Device and method for cultivating algae using biomass fuel kiln gas

Abstract

The present invention provides a device and method for cultivating algae using biomass fuel kiln gas, wherein the device for cultivating algae using biomass fuel kiln gas comprises: a stirrer, a press, a lime kiln, an algae cultivation device, a centrifugal dehydrator and a dryer arranged in sequence; the algae cultivation device comprises a cultivation pipe, the first end of the cultivation pipe is connected to an air inlet pipe, the second end of the cultivation pipe is connected to an algae culture liquid supplement pipe and a discharge pipe, and the air inlet pipe is connected to the air outlet of the lime kiln. The technical solution of the present invention effectively solves the problem of wasteful combustion of biomass fuel and environmental pollution in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of algae cultivation, and in particular to a device and method for cultivating algae using biomass fuel kiln gas. Background Art

[0002] Biomass fuel is a green renewable energy source that does not affect the overall balance of carbon dioxide in the atmosphere. Obtaining energy from biomass can reduce dependence on fossil fuels and energy imports, reduce damage to the environment, achieve zero carbon emissions, and improve the utilization rate of agricultural production waste. However, the use of biomass combustion for power generation will generate pollutants such as power plant ash and flue gas (mainly CO2 and nitrogen oxides (NOx)), and there are residual nutrients such as magnesium, potassium, and calcium in the ashes after combustion. The emission of these pollutants will cause damage to the ecological environment and need to be treated before they can be safely discharged.

[0003] Biochar, also known as regenerated charcoal and smokeless clean charcoal, is usually made of carbon rods made by extruding plant fiber fragments. Its raw materials come from a wide range of sources, and a variety of agricultural waste (such as rice husks, peanut shells, cotton shells, corn cobs, corn stalks, sorghum stalks, hemp stalks, bark, coconut shells, coffee grounds, bamboo scraps and other fiber-containing materials) can be used as raw materials to produce charcoal rods. Its characteristics: high density, high calorific value, smokeless, odorless, pollution-free, non-explosive, flammable, and it is an internationally recognized green and environmentally friendly product.

[0004] Biochar has the following advantages compared to other charcoals: 1. Environmental protection: It is produced by using waste materials, turning waste into treasure. 2. High energy: The fixed carbon content is about 80%, and the calorific value is 7500-8000kcal / kg, while the fixed carbon content of charcoal is low, and the calorific value is about 6500kcal / kg. 3. Clean and hygienic: No smoke and no charcoal heads, no sparks during combustion, the residual ash falls naturally during combustion and does not float up, the ash content is about 3% or 6%, and there is little residual ash after combustion, and it is easy to burn. 4. Regular shape, reasonable structure, and easy to use: There is a uniform length and size, hollow or solid structure, which is conducive to combustion and use. 5. Low water content, within 5%; ordinary charcoal has a large water content. 6. Mechanism charcoal does not contain chemicals, is non-toxic and odorless, pollution-free, and has a long burning time.

[0005] The market for biochar is vast. It is used as barbecue charcoal in catering (barbecue, hot pot, barbecue, etc.). The density of biochar is more than 3 times that of charcoal, and it burns smokelessly. In industry, biochar is used to produce carbon disulfide and steel smelting. Carbon rods are also used as supplementary fuel for boilers. Its density is similar to that of coal, and its calorific value is 7500-8000kcal / kg, but its ash content is significantly lower than that of coal.

[0006] Lime (also known as calcium oxide) is the product of calcining limestone, chalk or other carbonate raw materials at high temperature. At present, the main fuels for calcining lime are: coke, anthracite, bituminous coal, lignite, peat, firewood, heavy oil, various coal gases, etc. Among them, the best solid fuel is coke. Coke not only has a calorific value of 6000-7000 kcal / kg, a fixed carbon content of more than 90%, high mechanical strength, and is not easily crushed by limestone blocks, but also when coking, the volatile substances of coke almost all overflow (less than 2%), reducing the agglomeration phenomenon in the kiln and improving the product quality. However, due to the high price of coke, it is usually rarely used in calcining lime.

[0007] Microalgae refers to those tiny algae groups whose morphology can only be distinguished under a microscope. Microalgae usually refers to the general term for microorganisms that contain chlorophyll a and can perform photosynthesis, and are a type of protists. Microalgae that are cultivated or produced in large quantities using biotechnology belong to four algae phyla: Cyanobacteria, Chlorophyta, Chrysophyta, and Rhodophyta. These microalgae have important development value in the fields of medicine, food, aquaculture, chemical industry, energy, environmental protection, agriculture, and aerospace. Because microalgae reproduce very quickly, it is also easier to modify genes.

[0008] At present, the main fuel for calcining lime in my country is fossil fuels such as lump coal. The combustion of fossil fuels not only consumes limited fossil energy, but also produces a large amount of carbon dioxide and a certain amount of sulfide. Summary of the invention

[0009] The main purpose of the present invention is to provide a device and method for cultivating algae using biomass fuel kiln gas, so as to solve the problem of wasteful combustion of biomass fuel and environmental pollution in the prior art.

[0010] In order to achieve the above-mentioned purpose, according to the present invention, there is provided a device for cultivating algae using biomass fuel kiln gas, comprising: an agitator, a press, a lime kiln, an algae cultivation device, a centrifugal dehydrator and a dryer arranged in sequence; the algae cultivation device comprises a cultivation tube, a first end of the cultivation tube is connected to an air inlet pipe, a second end of the cultivation tube is connected to an algae culture liquid replenishing pipe and a discharge pipe, and the air inlet pipe is connected to the air outlet of the lime kiln.

[0011] Furthermore, the air intake pipe includes an air intake pipe section and a diffuser pipe section which are connected to each other. The diffuser pipe section is located inside the breeding pipe. The diameter of the diffuser pipe section gradually increases in the direction from the first end of the breeding pipe to the second end of the breeding pipe. A gas dispersion plate is provided at one end of the diffuser pipe section away from the air intake pipe section.

[0012] Furthermore, the diameter of one end of the diffusion pipe section away from the air inlet pipe section is d, and the diameter of the breeding pipe is D, wherein 1.3d≤D≤2d.

[0013] Furthermore, the gas dispersion plate has a plurality of gas outlet holes, and the gas dispersion plate is a plate-like structure with a concave middle portion, and the diameter of the gas outlet holes is between 1 / 8d and 1 / 15d.

[0014] Furthermore, the air intake pipe also includes an air baffle, which is arranged in the diffuser section, the plane of the air baffle is parallel to the cross-section of the diffuser section, the central axis of the air baffle coincides with the central axis of the diffuser, and the diameter of the air baffle is 1 / 2 of the diameter of the diffuser section at the corresponding installation location.

[0015] Furthermore, the algae culture liquid supplement pipe is connected to the side of the culture pipe, and the discharge pipe is connected to the central axis of the culture pipe.

[0016] Furthermore, the exhaust pipe includes a first outlet section and a second outlet section, the first outlet section is connected to the intake pipe, the second outlet section is connected to the exhaust gas recovery structure, and valves are provided on the first outlet section and the second outlet section.

[0017] Furthermore, the device for cultivating algae using biomass fuel kiln gas also includes a waste heat utilization structure, and the waste heat utilization structure is connected to the air inlet pipe.

[0018] According to another aspect of the present application, a method for cultivating algae using kiln gas of biomass fuel is also provided, the method adopts the above-mentioned device, and the method comprises the following steps: S10 crushing agricultural waste into straw fibers with a length of less than 1 cm by a crusher, mixing with calcium oxide, a bulking agent, and a structure improver, and extruding the mixture into a shape, and then carbonizing the mixture in a carbonization furnace to make biochar; S20 putting the biochar and limestone into a lime kiln for calcination, and introducing the kiln gas after lime calcination into a water washing tower for water washing and dust removal, and cooling the temperature to 30°C at the same time, and using the overburned lime calcined in the lime kiln for making soda ash; S30 The flue gas discharged from the water washing tower is introduced into a sealed, light-transmitting pipeline-type algae cultivation device through a duct by an induced draft fan for cultivating microalgae. The hot water after cooling and washing the flue gas in the water washing tower is circulated with water in the pipeline-type algae cultivation device through a heat exchanger for heat exchange. The flue gas contains more CO2 and nitrogen oxides, which can increase the microalgae yield through photosynthesis. The finished product obtained after dehydration and drying of the microalgae is rich in nutrients and oils, with an oil content of more than 60%, and can be used as a raw material for fish starter feed.

[0019] Furthermore, in the pipeline type algae cultivation device, the flue gas is introduced with the pH value of the microalgae culture solution being 7.26 as the dividing line, the flue gas is introduced when the pH value is higher than 7.26, and the flue gas introduction is stopped when the pH value is lower than 7.

[0020] By applying the technical solution of the present invention, the material is stirred evenly by a stirrer, extruded and formed by a press, and burned in a lime kiln. The gas after combustion is used for algae cultivation, and the particles after combustion are used to make soda ash. In this way, algae cultivation is achieved, environmental pollution can be avoided, and the material is fully utilized. The technical solution of the present application effectively solves the problem of wasteful combustion of biomass fuel and environmental pollution in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0022] Figure 1 A schematic diagram of a process according to an embodiment of the method of the present application is shown;

[0023] Figure 2 A schematic diagram of the process structure of an embodiment of the device according to the present application is shown;

[0024] Figure 3 Shows Figure 2 A schematic diagram of the process structure of an algae culture device of the device;

[0025] Figure 4 Shows Figure 3 Schematic diagram of the coordination structure of the cultivation pipe and the air inlet pipe, the algae culture liquid supplement pipe and the discharge pipe;

[0026] Figure 5 Shows Figure 4 Schematic diagram of the internal structure of the intake pipe.

[0027] The above drawings include the following reference numerals:

[0028] 10. Agitator; 20. Press; 30. Lime kiln; 40. Algae culture device; 41. Culture tube; 42. Air inlet pipe; 421. Air inlet pipe section; 422. Diffuser section; 423. Gas dispersion plate; 424. Air outlet; 425. Air baffle; 43. Algae culture solution replenishment pipe; 44. Discharge pipe; 50. Centrifugal dehydrator; 60. Dryer. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0031] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, rotated 90 degrees or in other orientations, and the spatially relative descriptions used herein are interpreted accordingly.

[0032] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for clarity, the thickness of the layers and regions is enlarged, and the same reference numerals are used to represent the same devices, so their description will be omitted.

[0033] like Figures 1 to 5 As shown, the device for cultivating algae using biomass fuel kiln gas in this embodiment includes: a stirrer 10, a press 20, a lime kiln 30, an algae cultivation device 40, a centrifugal dehydrator 50 and a dryer 60 arranged in sequence. The algae cultivation device 40 includes a cultivation pipe 41, a first end of the cultivation pipe 41 is connected to an air inlet pipe 42, a second end of the cultivation pipe 41 is connected to an algae culture liquid supplement pipe 43 and a discharge pipe 44, and the air inlet pipe 42 is connected to the air outlet of the lime kiln 30.

[0034] By applying the technical solution of this embodiment, the material is stirred evenly by a stirrer, extruded and formed by a press, and burned in a lime kiln. The gas after combustion is used for algae cultivation, and the particles after combustion are used to make soda ash. In this way, algae cultivation is achieved, environmental pollution can be avoided, and the material is fully utilized. The technical solution of this embodiment effectively solves the problem of wasteful combustion of biomass fuel and environmental pollution in the prior art.

[0035] like Figure 3 As shown, in the technical solution of this embodiment, the air intake pipe 42 includes an air intake pipe section 421 and a diffuser pipe section 422 which are connected to each other. The diffuser pipe section 422 is located inside the culture pipe 41. The diameter of the diffuser pipe section 422 gradually increases in the direction from the first end of the culture pipe 41 to the second end of the culture pipe 41. A gas dispersion plate is provided at one end of the diffuser pipe section 422 away from the air intake pipe section 421. The provision of the diffuser pipe section 422 allows the gas to enter the culture pipe 41 more evenly. The structure of the diffuser pipe section 422 located inside the culture pipe 41 avoids excessive damage to the main structure of the culture pipe 41. The diffuser pipe section is in a trumpet shape, and the central axis of the air intake pipe 42 overlaps with the central axis of the culture pipe 41.

[0036] like Figure 3 As shown, in the technical solution of this embodiment, the diameter of the end of the diffuser section 422 away from the air inlet section 421 is d, and the diameter of the culture tube 41 is D, wherein 1.3d≤D≤2d. The above structure is obtained by comprehensively considering the diameter relationship between the culture tube 41 and the diffuser section 422, the flow velocity and resistance factors of the airflow, and the factors of algae absorption and growth, and establishing a mathematical model. Specifically, in the technical solution of this embodiment, D=1.6d, such an airflow is relatively stable and is not easy to destroy the existing state in the culture tube 41.

[0037] In the technical solution of this embodiment, the gas dispersion plate 423 has a plurality of air outlets 424, and the gas dispersion plate 423 is a plate-like structure with a concave middle, and the diameter of the air outlet 424 is between 1 / 8d and 1 / 15d. The setting of multiple air outlets allows the gas to enter the breeding tube 41 in a more dispersed manner. Through the analysis of fluid software, the resistance in the middle is small, the speed is large, and the resistance at the edge is large, which is not conducive to the flow and diffusion of the gas. Therefore, the gas dispersion plate used is a plate-like structure with a concave middle. The diameter of the air outlet is between 1 / 8d and 1 / 15d, which makes the gas dispersion more uniform. If the air outlet is too large, the gas outlet will not be uniform. If the air outlet is too small, the resistance will increase greatly. It should be noted that the axis of the air outlet is inclined to the inner wall of the breeding tube 41, and the inclination angle is between 35° and 55°, so that the air flow direction can be more evenly diffused. The vertical distance from the middle of the gas dispersion plate to the edge of the gas dispersion plate is 1 / 5d, and the above structure will not block the outlet of the air outlet.

[0038] like Figure 3 and Figure 4As shown, in the technical solution of this embodiment, the air inlet pipe 42 also includes an air baffle 425, which is arranged in the diffuser section 422, the plane of the air baffle is parallel to the cross section of the diffuser section 422, the central axis of the air baffle coincides with the central axis of the diffuser, and the diameter of the air baffle is 1 / 2 of the diameter of the diffuser section at the corresponding installation location. The above structure not only takes into account the flow of gas entering the breeding pipe, but also takes into account the flow state of gas in the air inlet pipe 42. Through fluid mechanics simulation, the provision of the air baffle 425 can make the gas enter the breeding pipe 41 more uniformly and stably. The air baffle 425 should not be too large. If it is too large, a large cavity will be formed between the air baffle 425 and the gas dispersion plate 423, which is not conducive to the uniform flow of airflow. The distance between the air baffle 425 and the lowest point of the gas dispersion plate 423 can be between 1 / 2d and 3d.

[0039] like Figure 3 As shown, in the technical solution of this embodiment, the algae culture liquid replenishing pipe 43 is connected to the side of the culture pipe 41, and the exhaust pipe 44 is connected to the central axis of the culture pipe 41. The above structure can ensure the replenishment of the culture liquid and the exhaust gas is discharged as soon as possible. Specifically, the air inlet end of the exhaust pipe 44 is in a bell-mouth shape.

[0040] In the technical solution of this embodiment, the discharge pipe 44 includes a first outlet section and a second outlet section, the first outlet section is connected to the intake pipe 42, the second outlet section is connected to the tail gas recovery structure, and valves are provided on the first outlet section and the second outlet section. The above structure can be used in the breeding pipe 41 for the second time, and can also be used for other purposes or for environmental protection.

[0041] In the technical solution of this embodiment, the device for cultivating algae using biomass fuel kiln gas also includes a waste heat utilization structure, which is connected to the air inlet pipe 42. The above structure is conducive to energy saving and environmental protection, and can also save costs through the repeated use of heat. It should be noted that a water washing tower is also provided in this embodiment. After the flue gas comes out of the lime kiln 30, it is washed by the water washing tower. The water temperature coming out of the water washing tower is relatively high and can be reused. The water washing tower can play a role in dust removal and cooling of the flue gas.

[0042] The present application also provides a method for cultivating algae using kiln gas from biomass fuel, the method adopts the above-mentioned device, and the method includes the following steps: S10 Crush agricultural waste into straw fibers with a length of less than 1 cm with a crusher, stir and mix with calcium oxide, a bulking agent, and a structure improver, and extrude the mixture into a shape, and then carbonize it in a carbonization furnace to make biochar. Agricultural waste includes materials such as straw. S20 Put biochar and limestone into a lime kiln 30 for calcination, and introduce the kiln gas after lime calcination into a water washing tower for water washing and dust removal, and at the same time cool the temperature to 30°C, and use the overburned lime calcined from the lime kiln 30 for making soda ash. S30 The flue gas discharged from the water washing tower is introduced into a sealed, light-transmitting pipeline algae cultivation device through a duct by an induced draft fan for cultivating microalgae. The hot water after cooling and washing the flue gas in the water washing tower is circulated with water in the pipeline algae cultivation device through a heat exchanger. The flue gas contains more CO2 and nitrogen oxides, which can increase the yield of microalgae through photosynthesis. The finished product obtained after dehydration and drying of the microalgae is rich in nutrients and oil, with an oil content of more than 60%, which can be used as a raw material for fish starter feed. In the pipeline algae cultivation device, the flue gas is introduced at a pH of 7.26 for the microalgae culture solution. The flue gas is introduced when the pH is higher than 7.26, and the flue gas is stopped when the pH is lower than 7.

[0043] From the above, we can know that (1) agricultural waste such as sugarcane pith, bagasse and sugarcane peel are crushed into straw fibers with a length of less than 1 cm by a crusher, mixed with calcium oxide, bulking agent, structural improver, etc., shaped by an extruder, and finally carbonized in a carbonization furnace to make biochar. The particle size of the produced biochar is 20mm-40mm, the crushing strength (M25) is greater than 92.0%, the abrasion resistance (M10) is less than 7.0%, the fixed carbon content is greater than 85%, and the calorific value is about 7200-8000 kcal / kg. After the biochar is made in the carbonization furnace, it is transported to the loading trolley via a conveyor belt. The loading trolley transports the mixture of limestone and biochar to the kiln mouth of the lime kiln and pours it into the kiln for calcination. The ratio of limestone to biochar is: 1t limestone: 80kg biochar

[0044] (2) The biochar and limestone are placed in a lime kiln (lime kiln 30) for calcination. The kiln gas after lime calcination is introduced into a water scrubber for water washing and dust removal, and the temperature is cooled to 30°C. The overburned lime calcined in the lime kiln is used to make chemical raw materials such as soda ash. The calorific value of biochar is about 7200-8000 kcal / kg. The biochar releases a large amount of heat after combustion, which causes the limestone to be calcined at 1050°C. The mechanical kiln is divided into three zones according to the different functions of the kiln body at different heights: preheating zone, calcining zone, and cooling zone. The air is introduced into the lime kiln from the ventilation port through the fan at the bottom of the kiln, and the flue gas is discharged from the upper kiln port. The biochar and limestone just put into the kiln port are preheated by the flue gas at 150-300°C. As calcium oxide is continuously produced in the lower part (the material sinking speed is: 20-30mm / min), limestone and biochar enter the calcining zone for combustion. The combustion temperature is about 1050℃, which causes the limestone to be "overburned" and generates a large amount of carbon dioxide smoke and calcium oxide. The calcium oxide that has been generated, the incompletely burned biochar, and the solid matter such as ash are cooled by the air that has just entered the kiln body, and the overburned lime is produced through the ash discharger below. The calcination temperature control and calcination zone control are mainly controlled by the ventilation volume. The main parameters of the air input are: air flow velocity: 8-12m / s, the kiln bottom pressure is in a negative pressure state, 20-30Pa. When the calcination zone moves downward, increase the ventilation volume and temporarily stop the output of calcium oxide. When the calcination zone moves upward, reduce the ventilation volume and increase the output of calcium oxide.

[0045] (3) The flue gas discharged from the water scrubber is passed through a duct by an induced draft fan into a sealed, light-transmitting pipeline algae cultivation device for cultivating microalgae. Algae absorb CO2 and nitrogen oxides in the gas, and can increase the yield of microalgae through photosynthesis. The algae extraction is sucked out by the compressor through the upper pipeline and enters the centrifugal dehydration and drying process.

[0046] (4) The finished product obtained after centrifugal dehydration and drying of microalgae liquid is rich in nutrients and oil, with an oil content of more than 60%, and can be used as a raw material for feed.

[0047] In the step (2), the diameter of the limestone feed is 20-40 mm or 60-80 mm, the kiln temperature is 900° C., the calcination temperature is controlled at 1050° C., the lime calcination time is not less than 10 hours to generate more carbon dioxide gas, the kiln gas temperature at the lime kiln mouth is 150° C., and the volume fraction of carbon dioxide contained in the kiln gas is 35%.

[0048] The reaction mechanism of overburned lime and carbon dioxide generated in the lime kiln is:

[0049]

[0050] like Figure 2 and Figure 3As shown, the flue gas discharged from the water scrubber is passed through the duct by the induced draft fan into the sealed and light-transmitting pipeline algae cultivation device for cultivating microalgae. A seaweed cultivation unit device is a cylindrical pipe with a diameter of 0.3m and a height of 2.5m, mainly composed of plastic modified pipes such as heat-resistant polyethylene (PE-RT), with 10 pipes in a row and 6 pipes in a column, a total of 60 pipes 10×6 as a group of pipeline algae cultivation devices. The flue gas enters from the bottom of the cultivation device through the exhaust pipe, and the algae absorbs CO2 and nitrogen oxides in the gas, and the microalgae yield can be increased through photosynthesis. The remaining gas is discharged from the upper pipe. The algae supplement liquid is added from the top of the device through a special pipe. The microalgae culture solution is filled with 80%, the diameter of the flue gas aeration head is 0.2m, and the flue gas enters from the bottom of the cultivation device through the exhaust pipe. The flue gas aeration head breaks the gas into small bubbles and passes them into the microalgae culture solution. In the pipeline-type equipment, the algae absorbs CO2 and nitrogen oxides in the gas, and the microalgae yield can be increased through photosynthesis. When the pH of the algae culture solution is higher than 7.26, flue gas is introduced, and when the pH is lower than 7, the flue gas supply is stopped. 50% of the algae culture solution is extracted every 24 hours for centrifugal separation and drying. The algae extract is sucked out by the compressor through the upper pipeline and enters the centrifugal dehydration and drying process. Algae supplement liquid is added from the top of the device through a dedicated pipeline. The remaining flue gas is discharged from the upper pipeline.

[0051] The hot water after cooling and washing the flue gas in the water washing tower is circulated through the heat exchanger with the water of the pipeline algae cultivation device for heat exchange, so as to keep the culture medium temperature always within the range most suitable for the growth of algae cells.

[0052] In this embodiment, for every 100kg of biochar consumed, 322kg of lime can be generated, 583kg of carbon dioxide can be produced, and the volume is about 294 cubic meters (under standard conditions). According to practical experience, for every 100kg of microalgae produced, 91.1 cubic meters of CO2 can be consumed. That is, 100kg of biochar can cultivate 323kg of microalgae, and the microalgae recovery rate is calculated at 80%, and 258kg of microalgae raw materials for fish can be collected. Therefore, the method of using biomass fuel kiln gas for algae cultivation provided by the present invention has considerable economic and social benefits.

[0053] Through the cultivation of energy microalgae, not only can NOx and CO2 in flue gas be removed, residual inorganic elements in ash can be removed, and environmental pollution can be reduced, but also raw materials for biofuels can be provided and high value-added products can be produced.

[0054] If the fuel for burning lime is replaced with biochar, it will not only reduce the emission of harmful gases such as sulfide, but also generate higher concentrations of carbon dioxide. These gases carrying a large amount of carbon source and heat are the best raw materials for algae synthesis. Algae rich in high nutrients can finally be made into high-quality fish feed, promoting the increase of agricultural and fishery production and income.

[0055] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0056] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for cultivating algae using biomass fuel kiln gas, characterized in that: include: The following are arranged in sequence: a stirrer (10), a molding machine (20), a lime kiln (30), an algae culture device (40), a centrifugal dehydrator (50) and a dryer (60); The algae cultivation device (40) comprises a cultivation tube (41), a first end of the cultivation tube (41) is connected to an air inlet pipe (42), a second end of the cultivation tube (41) is connected to an algae culture liquid replenishing pipe (43) and a discharge pipe (44), and the air inlet pipe (42) is connected to an air outlet of the lime kiln (30); The air intake pipe (42) comprises an air intake pipe section (421) and a diffuser pipe section (422) which are connected to each other; the diffuser pipe section (422) is located inside the aquaculture pipe (41); the diameter of the diffuser pipe section (422) gradually increases in a direction from the first end of the aquaculture pipe (41) to the second end of the aquaculture pipe (41); and a gas dispersion plate is provided at one end of the diffuser pipe section (422) away from the air intake pipe section (421); The diameter of the end of the diffusion pipe section (422) away from the air inlet pipe section (421) is d, and the diameter of the breeding pipe (41) is D, wherein 1.3d≤D≤2d; The gas dispersion plate has a plurality of gas outlet holes. The gas dispersion plate is a plate-shaped structure with a concave middle. The diameter of the gas outlet holes is between 1 / 8d and 1 / 15d.

2. The device for cultivating algae using biomass fuel kiln gas according to claim 1 is characterized in that: The air inlet pipe (42) also includes an air baffle, which is arranged in the diffuser pipe section (422), the plane of the air baffle is parallel to the cross-section of the diffuser pipe section (422), the central axis of the air baffle coincides with the central axis of the diffuser pipe, and the diameter of the air baffle is 1 / 2 of the diameter of the diffuser pipe section at the corresponding installation location.

3. The device for cultivating algae using biomass fuel kiln gas according to claim 1, characterized in that: The algae culture liquid replenishing pipe (43) is connected to the side of the culture pipe (41), and the discharge pipe (44) is connected to the central axis of the culture pipe (41).

4. The device for cultivating algae using biomass fuel kiln gas according to claim 1, characterized in that: The exhaust pipe (44) comprises a first outlet section and a second outlet section, the first outlet section is connected to the intake pipe (42), the second outlet section is connected to the exhaust gas recovery structure, and valves are provided on the first outlet section and the second outlet section.

5. The device for cultivating algae using biomass fuel kiln gas according to claim 1, characterized in that: The device for cultivating algae using biomass fuel kiln gas also includes a waste heat utilization structure, and the waste heat utilization structure is connected to the air inlet pipe (42).

6. A method for cultivating algae using biomass fuel kiln gas, characterized in that: The method adopts the device described in any one of claims 1 to 5, and the method comprises the following steps: S10: crushing agricultural waste into straw fibers with a length of less than 1 cm by a crusher, mixing with calcium oxide, a bulking agent, and a structure improver, extruding the fibers into shapes, and then carbonizing them in a carbonization furnace to produce biochar; S20: calcine the biochar and limestone in a lime kiln (30); introduce kiln gas after lime calcination into a water scrubber for water scrubbing and dust removal; and cool the temperature to 30° C. The overburned lime calcined in the lime kiln (30) is used to make soda ash; S30: use an induced draft fan to pass the flue gas discharged from the water scrubber through a duct into a sealed, light-transmitting pipeline-type algae cultivation device for cultivating microalgae; the hot water after cooling and washing the flue gas in the water scrubber is circulated with water in the pipeline-type algae cultivation device through a heat exchanger for heat exchange; the flue gas contains more CO2 and nitrogen oxides, and the microalgae yield can be increased through photosynthesis; the finished product obtained after dehydration and drying of the microalgae is rich in nutrients and oil, with an oil content of more than 60%, and can be used as a raw material for fish starter feed.

7. The method for cultivating algae using biomass fuel kiln gas according to claim 6, characterized in that: In the pipeline type algae cultivation device, the flue gas is introduced with the pH value of the microalgae culture solution being 7.26 as the boundary, and the flue gas is introduced when the pH value is higher than 7.26, and the flue gas is stopped when the pH value is lower than 7.

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