A high-efficiency desalination preparation system and method of suaeda salsa

Abstract

This invention belongs to the field of biomass resource utilization technology, specifically a highly efficient desalination system and method for Suaeda salsa in saline-alkali land. The system includes a raw material pretreatment unit, an ultrasonic extraction and desalination unit, a pressing and desalination unit, a carbonization preparation unit, and a product collection unit. By coupling ultrasonic extraction and pressing desalination technologies, combined with a low-temperature carbonization process, highly efficient desalination and high-value conversion of Suaeda salsa are achieved. After crushing, ultrasonic extraction, and pressing and desalination, the desalinated solid material is dried and carbonized to produce biochar. The desalination filtrate can be used to recover salt for the preparation of plant salts, with no secondary pollution throughout the process. This system is rationally designed, operates stably, achieves a desalination rate of ≥50%, produces biochar with low salt content and excellent quality, and reduces energy consumption compared to traditional processes. It combines economic value and environmental benefits, providing a highly efficient solution for the resource utilization of Suaeda salsa.

Description

Technical Field

[0001] This invention relates to the field of biomass resource utilization technology, specifically to a highly efficient desalination preparation system and method for Suaeda salsa in saline-alkali land. Background Technology

[0002] Suaeda salsa is an annual herbaceous halophyte belonging to the genus Suaeda in the family Chenopodiaceae. It is a core dominant species in my country's coastal mudflats and inland saline-alkali land ecosystems, distributed along the coasts of the Bohai Sea, Yellow Sea, and East China Sea, as well as inland saline-alkali areas in Northwest and North China. The total suitable habitat area nationwide exceeds 100 million hectares, with an annual natural biomass exceeding 50 million tons. This plant exhibits extremely high stress tolerance, growing in extreme environments with salinity of 1%-3%. It not only absorbs soil salts through its roots, improving soil structure and achieving ecological restoration effects such as sand fixation, water purification, and mitigation of soil salinization, but also possesses significant environmental and economic value due to its high content of cellulose, hemicellulose, and lignin in its dry matter, low ash content, and stable calorific value, making it an ideal raw material for producing high-quality biochar.

[0003] However, the high salt content of Suaeda salsa in saline-alkali land has become a core bottleneck for its resource utilization. Traditional desalination methods, such as soaking and rinsing with water, suffer from incomplete desalination, high water consumption, and high energy consumption. If Suaeda salsa is directly carbonized, the resulting biochar will have an excessively high salt content, significantly limiting its application scenarios. In existing technologies, the lack of effective coupling between single desalination technology and carbonization process results in defects such as fragmented production processes, low resource utilization, and easy generation of secondary pollution, making it difficult to achieve efficient and clean conversion of Suaeda salsa.

[0004] Therefore, developing an integrated and efficient technology for the resource utilization of Suaeda salsa in saline-alkali land, achieving the synergistic goals of deep desalination, low-temperature carbonization, and salt resource recovery, and solving problems such as incomplete desalination, low-quality biochar, high energy consumption, and secondary pollution, and promoting a virtuous cycle of "ecological restoration, resource transformation, and industrial value-added" in saline-alkali land, has become an urgent technical problem to be solved in this field. To this end, we propose an efficient desalination preparation system and method for Suaeda salsa in saline-alkali land. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a highly efficient desalination preparation system and method for Suaeda salsa in saline-alkali land. By coupling ultrasonic extraction with pressing desalination and combining it with a low-temperature carbonization process, the system achieves highly efficient desalination and high-value conversion of Suaeda salsa in saline-alkali land, thus solving the problems mentioned earlier.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A highly efficient desalination preparation system for Suaeda salsa in saline-alkali land includes: a raw material pretreatment unit, an ultrasonic extraction and desalination unit, a pressing and desalination unit, a carbonization preparation unit, and a product collection unit; The raw material pretreatment unit includes a raw material crusher and a first conveying device; The ultrasonic extraction and desalting unit includes an ultrasonic extraction tank, a stirrer, and a liquid level controller; The pressing and desalting unit includes a press, a filter, and a filtrate collection tank; The carbonization preparation unit includes a dryer, a third conveying device, a third valve, a gas cylinder, a blower, and a carbonization furnace; The product collection unit includes a cooler and a finished product bin.

[0007] As a further part of the present invention, the outlet of the raw material crusher is connected to the inlet of the first conveying device, and the outlet of the first conveying device is connected to the ultrasonic extraction and desalination unit through a first valve. The inlet of the ultrasonic extraction tank is connected to the first valve, the stirrer is installed inside the ultrasonic extraction tank, the liquid level controller is set on the side wall of the ultrasonic extraction tank, and the outlet of the ultrasonic extraction tank is connected to the pressing and desalting unit through a conveyor and a second valve. The inlet of the press is connected to the outlet of the ultrasonic extraction tank, the filtrate outlet of the press is connected to the filtrate collection tank through a filter, and the solid outlet of the press is connected to the carbonization preparation unit through a second conveying device. The inlet of the dryer is connected to the second conveying device, the outlet of the dryer is connected to the feed inlet of the carbonization furnace through the third conveying device, and the blower is connected to the air inlet of the carbonization furnace through the third valve. The discharge port of the carbonization furnace is connected to the inlet of the cooler via a fourth conveying device, and the outlet of the cooler is connected to the finished product warehouse.

[0008] As a further part of the present invention, the ultrasonic extraction tank is equipped with an ultrasonic transducer with an ultrasonic power of 40kHz, which accelerates the dissolution of salt by destroying the cell wall of Suaeda salsa through ultrasonic cavitation effect. The stirring speed of the stirrer is 50-100 r / min, and the liquid level controller is used to control the solid-liquid ratio in the ultrasonic extraction tank to 1:5.

[0009] As a further part of the present invention, the press is a plate and frame press or a screw press, and the pressing pressure is 10MPa; the filter is a ceramic filter or a metal mesh filter, and the filtration accuracy is 5-20μm.

[0010] As a further part of the present invention, the carbonization furnace is a tubular carbonization furnace or a batch carbonization furnace, with a temperature control range of 200-250℃; the dryer is a box dryer, with a drying temperature of 80-100℃.

[0011] As a further part of the present invention, the first conveying device, the second conveying device, the third conveying device and the fourth conveying device are all screw conveyors; a drain valve is installed on the filtrate pipe of the press.

[0012] As a further part of the present invention, the raw material crusher is a hammer mill or a blade mill, which can crush the raw material of Suaeda salsa to 20-60 mesh.

[0013] A highly efficient desalination method for preparing Suaeda salsa in saline-alkali land includes the following steps: S1. Raw material pretreatment: After removing impurities from fresh salt-grown Suaeda salsa raw materials, they are fed into a raw material crusher and crushed to 20-60 mesh to obtain Suaeda salsa powder. The Suaeda salsa powder is then conveyed to an ultrasonic extraction tank through the first conveying device and the first valve. S2. Ultrasonic extraction and desalting: Add deionized water to the ultrasonic extraction tank, control the solid-liquid ratio to 1:5 using the liquid level controller, start the stirrer and ultrasonic transducer, set the stirring speed to 50-100 r / min and the ultrasonic frequency to 40 kHz, and extract at room temperature for 20-30 min. The ultrasonic cavitation effect is used to break down the cell wall and accelerate the dissolution of salts. At the same time, stirring promotes solid-liquid mass transfer. S3. Pressing and desalting: The solid-liquid mixture after extraction in S2 is fed into the press through a conveyor and a second valve. Pressing and desalting are carried out under a pressing pressure of 10MPa to achieve deep separation of solid and liquid. The solid material after pressing is desalted Suaeda salsa material, which is transported to the subsequent process through the second conveying equipment. S4. Drying treatment: The desalinated Suaeda salsa material is fed into the dryer via the second conveyor and dried at 80-100℃ until the moisture content is ≤20%;

[0014] S5. Low-temperature carbonization: The dried material is fed into the carbonization furnace, and air or inert gas is introduced through a blower. The carbonization furnace is heated to 200-250℃, and the carbonization time is 24 hours. S6. Product collection: The carbonized product is transported to the cooler via the fourth conveying equipment and cooled to room temperature. After cooling to room temperature, it is sent to the finished product warehouse for storage, and finally the biochar product is obtained.

[0015] As a further aspect of the present invention, the deionized water in step S2 can be replaced with a weakly alkaline ethanol aqueous solution with a pH value of 7.5-8.5 and an ethanol volume fraction of 5%-10%, which can further improve the salt dissolution efficiency.

[0016] As a further aspect of the present invention, in step S5, when an inert gas is introduced, the inert gas flow rate is 0.5-1 m³ / min, so that the carbonization furnace is in an oxygen-free carbonization atmosphere; when air is introduced, the air flow rate is 1-2 m³ / min, so that the carbonization furnace is in a weakly oxidizing carbonization atmosphere.

[0017] This invention provides a highly efficient desalination preparation system and method for Suaeda salsa in saline-alkali land. Compared with the prior art, it has the following advantages: 1. High desalination efficiency: The combination of ultrasonic extraction and pressing desalination achieves a desalination rate of ≥50%, solving the problem that traditional processes do not consider desalination; 2. Low energy consumption: Ultrasonic-assisted desalination shortens the extraction time by more than 30%, and the drying and carbonization processes are optimized, resulting in an overall energy consumption reduction of more than 30% compared to traditional processes; 3. High resource utilization rate: The desalination filtrate can recover salt, and the biochar is of excellent quality, realizing the full-component resource utilization of Suaeda salsa in saline-alkali land; 4. Environmentally friendly and pollution-free: The entire process produces no wastewater or exhaust gas emissions, meeting the requirements of green production and providing a demonstration scheme for the resource utilization of saline-alkali land plants; 5. Stable and reliable system: Flexible equipment selection, continuous process, and scale can be adjusted according to production capacity requirements, making it suitable for industrial production; 6. This invention achieves efficient desalination and high-value conversion of Suaeda salsa by organically coupling ultrasonic pressing desalination and carbonization processes. The system process is simple, energy-efficient, environmentally friendly and pollution-free, providing a new path for the resource utilization of Suaeda salsa and has broad application prospects. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the system structure of the present invention.

[0019] In the diagram: 1. Raw material crusher; 2. First conveying equipment; 3. First valve; 4. Ultrasonic extraction tank; 5. Agitator; 6. Liquid level controller; 7. Conveyor; 8. Second valve; 9. Press; 10. Drain valve; 11. Filter; 12. Filtrate collection tank; 13. Second conveying equipment; 14. Dryer; 15. Third conveying equipment; 16. Third valve; 17. Gas cylinder; 18. Blower; 19. Carbonization furnace; 20. Fourth conveying equipment; 21. Cooler; 22. Finished product silo. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The raw materials used in this embodiment and comparative example are all whole, naturally grown, wind-dried salt-tolerant plants of Suaeda salsa grown on the coastal mudflats of Bohai Bay, my country. The raw materials were pretreated to remove impurities such as sand, gravel, dead branches and leaves, and weeds. The initial basic indicators of the raw materials were tested as follows: initial moisture content 35±2%, initial salt content 8.2±0.3%, cellulose content 32%, hemicellulose content 25%, and lignin content 8% in dry matter.

[0022] All embodiments were prepared using the ultrasonic pressing desalination and low-temperature carbonization biochar preparation system of Suaeda salsa described in this invention, while the comparative example used the traditional halophyte biochar production process. After the preparation of each example was completed, four core quality indicators were uniformly tested: desalination rate, biochar salt content, specific surface area, and pH value. At the same time, the comprehensive energy consumption of each embodiment was calculated based on the comprehensive energy consumption of the comparative example (100%). The comprehensive energy consumption includes the electricity, gas, and water consumption of the entire process of raw material crushing, desalination, drying, and carbonization.

[0023] Example 1: Preparation of biochar in a tubular carbonization furnace and air carbonization atmosphere This embodiment uses a tubular carbonization furnace with air as the carbonization atmosphere, combined with a plate and frame press for pressing and desalting. The specific preparation steps are as follows: Raw material pretreatment: The air-dried salt-grown Suaeda salsa after impurity removal is fed into hammer mill 1 and crushed into 40-mesh Suaeda salsa powder. It is then quantitatively fed into ultrasonic extraction tank 4 through screw conveyor 2 and valve 3. Ultrasonic extraction and desalting: Add deionized water to ultrasonic extraction tank 4, control the solid-liquid ratio to 1:5 through liquid level controller 6, start stirrer 5 and ultrasonic transducer, and ultrasonically extract for 20 minutes at room temperature and pressure to obtain Suaeda salsa slurry. Pressing and desalting: The slurry is fed into the plate and frame press 9 through the conveyor 7 and valve 8, and is pressed under a pressing pressure of 10MPa for 8 minutes; the filtrate produced by pressing enters the ceramic filter 11 through the drain valve 10, and is stored in the filtrate collection tank 12 after filtration. After pressing, desalted Suaeda salsa solid material is obtained. Drying process: Desalinated Suaeda salsa solid material is fed into box dryer 14 through screw conveyor 13, the drying temperature is set to 100℃, and the material is dried until the moisture content is 9% to obtain dried Suaeda salsa material; Low-temperature carbonization: The dried Suaeda salsa material is fed into the tubular carbonization furnace 19 through the screw conveyor 15. Air is introduced into the furnace through the blower 18 and valve 16 at a flow rate of 1.5 m³ / min. The furnace temperature is raised to 200°C and maintained at a constant temperature. The material is fully pyrolyzed through the screw propulsion structure in the furnace. The total carbonization time is 24 hours, and the carbonized product is obtained. Product collection: The carbonized product is sent to the cooler 21 through the screw conveyor 20. The product is slowly cooled to room temperature of 25°C by circulating cooling water. After cooling, it is sent to the sealed finished product warehouse 22 for storage, thus obtaining the biochar product. The desalted filtrate in the filtrate collection tank 12 is used to recover sodium chloride through evaporation and crystallization process, and the purity of the recovered salt is 95.2%.

[0024] Example 2: Preparation of biochar in a batch carbonization furnace under nitrogen carbonization atmosphere This embodiment uses a batch carbonization furnace with nitrogen as the carbonization atmosphere, and is combined with a press 9 for continuous pressing and desalting. The specific preparation steps are as follows: Raw material pretreatment: The air-dried salt-grown Suaeda salsa after impurity removal is fed into the blade-type raw material crusher 1 and crushed into Suaeda salsa powder of 20 mesh. It is then quantitatively fed into the ultrasonic extraction tank 4 through the screw conveyor 2 and valve 3. Ultrasonic extraction and desalting: Add deionized water to ultrasonic extraction tank 4, control the solid-liquid ratio to 1:5 through liquid level controller 6, start stirrer 5 and ultrasonic transducer, and ultrasonically extract for 25 minutes at room temperature and pressure to obtain Suaeda salsa slurry. Pressing and desalting: The slurry is fed into the press 9 through the conveyor 7 and valve 8, and is continuously pressed under a pressing pressure of 10MPa with a material feed rate of 0.2m / min; the filtrate produced by pressing enters the filter 11 through the drain valve 10, and is stored in the filtrate collection tank 12 after filtration. After pressing, desalted Suaeda salsa solid material is obtained. Drying process: Desalinated Suaeda salsa solid material is fed into box dryer 14 through screw conveyor 13, the drying temperature is set to 90℃, and the material is dried until the moisture content is 15% to obtain dried Suaeda salsa material; Low-temperature carbonization: The dried Suaeda salsa material is fed into the autoclave carbonization furnace 19 through the screw conveyor 15. Nitrogen gas is introduced into the furnace through the blower 18 and valve 16 (gas flow rate 0.8 m³ / min, gas cylinder 17 is a nitrogen cylinder). The furnace temperature is raised to 220℃ and maintained at a constant temperature. The material is fully pyrolyzed in the furnace. The total carbonization time is 24 hours, and the carbonized product is obtained. Product collection: The carbonized product is sent to the cooler 21 through the screw conveyor 20 and cooled to room temperature of 25°C before being sent to the finished product warehouse 22 for storage, thus obtaining the biochar product; the desalted filtrate in the filtrate collection tank 12 is subjected to vacuum freeze drying process to recover salt, and the recovered salt purity is 96.5%.

[0025] Example 3: Preparation of biochar in a tubular carbonization furnace and argon carbonization atmosphere This embodiment uses a tubular carbonization furnace with argon as the carbonization atmosphere, increases the ultrasonic extraction time, extends the pressing and holding time, and pulverizes the raw material to the upper limit of particle size. The specific preparation steps are as follows: Raw material pretreatment: The air-dried salt-grown Suaeda salsa after impurity removal is fed into hammer mill 1 and crushed into 60-mesh Suaeda salsa powder. It is then quantitatively fed into ultrasonic extraction tank 4 through screw conveyor 2 and valve 3. Ultrasonic extraction and desalting: Add deionized water to ultrasonic extraction tank 4, control the solid-liquid ratio to 1:5 through liquid level controller 6, start stirrer 5 and ultrasonic transducer, and ultrasonically extract for 30 minutes at room temperature and pressure to obtain Suaeda salsa slurry. Pressing and desalting: The slurry is fed into the plate and frame press 9 through the conveyor 7 and valve 8, and is pressed under a pressing pressure of 10MPa for 10 minutes; the filtrate produced by pressing enters the filter 11 through the drain valve 10, and is stored in the filtrate collection tank 12 after filtration. After pressing, desalted Suaeda salsa solid material is obtained. Drying process: Desalinated Suaeda salsa solid material is fed into dryer 14 through screw conveyor 13, the drying temperature is set to 80℃, and the material is dried until the moisture content is 20% to obtain dried Suaeda salsa material; Low-temperature carbonization: The dried Suaeda salsa material is fed into the tubular carbonization furnace 19 through the screw conveyor 15. Argon gas is introduced into the furnace through the blower 18 and valve 16 (gas flow rate 0.5 m³ / min, gas cylinder 17 is an argon gas cylinder). The furnace temperature is raised to 250℃ and maintained at a constant temperature. The material is fully pyrolyzed through the screw propulsion structure in the furnace. The total carbonization time is 24 hours, and the carbonized product is obtained. Product collection: The carbonized product is sent to the cooler 21 through the fourth conveying device 20 and cooled to room temperature of 25°C before being sent to the finished product warehouse 22 for storage, thus obtaining the biochar product; the desalted filtrate in the filtrate collection tank 12 is subjected to an evaporation crystallization process to recover the salt, and the recovered salt has a purity of 95.8%.

[0026] Comparative example: Traditional water soaking desalination and direct high-temperature carbonization for biochar preparation This comparative example uses the conventional process for producing biochar from halophytes in existing technologies, without ultrasonic extraction or high-pressure mechanical pressing for desalination. Instead, it directly uses water soaking for desalination followed by high-temperature carbonization. The specific steps are as follows: Raw material pretreatment: Pulverize the air-dried salt-grown Suaeda salsa after removing impurities into 40-mesh Suaeda salsa powder; Desalination by soaking in clean water: Add Suaeda salsa powder to clean water at a solid-liquid ratio of 1:10, and let it stand at room temperature for 60 minutes, stirring manually twice for 5 minutes each time. Solid-liquid separation: The material is naturally drained using a filter screen, and the filtrate is directly discharged to obtain the drained Suaeda salsa solid material with a moisture content of 45%. Direct carbonization: The drained solid material of Suaeda salsa is directly fed into a tubular carbonization furnace, and air is introduced (air flow rate 2m³ / min) to raise the temperature inside the furnace to 250℃ and carbonize for 24 hours to obtain carbonized products. Cooling and collection: The carbonized products are naturally cooled to room temperature to obtain biochar products.

[0027] Comparison of test results between the examples and the comparative examples The biochar products prepared in Examples 1-3 and the comparative examples were tested for key indicators, and the overall energy consumption ratio of each example was calculated. The test and calculation results are shown in the table below: detection indicators Example 1 Example 2 Example 3 Comparative Example Desalination rate (%) 55.1 52.3 61.2 28.4 Salt content of biochar (%) 3.7 3.9 3.2 5.9 Specific surface area (m² / g) 2.133 2.3568 2.5892 1.0254 pH value 7.6 7.8 7.9 8.5 Overall energy consumption percentage (%, with the comparative ratio as 100%) 65 68 70 100 Purity of recovered salt (%) 95.2 96.5 95.8 Filtrate discharged directly Analysis of Results from Examples and Comparative Examples Desalination effect and biochar quality: The desalination rates of Examples 1-3 were all ≥50%, and the salt content of the biochar was ≤4%, which was far superior to the comparative example (desalination rate of only 28.4%, and salt content of biochar of 5.9%). This proves that the desalination process of the present invention, which combines ultrasonic extraction and high-pressure pressing, can effectively destroy the cell walls of Suaeda salsa in saline-alkali land and remove bound salts, thus solving the core problem of incomplete desalination in traditional processes. In addition, the pH value of the biochar prepared in the examples was 7.6-7.9, which is neutral to slightly alkaline and suitable for applications such as soil improvement, carbon sequestration and emission reduction. The pH value of the biochar in the comparative example reached 8.5, which is too alkaline and can easily cause soil alkalization, thus limiting its application scenarios.

[0028] Biochar structure and physicochemical properties: The specific surface area of ​​biochar in Examples 1-3 is 2.1336-2.5892 m² / g, which is much higher than that of the comparative example (1.0254 m² / g). This is because the present invention adopts a low-temperature carbonization process of 200-250℃, and the moisture content of the desalinated Suaeda salsa material is controllable, which avoids the collapse of the biochar pore structure caused by the traditional high-temperature carbonization of 300℃, thus ensuring the stability of the physicochemical properties of the biochar. Among them, Example 3 has the highest desalination rate and the best specific surface area of ​​biochar due to its finer particle size and longer ultrasonic extraction time.

[0029] Energy consumption and resource utilization: The overall energy consumption of Examples 1-3 is only 65%-70%, which is more than 30% lower than that of traditional processes. This is due to the fact that ultrasonic-assisted desalination significantly shortens the extraction time (20-30 min vs. traditional 60 min), and the drying process controls the moisture content of the material to less than 20%, which greatly reduces the energy consumption of the carbonization stage. At the same time, this invention realizes the salt recovery of the desalination filtrate, and the recovered salt purity is more than 95%, which can be used to prepare plant salt and industrial salt. Direct discharge of the comparative filtrate not only wastes salt resources, but also easily causes secondary water pollution, resulting in extremely poor resource utilization and environmental protection.

[0030] Process flexibility and industrial adaptability: Examples 1-3, using different types of carbonization furnaces, carbonization atmospheres, press types, and process parameters, all produced high-quality, low-salt biochar, demonstrating that the system and method of this invention possess good process flexibility within the parameter range protected by the claims. Equipment selection can be flexibly adjusted according to the capacity and cost requirements of industrial production (e.g., air atmosphere has the lowest cost, while inert gas atmosphere produces higher-quality biochar; plate and frame presses are suitable for batch production, while screw presses are suitable for continuous production), adapting to industrial applications of different scales.

[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency desalination preparation system of Suaeda salsa, characterized in that, The application relates to a salted Suaeda salsa processing device. The device comprises a raw material pretreatment unit, an ultrasonic extraction desalination unit, a pressing desalination unit, a carbonization preparation unit and a product collection unit. The raw material pretreatment unit comprises a raw material crusher (1) and a first conveying device (2). The ultrasonic extraction desalination unit comprises an ultrasonic extraction tank (4), a stirrer (5) and a liquid level controller (6). The pressing desalination unit comprises a press (9), a filter (11) and a filtrate collection tank (12). The carbonization preparation unit comprises a dryer (14), a third conveying device (15), a third valve (16), a gas cylinder (17), a blower (18) and a carbonization furnace (19). The product collection unit comprises a cooler (21) and a finished product bin (22).

2. The system for efficiently desalinating the Suaeda according to claim 1, wherein: The outlet of the raw material crusher (1) is connected with the feeding port of the first conveying device (2), and the discharge port of the first conveying device (2) is connected with the ultrasonic extraction desalination unit through a first valve (3). The inlet of the ultrasonic extraction tank (4) is connected with the first valve (3), the stirrer (5) is arranged in the ultrasonic extraction tank (4), the liquid level controller (6) is arranged on the side wall of the ultrasonic extraction tank (4), and the outlet of the ultrasonic extraction tank (4) is connected with the pressing desalination unit through a conveyor (7) and a second valve (8). The inlet of the press (9) is connected with the outlet of the ultrasonic extraction tank (4), the filtrate outlet of the press (9) is connected with the filtrate collection tank (12) through the filter (11), and the solid outlet of the press (9) is connected with the carbonization preparation unit through a second conveying device (13). The inlet of the dryer (14) is connected with the second conveying device (13), the outlet of the dryer (14) is connected with the feeding port of the carbonization furnace (19) through the third conveying device (15), the blower (18) is connected with the gas inlet of the carbonization furnace (19) through the third valve (16). The discharge port of the carbonization furnace (19) is connected with the inlet of the cooler (21) through a fourth conveying device (20), and the outlet of the cooler (21) is connected with the finished product bin (22).

3. The system for efficiently desalinating Suaeda salsa according to claim 2, characterized in that: An ultrasonic transducer is arranged in the ultrasonic extraction tank (4), the ultrasonic transducer has an ultrasonic power of 40 kHz, and the ultrasonic cavitation effect is used to destroy the cell wall of the salted Suaeda salsa and accelerate the dissolution of salt. The stirring speed of the stirrer (5) is 50-100 r / min, and the liquid level controller (6) is used to control the solid-liquid ratio in the ultrasonic extraction tank (4) to be 1:

5.

4. The system for efficiently desalinating Suaeda salsa according to claim 3, characterized in that: The press (9) is a plate-frame press or a screw press, the pressing pressure is 10 MPa, the filter (11) is a ceramic filter or a metal mesh filter, and the filtering precision is 5-20 mu m.

5. The system for efficient desalination of Suaeda acutus according to claim 4, characterized in that: The carbonization furnace (19) is a tubular carbonization furnace or a kettle-type carbonization furnace, the temperature control range is 200-250 DEG C, and the dryer (14) is a box-type dryer, and the drying temperature is 80-100 DEG C.

6. The system for efficient desalination of Suaeda acutus according to claim 5, characterized in that: The first conveying device (2), the second conveying device (13), the third conveying device (15) and the fourth conveying device (20) are all screw conveyors, and a liquid discharge valve (10) is arranged on the filtrate pipeline of the press (9).

7. The system for efficient desalination of Suaeda aegyptica according to claim 6, characterized in that: The raw material crusher (1) adopts a hammer crusher or a blade crusher, which can crush the raw material of Suaeda salsa to 20-60 mesh.

8. The method according to any one of claims 1-7, wherein the method is characterized in that, Includes the following steps: S1. Raw material pretreatment: After removing impurities from fresh salt-grown Suaeda salsa raw material, it is fed into a raw material crusher (1) and crushed to 20-60 mesh to obtain Suaeda salsa powder. The Suaeda salsa powder is then conveyed to an ultrasonic extraction tank (4) through the first conveying device (2) and the first valve (3). S2. Ultrasonic extraction and desalting: Add deionized water to the ultrasonic extraction tank (4), control the solid-liquid ratio to 1:5 through the liquid level controller (6), start the stirrer (5) and ultrasonic transducer, the stirring speed is 50-100r / min, the ultrasonic frequency is 40kHz, and extract at room temperature for 20-30min. Use the ultrasonic cavitation effect to destroy the cell wall and accelerate the dissolution of salt, while promoting solid-liquid mass transfer through stirring. S3. Pressing and desalting: The solid-liquid mixture after extraction in S2 is fed into the press (9) through the conveyor (7) and the second valve (8) and desalted under a pressing pressure of 10MPa to achieve deep separation of solid and liquid. The solid material after pressing is desalted alkali grass material, which is transported to the subsequent process through the second conveying device (13). S4. Drying treatment: The desalinated Suaeda salsa material is fed into the dryer (14) via the second conveying equipment (13) and dried at 80-100℃ until the moisture content is ≤20%; S5. Low-temperature carbonization: The dried material is fed into the carbonization furnace (19), and air or inert gas is introduced through the blower (18). The carbonization furnace (19) is heated to 200-250℃ and the carbonization time is 24h. S6. Product collection: The carbonized product is transported to the cooler (21) via the fourth conveying device (20) and cooled to room temperature. After cooling to room temperature, it is sent to the finished product warehouse (22) for storage, and finally the biochar product is obtained.

9. The method of claim 8, wherein the method is characterized by: The deionized water mentioned in step S2 can be replaced with a weakly alkaline ethanol aqueous solution with a pH of 7.5-8.5 and an ethanol volume fraction of 5%-10%, which can further improve the salt dissolution efficiency.

10. The method of claim 9, wherein the method is characterized by: In step S5, when inert gas is introduced, the inert gas flow rate is 0.5-1 m³ / min, so that the carbonization furnace (19) is an oxygen-free carbonization atmosphere; when air is introduced, the air flow rate is 1-2 m³ / min, so that the carbonization furnace (19) is a weakly oxidizing carbonization atmosphere.

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