Corn straw bio-enzyme-microwave synergistic saccharification and fermentation reactor

Abstract

The invention provides a corn straw bio-enzyme-microwave synergistic saccharification and fermentation reactor, and belongs to the technical field of biological energy sources. The first partition plate and the second partition plate are arranged on the inner side wall of the tank body, so that the reactor is provided with three stages of layered reaction areas to form a continuous reaction channel, the continuity and the automation level of reaction are further improved, and the contamination risk in the material transfer process is also greatly reduced. The device comprises a tank body, wherein a conical bottom is arranged at the bottom of the tank body; a first partition plate and a second partition plate are sequentially arranged in the tank body from bottom to top, the interior of the tank body is divided into a heating area, a catalysis area and a saccharification area from top to bottom by the first partition plate and the second partition plate, a microwave cavity is formed in the heating area, and the microwave cavity is fixedly mounted on the top surface of the second partition plate; a porous ceramic carrier and a PH adjusting system are arranged in the catalysis area, a heating ring and a passive mixing device are arranged in the saccharification area, the passive mixing device is connected with an external air pump through a pipeline, and a sugar-acid separation module is arranged below the passive mixing device.

Description

Technical Field

[0001] The present invention relates to a reactor for the synergistic saccharification and fermentation of corn straw by bioenzymes and microwaves, and specifically belongs to the technical field of bioenergy. Background Art

[0002] As an important part of renewable energy, the efficient conversion technology of biomass energy has attracted much attention; lignocellulosic biomass such as corn straw is considered an ideal raw material for bio-based chemicals due to its rich reserves and strong renewability; however, its complex natural structure (such as lignin wrapping and high cellulose crystallinity) leads to significant technical bottlenecks in traditional chemical or biological conversion methods: conventional dilute acid hydrolysis requires high temperature and high pressure conditions of 120-180°C, which easily causes side reactions to generate inhibitors such as furfural, and the equipment corrosion is serious; the pure enzymatic hydrolysis process is limited by cellulose crystallinity, with a slow reaction rate and a large amount of enzyme consumption;

[0003] In addition, although microwave-assisted saccharification can improve the reaction kinetics, it lacks precise temperature control means, and local overheating is likely to cause enzyme inactivation, and it is difficult to achieve the temperature gradient matching of saccharification and subsequent fermentation with a single heat source heating; in terms of product separation and purification, traditional centrifugation and filtration processes have insufficient retention rates for low molecular weight sugars, and cannot simultaneously achieve the efficient separation of organic acids and sugars, increasing the downstream purification cost by 30-50%;

[0004] The publication number "CN115011648B" is a fermentation method for enhancing sugar production from corn straw using Clostridium thermocellum, aiming to solve the problems that the existing method for producing sugar from straw using Clostridium thermocellum is a wet anaerobic fermentation, which has a large floor area and the biogas slurry generated after fermentation pollutes the environment. Method: First, use expanded corn straw as the fermentation substrate; second, sterilize the fermentation substrate, inoculate the Clostridium thermocellum seed liquid into the sterilized fermentation substrate in an anaerobic incubator, and carry out anaerobic fermentation for fermenting corn straw to produce sugar;

[0005] This equipment is a segmented design, that is, pretreatment - enzymatic hydrolysis - fermentation are carried out step by step. Frequent material transfer leads to a high risk of contamination, and the overall automation degree is insufficient, making it difficult to meet the requirements of industrial continuous production. Summary of the Invention

[0006] The purpose of the present invention is to provide a reactor for the synergistic saccharification and fermentation of corn straw by bioenzymes and microwaves, so as to construct a continuous reaction system integrating pretreatment, saccharification, and separation, which can significantly improve the biomass conversion efficiency and product yield, and provide key equipment support for the production of low-cost bio-based chemicals.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is as follows: The invention includes a tank body, and a conical bottom is provided at the bottom of the tank body; a first partition board and a second partition board are sequentially arranged in the tank body from bottom to top. The first partition board and the second partition board divide the inside of the tank body into a heating area, a catalytic area, and a saccharification area from top to bottom. A microwave cavity is arranged in the heating area, and the microwave cavity is fixedly installed on the top surface of the second partition board; a porous ceramic carrier and a PH adjustment system are arranged in the catalytic area, a heating coil and a passive mixing device are arranged in the saccharification area, the passive mixing device is connected to an external air pump through a pipeline, and a sugar-acid separation module is arranged below the passive mixing device.

[0008] Further, the microwave cavity is fixedly installed on the top surface of the second partition board. A dielectric window is installed on the top surface of the microwave cavity, a microwave feed source array and a temperature sensor are installed in the microwave cavity, the porous ceramic carrier is fixedly installed on the top surface of the first partition board, the PH adjustment system includes an atomizing nozzle and an acid-base storage tank, the acid-base storage tank is fixedly installed on the bottom surface of the second partition board, and the bottom surface of the acid-base storage tank is connected to the atomizing nozzle;

[0009] Furthermore, the heating coil is connected to the inner side wall of the tank body through a threaded structure, the sugar-acid separation module is fixedly installed on the inner side wall of the tank body, and a nano-ceramic membrane separation unit is arranged in the sugar-acid separation module;

[0010] The conical bottom is set at an included angle of 60 degrees in the downward position. A coil heat exchanger is installed on the outer side wall of the conical bottom. The coil heat exchanger is connected to a cooling water circulation device, and a sedimentation tank is arranged on the inner bottom surface of the conical bottom.

[0011] The tank body is of a cylindrical structure, the microwave cavity is of a cylindrical structure, and the microwave cavity is hermetically connected to the inner side wall of the tank body through a flange. A jacket cooling circuit is arranged outside the microwave cavity;

[0012] Further, the jacket cooling circuit is regulated by a temperature controller.

[0013] The dielectric window is made of ceramic material, and the microwave feed source array includes a microwave generator and a reflection suppressor. A catalyst is loaded on the porous ceramic carrier, and the porous ceramic carrier is located below the PH adjustment system.

[0014] Further, the heating coil is made of ceramic material, and the heating coil is of a conical structure. A nano-ceramic coating is coated on the surface of the heating coil. A coil cooling circuit is installed on the outer surface of the heating coil, and the coil cooling circuit is regulated by a temperature controller.

[0015] Further, nitrogen is uniformly distributed at the bottom of the passive mixing device, and a Venturi tube is connected to the top surface of the passive mixing device.

[0016] The beneficial effects of the present invention are:

[0017] 1. By adopting the synergistic method of microwave heating and enzymatic reaction in the heating zone, combining a 2.45GHZ variable-frequency microwave feed source array with a PID temperature controller, the reaction rate and energy transfer efficiency of the reactor are significantly improved. Microwave heating can strengthen mass transfer, with a penetration depth of up to 5 cm, effectively improving the efficiency of the saccharification reaction. At the same time, it reduces the temperature non-uniformity and energy waste caused by conventional heating methods. Secondly, through the precise PID temperature controller and jacket cooling circuit of the reactor, the temperature fluctuation throughout the process is ensured to be within ±1°C, avoiding the problem of enzyme inactivation caused by temperature fluctuations in the traditional system, enhancing the enzyme activity and reaction stability. At the same time, the catalytic zone uses a porous ceramic carrier to load a nano-level double-enzyme system, combined with an atomizing nozzle and a PH adjustment system, which can accurately adjust the local microenvironment and improve the specificity of the catalytic reaction and the utilization rate of the enzyme.

[0018] 2. Through the arrangement of the first partition and the second partition on the inner side wall of the tank body, the reactor has a three-stage stratified reaction zone, including a microwave heating zone, a dilute acid catalytic zone, and a high-temperature saccharification zone, thus forming a continuous reaction channel, which improves the reaction continuity and automation level, and also greatly reduces the risk of bacterial contamination during the material transfer process. Through the sugar-acid separation module adopting the separation mode of electrodialysis-ultrafiltration coupling, the efficient separation of sugar and acid can be realized, improving the purity and yield of the product. At the same time, the combination of the conical ceramic heating coil and the nano-coating technology not only improves the heating efficiency but also enhances the high-temperature resistance and corrosion resistance, reducing the equipment wear and corrosion problems and extending the service life of the equipment.

[0019] 3. Through the full-process PID joint adjustment strategy and modular expansion design of the reactor, it can adapt to the characteristics of different raw materials, especially the efficient saccharification process of lignocellulosic biomass. Through the flexible temperature control and enzymatic reaction adjustment system, the production process can be adjusted according to the characteristics of different raw materials to achieve flexible production and meet the needs of large-scale industrial production. Brief Description of the Drawings

[0020] Figure 1 is the overall sectional structure schematic diagram of the present invention;

[0021] Figure 2 is the front view structure schematic diagram of the present invention;

[0022] Figure 3 is the top view structure schematic diagram of the present invention.

[0023] 1. Tank body; 2. Conical bottom; 3. Coiled tube heat exchange device; 4. Sedimentation tank; 5. First partition; 6. Second partition; 7. Heating zone; 8. Catalytic zone; 9. Saccharification zone; 10. Microwave cavity; 11. Microwave feed source array; 12. Temperature sensor; 13. Dielectric window; 14. Temperature controller; 15. Jacket cooling circuit; 16. Flange; 17. PH adjustment system; 18. Atomizing nozzle; 19. Acid-base storage tank; 20. Porous ceramic carrier; 21. Heating coil; 22. Passive mixing device; 23. Thread; 24. Sugar-acid separation module; 25. Nano-ceramic membrane separation unit; 26. Coiled tube cooling circuit. Detailed implementation mode

[0024] Next, in combination with the attached Figures 1-3 , the technical solutions in the embodiments will be clearly and completely described.

[0025] Detailed implementation mode one: As Figures 1-3 shown, the overall device is composed of a tank body 1 and a conical bottom 2. The tank body 1 and the conical bottom 2 are integrally structured, and the tank body 1 is of a cylindrical structure. The tank body 1 is composed of a stainless steel inner liner with a thickness of 1.5 mm and a polyurethane insulation layer with a thickness of 200 mm. The total height-to-diameter ratio of the main body of the tank body 1 is set to 1:2 - 1:4; the conical bottom 2 is set at a downward angle of 60 degrees. A coiled tube heat exchange device 3 is installed on the outer side wall of the conical bottom 2. The coiled tube heat exchange device 3 is connected to a cooling water circulation device, and a yeast sedimentation tank 4 is arranged on the inner bottom surface of the conical bottom 2. Two-way temperature control is realized through the cooling water circulation interface; the first partition 5 and the second partition 6 are hermetically installed on the inner side wall of the tank body 1 through a bolt-flange structure. The first partition 5 and the second partition 6 have a thickness of 10 mm, thus forming a continuous reaction channel, reducing the risk of bacterial contamination caused by material transfer in the traditional segmented process. The tank body 1 is divided into three parts: a heating zone 7, a catalytic zone 8, and a saccharification zone 9 from top to bottom through the cooperation of the first partition 5 and the second partition 6, so that the reactor adopts a layered modular structure, integrating three functional zones: microwave heating, dilute acid catalysis, and high-temperature saccharification.

[0026] A cylindrical-structured microwave cavity 10 is configured in the heating zone 7. A dielectric window 13 is installed on the top surface of the microwave cavity 10. The dielectric window 13 is made of ceramic material. The dielectric constant of the dielectric window 13 ≥ 100, and the thickness of the dielectric window 13 is 2 mm. A microwave feed source array 11 and a temperature sensor 12 are installed inside the microwave cavity 10;

[0027] The microwave cavity 10 is hermetically connected to the inner side wall of the tank body 1 through a flange 16. A jacket cooling circuit 15 is arranged outside the microwave cavity 10, and the flow rate of the jacket cooling circuit 15 is 20 - 30 m 3 / h, with a flow rate of 0.5 - 1.2 m / s. The jacket cooling circuit 15 is regulated by the temperature controller 14 to keep the combined temperature fluctuation within ±1°C; the microwave feed array 11 includes a microwave generator and a reflection suppressor. The microwave generator is set at 2.45 GHZ, and the reflection loss of the reflection suppressor is less than or equal to -20 dB;

[0028] The heating zone 7 realizes efficient energy penetration through the microwave feed array 11 with 2.45 GHz frequency conversion and the PID temperature controller 14 with an accuracy of ±1°C, combined with the ceramic dielectric window 13. The microwave energy penetration depth reaches 5 cm, increasing the reaction rate by more than 3 times compared with traditional methods;

[0029] In the catalytic zone 8, a porous ceramic carrier 20 and a PH adjustment system 17 are provided. The porous ceramic carrier 20 is fixedly installed on the top surface of the first partition 5, and the porous ceramic carrier 20 is loaded with a cellulase-xylanase composite biocatalyst. The pore size distribution of the porous ceramic carrier 20 is 20 - 200 nm, and the specific surface area is 800 - 1200 m 2 / g. The PH adjustment system 17 includes an atomizing nozzle 18 and an acid-base storage tank 19. There are six groups of atomizing nozzles 18 and acid-base storage tanks 19. The particle size of the atomizing nozzle 18 is less than or equal to 50 μm. The acid-base storage tank 19 is fixedly installed on the bottom surface of the second partition 6, and the bottom surface of the acid-base storage tank 19 is connected to the atomizing nozzle 18; the catalytic zone 8 is loaded with a nanoscale dual-enzyme system through the porous ceramic carrier 20, and the PH adjustment system 17 realizes precise regulation of the local microenvironment through the atomizing nozzle 18, and the enzyme activity retention rate is remarkable;

[0030] In the saccharification zone 9, a heating coil 21 and a passive mixing device 22 are provided. The heating coil 21 is connected to the inner wall of the tank body 1 through a threaded 23 structure, and the heating coil 21 is set as a conical structure. The outer layer of the heating coil 21 is coated with a nano-ceramic coating with a thickness of 50 μm and a temperature resistance of greater than or equal to 1200°C. The outer diameter of the heating coil 21 is 150 mm, the height is 300 mm, and the power density is 800 W / cm 3 , and the micropores at the bottom of the passive mixing device 22 are evenly distributed with a diameter of 0.5 mm and a pore density of 400 pores / m 2 of nitrogen. The top of the passive mixing device 22 is connected to an external air pump with an air volume of 0.5 - 2 m 3 / h; the saccharification zone 9 combines the heating coil 21 with nano-coating technology, supplemented by nitrogen disturbance of the passive mixing device 22 to form a gradient temperature rise field, increasing the substrate conversion rate to 92%;

[0031] A sugar-acid separation module 24 is provided below the passive mixing device 22. The sugar-acid separation module 24 is installed on the inner side wall of the tank body 1 through a three-way valve group. The sugar-acid separation module 24 integrates an electrodialysis membrane group and a nano-ceramic membrane separation unit 25 with a molecular weight cut-off of 100 Da. A coiled pipe cooling circuit 26 is installed on the outer side wall of the heating coil 21. The flow rate of the coiled pipe cooling circuit 26 is 40 - 60 m 3 / h, and the flow velocity is 1.5 - 2.5 m / s. The coiled pipe cooling circuit 26 is regulated by a temperature controller 14, and the precision of temperature control is ±1°C; efficient separation of sugar and acid is achieved through a supporting electrodialysis-ultrafiltration coupling separation module, which improves the product purity by 35% and reduces the downstream purification cost by 50%.

[0032] Through the full-process PID joint adjustment strategy, the temperature fluctuation of the device is <±1°C and the modular expansion design not only adapts to the flexible production requirements of lignocellulosic raw materials such as corn straw, but also reflects significant environmental and economic benefits through energy conservation, consumption reduction, emission reduction and efficiency increase, providing an efficient and sustainable industrial solution for biomass energy conversion;

[0033] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiments according to the technical essence of the present invention within the spirit and principle of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A corn straw bio-enzyme - microwave synergistic saccharification and fermentation reactor, characterized in that, It includes a tank body (1), and a conical bottom (2) is provided at the bottom of the tank body (1); Inside the tank body (1), a first partition board (5) and a second partition board (6) are successively arranged from bottom to top. The first partition board (5) and the second partition board (6) divide the inside of the tank body (1) into a heating zone (7), a catalytic zone (8) and a saccharification zone (9) from top to bottom. A microwave cavity (10) is arranged in the heating zone (7), and the microwave cavity (10) is fixedly installed on the top surface of the second partition board (6); A porous ceramic carrier (20) and a PH adjustment system (17) are arranged in the catalytic zone (8). A heating coil (21) and a passive mixing device (22) are arranged in the saccharification zone (9). The passive mixing device (22) is connected to an external air pump through a pipeline, and a sugar-acid separation module (24) is arranged below the passive mixing device (22).

2. The corn straw bio-enzyme-microwave synergistic saccharification and fermentation reactor according to claim 1, characterized in that, The conical bottom (2) is arranged at a 60-degree angle in the downward position. A coil heat exchange device (3) is installed on the outer side wall of the conical bottom (2). The coil heat exchange device (3) is connected with a cooling water circulation device, and a sedimentation tank (4) is arranged on the inner bottom surface of the conical bottom (2).

3. A corn straw bio-enzyme - microwave synergistic saccharification fermentation reactor according to claim 1, characterized in that, The tank body (1) is of a cylindrical structure, the microwave cavity (10) is of a cylindrical structure, and the microwave cavity (10) is hermetically connected to the inner side wall of the tank body (1) through a flange (16). A jacket cooling circuit (15) is arranged outside the microwave cavity (10).

4. A corn straw bio-enzyme - microwave synergistic saccharification fermentation reactor according to claim 1, characterized in that, The dielectric window (13) is made of ceramic material, and the microwave feed array (11) includes a microwave generator and a reflection suppressor.

5. A corn straw bio-enzyme - microwave synergistic saccharification fermentation reactor according to claim 1, characterized in that, The porous ceramic carrier (20) is loaded with a catalyst, and the porous ceramic carrier (20) is located below the PH adjustment system (17).

6. The corn straw bio-enzyme-microwave synergistic saccharification and fermentation reactor according to claim 1, wherein, The heating coil (21) is made of ceramic material, and the heating coil (21) is arranged in a conical structure. The surface of the heating coil (21) is coated with a nano-ceramic coating, and a coil cooling circuit (26) is installed on the outer surface of the heating coil (21).

7. A corn straw bio-enzyme - microwave synergistic saccharification and fermentation reactor according to claim 1, characterized in that, Nitrogen is evenly distributed at the bottom of the passive mixing device (22), and a Venturi tube is connected to the top surface of the passive mixing device (22).

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