WO2013149442A1

WO2013149442A1 - Novel internal component and photobioreactor based on enhanced mixing along light direction

Info

Publication number: WO2013149442A1
Application number: PCT/CN2012/078265
Authority: WO
Inventors: 李元广; 黄建科; 康少锋; 沈国敏; 王军; 孙炳耀; 严逸
Original assignee: 华东理工大学; 上海泽元海洋生物技术有限公司; 嘉兴泽元生物制品有限责任公司
Priority date: 2012-04-05
Filing date: 2012-07-06
Publication date: 2013-10-10
Also published as: CN104640970A; CN103361257A; CN104640970B

Abstract

The present invention provides a novel photobioreactor and an internal component thereof. The photobioreactor comprises a transparent housing and multiple regularly arranged transparent baffle plates. The baffle plates are axially placed in the housing and tilt horizontally. A trapezoidal partial space is formed between the baffle plates. The photobioreactor enables fluid in a central area (dark area) of the reactor and fluid in a surface area (light area) of the reactor to rapidly and periodically circulate, thereby enhancing mixing of fluid along a radial direction (light direction) of the reactor.

Description

Novel internal component and photobioreactor based on enhanced illumination direction mixing

The invention belongs to the field of microalgae biotechnology, and relates to a novel photobioreactor and an internal mixing member thereof, which can realize high density and high yield cultivation of microalgae. Further, the present invention is also applicable to other fields of culture or chemical reaction (e.g., photosynthetic bacteria culture, plant cell culture, photocatalytic reaction, etc.) which require light irradiation. Background technique

Microalgae is rich in various high value-added substances such as protein, polysaccharide, polyunsaturated fatty acid and carotenoid. At the same time, microalgae has the ability to absorb N/P elements and accumulate oil during cultivation. Therefore, microalgae are in bioenergy. It is widely used in many aspects such as biological carbon sequestration, environmental protection, food, feed and medicine. In particular, in recent years, in terms of bioenergy, microalgae is considered to be the most promising raw material for biofuels such as biodiesel.

Photobioreactor is the core device for micro-algae photoautotrophic culture. The performance of photobioreactor directly affects the cell density and yield of microalgae culture. Currently, photobioreactors for microalgae culture are available in both open and closed configurations. Open photobioreactors are mainly open-ended runway pools and round pools, which are the most widely used reactor types in the current large-scale outdoor culture of microalgae. Although open photobioreactors have the advantages of easy construction, convenient operation and low operating cost, they also have many disadvantages, such as low density and yield of algae cells, unsuitable control of culture conditions, and vulnerability to contamination by protozoa. Another type of photobioreactor is a closed photobioreactor, which has the advantages of high culture density, high cell yield, easy control of culture conditions, and low contamination by protozoa compared with open photobioreactors. Therefore, the closed photobioreactor has a wide range of applications in high-density culture of microalgae, production of high value-added substances in microalgae and experimental research. In particular, in recent years, the large-scale cultivation of energy microalgae requires a large number of algae species, and the traditional large-scale step-by-step expansion method has problems such as long cycle and easy to be contaminated (which may lead to failure of expansion). The reactor is used as a seed expansion device for energy microalgae (non-heterotrophic culture or algal species with very low heterotrophic culture rate), which can greatly reduce the risk of failure of energy microalgae seed expansion. When the seed expansion period is shortened, the energy microalgae culture efficiency is improved.

At present, closed photobioreactors are mainly of three types: column type, tube type and flat type. Tubular photobioreactors have a large specific surface area and generally achieve higher algal cell density and yield. However, the pipeline reactor has poor mixing ability, serious accumulation of dissolved oxygen, and difficulty in cleaning and maintaining the inner wall. Compared with tubular photobioreactors, column photobioreactors have the advantages of uniform mixing and easy oxygen analysis, but amplification is the main problem, and it is difficult to amplify in the longitudinal or radial direction; flat photobioreactor It has the advantages of large specific surface area, short optical path, easy oxygen analysis, and relatively easy amplification. Furthermore, the slab photobioreaction can adjust the placement angle of the flat reactor according to the angle of the sunlight, so that the reactor is fully exposed to light. Therefore, the flat-type photobioreactor is a kind of photobioreactor developed by various research institutes and companies at home and abroad.

In recent years, the literature and invention patents on flat-panel photobioreactors at home and abroad mainly include:

1) Degen et al. reported an air-lift slab photobioreactor (volume 1.5L, width 1.5cm) with a horizontally placed partition layer. The fluid descending channel is located on one side of the reactor width, and the ascending channel is The five horizontal baffles are divided into six communicating sections. The five baffles are alternately attached to the front and rear panels of the reactor, and when the fluid rises, a vortex is formed in the two partition sections, causing the algae cells to periodically circulate between the light zone and the dark zone. (Degen J, Uebele A, Retze A, et al. A novel airlift photobioreactor with baffles for improved light utilization through the flashing light effect. Journal of Biotechnology, 2001, 92(2): 89-94).

2) Tredici et al. designed a flat-type photobioreactor in the form of a plastic bag made of transparent soft material with external support, called Green Wall Panel. This design greatly reduces the manufacturing cost of the photobioreactor and is suitable for low-cost cultivation of microalgae (WO2004/074423 A2).

3) Solix Company of the United States has developed a plate type photobioreactor placed in water. The main body is a film bag, which is placed in water. The external water can not only support the bag reactor, but also maintain good temperature control and light intensity distribution. The role of (US2008/0160591 A1).

4) Li Yuanguang et al. Invented a new multi-section flat photobioreactor with multiple hollow baffle baffles in the reactor. Artificial light sources can be placed inside the cavity, and the baffle chambers are There is a gap between them. The reactor can significantly improve the light utilization efficiency by enhancing the mixing of the algae cells with the fluid in the direction of illumination, while avoiding direct contact between the internal light source tube and the culture solution (CN1880442).

5) Hu et al. invented a flat photobioreactor that is expandable in the length direction. This reactor consists of It is composed of a plurality of ordinary flat reactor units, and the units are connected by plastic or metal link members. The reactor can be made to different widths (light path) as needed, and can be arranged in a linear or curved form, and can be placed at different tilt angles according to the angle of the sunlight to fully receive the light.

(US2010/0028976A1).

6) Subitec of Germany designed a flat airlift photobioreactor with a volume of 180L per unit. The two layers of PVC film are staggered to form a groove, and the bottom is blown in each groove. Fluid eddies are formed in the chamber, which increases the frequency of alternating algae cells in the light and dark regions, thereby increasing cell growth rates (Morweiser M, Kruse O, Hankanmer B, et al. Developments and perspectives of photobioreactors for biofuel production. Applied Microbiology and biotechnology, 2010, 87: 1291-1302).

At present, the main problems encountered in closed photobioreactors in practical applications are as follows: 1) high production and operation costs; 2) difficulty in amplification. From the above-mentioned development trend of flat-type photobioreactors in recent years, it is obvious that in order to solve the problem of high cost, the material of the reactor is generally improved, and the conventional hard materials such as plexiglass and ordinary glass are developed into softness such as plastic film. The material can reduce the production cost of the reactor. In addition, the lighter soft material also facilitates reactor movement. In view of the difficulty in the amplification of photobioreactors, there is still no good technical means. Generally, when the scale is enlarged, the number of small reactor units is increased to increase the overall liquid volume of the reactor.

Internal mixing components are used in pipeline photobioreactors, usually in different forms of static mixers, which can change the fluid state in a pipeline reactor from a conventional laminar flow to a turbulent flow to enhance the algae in the reactor. The degree of mixing of the liquid. While the internal components are generally less used in the internal components of the flat and column reactors, one or two baffles are generally installed in the flat reactor to form a baffle or airlift flat reactor; A draft tube is typically installed in the reactor to form an airlift column photobioreactor. These internal components generally allow the fluid flow in the reactor to become ordered, which promotes the growth of algae cells to some extent. However, the lack of such internal components makes the fluid continuously circulate in the direction of light attenuation, which does not enhance the mixing of the fluid in the direction of illumination, and the ability of algae cells to receive light is limited.

Therefore, there is still a need in the art for a photobioreactor that enables algae cells to make full use of the light energy in a limited area (light zone) in the reactor, to increase the light intensity of algae cells, and to promote photoautotrophic growth of algae cells. Summary of the invention The invention adopts the design concept of enhancing the mixing of the fluid (microalgae culture liquid) in the light (light attenuation) direction of the photobioreactor, focusing on improving the full utilization of the light energy by the algae cells in the reactor and improving the light and darkness of the algae cells. At the cycle frequency angle, a novel photobioreactor with internal structure and its internal components are designed. It can not only achieve high-density and high-efficiency photoautotrophic culture of microalgae, but also realize the effectiveness of photobioreactor in the optical path direction. amplification.

Accordingly, it is an object of the present invention to provide a periodic circulation motion in which a fluid (algae liquid) is generated in a direction of light (light attenuation direction) so that algae cells make full use of light energy in a limited area (light region) in the reactor Increase the light intensity of algae cells. The invention not only makes the fluid flow in the reactor more orderly, but also greatly promotes the mixing intensity of the fluid in the illumination direction, so that the algae cells are rapidly between the light zone and the dark zone (due to light attenuation) in the reactor. Moving, increasing the light-dark cycle frequency of algae cells can greatly promote the photoautotrophic growth of algal cells

In particular, the present invention provides a novel photobioreactor internal component and a corresponding photobioreactor, characterized in that the photobioreactor comprises:

Transparent outer casing;

In the axial direction of the casing (ie, the direction of the main flow of the algae liquid, such as a flat plate placed perpendicular to the ground, the height direction) is provided with a plurality of regularly arranged horizontally inclined transparent partitions. The partition plate forms a certain angle with the wall surface of the casing, and a partitioned partial space region is formed between the upper and lower adjacent partition plates and the casing, and the configuration makes the fluid and the reactor surface of the central region (light dark region) of the reactor Rapid periodic cyclical motion between the fluids in the area (lighting zone), enhancing the mixing of the fluid in the radial direction of the reactor (lighting direction);

Supply a gas device or other power device.

In a specific embodiment, the transparent outer casing is in the form of a flat plate, a cylinder, a pipe, and the like.

In a specific embodiment, the inner member is a plurality of regularly arranged horizontally inclined transparent partitions, and a partitioned partial space region is formed between the partitions. The baffle can be hollowed out to form a hollow cavity.

In a specific embodiment, the gas supply or other power plant is an air pump, a gas distributor, or other associated power plant that can cause algae to flow within the photobioreactor.

In a specific embodiment, the transparent casing may have a transparent material having a certain mechanical strength such as plexiglass, inorganic glass (common glass or tempered glass, etc.); or a transparent plastic film, etc. Made of soft materials.

In a specific embodiment, the photobioreactor internals may be solid transparent separators or hollow body separators. If the separator is a transparent solid plate, it can be separated from the reactor casing, and the separator can be freely inserted into the reactor; if the separator is a hollow body separator, it needs to be integrated with the reactor casing.

In a specific embodiment, the hollowed out space is formed by hollowing out the partition to form a human light source.

In a specific embodiment, the photobioreactor can further include a temperature detection and control system, a pH detection and feedback control system, a dissolved oxygen detection system, and an internal light intensity detection system.

Another aspect of the invention relates to the above photobioreactor and its internal components in the field of microalgae photoautotrophic culture (including other cultures or chemical reactions requiring illumination, such as photosynthetic bacteria culture, plant cell culture, photocatalytic reaction, etc. ) in the application.

The photobioreactor with novel internal components designed by the invention (taking the outer casing as a flat plate as an example) has fluid motion order and light direction mixing compared with a conventional flat reactor (no internal component, bubbling type) The advantages of violent and so on, algae cell growth rate and algal cell density are significantly higher than algal cell growth rate and algal cell density in conventional plate reactors (see Example 1).

The airlift slab photobioreactor with built-in staggered partition plate designed by Degen et al. can also promote the circulation of fluid in the direction of illumination, but the scale of the reactor is only 1.5L; the internal partition is horizontally placed, flow The field is unreasonable (the reactor separator of the present invention has a certain inclination angle, so that the flow field is more reasonable), which will cause more dead zones; and the separator cannot be separated from the outer casing, making the reactor difficult to clean. In addition, the reactor designed by Degen et al. is a single layer in the width (light path or optical path) direction, which is narrow and cannot be as wide as possible in the direction of the light path (ie, the direction of illumination), which is disadvantageous for the direction of the reactor in the direction of the light path. Magnification above (the reactor designed by the present invention has two portions symmetrical in the width direction, so that the reactor can be as wide as possible in the width direction).

The airlift slab photobioreactor developed by Subitec also has problems with cleaning difficulties, especially for microalgae cultures that are easy to attach to the wall. The internal components designed in accordance with the present invention can be separated from the reactor housing to facilitate thorough cleaning of the reactor.

The plate reactor designed by Tredici mainly uses the membrane soft plastic material to make the reactor shell, and the soft shell is made of a simple thin metal wire or plastic wire on the outside. Support, while the interior of the reactor has no internals, with conventional flat reactors Similarly, there is no ability to promote the mixing of algae in the direction of illumination.

Similarly, the slab photobioreactor invented by Hu in the length direction is also a conventional flat-plate reactor, and the internal fluid mixing is disordered and disordered, which is disadvantageous for algae cell growth. Hu's invention is primarily from the perspective of reactor amplification, but its amplification is primarily based on increasing the number of small reactor units in the reactor length, not the amplification of a single reactor volume in the traditional sense.

Solix's membrane flat-plate reactors, designed in water, are also simple bubbling types from a mixing point of view, with a mixed flow field disorder. Moreover, the reactor is placed in a water body, and the reactor indicates that the light intensity is weak, which is disadvantageous for the cultivation of microalgae requiring high light intensity.

The reactor designed by the invention mainly considers from the fluid point of view, strengthens the mixing of the algae cells in the illumination direction, and improves the utilization efficiency of the algae cells for the light energy, and the material of the reactor may be a transparent material such as plexiglass or inorganic glass. It may be a soft material such as a plastic film, and the amplification of the reactor may be amplified from the length direction or the width direction. Multi-section flat photobioreactor designed in the past

(CN1880442), although it also promotes the flow of fluid in the radial direction, because the fluid forms a periodic overall circulation, the circulation period of the fluid in the direction of illumination is long and the frequency is low, which is not enough to form an advantage for algae cells. "Flash effect". The invention is a further development of a multi-section flat reactor. By adding a horizontally inclined partition plate in the reactor, a plurality of trapezoidal partial spaces are formed, which causes a fluid to form a cycle cycle with a faster cycle frequency in each partial space. Flow, promote the full acceptance of light by algae cells.

As summarized in the review, the present invention focuses on the mixing of the enhanced fluid in the direction of illumination in the reactor compared to other photobioreactors, so as to facilitate amplification of the reactor in the optical path direction, which is for photobioreactor amplification and microalgae. The self-cultivation of light is very critical. From the viewpoint of cost reduction, the reactor designed by the present invention can be made of an inexpensive soft film material; from the viewpoint of magnification, the reactor designed by the present invention can be from the width (ie, the optical path direction) as well as the length direction and the height direction. Zoom in.

In summary, in view of the shortcomings of poor mixing performance and difficulty in amplification of the existing closed photobioreactor, the present invention is placed in the axial direction of the reactor housing (ie, the main flow direction of the algae liquid, such as the housing is placed perpendicular to the ground) Plate type, height direction) A plurality of regularly arranged horizontally inclined transparent partitions are placed to enhance the mixing of the fluid in the radial direction of the reactor (light direction), so that the new internal components are installed. The photobioreactor has the unique advantages of being scalable in the optical path direction, and at the same time, allowing the fluid to have a strong periodic cycle in the illumination side and promoting the rapid growth of algae cells. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a series of new photobioreactors (side view) of internal components used in flat photobioreactors. The meanings of the symbols are as follows: w is the width of the reactor, h is the height of the reactor, hO is the distance from the bottom of the vent pipe, hi is the lower edge of the baffle (type b) and the lower edge of the baffle (types a and c) The distance from the bottom of the reactor, h2 is the distance between the upper edge of the separator (type b) and the lower edge of the separator (types a and c) from the bottom, h3 is the distance between the two separators, and h4 is the partition (type b ) and the upper edge of the baffle (types a and c) from the top of the reactor, wl is the horizontal spacing between the two separators (type b), w2 is the spacing between the separator and the reactor wall (type a and c), w3 is the distance between the two baffles (type c), and αθ is the angle of intersection of the partition and the wall.

Figure 2 shows a physical diagram of a novel internal structure flat photobioreactor and a control reactor.

Figure 3 shows the internal flow field of a new internal structure slab photoreactor and a control reactor (calculated by computational fluid mechanics software).

Figure 4 shows a comparison of the chlorella culture process of a novel internal structure plate reactor with a control reactor. The "control" in the figure refers to a bubbling reactor.

Figure 5 shows a comparison of the new internal structure plate reactor with the photoautotrophic culture process of Chlorella in the respective control reactors. The "control" in the figure refers to a bubbling reactor. Specific implementation

In general, light is the most critical factor affecting the photoautotrophic growth of algal cells. The algae cells in the photobioreactor absorb light, and the algae cells block each other, causing the light to decay exponentially with increasing optical path (culture depth) and cell concentration. Therefore, the photobioreactor exists. The light area (the area where the light intensity satisfies the growth of algae cells) and the dark area (the area where the light intensity is lower than the growth of algae cells). Strengthening the frequency of movement of algae cells between the light and dark areas facilitates the algae cells to receive as much light as possible and increase the growth rate of the algae cells. This phenomenon is called the "Flashing Light Effect". Therefore, the light-dark cycle frequency becomes an important parameter in the design of photobioreactor. There are generally two ways to increase the frequency of light-dark alternation in the reactor: 1) Increasing the mixing intensity in the reactor so that the algae cells can be in a shorter time. Complete the movement from the dark zone to the light zone; 2) Set internal components (such as static mixers, baffles, etc.) in the reactor, separate the reactor into a number of small circulation units, and rely on the vortex generated by the fluid flow to make the algae The cells undergo periodic cyclic movements between the small units to increase the light-dark alternating frequency of the algal cells. The invention designs a novel internal component, which is mainly a series of partitions arranged in an orderly manner according to certain rules, which can cause the algae liquid to periodically move in a rapid direction in the illumination direction, strengthen the mixing of the algae cells in the illumination direction, and raise the algae. The frequency of the light-dark cycle of the cells, thereby increasing the growth rate of the algae cells.

In particular, the present invention provides a novel internal component and a corresponding photobioreactor, the photobioreactor comprising a transparent housing; a plurality of transparent spacers arranged in a regular arrangement are disposed inside the housing Plates, which form a localized spatial region with a trapezoidal shape, which allows rapid periodic cyclical motion between the fluid in the central region of the reactor (light dark zone) and the fluid in the reactor surface region (lighting zone), enhancing the fluid in response Mixing of the radial direction (ie, the direction of illumination); and supplying a gas device or other power device. The plurality of sets of transparent baffles can cause rapid periodic cyclical movement of the fluid therein, enhancing the mixing of the fluid in the radial direction of the reactor (i.e., the direction of illumination).

It should be understood that the "trapezoid" as used herein means that the area formed by the wall of the reactor and the adjacent upper and lower partitions is trapezoidal in view of the cross section of the reactor.

The invention has the advantages of enhancing the mixing of the fluid (algae liquid) in the illumination direction, increasing the light-dark cycle frequency of the algae cells and fully utilizing the light energy of the algae cells, and effectively overcoming the occurrence of the photobioreactor in the optical path direction amplification. Problems (such as algae cells inside the reactor can not fully receive light, cell yield decline, etc.). The method of the present invention will be specifically described below from various aspects.

1) Composition and structure of internal components

The internal components consist of a series of baffles (plates placed horizontally in the reactor) or baffles plus baffles (plates placed vertically in the reactor). The separator comprises a separator directly in contact with the wall of the reactor and a separator spaced apart from the wall by a distance w2, preferably two separators appear alternately. The length of each separator in the horizontal direction preferably does not exceed half of the reactor width w. Each baffle is at an angle α0 to the wall surface of the reactor, and the angle αθ formed by each baffle and the wall surface may be the same or different, but between the adjacent upper and lower baffles and the reactor wall and the central axis of the reactor (refer to The vertical dashed line of type 1 in Figure 1 forms a trapezoidal shaped area in which liquid (algae) forms a periodic cycle, causing algae cells to be in the center of the reactor (inside the reactor, typically The dark region) and the near wall region (outside the reactor, generally the light region) perform a continuous circular motion, so that the algae cells make full use of the light energy in the near wall region.

In a specific embodiment, the inner member of the present invention, as shown in type b of Figure 1, includes a baffle in contact with the wall and an angled spacer spaced from the two walls by a distance w2 such that adjacent The upper and lower partitions form a trapezoidal shaped area with the reactor wall and the central axis of the reactor. A plurality of sets of slots may be provided in both side walls (width direction) of the photobioreactor, and the partition plate may be fixed by inserting the partition into the slot; a separate combined component body may also be fabricated (all the partitions and The baffles are combined to form a unitary member that can be separated from the outer casing, and the combined integral member can be directly inserted into the casing when in use. This makes it easy to remove the separator or remove the entire internal components to facilitate thorough cleaning of the reactor and separator. In order to enhance the overall mixing in the reactor, the internal components can be appropriately adjusted to change from a full partition to a partial partition and a baffle, and a flow path is formed between the baffle and the wall or the baffle and the baffle, so that the fluid It has an overall circulation that enhances the overall mixing effect in the reactor.

Examples of exemplary baffle-containing internal members can be found in types a and c of Figure 1. Type a includes a baffle, a portion of the baffle is in contact with the reactor wall, and a portion of the baffle is in contact with the baffle. Each of the two types of baffles forms an angle α0, αθ, which may be the same or different from the reactor wall and the baffle, but A trapezoidal region is formed between the adjacent upper and lower partitions and the wall surface of the reactor and the baffle; in addition, a distance w2' (horizontal direction) between the partition plate in contact with the wall surface of the reactor and the baffle is in contact with the baffle There is a certain distance w2 between the separator and the wall of the reactor, and w2' and w2 may be the same or different. Preferably, the length of each separator in the horizontal direction does not exceed half of the reactor width w. More preferably, the length in the horizontal direction of the separator plus w2 or w2' is equal to or less than half the reactor width w.

Typically, when the inner member containing the baffle is placed in the reactor, it is placed on the central axis of the reactor.

In the type c of Figure 1, two baffles are placed in the reactor, some of the baffles are in contact with the reactor wall, and some of the baffles are in contact with the first baffle and the second baffle, respectively. The walls of the reactor and the corresponding baffles form an angle α0, which may be the same or different, but a trapezoidal region is formed between the adjacent upper and lower baffles and the reactor wall and the respective baffles. The distance between the two baffles can be optimized by the technician based on actual production conditions. It should be understood that the length in the horizontal direction of each separator and the distance between the separator and the reactor wall and the baffle should be appropriately adjusted.

The shape of the separator may vary depending on the type of reactor. For example, for a flat reactor, the separator can be square. For a column or tubular reactor, the baffle may be fan shaped such that the side in contact with the reactor housing may be curved to match the housing.

For column or pipeline reactors with baffles, the baffles themselves may be square or cylindrical. When the baffle is square, the side of the baffle that is in contact with the baffle should also be square, while the other side may be curved. When the baffle is cylindrical, the baffle may be fan shaped. The distance between the lower edge of the baffle (type b) and the lower edge of the baffle (types a and c) from the bottom of the reactor hl, the upper edge of the baffle (type b) and the lower edge of the baffle (types a and c) from the bottom H2, the distance h3 between the partitions, the partition (type b) and the upper edge of the baffle (types a and c) from the top of the reactor h4, the horizontal spacing between the two partitions (type b) wl , the spacing between the separator and the reactor wall (types a and c) w2, the distance between the two baffles (type c) w3, the angle of intersection of the partition and the wall surface αθ can be optimally adjusted to obtain the most The size of the good structure.

In a specific embodiment, a 15 L flat photobioreactor is exemplified. The reactor has a length of 25 cm, a width w of 15 cm, and a height h of 40 cm. Hi range is l~20cm, h2 ranges from l~20cm, h3 ranges from l~20cm, h4 ranges from l~10cm, wl ranges from 0.5~10cm, w2 ranges from 0.5~6cm, w3 The range is l~12cm, and the angle of αθ is 1~85 °. In a preferred embodiment, hi ranges from 1 to 10 cm, h2 ranges from 1 to 15 cm, h3 ranges from 1 to 8 cm, h4 ranges from 1 to 8 cm, and wl ranges from 0.5 to 5 cm, w2. The range is 0.5~4cm, the range of w3 is l~6cm, and the angle of αθ is 45 85 °.

Furthermore, in order to prevent the angled region between the separator and the reactor casing from forming a dead zone, there may be a small gap or small hole between the separator and the reactor casing so that the fluid can flow in the angular region. At the same time, the partition and the baffle are made of a transparent material and have a thin thickness to reduce absorption and obstruction of light. In addition, the baffle and the baffle may be separated from the outer casing and may be separately disassembled and taken out of the casing to clean the reactor and internal components. 2) Reactor main structure and material

The main structure (housing) of the photobioreactor can be flat, column or pipe. The internal components can be appropriately adjusted according to the shape of the outer casing. Since the flat photobioreactor has the advantage of being relatively easy to amplify relative to other closed photobioreactors, the internal components of the present invention are first applied in a flat photobioreactor. The photobioreactor is made of a transparent material outside the casing, and may be a hard material such as plexiglass, inorganic glass (ordinary glass tempered glass, etc.) or a soft material such as a plastic film. If a soft material is used, a support structure such as a metal mesh needs to be attached to the outside of the reactor.

3) Built-in artificial light source in the baffle and partition cavity

The baffles and baffles can be made in the form of hollow cavities, so that the baffles and baffles not only affect the fluid The flow in the reactor promotes the mixing of the fluid in the direction of illumination and can also be used as a place for artificial light sources. The baffles and partitions in the form of hollow cavities can increase the specific surface area of the reactor on the one hand, and avoid direct contact between the artificial light source and the algae liquid on the other hand, so as to avoid many problems caused by direct contact of the light source with the liquid. For example, the algae cells are attached to the surface of the light source, etc.; at the same time, the artificial light source is placed inside the cavity, so that the artificial illumination is fully absorbed by the algae cells in the reactor. 4) Power unit and detection system

When the shell of the photobioreactor is in the form of a flat plate or a cylinder, the algae liquid in the reactor is mixed by means of aeration, and when the casing of the reactor is a pipeline type, generally through a pump device or an airlift system The algae fluid flows in the pipeline. In addition, various detection and control systems such as temperature detection and control systems, pH detection and feedback control systems, dissolved oxygen detection systems, and light intensity detection systems can be deployed in the photobioreactor. The structure of the novel internal mixing member and photobioreactor of the present invention and the internal mixing thereof (especially the fluid vortex unique in the direction of illumination) will be further described below with reference to the accompanying drawings.

Figure 1 is a series of novel flat reactors (structure schematic, side view) formed by the internal mixing member applied to a flat photobioreactor. Figure 2 is a physical diagram of a novel internal structure plate reactor and a control reactor. The internal components of the type a reactor consist of a central baffle and a sloping baffle. The left side of the reactor is a descending channel. The channel is provided with inclined baffles placed upside down to promote the mixing of the algae in the direction of illumination, while the right side is a fluid. With the ascending channel, the entire reactor can achieve an overall flow. Type b The internal components in the reactor are built-in inclined baffles that are placed upside down. The trapezoidal area is formed vertically between the baffles and the baffles. At the same time, the left and right sides of the reactor are symmetrically distributed. The type c reactor is also composed of a baffle and a sloping baffle. The two baffles form a rising channel for the fluid in the center of the reactor. Two fluid descending channels are placed on both sides of the inner wall of the reactor, and staggered are placed therein. The inclined partitions are used to promote the mixing of the algae liquid in the direction of illumination.

Figure 3 shows the flow field distribution in each type of flat-panel photobioreactor (calculated by CFD calculation software Ansysl2.0 CFX, under the condition of aeration of l.Ovvm).

The type a reactor has one overall flow cycle and has a small fluid circulation on it as in reactor b. The large circulation of the fluid interacts with many small cycles and mixes with each other. Type a reactor liquid in the left channel is mainly vertical (axial) flow, in the right channel of the reactor due to production The fluid circulation is generated, and the radial flow and mixing of the liquid are more obvious. Type a is formed on the basis of a single baffle airlift reactor (multiple sets of baffles with increased horizontal tilt in the downcomer of a single baffle airlift reactor). It can be seen from Fig. 3 that there is only one overall flow cycle in the single-chamber airlift reactor, and the fluid flow is mainly in the axial direction, and the flow in the radial direction (light direction) is very weak, which is not conducive to the light of the microalgae. Self-supporting growth.

The type b reactor is divided by the internal partition into a number of special "cells" (the space between the two partitions), and the gas flows up the inclined partitions due to buoyancy (internal partitions are similar to gas flow) The baffle), under the action of gas, the fluid (referred to as liquid) in each "cell" can produce rapid periodicity between the central area of the reactor (light dark area) and the surface area of the reactor (light area) Cycling movement. There are no baffles between the two "chambers" on the same floor, so the two fluid cycles in the same layer interact and blend with each other, making the two cycles not very regular. The liquid in the type b reactor mainly circulates mainly in the respective chambers, and the flow in the radial direction is very obvious, which is beneficial to the algae cells in the dark area to fully accept and utilize the light in the light region. Improve the efficiency of light energy utilization of algae cells. The type b reactor can be seen as being formed on the basis of a bubbling reactor (multiple sets of staggered and horizontally inclined separators are added to the bubbling reactor), as can be seen from Figure 3, the control plate reaction The fluid in the device (i.e., bubbling, no internals) forms two large cycles, with the fluid flowing vertically up and down, with only the flow in the radial direction (i.e., the direction of illumination) at the top and bottom of the reactor.

Type c reactors have two integral flow cycles with many small cycles on them. In the ascending channel, the liquid flows axially, and the axial and radial movements are strong in the descending channels on both sides. Type c is formed on the basis of a double baffle airlift reactor (multiple sets of baffles with horizontal inclination added to both sides of the downcomer of the airlift reactor). Similarly, Figure 3 shows that there are two overall flow cycles in the double-plot airlift reactor, and the fluid flow is mainly in the axial direction, and the flow in the radial direction (light direction) is weak, which is not conducive to microalgae. The light grows autotrophically.

It can be seen that the liquids in the control reactor (bubbling type), single separator and double-barrier airlift reactor are mainly axial flow, and the liquid in the type b reactor is mainly radial flow. , Types a and c The axial and radial flow of liquid in the reactor is relatively obvious. In order to explain in detail the advantages of the novel internal components of the present invention and their photobioreactors, an example will be specifically described below: Example 1: Comparison of photoautotrophic culture process of chlorella in a novel plate reactor and a control reactor. 14 L of tap water was placed in a flat photobioreactor and a control reactor of 3 different internal components, and 2 ml of sodium hypochlorite was added. Solution (effective chlorine content 10%), after aeration and mixing, treatment for 12 hours, then add sodium thiosulfate to neutralize the remaining sodium hypochlorite, check with potassium iodide starch test paper, confirm that there is no sodium hypochlorite (usually excess sodium thiosulfate), continue After ventilating the excess sodium thiosulfate for a period of time, then placing the microalgae photoautotrophic medium (f/2 medium) in the reactor, and mixing well, then accessing the chlorella seed chlorella seed, light Self-cultivation begins. The initial algal cell density was about 0.15g/L, the aeration was 1.0Vvm, and the plate reactor had illumination on both sides, and the light intensity on each side was 10klx.

As can be seen from Figure 4, the growth of algae cells in the control reactor (bubble reactor, no internal components) was the worst, with the highest algal cell density of only 0.916 g/L. The growth of algae cells in the three reactors with different internal components was better than that of the control reactor. The highest cell density of the microalgae in the type b reactor was 1.31 1 g/L, and the highest cell of the microalgae in the type a reactor. The density was 1.189 g/L, and the highest cell density of the microalgae in the type c reactor was 1.241 g/L. At the same time, the specific growth rate of algae cells in the exponential growth phase of the four different plate reactors was calculated. The result is that the specific growth rate of algae cells in the control reactor is O.OS lh- ¹ , algae cells in the type b reactor. The specific growth rate is 0.0619 h, the specific growth rate of algae cells in type a reactor is 0.0574 h, and the growth rate of algae cells in type c reactor is 0.0604 h - from the above data, the flat reactor with new internal components is added. The highest density and growth rate of algae cells were significantly higher than that of ordinary flat photobioreactors (bubbling, without adding any internal components). It can be seen that the novel internal components designed by the present invention and the novel flat reactor after adding the internal components have a good culture effect. Example 2: Comparison of photoautotrophic culture process of chlorella in a new type of flat reactor and respective control reactors

In a new flat-plate photobioreactor with trapezoidal internals and three respective control reactors (the control of type b reactor is a bubbling reactor, the control of type a reactor is a single-chamber airlift reaction). , type c rice control is double baffle airlift reactor) separately loaded with 14L tap water, added 2ml sodium hypochlorite solution (effective chlorine content 10%), after aeration and mixing, treatment for 12 hours, then add thiosulfuric acid Sodium neutralized the remaining sodium hypochlorite, after testing with potassium iodide starch test paper, confirming that there is no sodium hypochlorite (usually excess sodium thiosulfate), and continuing to ventilate for a period of time after oxidizing excess sodium thiosulfate. Then, the microalgae photoautotrophic medium (f/2 medium) was placed in the reactor, and after fully mixing, the seeds of Chlorella pyrenoidosa were added, and the photoautotrophic culture was started. The initial algal cell density was about 0.077 g/L, the aeration was 0.6 vvm, and the plate reactor had illumination on both sides, and the light intensity on each side was 20 klx.

It can be seen from Fig. 5 that the growth of algae cells in the three novel flat-panel bioreactors with trapezoidal internals is superior to the respective control reactors. The average growth rate of algae cells in the type b reactor is higher than the average growth rate of algae cells in the bubbling reactor, and the average growth rate of algae cells in the type a reactor is higher than that in the single separator airlift reactor. The average growth rate of the cells, the average growth rate of the algal cells in the type c reactor is higher than the average growth rate of the algal cells in the double separator airlift reactor. The highest density of algae cells in each reactor was the highest algal cell density in the new reactor compared to the highest algal cell density in the respective control reactor. It can be seen that the highest density and growth rate of algae cells in the flat reactor with new internal components are higher than those of the respective control flat photobioreactors. In summary, the novel internal components designed by the present invention and the novel flat reactor after adding the internal components have a good culture effect.

Claims

Claim

A photobioreactor, characterized in that the photobioreactor comprises:

Transparent outer casing; and

An inner member, wherein the inner member includes a plurality of regularly arranged horizontally inclined transparent partitions disposed in an axial direction of the casing, the partition forming an angle with the wall surface of the casing such that the upper and lower adjacent partitions Forming a trapezoidal localized spatial region with the housing, the transparent baffle being arranged to produce a rapid periodic cyclical motion between the fluid in the central region of the reactor and the fluid in the surface region of the reactor.

2. The photobioreactor of claim 1 wherein the transparent outer casing is in the form of a flat plate, a cylinder, a pipe, and the like.

3. The photobioreactor of claim 1 wherein the separator is hollowed out to form a hollow cavity.

4. The photobioreactor according to claim 1, wherein the gas supply device or other power device is an air pump and a gas distributor or other related power that can cause the algae liquid to flow in the photobioreactor. device.

5. The photobioreactor according to claim 2, wherein the transparent casing is made of a transparent material having a certain mechanical strength; or is made of a soft material.

6. The photobioreactor according to claim 3, wherein if the separator is a transparent solid plate, the separator can be separated from the reactor casing, and the separator can be freely inserted into the reactor; The separator is a hollow body separator, and the separator and the reactor outer casing are integrated.

7. The photobioreactor according to claim 3, wherein the artificial cavity is placed in the hollow cavity formed by the hollowing out of the partition.

8. The photobioreactor according to claim 1, wherein the photobioreactor further comprises a gas supply device or other power device, a temperature detection and control system, a pH detection and feedback control system, and dissolved oxygen. Detection system and internal light intensity detection system.

9. A member for use in a photobioreactor according to claim 1, wherein the member is a plurality of regularly arranged horizontally inclined transparent partitions, and a trapezoidal partial space is formed between the partitions. region.

10. The photobioreactor of any of claims 1-8 or the component of claim 9 Application in culture or chemical reaction requiring illumination