KR101408800B1 - Photobioreactor including multilayered structure - Google Patents

Abstract

A photobioreactor for culturing microalgae in a culture chamber comprises a casing forming a culture chamber for accommodating a culture medium containing microalgae, a hollow inner cylinder provided in the culture chamber, and a culture medium And an impeller for circulating the air.

Description

[0001] PHOTOBIOREACTOR INCLUDING MULTILAYERED STRUCTURE [0002]

The present invention relates to a photobioreactor, and more particularly, to a photobioreactor having a multi-barrier structure suitable for light propagation in culturing microalgae.

Due to its diverse abilities, microalgae continue to expand their use, such as wastewater treatment, carbon dioxide immobilization, fuel material production, pharmaceutical production, and cosmetics production. Thus, in order to mass produce biomass and useful products, it is necessary to develop an efficient incubator capable of providing a uniform environment while safely culturing microalgae.

There are many factors influencing the biomass weight and useful product growth of microalgae such as medium composition, temperature, pH, luminous intensity, and light intensity. However, light has the largest proportion of the microalgae .

Micro-algae are cultivated by a photobioreactor that maintains a closed system. Micro-algae cultivation environments using photobioreactors are generally classified into active and dark reactions. In order to maximize the incubation time and extracting amount of microalgae through photobioreactor for photochemical reaction, various conditions must be satisfied. Among them, the amount of light to be irradiated and the injection amount (density) of carbon dioxide have the greatest influence.

However, the conventional photobioreactor has a disadvantage in that it does not transmit effective light internally, slows the growth rate of microalgae, requires low growth rate of microalgae, and requires a wider installation space than its efficiency.

Korean Patent No. 10-897019 discloses a technique for increasing the light source irradiation efficiency by using a plurality of light guide plates, including a cylindrical reactor, a plurality of light guide plates provided in a radial direction around the central rotation axis, and a carbon dioxide supply device have. However, since the density of microalgae is not uniform in the cylindrical reactor and the light guide plate can act as a kind of flat impeller and continuously strike with microalgae, it can give lethal stimulation to microalgae, have.

Korean Patent No. 10-0945153 discloses that a cylindrical light source is inserted into a reaction chamber, and carbon dioxide introduced from the gas injection port in the vicinity is discharged to the outside through a gas exhaust port in the upper center. Although microalgae are cultured in large quantities among a plurality of cylindrical light sources, the density of microalgae in the reaction chamber is not uniform and it is not easy to move the microalgae up and down.

The present invention provides a photobioreactor capable of uniformly maintaining the density of microalgae in a culture chamber of a photobioreactor and uniformly exposing microalgae to light through continuous circulation.

The present invention provides a photobioreactor capable of minimizing damages or destruction of microalgae by means of an impeller while forming forced circulation by using an impeller.

The present invention provides a photobioreactor capable of maximizing the effect of surface-to-volume ratio or S / V ratio provided with light and uniformizing the density of carbon dioxide in water.

According to an exemplary embodiment of the present invention, a photobioreactor for culturing microalgae in a culture chamber includes a casing forming a culture chamber for accommodating a culture liquid containing microalgae, a hollow interior A cylinder, and an impeller which is located inside the hollow cylinder and circulates the culture liquid.

The photobioreactor can use natural light supplied from the outside or artificial light supplied from the inside, and the casing forms a culture chamber which is temporarily closed to cultivate the microalgae of the culture liquid to a certain level .

To this end, a hollow inner cylinder having an open upper end and a lower end is provided in the casing, and the impeller is located inside the inner cylinder to circulate the culture liquid. The impeller can be forced to flow the culture liquid upward in the interior of the inner cylinder, assuming that the carbon dioxide is supplied from the lower portion of the culture chamber, and the culture liquid deviating from the upper end of the inner cylinder can pass through the space between the inner cylinder outer wall and the casing inner wall, And the culture liquid can be circulated as a whole while entering the inner cylinder at the lower end of the inner cylinder again.

The microalgae can be continuously exposed to natural light or artificial light while the culture liquid circulates and the gas density such as carbon dioxide can be uniformly maintained as a whole.

Here, the impeller may include a rotating shaft provided parallel to the inner cylinder and a helical blade continuously connected along the rotating shaft. That is, a screw type or helical ribbon type impeller can be used, and the culture liquid can flow in one direction inside the inner cylinder, so that the microalga can be forcibly moved.

However, since the micro-algae may be damaged or destroyed by the impeller blades, carbon dioxide may be supplied from the lower portion of the impeller to form an air bed at the bottom of the blades, and the micro- Direct contact can be minimized.

The inner cylinder may be provided with a light source that irradiates the inside or the outside entirely with artificial light. Even if the external natural light is blocked by the shadow effect, the internal micro-algae can be exposed to the light by the internal light source part, and the light area ratio can be maximized.

The internal light source unit can irradiate light toward the inside of the inner cylinder, but can also irradiate light toward the outside. It is possible to use the light of the internal light source portion directed to the outside, in addition to increasing the above-described light spot area ratio, even when natural light from outside is insufficient.

The photobioreactor of the present invention can uniformly maintain the density of the microalgae in the culture chamber and allow the microalgae to be uniformly exposed to light through continuous circulation.

The photobioreactor of the present invention is capable of minimizing damages or destruction of microalgae by means of an impeller to form a forced circulation by using an impeller.

The photobioreactor of the present invention can maximize the effect of the S / V ratio and can uniformize the density of carbon dioxide in water.

FIG. 1 is a perspective view of a photobioreactor according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the photobioreactor of FIG. 1, and FIG. 3 is a partial cutaway view And FIG. 4 is a cross-sectional view for explaining the flow of the culture liquid inside the photobioreactor of FIG.
FIG. 5 is a partial enlarged view for explaining the action of the impeller of FIG. 1, and FIG. 6 is a view showing the distribution of particles having fluidity in FIG. 1 in view of the finite element analysis.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments. For reference, the same numbers in this description refer to substantially the same elements and can be described with reference to the contents described in the other drawings under these rules, and the contents which are judged to be obvious to the person skilled in the art or repeated can be omitted.

FIG. 1 is a perspective view of a photobioreactor according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the photobioreactor of FIG. 1, and FIG. 3 is a partial cutaway view And FIG. 4 is a cross-sectional view for explaining the flow of the culture liquid inside the photobioreactor of FIG.

1 to 4, the photobioreactor 100 according to the present embodiment includes a casing 110, an inner cylinder 120, an impeller 130, an impeller driving unit 140, and a gas supply unit 160 do. The casing 110 may contain a culture medium containing microalgae, and the culture medium may be forced to circulate along a path defined by the inner cylinder 120.

In the present embodiment, the inner cylinder 120 is provided as one in the center, but in some cases, two or more inner cylinders may be provided, and two or more inner cylinders may be disposed in parallel with each other and each may include an impeller, It can be provided with a substantially concentric structure around one impeller. Of course, there may also be an internal cylinder that does not receive the impeller.

In the present embodiment, the inner light source unit 150 is mounted on the inner cylinder 120 to irradiate light toward the inside and outside. As described above, when a plurality of inner cylinders are provided, the inner light portion of each inner cylinder generates light to the inside, outside, or inside / outside, thereby maximizing the light area ratio.

The casing 110 may be provided with a light-transmitting or transparent side wall for using external natural light. For this purpose, it may be provided by using ABS resin or PET resin, and may also be provided by glass.

The inner cylinder 120 is also provided inside the casing 110 using a similar material. The inner cylinder 120 may be provided in a cylindrical shape corresponding to the cylindrical casing 110. Alternatively, the inner cylinder 120 may be formed in a shape corresponding to the shape of the casing such as a column, a cone or a prism column or an irregular shape, Does not limit the shape of the inner cylinder.

A screw-type or helical-type impeller 130 may be provided inside the inner cylinder 120. The impeller 130 forms an axial flow and is continuously formed to correspond to the entire length of the inner cylinder 120 so that a uniform carbon dioxide distribution can be formed even at a low rpm flow.

The mixture of microalgae, culture liquid and carbon dioxide can be continuously supplied from the gas supply unit 160 in the lower part of the culture chamber to the inside of the inner cylinder 120 by the impeller 130, The mixture moving from the upper end of the inner cylinder 120 moves down through a space between the outer wall of the inner cylinder 120 and the inner wall of the casing 110, And can enter the inside of the inner cylinder 120. As shown in FIG. 3, the microalgae, the culture solution, and the carbon dioxide are continuously circulated, and the microalgae can be uniformly exposed to external natural light. In this embodiment, carbon dioxide can be supplied at a flow rate of about 0.0001 kg / s.

FIG. 5 is a partially enlarged view for explaining the operation of the impeller of FIG. 1, and FIG. 6 is a view showing a distribution of particles having fluidity in the photobioreactor of FIG. 1 in view of finite element analysis.

5, the carbon dioxide 20 supplied from the lower portion of the impeller 130 may be used for producing an effective substance by melting in the culture liquid or reacting with the microalgae. However, the carbon dioxide 20 may be generated on the surface of the helical blade 134 of the impeller 130 An air bed can be formed.

If the blades of the impeller 130 come into direct contact with the microalgae, the microalgae can be damaged or destroyed, which can cause the light to be transferred to other microalgae as a suspension and lower the overall yield.

However, as shown, when the carbon dioxide is finely broken by the helical blade 134 and the carbon dioxide forms an air bed around the helical blade 134, the micro-algae are moved directly to the blade 134 by the air bed Contact can be minimized.

6, a helical blade 134 is formed in a spiral shape along the entire length inside the inner cylinder 120, and particles having fluidity around the helical blade 134, for example, microalgae, strain Or carbon dioxide is provided at a relatively high density, and thus the importance of the air bed can be more clearly explained.

Referring again to FIGS. 2 to 4, an internal light source unit 150 is provided inside the internal cylinder 120. The internal light source unit 150 may include a plurality of light emitting devices 154 mounted on the flexible substrate 152 and the flexible substrate 152. The plurality of light emitting devices 154 may be formed on a substrate capable of being bent, and may be provided to face inward and outward.

The inner light source unit 150 may be bent like a paper sheet and inserted into the inner cylinder 120 and may be a light source that irradiates the inner or outer surface of the inner cylinder 120 as a whole. Accordingly, even if the micro-algae inside the inner cylinder 120 are shielded from natural light by the shadow effect, the micro-algae inside the inner cylinder 120 can be exposed to the light by the internal light source unit 150. Through this process, the area ratio of the light spot can be maximized.

FIG. 7 is a graph showing the flow rate in the reactor according to an embodiment of the present invention, and FIG. 8 is a graph showing the density of the interior of the reactor according to an embodiment of the present invention.

7, when the flow speed of the internal photobioreactor to check to be kept at about 95mm / s across over, under, with reference to Figure 8, the density inside the photobioreactor evenly with about 1mg / m ³ Distribution .

This shows that the culture chamber inside the casing 110 is separated by the inner cylinder 120 and the impeller 130 of the inner cylinder 120 maintains the flow rate and density uniformly while forcibly circulating the culture liquid have.

Although the present invention has been described with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the following claims. It can be understood that

100: photobioreactor 110: casing
120: inner cylinder 130: impeller
150: internal light source unit 160: gas supply unit

Claims (9)

In a photobioreactor for culturing microalgae,
A casing forming a culture chamber for accommodating a culture liquid containing the microalgae;
A hollow inner cylinder provided in the culture chamber; And
And an impeller which is located inside the hollow cylinder and circulates the culture liquid containing the microalgae,
Wherein the impeller includes a rotating shaft provided parallel to the inner cylinder and a helical blade continuously connected along the rotating shaft,
And a gas supply unit for supplying carbon dioxide at a lower portion of the inner cylinder,
And the carbon dioxide supplied from the gas supply unit forms an air bed along the helical blade. delete delete The method according to claim 1,
Further comprising an internal light source part for irradiating light to the inner wall of the inner cylinder. 5. The method of claim 4,
Wherein the inner light source unit emits light toward the outside in addition to the inside of the inner cylinder. 5. The method of claim 4,
Wherein the internal light source portion includes a flexible substrate and a plurality of light emitting elements mounted on the flexible substrate. The method according to claim 1,
Wherein the casing includes light-transmissive sidewalls and utilizes light from the outside. The method according to claim 1,
Wherein a plurality of the inner cylinders are provided in the casing. The method according to claim 1,
Wherein the plurality of inner cylinders are arranged in parallel or concentrically.

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