A high solid enzymatic hydrolysis system and method

Abstract

This invention provides a high-solids enzymatic hydrolysis system and method. The system includes a screw feeder, a rotary enzymatic hydrolyzer, a discharge pump, and a vertical saccharification tank. The rotary enzymatic hydrolyzer includes a hydrolyzer cylinder, a central tube, rotary and fixed lifting plates, a collection tank, an electric heating system, and a drive device. Pretreated lignocellulosic high-solids substrates, after pH adjustment, enter the hydrolyzer cylinder. The rotating cylinder causes the rotary and fixed lifting plates to agitate, disperse, and mix the substrates. Three independent enzyme delivery lines are installed in the central tube, sequentially spraying different functional enzyme preparations in stages. The liquefied product containing lignin residue enters the vertical saccharification tank via the collection tank and discharge pump for further saccharification. Finally, solid-liquid separation is completed via a slag discharge tank. The sugar solution is collected through a screen, and the dry residue is discharged intermittently. This system helps to improve the problems of difficult mixing, low enzyme utilization, low heat and mass transfer efficiency, and low raw material conversion efficiency in the initial stage of high-solids substrate enzymatic hydrolysis.

Description

Technical Field

[0001] This invention relates to the field of biomass enzymatic hydrolysis equipment technology, and in particular to a high-solids enzymatic hydrolysis system and method suitable for lignocellulose. Background Technology

[0002] Lignocellulosic biomass can be enzymatically hydrolyzed and saccharified to obtain fermentable sugars, which is one of the important ways to utilize biomass resources at high value. The substrates of lignocellulosic biomass after alkali treatment, acid treatment, steam explosion, or ionic liquid treatment have high solids content, and lignin, cellulose, and hemicellulose aggregate and adhere, resulting in high viscosity and poor flowability. To increase product concentration, reduce wastewater volume, and lower subsequent separation energy consumption, high-solids-content enzymatic hydrolysis has gradually attracted attention.

[0003] Traditional paddle-type vertical mixers are prone to problems such as insufficient mixing, localized agglomeration, and difficulties in heat and mass transfer, leading to increased reaction volume and mixing energy consumption. Adding the entire complex enzyme at once cannot match the stepwise hydrolysis pattern of lignocellulose. Lignin ineffectively absorbs large amounts of enzyme, and cellulase struggles to access the effective substrate when the hemicellulose coating is not broken. Simultaneously, the accumulation of cellobiose in the middle of the reaction generates strong product inhibition, resulting in reduced enzymatic hydrolysis efficiency, increased enzyme dosage, and sugar loss in the residue reaching up to 20%. High-solids substrate fibers can also entangle the mixer shaft, causing frequent shutdowns.

[0004] While existing spray-mixing enzyme or substrate water content control schemes can improve enzyme-substrate contact, they still cannot solve the problems of lack of fluidity of high-solids substrates in the early stage of enzymatic hydrolysis and the low efficiency of conventional stirring equipment.

[0005] Therefore, it is necessary to develop a high-solids enzymatic hydrolysis reaction system and method to improve the mixing, heat and mass transfer and liquefaction effects in the initial stage of high-solids substrate enzymatic hydrolysis, and to improve the stability of subsequent saccharification treatment. Summary of the Invention

[0006] The purpose of this invention is to provide a high-solids enzymatic hydrolysis reaction system and method to solve the problems mentioned in the background art, such as high viscosity and lack of fluidity of high-solids substrates in the early stage of enzymatic hydrolysis, low enzymatic hydrolysis efficiency, high enzyme dosage, and difficulty in fully mixing and effectively transferring heat and mass by traditional paddle vertical stirring.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: According to one aspect of the present invention, a high-solids enzymatic hydrolysis reaction system is provided, comprising a screw feeder, a rotary enzymatic hydrolyzer, a discharge pump, and a vertical saccharification tank; The rotary enzyme hydrolyzer includes an enzyme hydrolyzer body, a central tube, a rotary scraper plate, a fixed scraper plate, and a driving device. The screw feeder is connected to the enzymatic hydrolyzer cylinder, the liquid phase outlet of the enzymatic hydrolyzer cylinder is connected to the inlet of the discharge pump through a central rotary joint, and the outlet of the discharge pump is connected to the inlet of the vertical saccharification tank. The driving device is used to drive the enzyme hydrolyzer cylinder to rotate, and the central tube passes through the enzyme hydrolyzer cylinder and is fixedly disposed relative to the enzyme hydrolyzer cylinder. The rotary scraper plate is disposed on the inner wall of the enzyme digester cylinder, and the fixed scraper plate is disposed on the central tube. The rotary scraper plate rotates with the enzyme digester cylinder and cooperates with the fixed scraper plate.

[0008] Furthermore, the central tube is a hollow main tube, with multiple independent enzyme infusion tubes of different lengths running parallel inside the main tube. Each enzyme infusion tube is independently connected to a metering pump. Each enzyme infusion tube has multiple sets of atomizing nozzles spaced axially in its corresponding section.

[0009] Furthermore, the atomizing nozzle is a fan-shaped atomizing nozzle with a fan angle of 30~60°. The nozzle has a built-in one-way check valve and a miniature stainless steel filter screen, which are used to introduce the enzyme preparation in the enzyme infusion tube into the enzyme digester cylinder.

[0010] Furthermore, there are three enzyme infusion tubes, each with a corresponding enzyme inlet. The first enzyme infusion tube extends to the feeding section of the enzyme digester cylinder, the second enzyme infusion tube extends to the main enzyme digestion section of the enzyme digester cylinder, and the third enzyme infusion tube extends to the liquefaction section of the enzyme digester cylinder. The three enzyme infusion tubes are arranged in a triangular staggered pattern inside the hollow main tube.

[0011] Furthermore, the vertical saccharification tank includes a reaction vessel body, a stirrer, a slag discharge chamber, a screen, and a discharge screw; the slag discharge chamber is directly connected to the bottom of the reaction vessel body; the screen is laid on the inner wall of the slag discharge chamber, and a closed liquid collection chamber is formed outside the screen and connected to the sugar liquid outlet; the discharge screw is coaxially inserted with the stirrer inside the slag discharge chamber; a slag discharge port is provided at the end of the slag discharge chamber for intermittent slag discharge.

[0012] Furthermore, the rotary enzymatic hydrolyzer also includes a slip ring brush assembly and an electric heating jacket; the slip ring brush assembly is installed at the front rotating end of the enzymatic hydrolyzer cylinder and is used to continuously supply power to the electric heating jacket that rotates synchronously with the cylinder. The slip ring brush assembly includes a collector ring and a corresponding carbon brush. The carbon brush is pressed against the surface of the collector ring by a spring to supply heat to the electric heating jacket. The slip ring brush assembly also includes a PLC closed-loop temperature control unit.

[0013] Furthermore, the rotary enzymatic hydrolyzer also includes a liquid collection tank, which is disposed on the inner wall of the rear end of the enzymatic hydrolyzer cylinder and communicates with the liquid phase outlet; The liquid collection tank has a double-layer conical structure with an inner cone apex angle of 30~60° and an outer cone apex angle of 60~90°. The inner cone is located on the inner wall of the enzyme digester cylinder and rotates with the enzyme digester cylinder. The outer cone is connected to the liquid phase outlet through a rotary joint.

[0014] Furthermore, the rotary enzymatic hydrolyzer also includes an adjustable support wheel and a fixed support wheel. The enzymatic hydrolyzer cylinder is supported on the adjustable support wheel and the fixed support wheel. The bottom height of the adjustable support wheel is adjustable to adjust the tilt of the enzymatic hydrolyzer cylinder downward relative to the horizontal plane by 1° to 5°, so that the high solids substrate moves towards the side where the collection tank is located during the rotation of the enzymatic hydrolyzer cylinder.

[0015] According to one aspect of the present invention, a high-solids enzymatic hydrolysis method is provided, comprising the following steps: S1: The pretreated high-solids substrate is fed into the enzymatic hydrolyzer cylinder through the screw feeder, and the pH of the enzymatic hydrolysate is adjusted to 4.5~5.5; S2: Drive the enzyme hydrolyzer cylinder to rotate via the drive device, so that the rotating scraper plate and the fixed scraper plate form relative motion to shear and break up the high solids substrate; control the temperature inside the enzyme hydrolyzer cylinder to be 45~55℃; S3: Add enzyme preparation into the enzymatic hydrolator cylinder in stages through the central tube; S4: The high-solids substrate is enzymatically hydrolyzed in the enzymatic hydrolyzer cylinder for 6-12 hours to form a mixed slurry; the mixed slurry is sent into the vertical saccharification tank through the liquid phase outlet and the discharge pump. S5: The mixed slurry continues to be stirred and saccharified in the vertical saccharification tank at a speed of 10-20 rpm for 4-6 hours; S6: Separate the solid and liquid components in the vertical saccharification tank, discharge the sugar solution, and squeeze out the remaining residue.

[0016] Furthermore, the high-solids substrate is a lignocellulose-based high-solids substrate, which is pretreated by at least one of the following methods: pulverization, ionic liquid treatment, acid treatment, alkali treatment, and steam explosion treatment.

[0017] As can be seen from the above technical solution, the present invention has at least the following advantages and positive effects compared with the prior art: (1) The rotating and fixed lifting plates are combined in a dynamic and static structure. During the rotation of the cylinder, the high solids agglomerated materials can be continuously sheared and dispersed, which can effectively enhance the mass and heat transfer of materials, solve the problems of uneven mixing of high solids substrates and insufficient enzymatic hydrolysis, and meet the enzymatic hydrolysis reaction requirements of high solids systems. (2) Three independent segmented enzyme delivery tubes are set up to achieve precise zoning of enzyme delivery in the feeding section, main enzymatic hydrolysis section and liquefaction section, matching the stepwise hydrolysis mechanism of lignocellulose. Corresponding functional enzymes are delivered at different stages, which greatly improves the utilization rate of enzyme preparations and reduces the cost of enzymatic hydrolysis. The triangular staggered arrangement of enzyme delivery tubes with fan-shaped atomizing nozzles can achieve uniform spraying and wetting of materials with enzyme solution. The nozzles have built-in check and filter structures to effectively prevent material backflow and blockage, and the equipment has strong stability. (3) The present invention uses a slip ring brush assembly with an electric heating jacket for heating, and a PLC closed-loop temperature control unit. The temperature control accuracy can reach ±0.3℃, which can accurately control the temperature of the enzymatic hydrolysis reaction, stably maintain the highest activity of the enzyme preparation, avoid the defects of large temperature fluctuation and easy deactivation of enzyme activity in traditional heating methods, and significantly improve the efficiency of enzymatic hydrolysis reaction. (4) The present invention is equipped with adjustable support wheels, which can precisely adjust the tilt angle of the cylinder and use gravity to assist the material to move towards the liquid collection tank. Combined with the rotary liquid collection structure of the double-layer conical liquid collection tank, it can completely solve the problems of bridging, blockage and incomplete discharge of high solids viscous slurry, and realize the full and stable transportation of slurry. (5) The bottom of the vertical saccharification tank is equipped with an integrated slag discharge bin, screen and discharge screw, which can realize the automatic solid-liquid separation of the slurry after saccharification, the sugar liquid is efficiently collected through the screen, and the moisture content of the residue can be controlled at 50~55% after the residue is dehydrated by the screw extrusion, which greatly reduces the sugar content of the residue and improves the sugar liquid recovery rate. At the same time, it realizes intermittent automatic slag discharge, which is suitable for continuous industrial production. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0019] Figure 1 This is a schematic diagram of the overall structure of a high-solids enzymatic hydrolysis reaction system provided in an embodiment of the present invention.

[0020] Figure 2 for Figure 1 A schematic diagram of the structure of a rotary enzyme digester.

[0021] Figure 3 This is a schematic diagram of the central tube assembly in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the process of a vertical saccharification tank in an embodiment of the present invention.

[0023] The components include: 1. Screw feeder; 2. Rotary enzymatic hydrolyzer; 3. Discharge pump; 4. Vertical saccharification tank; 201. Central tube; 202. Atomizing nozzle; 203. Rotary lifting plate; 204. Fixed lifting plate; 205. Slip ring brush assembly; 206. Liquid collection tank; 207. Adjustable support wheel; 208. Enzymatic hydrolyzer cylinder; 209. Drive device; 210. Drive gear; 211. Fixed support wheel; 212. Central rotary joint; 213. Fixed end of enzymatic hydrolyzer cylinder; 401. Reactor cylinder; 402. Stirrer; 403. Slag discharge bin; 404. Screen; 405. Discharge screw; N1. Raw material inlet; N2. pH adjustment port; N3a, N3b, N3c. Enzyme inlet; N4. Liquid phase outlet; N5. Vertical saccharification tank inlet; N6. Sugar solution outlet; N7. Slag discharge port. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the following embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention. Where there is no contradiction, the technical features in the following embodiments can be combined with each other. Example 1

[0025] This embodiment provides a high-solids enzymatic hydrolysis system for the enzymatic hydrolysis and saccharification of lignocellulosic high-solids substrates, especially suitable for high-solids substrates with low moisture content, low free water content, high viscosity, and difficult to mix effectively using traditional paddle mixers. The system includes a screw feeder 1, a rotary enzymatic hydrolyzer 2, a discharge pump 3, and a vertical saccharification tank 4.

[0026] like Figure 1 As shown, the screw feeder 1 is connected to the rotary enzymatic hydrolyzer 2, and is used to continuously or intermittently transport the pretreated high-solids substrate into the rotary enzymatic hydrolyzer 2. The rotary enzymatic hydrolyzer 2 is used for preliminary enzymatic hydrolysis and liquefaction of the high-solids substrate. Its liquid phase outlet N4 is connected to the inlet of the discharge pump 3 through a central rotary joint. The discharge pump 3 is used to transport the liquefied product formed in the rotary enzymatic hydrolyzer 2 to the inlet N5 of the vertical saccharification tank 4. The vertical saccharification tank 4 is used to further saccharify the liquefied product to obtain hydrolysate.

[0027] With the above settings, this embodiment divides the processing of high-solids substrates into a preliminary enzymatic hydrolysis and liquefaction stage in the rotary enzymatic hydrolyzer 2 and a further saccharification stage in the vertical saccharification tank 4. This can reduce the dependence of high-solids substrates on vertical stirring equipment in the initial stage and improve the mixing efficiency and saccharification effect of high-solids substrates.

[0028] Specifically, the screw feeder 1 is connected to the material inlet N1, the pH adjustment port N2, and the enzymatic hydrolyzer cylinder 208.

[0029] like Figure 2As shown, the rotary enzyme digester 2 includes a central tube 201, a rotary scraper plate 203, a fixed scraper plate 204, a collection tank 206, an enzyme digester cylinder 208, a drive device 209, a drive gear 210, and a rotary joint 212.

[0030] The enzyme digester cylinder 208 is a rotatable cylindrical structure, and the driving device 209 is used to drive the enzyme digester cylinder 208 to rotate.

[0031] Specifically, the drive device 209 may include a motor and a reducer. The drive device 209 is connected to the drive gear 210 for driving the enzyme digester cylinder 208 to rotate. It is understood that in other embodiments, the drive device 209 may also adopt chain drive, belt drive, gear ring drive, or other transmission forms capable of driving the enzyme digester cylinder 208 to rotate.

[0032] Specifically, the enzymatic hydrolyzer cylinder 208 is equipped with an enzyme inlet N3 (N3a, N3b, N3c) and a liquid phase outlet N4. Pretreated high-solids substrate enters the enzymatic hydrolyzer cylinder 208 via the material inlet N1 of the screw feeder 1. The pH adjustment port N2 is used to add enzyme preparations to the raw materials, allowing the enzyme preparations to enter the enzymatic hydrolyzer cylinder 208 along with the high-solids substrate and undergo enzymatic hydrolysis. The liquid phase outlet N4 of the enzymatic hydrolyzer cylinder 208 is connected to the inlet of the discharge pump 3 via a central rotary joint, and the outlet of the discharge pump 3 is connected to the inlet N5 of the vertical saccharification tank, enabling the liquefied product to be transported from the rotary enzymatic hydrolyzer 2 to the vertical saccharification tank 4.

[0033] Specifically, the central tube 201 is inserted into the enzyme digester cylinder 208 and fixedly positioned relative to the enzyme digester cylinder 208. That is, when the enzyme digester cylinder 208 is driven to rotate by the driving device 209, the central tube 201 does not rotate synchronously with the enzyme digester cylinder 208. The central tube 201 can be mechanically sealed to the front end of the enzyme digester cylinder 208 to ensure that the enzyme digester cylinder 208 can rotate relative to the central tube 201, while reducing material leakage.

[0034] Specifically, the rotary enzymatic hydrolyzer 2 further includes a collection tank 206, which is disposed on the inner wall of the rear end of the enzymatic hydrolyzer cylinder 208 and communicates with the liquid phase outlet N4. In one specific embodiment, the collection tank 206 has a double-layer conical structure, with an inner cone apex angle of 30~60° and an outer cone apex angle of 60~90°. The inner cone is disposed on the inner wall of the enzymatic hydrolyzer cylinder 208 and rotates with the enzymatic hydrolyzer cylinder 208, while the outer cone is communicated with the liquid phase outlet N4 through a rotary joint 212. The high-solids substrate is gradually liquefied by enzymatic hydrolysis in the enzymatic hydrolyzer cylinder 208 to form a liquefied product. The liquefied product flows into the collection tank 206 and is then transported to the vertical saccharification tank 4 via the rotary joint 212, the liquid phase outlet N4, and the discharge pump 3.

[0035] Optionally, a filter element may not be installed at the liquid phase outlet N4. After the high-solids substrate is enzymatically hydrolyzed to form a liquefied product, the liquefied product can be collected by the collection tank 206 and discharged through the liquid phase outlet N4 when it is fluid. Fine solids or impurities that are not completely hydrolyzed can enter the vertical saccharification tank 4 with the liquefied product and undergo post-processing after being discharged from the vertical saccharification tank 4. This method can reduce the risk of blockage at the liquid phase outlet N4 and also helps to maintain the continuity of the transfer of liquefied product from the rotary enzymatic hydrolyzer 2 to the vertical saccharification tank 4.

[0036] In one embodiment, the rotary enzymatic hydrolyzer 2 may further include an adjustable support wheel 207 and a fixed support wheel 211, with the hydrolyzer cylinder 208 supported on the adjustable support wheel 207 and the fixed support wheel 211. The bottom height of the adjustable support wheel 207 is adjustable to adjust the hydrolyzer cylinder 208 to tilt downwards relative to the horizontal plane by 1° to 5°, allowing the high-solids substrate to move towards the side where the collection tank 206 is located during the rotation of the hydrolyzer cylinder 208. Through this tilting arrangement, while the high-solids substrate is mixed by the rotary scraper plate 203 and the fixed scraper plate 204, it can gradually move towards the rear along the length direction of the hydrolyzer cylinder 208, which is beneficial for the collection and discharge of liquefied products.

[0037] In one embodiment, the rotary enzymatic hydrolyzer 2 further includes a slip ring brush assembly 205 and an electric heating jacket; the slip ring brush assembly 205 is installed at the front rotating end of the enzymatic hydrolyzer cylinder 208 and is used to continuously supply power to the electric heating jacket, which rotates synchronously with the cylinder. The slip ring brush assembly 205 includes a collector ring and a corresponding carbon brush, the carbon brush being pressed against the surface of the collector ring by spring pressure to supply heat to the electric heating jacket; the slip ring brush assembly 205 also includes a PLC closed-loop temperature control unit.

[0038] like Figure 3 As shown, the central tube 201 is preferably a hollow main tube, with multiple independent enzyme delivery tubes of different lengths running parallel inside. Each enzyme delivery tube is independently connected to a metering pump. Each enzyme delivery tube has multiple sets of atomizing nozzles 202 spaced axially in its corresponding section. The atomizing nozzles 202 are fan-shaped nozzles with a fan angle of 30-60°. Each nozzle has a built-in one-way check valve and a miniature stainless steel filter screen, used to introduce the enzyme preparation from the enzyme delivery tubes into the enzymatic hydrolyzer cylinder 208, ensuring uniform atomization and spraying of the enzyme solution and preventing backflow and blockage. In this embodiment, there are three enzyme delivery tubes, corresponding to three enzyme inlets N3a, N3b, and N3c. The first enzyme delivery tube extends to the feeding section of the enzymatic hydrolyzer cylinder 208, the second extends to the main enzymatic hydrolysis section of the enzymatic hydrolyzer cylinder 208, and the third extends to the liquefaction section of the enzymatic hydrolyzer cylinder 208. The three enzyme delivery tubes are arranged in a triangular staggered pattern within the hollow main tube.

[0039] A rotary scraper plate 203 is disposed on the inner wall of the enzyme digester cylinder 208, and a fixed scraper plate 204 is disposed on the central tube 201. Since the enzyme digester cylinder 208 can rotate, and the central tube 201 is fixed relative to the enzyme digester cylinder 208, when the enzyme digester cylinder 208 rotates, the rotary scraper plate 203 rotates with the enzyme digester cylinder 208, while the fixed scraper plate 204 remains relatively fixed. The rotary scraper plate 203 and the fixed scraper plate 204 cooperate to tumble, disperse, shear, mix, and enzymatically hydrolyze the high-solids substrate entering the enzyme digester cylinder 208. For high-solids substrates with little or no free water, traditional paddle-type stirring structures are prone to problems such as high stirring resistance, local agglomeration, and difficulty in heat and mass transfer. In this embodiment, the rotating lifting plate 203 and the fixed lifting plate 204 use relative motion to continuously disturb the high-solids substrate, so that the high-solids substrate is continuously lifted, dropped, dispersed, and remixed in the enzymatic digester cylinder 208, which helps to improve the contact efficiency between the enzyme preparation and the substrate, and improves the heat and mass transfer conditions inside the high-solids substrate.

[0040] like Figure 4 As shown, the vertical saccharification tank 4 includes a reaction vessel cylinder 401, a stirrer 402, a slag discharge bin 403, a screen 404, and a discharge screw 405; the slag discharge bin 403 is directly connected to the bottom of the reaction vessel cylinder 401; the screen 404 is laid on the inner wall of the slag discharge bin 403, and a closed liquid collection chamber is formed outside the screen, which is connected to the sugar liquid outlet N6; the discharge screw 405 is coaxially inserted with the stirrer 402 inside the slag discharge bin 403; the end of the slag discharge bin 403 is provided with a slag discharge port N7 for intermittent slag discharge. Example 2

[0041] This embodiment also provides a high-solids enzymatic hydrolysis method, which can be carried out using the high-solids enzymatic hydrolysis reaction system described above. The high-solids enzymatic hydrolysis method includes the following steps: S1: The pretreated corn stalk lignocellulose high-solids substrate, which has undergone steam explosion pretreatment, is fed into the fixed end 213 of the enzymatic hydrolyzer cylinder through the material inlet N1 via the screw feeder 1. A pH buffer salt, acid, or alkali is added at the pH adjustment port N2 to adjust the pH of the enzymatic hydrolysate to 5.0~5.2. The fixed end 213 of the enzymatic hydrolyzer cylinder is connected to the enzymatic hydrolyzer cylinder 208 via a rotary joint. S2: The drive device 209 drives the enzyme hydrolyzer cylinder 208 to rotate, causing the rotating scraper plate 203 to rotate with the enzyme hydrolyzer cylinder 208 and form relative motion with the fixed scraper plate 204, shearing and breaking up the high-solids substrate, and enhancing mass and heat transfer; the slip ring brush assembly heats and controls the temperature inside the enzyme hydrolyzer cylinder 208 at 48~50℃. S3: Enzyme preparation is added into the enzymatic hydrolyzer cylinder 208 through the central tube 201. Specifically, three independent metering pumps deliver the corresponding enzyme preparation to three enzyme delivery tubes respectively. The feeding section is sprayed with hemicellulase, which accounts for 20% of the total enzyme amount; the main enzymatic hydrolysis section is sprayed with cellulase complex, which accounts for 60% of the total enzyme amount; and the liquefaction section is sprayed with β-glucosidase, which accounts for 20% of the total enzyme amount. The fan-shaped spray nozzles pass through the central tube to evenly wet the material. S4: The high-solids substrate is enzymatically hydrolyzed in the enzymatic hydrolyzer cylinder 208 for 8 hours, gradually forming a fluid mixed slurry containing lignin residue; the liquid collection tank 206 rotates with the cylinder and collects the mixed slurry, which is then sent to the vertical saccharification tank 4 through the liquid phase outlet N4, the central rotary joint 212 and the discharge pump 3. S5: The mixed slurry is stirred at 15 rpm in the vertical saccharification tank 4 for 5 hours to achieve secondary hydrolysis of the incompletely hydrolyzed fine cellulose residue; S6: The slurry from the vertical saccharification tank 4 flows into the bottom slag discharge bin 403, and the sugar solution flows through the screen 404 into the liquid collection chamber and out through the sugar solution outlet N6; the remaining lignin residue is intercepted by the screen and continuously squeezed by the discharge screw 405 to form a slag with a moisture content of 52%, which is intermittently or periodically discharged through the slag discharge port N7.

[0042] Through the above method, the rotary enzymatic hydrolyzer 2 and the vertical saccharification tank 4 form a staged enzymatic hydrolysis and saccharification process: the rotary enzymatic hydrolyzer 2 is suitable for processing initial substrates with high viscosity, high solid content, and low free water, while the vertical saccharification tank 4 is suitable for processing liquefied products that have already been liquefied and have fluidity. This can improve substrate utilization and saccharification rate, and reduce the mixing difficulty in the initial enzymatic hydrolysis stage of high solid substrates.

[0043] Testing showed that this embodiment has a high enzymatic hydrolysis saccharification rate and a sugar recovery rate of over 98%. The equipment operates stably throughout the process, without problems such as material blockage, temperature fluctuations, or enzyme waste, making it suitable for continuous industrial production. Example 3

[0044] This embodiment uses wheat straw as raw material, employs ionic liquid pretreatment combined with water washing to remove lignin, and matches it with the high-solids enzymatic hydrolysis reaction system of this invention to complete segmented and precise enzymatic hydrolysis. Simultaneously, the standard enzyme activity parameters of each functional enzyme are clearly defined, as follows: 1. Raw material pretreatment: Select air-dried wheat straw, crush it and pass it through a 40-mesh sieve. Use 1-ethyl-3-methylimidazolium acetate ionic liquid for constant temperature pretreatment at 120℃ for 2 hours to destroy the dense structure of wheat straw lignocellulose and dissolve some lignin and hemicellulose. After pretreatment, wash the material multiple times with 60℃ warm water to fully remove the ionic liquid and dissolved lignin, reduce the steric inhibition and non-specific adsorption of lignin on enzymatic hydrolysis. After washing, filter and squeeze to adjust the substrate solid content to 28% for later use.

[0045] 2. Enzyme selection and standard enzyme activity parameters: This embodiment strictly matches the segmented enzyme dosing process. The enzymes used in each segment are all industrial standard high-activity enzymes. The specific enzyme activities are as follows: (1) Hemicellulase (main components are endoxylanase, arabinofuranase, and acetylxylan esterase): enzyme activity ≥850 FPU / g, specifically hydrolyzes hemicellulose side chain and main chain structure, used to break the lignin coating layer in the early stage; (2) Cellulose complex enzyme (including endoglucanase EG and exoglucanase CBH): filter paper enzyme activity FPU≥220FPU / g, which is the core hydrolytic enzyme responsible for degrading crystalline and amorphous cellulose long chains; (3) β-glucosidase: enzyme activity ≥450 FPU / g, specifically decomposes cellobiose and short-chain cellooligosaccharides, completely eliminates product inhibition and improves glucose yield.

[0046] 3. Enzymatic hydrolysis process steps: S1: The pretreated and lignin-free wheat straw high-solids substrate is fed into the fixed end 213 of the enzymatic hydrolyzer cylinder through the material inlet N1 via the screw feeder 1. An acetate-sodium acetate buffer system is added through the pH adjustment port N2 to stabilize the pH of the material system to 5.1. S2: Start the drive device 209 and adjust the downward tilt of the enzymatic hydrolyzer cylinder 208 to 3° via the adjustable support wheel 207. Control the rotation speed of the enzymatic hydrolyzer cylinder 208 to 3r / min. The rotating and fixed lifting plates move relative to each other continuously, shearing and breaking up the high-solids material and eliminating the dead corners of material agglomeration. The temperature is controlled by the slip ring brush assembly and the PLC closed-loop temperature control unit in zones. The temperature of the feeding section is 52℃, the temperature of the main enzymatic hydrolysis section is 50℃, and the temperature of the liquefaction section is 48℃. The overall temperature control accuracy is ±0.3℃. S3: Start three independent variable frequency metering pumps and accurately add the corresponding enzyme preparations according to the segment ratio. The total enzyme addition is 150 FPU / g oven-dry substrate. Among them, the feeding section is sprayed with 20% of the total enzyme amount of high-activity hemicellulase, the main enzymatic hydrolysis section is sprayed with 60% of the total enzyme amount of cellulase complex enzyme, and the liquefaction section is sprayed with 20% of the total enzyme amount of β-glucosidase. Each enzyme solution is evenly atomized and wetted by fan-shaped atomizing nozzles with a fan angle of 45° arranged in a triangular staggered manner. The nozzles have built-in filters and one-way check valves to prevent backflow and clogging. S4: High-solids wheat straw substrate is continuously enzymatically hydrolyzed in the enzymatic hydrolyzer cylinder for 10 hours, gradually transforming from solid agglomerated material into a mixed slurry with good fluidity and trace amounts of lignin residue; the double-layered conical liquid collection tank with an inner cone apex angle of 40° and an outer cone apex angle of 80° continuously scoops up and collects the slurry as the cylinder rotates, and then completely transports it to the vertical saccharification tank 4 through the liquid phase outlet N4, the central rotary joint 212 and the discharge pump 3; S5: The stirring speed of the stirrer in the vertical saccharification tank 4 is kept constant at 15 rpm, and the stirring is carried out continuously for 5 hours under the constant temperature of 50℃. The fine cellulose residues that are not completely hydrolyzed in the tank are subjected to secondary deep hydrolysis, which further improves the saccharification rate. S6: After saccharification, the mixed slurry flows into the bottom slag discharge chamber 403 by gravity. The sugar solution passes through the screen 404 and enters the closed collection chamber, and is continuously collected by the sugar solution outlet N6. The residual lignin residue is intercepted by the screen and continuously squeezed and dehydrated by the coaxial discharge screw 405, finally obtaining lignin residue with a moisture content of 53%, which is intermittently and tightly discharged through the slag discharge port N7.

[0047] 4. Implementation Results: This embodiment significantly reduces the adsorption loss of enzymes by lignin through ionic liquid pretreatment and water washing to remove lignin. Combined with segmented temperature control and segmented precise enzyme dosing, the saccharification rate of wheat straw substrate can reach 90.2%, the reducing sugar concentration is stable and meets the standard, and the sugar recovery rate is ≥98.2%. The entire set of equipment operates continuously and stably, with uniform atomization spraying, good material mass transfer effect, and thorough solid-liquid separation. Compared with the traditional single enzyme dosing and overall temperature control process, the enzyme preparation utilization rate is increased by more than 12%, making it suitable for industrial production scenarios of high-solids enzymatic hydrolysis of lignocellulose with ionic liquid pretreatment.

[0048] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-solids enzymatic hydrolysis reaction system, characterized in that, It includes a screw feeder (1), a rotary enzymatic hydrolyzer (2), a discharge pump (3), and a vertical saccharification tank (4). The rotary enzymatic hydrolyzer (2) includes an enzymatic hydrolyzer cylinder (208), a central tube (201), a rotary scraper plate (203), a fixed scraper plate (204), and a driving device (209). The screw feeder (1) is connected to the enzymatic hydrolyzer cylinder (208), the liquid phase outlet (N4) of the enzymatic hydrolyzer cylinder (208) is connected to the inlet of the discharge pump (3) through the central rotary joint, and the outlet of the discharge pump (3) is connected to the inlet (N5) of the vertical saccharification tank (4). The driving device (209) is used to drive the enzyme hydrolyzer cylinder (208) to rotate, and the central tube (201) is inserted into the enzyme hydrolyzer cylinder (208) and fixedly disposed relative to the enzyme hydrolyzer cylinder (208); The rotary plate (203) is disposed on the inner wall of the enzyme digester cylinder (208), and the fixed plate (204) is disposed on the central tube (201). The rotary plate (203) rotates with the enzyme digester cylinder (208) and cooperates with the fixed plate (204).

2. The high-solids enzymatic hydrolysis reaction system according to claim 1, characterized in that, The central tube (201) is a hollow main tube, with multiple independent enzyme infusion tubes of different lengths running parallel inside the main tube. Each enzyme infusion tube is independently connected to a metering pump. Each enzyme infusion tube has multiple sets of atomizing nozzles (202) spaced along the axial direction in the corresponding section.

3. The high-solids enzymatic hydrolysis reaction system according to claim 2, characterized in that, The atomizing nozzle (202) is a fan-shaped atomizing nozzle with a fan angle of 30~60°. The nozzle has a built-in one-way check valve and a miniature stainless steel filter screen, which are used to introduce the enzyme preparation in the enzyme infusion tube into the enzyme digester cylinder (208).

4. The high-solids enzymatic hydrolysis reaction system according to claim 2, characterized in that, The enzyme infusion tube consists of three tubes, each with a corresponding enzyme inlet (N3a), (N3b), and (N3c). The first enzyme infusion tube extends to the feeding section of the enzyme digester cylinder (208), the second enzyme infusion tube extends to the main enzyme digestion section of the enzyme digester cylinder (208), and the third enzyme infusion tube extends to the liquefaction section of the enzyme digester cylinder (208). The three enzyme infusion tubes are arranged in a triangular staggered pattern within the hollow main tube.

5. The high-solids enzymatic hydrolysis reaction system according to claim 1, characterized in that, The vertical saccharification tank (4) includes a reactor body (401), a stirrer (402), a slag discharge bin (403), a screen (404), and a discharge screw (405); the slag discharge bin (403) is directly connected to the bottom of the reactor body (401); the screen (404) is laid on the inner wall of the slag discharge bin (403), and a closed liquid collection chamber is formed outside the screen and connected to the sugar liquid outlet (N6); the discharge screw (405) and the stirrer (402) are coaxially inserted inside the slag discharge bin (403); the end of the slag discharge bin (403) is provided with a slag discharge port (N7) for intermittent slag discharge.

6. The high-solids enzymatic hydrolysis reaction system according to claim 1, characterized in that, The rotary enzymatic hydrolyzer (2) also includes a slip ring brush assembly (205) and an electric heating jacket; the slip ring brush assembly (205) is installed at the front rotating end of the enzymatic hydrolyzer cylinder (208) and is used to continuously supply power to the electric heating jacket that rotates synchronously with the cylinder. The slip ring brush assembly (205) includes a collector ring and a corresponding carbon brush. The carbon brush is pressed against the surface of the collector ring by a spring to supply heat to the electric heating jacket. The slip ring brush assembly (205) also includes a PLC closed-loop temperature control unit.

7. The high-solids enzymatic hydrolysis reaction system according to claim 1, characterized in that, The rotary enzymatic hydrolyzer (2) also includes a liquid collection tank (206), which is located on the inner wall of the rear end of the enzymatic hydrolyzer cylinder (208) and is connected to the liquid phase outlet (N4). The liquid collection tank (206) has a double-layer conical structure with an inner cone apex angle of 30~60° and an outer cone apex angle of 60~90°. The inner cone is located on the inner wall of the enzyme digester cylinder (208) and rotates with the enzyme digester cylinder (208). The outer cone is connected to the liquid phase outlet (N4) through a rotary joint (212).

8. The high-solids enzymatic hydrolysis reaction system according to claim 7, characterized in that, The rotary enzymatic hydrolyzer (2) also includes an adjustable support wheel (207) and a fixed support wheel (211). The enzymatic hydrolyzer cylinder (208) is supported on the adjustable support wheel (207) and the fixed support wheel (211). The bottom height of the adjustable support wheel (207) is adjustable to adjust the enzymatic hydrolyzer cylinder (208) to tilt downwards relative to the horizontal plane by 1° to 5°, so that the high solids substrate moves towards the side where the liquid collection tank (206) is located during the rotation of the enzymatic hydrolyzer cylinder (208).

9. A high-solids enzymatic hydrolysis method, characterized in that, The reaction is carried out using the high-solids enzymatic hydrolysis system according to any one of claims 1 to 8, comprising the following steps: S1: The pretreated high-solids substrate is fed into the enzymatic hydrolyzer cylinder (208) through the screw feeder (1), and the pH of the enzymatic hydrolysate is adjusted to 4.5~5.5; S2: The drive device (209) drives the enzymatic hydrolyzer cylinder (208) to rotate, so that the rotating scraper plate (203) and the fixed scraper plate (204) form relative motion to shear and break up the high solids substrate; the temperature inside the enzymatic hydrolyzer cylinder (208) is controlled to be 45~55℃; S3: Add enzyme preparation into the enzymatic hydrolyzer cylinder (208) in stages through the central tube (201); S4: The high-solids substrate is enzymatically hydrolyzed in the enzymatic hydrolyzer cylinder (208) for 6-12 hours to form a mixed slurry; the mixed slurry is sent into the vertical saccharification tank (4) through the liquid phase outlet via the discharge pump (3). S5: The mixed slurry continues to be stirred and saccharified in the vertical saccharification tank (4) at a speed of 10-20 rpm for 4-6 hours; S6: Separate the solid and liquid components in the vertical saccharification tank (4), discharge the sugar solution, and squeeze out the remaining residue.

10. The high-solids enzymatic hydrolysis method according to claim 9, characterized in that, The high-solids substrate is a lignocellulose-based high-solids substrate, which is pretreated by at least one of the following methods: pulverization, ionic liquid treatment, acid treatment, alkali treatment, and steam explosion treatment.

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