KR102101022B1 - apparatus for disrupting and separating cell wall of microalgae using ultrasound - Google Patents

Abstract

The present invention relates to a device for breaking down and separating cell walls of microalgae using ultrasonic waves, and more specifically, by breaking the cell wall by applying ultrasound to the microalgae to separate lipids, thereby separating lipids from microalgae. Destruction and separation device.
The apparatus for crushing and separating microalgae using ultrasonic waves according to the present invention includes an ultrasonic disrupting unit that destroys the cell walls of microalgae by applying ultrasonic waves while stirring the microalgal culture medium flowing from the microalgal incubator, and a lipid layer from the discharged material from the ultrasonic disrupting unit It is provided with a lipid separation portion for separating.

Description

Apparatus for disrupting and separating cell wall of microalgae using ultrasound}

The present invention relates to a device for breaking down and separating cell walls of microalgae using ultrasonic waves, and more specifically, by breaking the cell wall by applying ultrasound to the microalgae to separate lipids, thereby separating lipids from microalgae. Destruction and separation device.

Due to global warming and concerns about fossil fuels, fuel production using biomass is in the spotlight. On the other hand, however, the production of biodiesel using grain resources is a growing concern due to environmental burdens and competition with food resources. Therefore, a method of producing biodiesel using microalgae or forest resources without competition from food is attracting attention.

Among these, microalgae have the advantage of having better photosynthetic efficiency than land plants, and can directly use carbon dioxide emitted from a thermal power plant, and a significant portion of the body is composed of lipids that can be converted into fuel.

Among the components of the microalgal biomass, lipid is a component that is easily converted into fuel, and can be converted into transportation fuel by a transesterification method or a deoxygenation method.

In general, the main processes for producing biodiesel from microalgae include cultivation of microalgae, lipid extraction (cell destruction) and transesterification.

In particular, a method commonly used as a conventional lipid extraction method is a method for extracting lipids in microalgae using a non-polar organic solvent such as hexane (Bligh EG, Dyer WJ, A rapid method of total) lipid extraction and purification, Can J Biochem Physiol, Vol 37, 1959, pp 911-917). This is a method of recovering lipids and residual biomass by dehydrating the microalgae through physical and thermal treatment, drying it, and then extracting it with an organic solvent such as hexane through a pre-treatment process to destroy the cell wall.

Since microalgae have a problem in that extraction efficiency is extremely low due to the solid cell walls surrounding them, cell wall destruction technology is very important to solve this.

However, the conventional lipid extraction method consumes a considerable amount of energy for the dehydration process, and is complicated and expensive because it has to undergo several steps such as cell wall destruction and solvent extraction, and the lipid is not pure due to chemical solvent treatment. There is a problem that can not.

In particular, in the case of a conventional dewatering process for lipid extraction (pre-treatment process), after physically removing water from the microalgae slurry, additionally heat-drying or freeze-drying such that the water content of the microalgae itself is 10% or less. It has to be done and there is a significant amount of energy, cost and time consuming in this process.

Korean Patent Registration No. 10-1205780 discloses a method for recovering lipids through heat treatment on microalgae without crushing a separate cell wall, but this also consumes excessive energy in that a dewatering process is inevitably required. It does not solve the problem of having to go through several steps.

Republic of Korea Patent Registration No. 10-1205780: lipid recovery from microalgae by two-step pyrolysis

The present invention was created to improve the above problems, and provides a device for destroying and separating cell walls of microalgae capable of effectively extracting lipids from microalgae by separating lipids by breaking the cell walls by applying ultrasound to the microalgae. There is a purpose.

In addition, it is an object of the present invention to provide a device capable of automatically constructing a harvesting, destruction, and separation system in conjunction with a microalgae incubator.

The apparatus for crushing and separating microalgae using ultrasonic waves of the present invention for achieving the above object comprises: an ultrasonic breaking unit that destroys the cell walls of microalgae by applying ultrasonic waves to the microalgal culture medium flowing from the microalgal incubator; It is provided with; a lipid separation unit for separating the lipid layer from the discharged from the ultrasonic destruction unit; the ultrasonic destruction unit, an extraction tank connected to the incubator and the connection unit, and ultrasonic generating means for generating ultrasonic waves inside the extraction tank, A pulse electric field unit for applying a pulse electric field to the culture medium moving along the connection unit and a gas supply unit for injecting carbon dioxide into the culture medium moving along the connection unit.

The ultrasonic generating means applies ultrasonic waves of 20 to 60 kHz for about 10 to 60 minutes.

The pulse electric field unit includes an electrode installed in the connection unit, a power unit for supplying power to the electrode, and a controller for controlling pulses and electric fields generated through the electrode.

The connection part, an inlet pipe connected to the incubator, a cylindrical chamber in which the inlet pipe is connected to one side, an outlet pipe connected to the other side of the chamber, and a circular core portion installed in the center of the chamber, A gas injection pipe extending through the chamber into the core portion and connected to the gas supply portion to supply carbon dioxide, a gas chamber formed in an annular shape inside the core portion and connected to the gas injection pipe, and the core in the gas chamber It is formed to extend to the outer circumferential surface of the part, and a plurality of spouts for ejecting carbon dioxide into the culture fluid introduced into the chamber, a streamlined first ridge formed protruding from the inner circumferential surface of the chamber, and protruding from the outer circumferential surface of the core part And a streamlined second raised portion formed to face the first raised portion.

As described above, the present invention can separate and recover lipids through single step extraction instead of conventional multi-step process extraction by extracting lipids by applying ultrasound to microalgae. Therefore, the present invention can effectively separate and recover lipids with low energy, low cost, and simple process, and can obtain pure lipids without chemical solvent treatment.

In addition, the present invention can effectively extract lipids from microalgae by separating lipids by destroying cell walls by applying a pulsed electric field and carbon dioxide together with ultrasonic waves.

In addition, the present invention can provide a device capable of automatically constructing a harvesting, destruction, and separation system in conjunction with a microalgae incubator.

1 is a block diagram showing the configuration of the cell wall destruction and separation device of the microalgae according to an example of the present invention,
Figure 2 is a schematic view showing the configuration of the cell wall destruction and separation device of the microalgae according to an embodiment of the present invention,
Figure 3 is a cross-sectional view showing the main portion of Figure 2,
Figure 4 is a cross-sectional view showing a main portion of the cell wall destruction and separation device of the microalgae according to another example of the present invention.

Hereinafter, a cell wall destruction and separation device of microalgae using ultrasonic waves according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3, the cell wall destruction and separation device of the microalgae of the present invention is an ultrasonic destruction unit (10) that destroys the cell walls of microalgae by applying ultrasonic waves to the microalgal culture medium flowing from the microalgal incubator (1) And, a lipid separation unit 30 for separating the lipid layer 31 from the discharged from the ultrasonic destruction unit (10).

The ultrasonic destruction unit 10 is connected to the microalgal incubator 1, and the microalgal culture medium cultured from the incubator 1 is introduced.

The microalgae culture medium flowing into the ultrasonic destruction unit 10 may be used in a concentrated form to increase lipid extraction efficiency. Concentration of the culture medium may be performed by electrical or chemical methods, evaporation of moisture, or by physical filtration.

The microalgae used in the present invention is not particularly limited as long as it can extract lipids as biomass. Ankistrodesmus genus, Scenedesmus genus, Chlorella genus, Anabaena genus, Oscillatoria genus, Botryococcus genus, Neochloris genus, Tetraselmis genus, Porphyridium genus, Phaeodactylum genus, Nannochloropsis genus, Ellipsoidion genus, Isochrysis genus, Pavlova genus, Thalassiosira genus, Skeletonema genus Chlorococcum genus, Dunaliella genus, Aphanizomenon genus, Haematococcus genus, Crypthecodinium genus, Shizochytrium genus, Hormidium genus, Chlamydomonas genus, Monallanthus genus, Nannochloris genus, Cylindrotheca genus, Nitzschia genus, Pleurochrysis genus, Prymnesium genus, Spirulina genus Any one of the microalgae can be used.

The ultrasonic destruction section 10 pulses the extraction tank 11 connected to the incubator 1, the ultrasonic generating means for generating ultrasonic waves inside the extraction tank 11, and the culture medium moving along the connection section 50 It is provided with a pulse electric field portion for applying an electric field, and a gas supply portion for injecting carbon dioxide into the culture medium moving along the connection portion 50.

The extraction tank 11 is connected to the incubator 1 and the connecting portion 50. The connecting portion is, for example, a pipe structure having a flow path formed therein. The culture solution supplied from the incubator 1 flows into the extraction tank 11 through the connection part 50. An impeller stirrer may be installed inside the extraction tank 11 to stir the culture medium.

The ultrasonic generating means generates ultrasonic waves inside the extraction tank 11 to destroy the cell walls of the microalgae. For example, the ultrasonic generating means may apply ultrasonic waves of 20 to 60 kHz for about 10 to 60 minutes. When ultrasonic waves are applied to the culture medium, the cell walls are destroyed and intracellular lipids are released out of the cells. Since the lipid extraction method using ultrasonic waves proceeds in a physical manner, unlike conventional chemical methods, there is no emission of harmful substances and the purification process can be omitted.

The ultrasonic generating means for generating ultrasonic waves has a conventional structure. Although not shown, the ultrasonic generating means may include a controller and a vibrator. The controller generates ultrasonic waves of a suitable frequency for a certain time through the vibrator by applying a high frequency current to the vibrator. Of course, one or more oscillators may be installed in the extraction tank 11.

The pulse electric field and the gas supply unit increase the extraction efficiency of lipids by adding a pulse electric field and carbon dioxide into the culture medium flowing into the extraction tank 11.

When pulsed electric fields (PEF) are applied into the culture medium, cells are damaged by a high voltage, strong pulsed electric field. When a strong electric field is applied to the cell from the outside, the potential difference between the cell membranes increases, and charges generated on both surfaces of the cell membrane have opposite charges, so that an attractive force acts between the two charges. This attraction compresses the cell membrane and reduces the thickness of the membrane. Accordingly, the attraction force between the cell membranes with reduced thickness is further increased, and as a result, the increased attraction force further decreases the thickness of the cell membrane, and at the same time, the same charges on both sides of the cell membrane form a repulsive force. If this action continues, pores are eventually formed on the cell membrane, and when the intensity of the external electric field exceeds a certain level, irreversible pores are formed and the cell membrane is destroyed.

Although not shown, the pulse electric field unit includes an electrode, a power unit that supplies power to the electrode, and a controller that controls pulses and electric fields generated through the electrode.

The electrode is installed in the connection portion 50. One side of the connection part 50 is connected to the incubator 1, and the other side is connected to the extraction tank 11. The connecting portion 50 is provided with a shaft pipe portion 55 in which a flow path is narrowed, and an electrode may be installed on the inner wall of the shaft pipe portion 55. 3, the electrodes 21 and 22 are installed in pairs to face each other on the inner wall of the shaft tube portion 55. The pair of electrodes 21 and 22 may be installed at intervals of 0.1 to 10 cm.

A DC power supply may be used as a power supply for supplying power to the electrodes. In addition, the controller controls the power supplied to the electrode to control the pulse width and electric field strength. The pulse electric field unit may apply a pulse electric field having a power of 20 to 100 W and a frequency of 10 to 60 Hz to the culture medium.

The gas supply unit injects carbon dioxide into the culture medium moving along the connection unit 50. As an example, the gas supply unit may be formed of a gas boom 25 where carbon dioxide is stored, and a gas supply pipe 27 connecting the gas boom 25 and a connection portion.

When carbon dioxide is injected into the culture solution, carbon dioxide bubbles are generated, and the carbon dioxide bubbles promote the transfer of electromagnetic waves in the liquid. In addition, carbon dioxide lowers the pH value of the culture medium to facilitate cell destruction.

As described above, the present invention can effectively increase the extraction efficiency of lipids by effectively destroying cells by applying ultrasound together with pulsed electric field and carbon dioxide into the culture medium.

When the lipids are discharged from the cells in the extraction tank 11, lipids having a low specific gravity are mainly present in the upper layer of the extraction tank 11. Therefore, in order to increase the extraction amount of lipids, it is preferable that only the supernatant of the extraction tank 11 is discharged to the lipid separation unit 30, and the lower layer liquid is again introduced into the connection unit 50 and repeatedly extracted. To this end, a circulation pipe 13 is installed under the extraction tank 13. The circulation pipe 13 is connected to the connection part 50.

The lipid separating unit 30 separates the lipid layer 31 from the discharged material from the extraction tank 11.

The effluent discharged from the extraction tank 11 contains lipids discharged from cells, water, and dead microalgae. The lipid separation unit 30 separates the discharge into each component by gravity. A clarity may be used as the lipid separation unit 30.

The effluent transferred to the lipid separation unit 30 is separated from the lipid layer 31 and the aqueous layer 33 by gravity. The lipid layer 31 may be separated from the aqueous layer 33 and recovered by recovering the supernatant. In addition, the microalgae that have been killed due to the destruction of the cells are settled to the bottom to form a solid material layer 35.

As described above, the present invention can separate and recover lipids through single step extraction instead of conventional multi-step process extraction by extracting lipids by applying ultrasound to microalgae. Therefore, the present invention can effectively separate and recover lipids with low energy, low cost, and simple process, and can obtain pure lipids without chemical solvent treatment.

In addition, the present invention can effectively extract lipids from microalgae by separating lipids by destroying cell walls by applying a pulsed electric field and carbon dioxide together with ultrasonic waves. In addition, the present invention can provide a device capable of automatically constructing a harvesting, destruction, and separation system in conjunction with a microalgae incubator.

On the other hand, the present invention can be applied to the structure of the connecting portion as shown in FIG. 4 so that the carbon dioxide bubbles generated in the connecting portion can be finely dispersed at the same time as other examples.

Referring to FIG. 4, the connection part includes an inlet pipe 61 connected to the incubator, a cylindrical chamber 63 in which the inlet pipe 61 is connected to one side, and an outlet pipe 65 connected to the other side of the chamber 63 ), A circular core portion 67 installed at the center of the chamber 63 and a gas injection pipe that penetrates the chamber 63 and extends into the core portion 67 and is connected to the gas supply portion to supply carbon dioxide. (69), a gas chamber 71 formed in an annular shape inside the core portion 67 and connected to the gas injection pipe 69, and a chamber formed to extend from the gas chamber 71 to the outer circumferential surface of the core portion 67 A plurality of spouts 73 for ejecting carbon dioxide into the culture medium introduced into the inside of 63, the streamlined first raised portion 75 formed by protruding from the inner circumferential surface of the chamber 63, and the core portion 67 It has a streamlined second raised portion 77 formed to face the first raised portion 75 protruding from the outer circumferential surface.

The inlet pipe 61 connects the incubator and the chamber 63. The culture liquid discharged from the incubator is introduced into the chamber 63 through the inlet pipe 61. The inlet pipe 61 is disposed in a direction out of the center without facing the center of the chamber 63 so that the culture fluid flowing into the chamber 63 can rotate along the periphery of the core portion 67.

The culture liquid introduced into the chamber 63 is discharged through the outlet pipe 65. The outlet pipe 65 is connected to the extraction tank of the ultrasonic breaking portion. Therefore, the culture liquid discharged from the chamber 63 flows into the extraction tank through the outlet pipe 65. The outlet pipe 65 is also disposed in a direction out of the center of the chamber 63 like the inlet pipe 61.

The core portion 67 is installed inside the chamber 63. The diameter of the core portion 67 is formed smaller than the inner diameter of the chamber 63. A passage through which the culture medium flows is formed between the core portion 67 and the chamber 63.

The core portion 67 is formed in a rod shape. Inside the core portion 67, an annular gas chamber 69 is formed, and a plurality of spouts 73 are formed around the gas chamber 69. The spout 73 is formed to be bent in the turning direction of the culture medium.

The gas injection pipe 69 is connected to the gas supply pipe of the gas supply unit. Therefore, the carbon dioxide supplied from the gas supply unit flows into the gas chamber 71 through the gas injection pipe 69.

The culture liquid flowing into the chamber 63 through the inlet pipe 61 forms a swirl flow flowing around the core portion 67. The carbon dioxide discharged through the spout 73 forms a myriad of vortices while colliding with the culture medium to enhance the gas-liquid contact effect. And since the width of the passage through which the culture medium passes is narrowed by the first raised portion 75 and the second raised portion 77, the expansion and contraction of the fluid is repeated while the velocity and pressure of the fluid change, thereby forming fine bubbles. You can.

Also, although not shown, an electrode may be installed on the inner circumferential surface of the chamber so as to apply a pulsed electric field into the chamber.

On the other hand, in the embodiment of Figures 1 to 4, the ultrasonic destruction portion may be omitted only the pulse electric field is made of only extraction tank, ultrasonic generating means, gas supply unit.

As described above, the present invention has been described with reference to one embodiment, but this is only exemplary, and those skilled in the art will understand that various modifications and equivalent embodiments are possible therefrom. Therefore, the true protection scope of the present invention should be defined only by the appended claims.

1: Microalgae incubator 10: ultrasonic destruction
11: extraction tank 30: lipid separation unit
50: connection

Claims (4)

An ultrasonic destruction unit that destroys the cell wall of the microalgae by applying ultrasonic waves to the microalgal culture medium flowing from the microalgal incubator;
It is provided with; a lipid separation unit for separating the lipid layer from the discharged from the ultrasonic destruction unit,
The ultrasonic destruction part is connected to the incubator and the incubator, an extraction tank for discharging the supernatant to the lipid separation unit, ultrasonic generating means for generating ultrasonic waves inside the extraction tank, and a frequency of 10 to 60 kHz in the culture medium moving along the connection unit The pulsed electric field for applying a pulsed electric field, and a gas supply portion for injecting carbon dioxide into the culture medium moving along the connection portion to promote electromagnetic transmission in the culture liquid, and installed at a lower portion of the extraction tank to be connected to the connection portion. It is provided with a circulation pipe for introducing the lower layer liquid of the extraction tank to the connection,
The connection part is an inlet pipe connected to the incubator, a cylindrical chamber to which the inlet pipe is connected to one side, an outlet pipe connected to the other side of the chamber, and a diameter smaller than the inner diameter of the chamber A core portion formed in a circular shape and forming a passage through which the culture medium flows between the chamber, a gas injection pipe extending through the chamber into the core portion and connected to the gas supply portion to supply carbon dioxide, and the core It is formed in an annular shape in the interior of the gas chamber connected to the gas injection pipe, and extends from the gas chamber to the outer circumferential surface of the core portion and is bent in a direction in which the culture fluid rotates to eject carbon dioxide into the culture fluid introduced into the chamber. A number of spouts and the culture medium passing through the passage by narrowing the width of the passage expand and It has a streamlined first raised portion formed to protrude from the inner circumferential surface of the chamber so as to repeat the contraction and a streamlined second raised portion formed to protrude from the outer circumferential surface of the core portion to face the first raised portion,
The inlet pipe is disposed in a direction out of the center of the chamber so that the culture fluid flowing into the chamber can be rotated along the periphery of the core,
The pulsed electric field unit includes an electrode installed in the chamber, a power supply unit for supplying power to the electrode, and a controller for controlling the pulse and electric field generated through the electrode. Separation device. The apparatus for crushing and separating microalgae using ultrasonic waves according to claim 1, wherein the ultrasonic generating means applies ultrasonic waves of 20 to 60 kHz for 10 to 60 minutes. delete delete

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