit area is deteriorated as a result. The present inventors have found that the prevention of deformation of the culture vessel 130 in the form of the algae 150 facilitates smooth mixing of the microalgae culture liquid 120 in the culture vessel 130, As a result, it has been developed a subtype microalgae incubator (100) having a support capable of supporting the shape retention at the bottom of the incubator.

2 shows a schematic view of a subtype microalgae incubator 100 for microalgae mass culture with a shape-retaining support 140, as described above. Since the shape-retaining support 140 is firmly installed at the bottom of the micro-algae incubator 100 to maintain the overall shape of the micro-algae incubator 100, the microalgae culture medium 110 (120) is prevented from leaning, the mixing efficiency of the culture liquid is improved, and all the microalgae are supplied with sufficient sunlight, thereby increasing the use efficiency of the sunlight. As a result, productivity of microalgae per unit area is of course increased. Experimental examples 1 and 2 will now be described in detail with reference to experimental results comparing the productivity of the culture solution with the efficiency of solar irradiation.

The subtype microalgae incubator (100) of the present invention comprises a culture vessel (130) surrounded by a microalgae culture medium containing a photosynthetic microorganism and a flexible barrier separating environmental water and a culture vessel (130) And a shape-retaining support body 140 provided on one or both sides of the lower end of the culture vessel 130 to support the original shape of the culture vessel 130. [ The culture container 130 surrounded by the flexible barrier is characterized in that environmental water, gas, and nutrients can be freely flown in and out, and free diffusion of photosynthetic microorganisms or contaminating microorganisms is blocked. More specifically, by allowing the influx of environmental water, waste materials discharged from the supply of nutrients and growth of photosynthetic microorganisms, which are required to grow photosynthetic microorganisms, can be removed along with the environmental water. This eliminates the need for separate nutrition and purification devices, thus providing cost, time and labor savings. In addition, as the carbon dioxide supply and the release of the generated oxygen can be easily performed in the photosynthesis process of the photosynthetic microorganism and the photosynthetic microorganisms are cultivated in the restrictive culture container in which the photosynthetic microorganisms can be managed, the prevention of environmental pollution due to the mass propagation of the photosynthetic microorganisms And it has an advantage that it is easy to harvest a large amount of cultured photosynthetic microorganisms. The flexible barrier may comprise an impermeable polymer film, a semi-permeable membrane or a mesh material.

In the case of a conventional microalgae incubator, a photobioreactor having a partition wall in order to facilitate the flow of a microalgae culture solution in a marine photobioreactor has been developed. However, in order to form the partition wall, Therefore, it is not applicable to an open type incubator, and the durability of the culture container is weakened by thermal bonding for forming the barrier ribs, so that it is not easy to enlarge the size of the photobioreactor. However, the subtype microalgae incubator 100 of the present invention has an advantage that it can be used in a large-scale microalgae culture or in an open type or closed type photobioreactor.

When the sub-type microalgae incubator 100 is installed on the water surface with environmental water, the culture container 130 is fixed by the lifting means and floated on the water surface due to its buoyancy, thereby providing a condition for culturing the microalgae . As described above, since the shape-retaining support 140 is installed at the lower end of the subtype microalgae incubator 100, the solar energy is not affected by the flow generated in the water, It is possible to use it efficiently in the area, so that the optimum condition for microalgae cultivation is attained. The shape-retaining support 140 may be a chain or a sling and the environmental water may be seawater, fresh water or water, and the underwater flow may be a tidal current, an oceanic current or a wave .

2 is a perspective view of the shape-retaining support 140 to emphasize the features of the subtype microalgae incubator 100 of the present invention in which the shape of the culture vessel 130 remains unchanged from the pressure of water such as algae or waves. The shape-retaining support 140 may be installed on one side or the entire surface of the culture container 130 to maintain the shape of the entire culture container 130 and maintain the shape of a part of the surface of the culture container 130 . Also, although the shape of the shape-retaining support body 140 is described as a line like the above, other types of supports such as wooden rods or plastics that can maintain the shape of the culture vessel 130 from algae can also be used. The configuration of the subtype microalgae incubator 100 according to the type of the shape-retaining support 140 will be described in detail with reference to FIGS. 3 and 4. FIG.

FIG. 3 shows an embodiment in which a chain support 142, which is one type of shape-retaining support 140, is installed at the bottom of the subtype microalgae incubator 100 of the present invention. As shown in the figure, a chain support 142 is installed on the entire lower surface of the culture container 130 accommodating the microalgae culture liquid 120, so that the culture container 130 ) Can be prevented and the original shape can be maintained. The chain support 142 shown in FIG. 3 is installed on the entire lower surface of the culture container 130 in order to easily understand the characteristics of the present invention. However, depending on the installation environment and structure of the incubator, It can be installed in various variants such as installation.

4 shows another embodiment in which a rope support 142, which is one type of shape-retaining support 140, is installed at the bottom of the subtype microalgae incubator 100 of the present invention. Unlike the chain support 142 of FIG. 3, the rope support 145 is installed horizontally at a certain distance from the lower end of the culture container 130. It is also possible to make various modifications, such as installing the rope support 145 in a diagonal direction rather than horizontally, in a manner different from the above-described configuration, in order to facilitate the understanding of the structure in which the rope support body 145 is installed. The number of the rope supporting bodies 145 may be increased or decreased depending on the purpose of maintaining the shape. In the present invention, the shape-retaining support 140 is installed in the rectangular culture container 130. However, even if the shape of the culture container 130 is circular, rhombic, or other shape, So that the efficiency of culturing the microalgae can be improved.

FIG. 5 is a photograph for showing a comparison of migration phenomena according to presence or absence of the shape-shape holding support 140. As shown in FIG. 5, it is possible to visually observe the leaching phenomenon of the culture solution of the conventional microalgae incubator, 100 can be easily understood.

5A shows a microalgae incubator in which a separate shape-retaining support body 140 is not provided, and the culture container 130 is tilted through a portion marked with an asterisk (*), It is showing the floor being exposed. This is because the bottom surface of the microalgae culture medium 120 is deepened due to the modified culture vessel 130 as described above, and micro-algae present in the lower surface of the microalgae culture medium 120 are not sufficiently supplied with solar energy, (120) is not smoothly mixed in the culture container (130), which leads to a decrease in production efficiency per unit area. 5B, when the shape-retaining support 140 is provided under the culture container 130, the shape of the culture container 130 can be maintained, so that the solar energy can be efficiently supplied to all the areas of the incubator It is possible to economically improve the productivity of microalgae. Further, as shown in Fig. 5, lifting means for fixing the culture container 130 and floating it on the water surface are shown. The lifting means is coupled in parallel or in series around the culture container 130 to fix the culture container 130 and facilitate the entry and exit of workers. In addition, the lifting means is preferably a pontoon, since it is required to provide sufficient buoyancy on the water surface, but a plastic pail, a styrofoam, a buoy, a pipe or a piece of wood can also be used.

How the installation of the shape-retaining support 140 installed in the subtype microalgae incubator 100 for mass culture of the microalgae of the present invention affects the mixing efficiency of the microalgae culture solution 120 is explained through Experimental Example 1 do.

Hereinafter, the present invention will be described in more detail through experimental examples. It should be understood, however, that the invention is not limited to the disclosed exemplary embodiments, but is capable of other various forms of implementation. The following examples are intended to be illustrative of the present invention, Is provided to fully inform the user.

Experimental Example 1: Analysis of mixing efficiency of microalgae culture

The difference in the mixing efficiency (%) of the microalgae cultures according to the installation of the shape-retaining supports included in the micro-algae incubator manufactured according to one embodiment of the present invention was observed.

First, a 1.1 kg mass of sodium nitrate salt was added to 5 kL of seawater in an incubator equipped with a chain support as an experimental group, a culture vessel equipped with a rope support, and a culture vessel without a shape support as a control, and the sodium nitrate solution And the time taken for the concentration of nitrate ions in the culture solution to reach equilibrium was measured.

As a result, the mixing efficiency was somewhat reduced when the chain support was provided, but the mixing efficiency of the incubator equipped with the rope support 145 was significantly increased as compared with the control without the shape-retaining support. The above results show that, compared to a chain support which only firmly fixes the shape of the culture vessel, the rope support not only prevents the culture liquid inside the incubator from leaking but also allows the movement of the incubator to some extent to transfer the wave energy to the culture liquid Higher mixing efficiency was shown by further promoting the mixing of the culture medium (Fig. 6).

EXPERIMENTAL EXAMPLE 2: Analysis of Efficiency of Photovoltaic Efficiency with Enhanced Microalgae Productivity

The difference in the productivity of microalgae and the efficiency of solar utilization was observed according to the presence or absence of the shape-retaining support included in the micro-algae incubator manufactured according to one embodiment of the present invention. First, an incubator equipped with a basic type incubator with a working area of 16 m ² and a working volume of 2.5 kL, a chain support and a rope support was used. To 2.5 kL of natural seawater was added 1.1 kg of sodium nitrate (NaNO ₃ ), sodium dihydrogen phosphate ₂ PO ₄₎ by using the medium supplemented with 0.075 kg culture was performed for 14 days. The solar utilization efficiency means the ratio of energy stored in the microalgae biomass through photosynthesis relative to the total solar energy supplied to the incubator during the incubation period.

As a result, the microalgae productivity and solar utilization efficiency of the experimental group with the support for shape maintenance were higher than those of the control group without any type of support. In particular, the rope support showed higher microalgae productivity than the chain support. This result shows that since the culture solution is more easily mixed in the incubator having the rope support, the effect of spreading the culture solution evenly by the shape maintenance and the effect of enhancing the mixture of the culture solution It is because it is added. The results of Experimental Example 2 are shown in Table 1 below.

Control Chain support Rope support Micro-algae productivity (g / m ² / d) 1.3 2.3 3.2 Solar efficiency (%) 0.14 0.26 0.36

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. will be. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: Subtype microalgae incubator
110: General microalgae incubator
120: Microalgae culture solution
130: culture container
140: Shape retaining support
142: chain support
145: rope support
150: Birds

Claims

A culture vessel surrounded by a microalgae culture medium containing a photosynthetic microorganism to be cultured and a flexible barrier for partitioning environmental water;
Lifting means for lifting the culture vessel above the water surface while fixing it; And
And a shape-retaining support body capable of maintaining the original shape of the culture vessel at the lower end of the culture vessel.

The method according to claim 1,
Wherein said environmental water is seawater, fresh water, or nadir; and a micro-algae incubator for mass culture of microalgae.

The method according to claim 1,
Wherein said support means is a pontoon, a plastic canister, a styrofoam, a buoy, a pipe or a piece of wood, and a subtype microalgae incubator for massive microalgae culture.

The method according to claim 1,
Wherein the flexible barrier comprises an impermeable polymer film, a semi-permeable membrane or a mesh material.

The method according to claim 1,
Wherein said shape-retaining support is a linear or bar-shaped micro-algae incubator for massive micro-algae culture.

6. The method of claim 5,
Wherein the linear shape-retaining support is a chain or a sling, the micro-algae incubator for mass culture of microalgae.

The method according to claim 1,
The shape-retaining support is a subtype microalgae incubator for large-scale microalgae culture, which allows uniform solar energy to be accommodated in all the areas inside the culture container by preventing deformation of the culture container due to flow (flow) .

8. The method of claim 7,
Wherein the flow is a tidal current, an oceanic current or a wave. A micro-algae incubator for mass culture of microalgae.

The method according to claim 1,
Wherein said culture vessel is an open type culture vessel with an open upper part; and a subtype microalgae incubator for mass culture of microalgae.