Biomass gasification control system and biomass gasification control method

Abstract

The present invention provides a biomass gasification control system and a biomass gasification control method, and belongs to the field of biosynthesis, the biomass gasification control system comprises: a first-stage fluidized bed pyrolysis reactor for performing a preliminary pyrolysis reaction on a biomass raw material to obtain a pyrolysis reactant; the second-stage fluidized bed gasification reactor is used for carrying out gasification reaction on the pyrolysis reactant by utilizing various gasification agents to obtain target synthesis gas, including H2 and CO; wherein the multiple gasifying agents comprise oxygen, water vapor and carbon dioxide; the sensor monitoring module is used for monitoring real-time state data in the first-stage fluidized bed pyrolysis reactor and the second-stage fluidized bed gasification reactor; the central control module is used for sending out an adjusting instruction according to the real-time state data, and the adjusting instruction is used for adjusting and controlling the flow of the multiple gasifying agents, the rotating speed of the fan and the reaction temperature, so that the molar ratio of H2 to CO in the generated target synthesis gas is within a first threshold value range.

Description

Technical Field

[0001] This application belongs to the field of biosynthesis, specifically relating to a biomass gasification control system and a biomass gasification control method. Background Technology

[0002] Biomass gasification refers to the process of feeding biomass feedstock into a high-temperature gasification reactor, where, under the action of a gasification medium, the biomass undergoes drying, pyrolysis, partial oxidation, and reduction to obtain a mixture of gases such as CO, H2, and CH4.

[0003] In traditional gasification processes, the gasifying agent is usually injected in a fixed proportion or in stages, lacking a dynamic synergistic mechanism, which leads to large fluctuations in the composition of the produced gas and low gasification efficiency. Summary of the Invention

[0004] This application provides a biomass gasification control system and a biomass gasification control method for achieving flexible control of the gasifying agent.

[0005] In a first aspect, a biomass gasification control system, the system comprising: A primary fluidized bed pyrolysis reactor is used to feed biomass raw materials into a fluidized bed for preliminary pyrolysis reaction to obtain pyrolysis reactants, which include: bio-oil and initial syngas; A two-stage fluidized bed gasification reactor is used to gasify the pyrolysis reactants using a variety of gasifying agents to obtain a target syngas, wherein the target syngas includes H2 and CO; wherein the various gasifying agents include at least: oxygen, water vapor, and carbon dioxide; Sensor monitoring module: used to monitor real-time status data in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor; Central control module: Used to issue adjustment commands based on the real-time status data. The adjustment commands are used to regulate the flow rate of the various gasifying agents, as well as the fan speed and reaction temperature in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, so that the molar ratio of H2 to CO in the generated target syngas is within a first threshold range.

[0006] In one possible implementation, the real-time status data includes at least: the actual molar ratio of H2 to CO in the target syngas generated at the current moment; the central control module issues the adjustment command based on the real-time status data according to the following steps: Based on the real-time status data, the ratio deviation value of H2 and CO, as well as the rate of change of the deviation, are determined; the ratio deviation value represents the difference between the actual molar ratio of H2 and CO and the target molar ratio, where the target molar ratio is 2; The proportional deviation value and the deviation change value are mapped to fuzzy variables; A fuzzy rule library built based on operational experience maps the fuzzy variables to fuzzy outputs. The fuzzy output is converted into adjustment instructions using the center of gravity method. The adjustment instructions include at least: instructions to adjust the opening degree of each gasifying agent valve, instructions to adjust the fan frequency of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and instructions to adjust the electric heating power of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor.

[0007] In one possible implementation, the real-time status data includes: temperature status data, concentrations of various gases in the reactor, and tar concentration; the sensor monitoring module includes: The temperature monitoring unit is used to monitor the reaction temperature in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and to collect temperature status data. The gas composition analysis unit is used to collect the concentration of each gas in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, as well as the actual molar ratio of H2 and CO in the target synthesis gas generated at the current moment; A tar monitoring unit is used to monitor the concentration of tar in the bio-oil.

[0008] In one possible implementation, the temperature monitoring unit includes a plurality of K-type thermocouples; the plurality of K-type thermocouples are respectively located at one or more of the following monitoring points in the system: The feed inlet location of the primary fluidized bed pyrolysis reactor; The fluidized bed in the primary fluidized bed pyrolysis reactor is located in the middle position. The reactant outlet location of the primary fluidized bed pyrolysis reactor; The location of the supply port for each gasifying agent in the secondary fluidized bed gasification reactor; The fluidized bed in the secondary fluidized bed gasification reactor is located in the middle position. The outlet position of the fluidized bed in the secondary fluidized bed gasification reactor.

[0009] In one possible implementation, the primary fluidized bed pyrolysis reactor includes: The first temperature control module is used to control the temperature by combining electric heating and flue gas circulation to maintain the reaction temperature of the primary fluidized bed pyrolysis reactor at 400-500℃. A fluidizing medium control module is used to adjust the gas flow rate of the fluidizing medium to 0.5-1.0 m / s using a variable frequency fan, wherein the fluidizing medium is nitrogen. The bottom discharge module is used to discharge the biochar produced by the reaction from the bottom of the primary fluidized bed pyrolysis reactor.

[0010] In one possible implementation, the system further includes a cyclone separator for separating the bio-oil and the initial syngas produced in the initial pyrolysis reaction and conveying them to the secondary fluidized bed gasification reactor.

[0011] In one possible implementation, the secondary fluidized bed gasification reactor includes: The second temperature control module is used to jointly regulate the temperature using the burner and the waste heat recovery module to maintain the reaction temperature of 700-800°C in the secondary fluidized bed gasification reactor. The pressure control module is used to maintain a slightly positive pressure environment of 0.1-0.3 MPa in the secondary fluidized bed gasification reactor; The gasifying agent flow control module is used to independently control the gas flow rate of each gasifying agent, including at least: an oxygen flow control module, a water vapor flow control module, and a carbon dioxide flow control module.

[0012] In one possible implementation, the system further includes: a raw material pretreatment module, the raw material pretreatment module comprising: A pulverizing device is used to pulverize biomass raw materials so that the particle size of the biomass raw materials is 3-5 mm; A rotary dryer is used to control the moisture content of the biomass raw material to 10-15% at 80-100℃.

[0013] A second aspect of this application also provides a biomass gasification control method, applied to the biomass gasification control system described in the first aspect of this application, the method comprising: In a primary fluidized bed pyrolysis reactor, biomass feedstock is fed into the fluidized bed for preliminary pyrolysis reaction to obtain pyrolysis reactants, which include: bio-oil and initial syngas; In a two-stage fluidized bed gasification reactor, the pyrolysis reactants are gasified using a variety of gasifying agents to obtain target syngas, which includes H2 and CO; wherein the various gasifying agents include at least: oxygen, water vapor, and carbon dioxide; Monitor the real-time status data of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor; Based on the real-time status data, an adjustment command is issued to regulate the flow rate of the various gasifying agents, as well as the fan speed and reaction temperature in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, so that the molar ratio of H2 to CO in the generated target syngas is within a first threshold range.

[0014] In one possible implementation, the real-time status data includes at least: the actual molar ratio of H2 to CO in the target synthesis gas generated at the current moment; the step of issuing an adjustment command based on the real-time status data includes: Based on the real-time status data, the ratio deviation value of H2 and CO, as well as the rate of change of the deviation, are determined; the ratio deviation value represents the difference between the actual molar ratio of H2 and CO and the target molar ratio, where the target molar ratio is 2; The proportional deviation value and the deviation change value are mapped to fuzzy variables; A fuzzy rule library built based on operational experience maps the fuzzy variables to fuzzy outputs. The fuzzy output is converted into adjustment instructions using the center of gravity method. The adjustment instructions include at least: instructions to adjust the opening degree of each gasifying agent valve, instructions to adjust the fan frequency of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and instructions to adjust the electric heating power of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor.

[0015] The beneficial effects of this application are as follows: The central control module in the control system proposed in this application issues adjustment commands based on the real-time status data to regulate the flow rate of various gasifying agents, the fan speed, and the reaction temperature, so that the molar ratio of H2 to CO in the generated target syngas is within a first threshold range. By adopting a multi-variable (temperature, gas composition, gasifying agent ratio) collaborative feedback mechanism, the coupling effect between the catalyst and the gasifying agent is fully utilized, thereby improving the gasification control accuracy and gasification efficiency.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the scale in the drawings is for illustration only and does not represent the actual scale.

[0018] Figure 1 This is a schematic diagram of the structure of a biomass gasification control system according to an embodiment of this application; Figure 2This is a schematic diagram of the structure of a pyrolysis gasification reactor according to an embodiment of this application; Figure 3 This is a schematic diagram of the control logic of a central control module in one embodiment of this application; Figure 4 This is a flowchart of the steps of a biomass gasification control method in an embodiment of this application; Figure description: Primary fluidized bed pyrolysis reactor 1, secondary fluidized bed gasification reactor 2, and cyclone separator 3. Detailed Implementation

[0019] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, the first object can be one or at least two. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] Biomass gasification refers to the process where biomass feedstock is fed into a high-temperature gasification reactor, where, under the action of gasification media such as CO2, oxygen, and steam, the biomass undergoes drying, pyrolysis, partial oxidation, and reduction to produce a mixture of gases including CO, H2, and CH4. The gasifying agent refers to the gaseous medium participating in the pyrolysis and gasification reaction; common types include air, oxygen, steam, and carbon dioxide. Its type and proportion directly affect product distribution and reaction efficiency. Multi-gasifying agent synergistic control refers to the precise control of the gasification process by dynamically adjusting the proportions, injection locations, and flow rates of various gasifying agents (such as oxygen, steam, and carbon dioxide) to optimize gas composition, improve gasification efficiency, and reduce byproducts (such as tar). Syngas is the main gaseous product of gasification, primarily composed of CO, H2, and CH4, and can be used as fuel or chemical feedstock.

[0022] Biomass gasification is an important way to achieve efficient utilization of renewable energy. However, existing gasification technologies lack a synergistic feedback mechanism for multiple variables (temperature, gas composition, and gasifying agent ratio) and do not fully utilize the coupling effect between catalyst and gasifying agent, resulting in insufficient control precision and efficiency.

[0023] In traditional gasification processes, gasifying agents are typically injected in fixed proportions or in stages, lacking a dynamic synergistic mechanism. This results in large fluctuations in the composition of the produced gas and low gasification efficiency (e.g., CO+H2 content less than 70%). Quantitative control of the syngas production ratio is also difficult. Traditional single-agent systems exhibit inherent contradictions in H2 / CO regulation. For example, water vapor as a single gasifying agent generates more H2 and CH4, and less CO; CO2 as a single gasifying agent generates more CO and less H2. The H2 / CO ratio can reach 3.2±0.5 with water vapor gasification, but drops to 0.8±0.3 with CO2 gasification, indicating that the H2 / CO ratio in the syngas is significantly affected by the gasifying agent. The use of a single gasifying agent cannot precisely meet the stoichiometric ratio requirements for methanol synthesis (H2 / CO = 2.0±0.1). Therefore, introducing multiple gasifying agents is necessary to solve the problem of quantitatively controlling H2 / CO production during gasification to meet the requirements for direct methanol synthesis.

[0024] Introducing CO2 can further reduce the tar content produced in the gasification reaction and facilitate the control of the H2 to CO ratio in the syngas. However, the syngas ratio still fluctuates greatly and is difficult to control precisely. The main reasons are as follows: 1) Single gasifying agent control: Most studies use a single gasifying agent (such as CO2 or steam). A certain component of the syngas will increase significantly due to the gasifying agent, but it is impossible to achieve coordinated control of multiple syngas ratios. 2) Outdated control strategies: Relying on empirical parameters or simple PID control, these strategies cannot adapt to fluctuations in biomass composition and the nonlinear characteristics of the reaction. The slow response time leads to large product fluctuations and makes precise feedback control difficult. 3) Weak product control capability: It is difficult to directionally control the H2 / CO ratio in the syngas (e.g., for methanol fuel synthesis, H2 / CO≈2 is required).

[0025] In view of the above problems, the first aspect of this application proposes a biomass gasification control system, referring to... Figure 1 , Figure 1 A schematic diagram of a biomass gasification control system is shown, such as... Figure 1 As shown, the system includes: A primary fluidized bed pyrolysis reactor is used to feed biomass raw materials into a fluidized bed for preliminary pyrolysis reaction to obtain pyrolysis reactants, which include: bio-oil and initial syngas; A two-stage fluidized bed gasification reactor is used to gasify the pyrolysis reactants using a variety of gasifying agents to obtain a target syngas, wherein the target syngas includes H2 and CO; wherein the various gasifying agents include at least: oxygen, water vapor, and carbon dioxide; Sensor monitoring module: used to monitor real-time status data in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor; The central control module is used to issue adjustment commands based on the real-time status data. These commands regulate the flow rates of the various gasifying agents, as well as the fan speeds and reaction temperatures in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, to ensure that the molar ratio of H2 to CO in the generated target syngas is within a first threshold range. This first threshold range can be 1.9-2.1.

[0026] This application proposes an integrated system for simultaneously synthesizing H2 / CO syngas. It directly pyrolyzes and gasifies biomass to generate H2 / CO-rich gas, employing multi-stage dynamic regulation of the gasifying agent and precise fuzzy PID control to directly generate H2 / CO syngas with the required ratio for methanol synthesis. Combined with waste heat recovery and tar cracking technologies, this system significantly improves energy efficiency and environmental performance, making it suitable for large-scale processing of various biomass raw materials such as straw and sawdust.

[0027] In one possible implementation, the system further includes: a raw material pretreatment module, the raw material pretreatment module comprising: A pulverizing device is used to pulverize biomass raw materials so that the particle size of the biomass raw materials is 3-5 mm; A rotary dryer is used to control the moisture content of the biomass raw material to 10-15% at 80-100℃.

[0028] Specifically, in this embodiment, before the biomass feedstock is fed into the primary fluidized bed pyrolysis reactor, it needs to pass through a feedstock pretreatment module to pulverize and dry the biomass feedstock. The raw material pretreatment module includes a pulverizing device for processing biomass raw materials to a specific particle size range. The pulverizing device can be a twin-shaft shear pulverizer, crushing the biomass raw materials to a particle size of 3-5 mm, with a particle size uniformity of ±0.5 mm. The raw material pretreatment module also includes a drying system, equipped with a rotary dryer (80-100℃), to control the moisture content of the raw materials at 10-15% to avoid excessive pyrolysis energy consumption.

[0029] Reference Figure 2 , Figure 2 A schematic diagram of a pyrolysis gasification reactor is shown, as follows. Figure 2As shown, after the raw material pretreatment module has processed the biomass through crushing and drying, the processed biomass raw material is transported to... Figure 2 In the primary fluidized bed pyrolysis reactor 1 shown, biomass feedstock is fed into the fluidized bed for preliminary pyrolysis reaction to obtain pyrolysis reactants, which include bio-oil and initial syngas.

[0030] The bio-oil (including tar), being gaseous at 400-500℃, will enter the secondary reactor along with the syngas. The bio-oil may include oxygenated compounds such as acetic acid, methanol, acetone, aldehydes (e.g., formaldehyde), and phenols (e.g., phenol), and tar (e.g., polycyclic aromatic hydrocarbons such as naphthalene and anthracene), benzene compounds (e.g., toluene and xylene), and long-chain hydrocarbons. The initial syngas includes H2, CO, and CH4.

[0031] Specifically, biomass raw materials can be one or more types of biomass, such as straw (C / H≈0.6), sawdust (C / H≈0.8), and other different biomass.

[0032] In one possible implementation, the primary fluidized bed pyrolysis reactor includes: The first temperature control module is used to control the temperature by combining electric heating and flue gas circulation to maintain the reaction temperature of the primary fluidized bed pyrolysis reactor at 400-500℃. A fluidizing medium control module is used to adjust the gas flow rate of the fluidizing medium to 0.5-1.0 m / s using a variable frequency fan, wherein the fluidizing medium is nitrogen. The bottom discharge module is used to discharge the biochar produced by the reaction from the bottom of the primary fluidized bed pyrolysis reactor.

[0033] Specifically, the primary fluidized bed pyrolysis reactor 1 is equipped with a temperature control system (i.e., the first temperature control module) to maintain a reaction environment of 400-500℃. The pulverized biomass feedstock is fed into the primary fluidized bed for preliminary pyrolysis (400-500℃), yielding ash, biochar, bio-oil, and a small amount of syngas (i.e., initial syngas). During the low-temperature pyrolysis stage, biomass generates tar (such as benzene, phenols, and polycyclic aromatic hydrocarbons), which enters the secondary gasification reactor along with the bio-oil and syngas. The first temperature control module uses a combination of electric heating and flue gas circulation to maintain a temperature of 400-500℃ (±5℃). The fluidizing medium control module uses nitrogen (purity >99.9%) as the fluidizing medium, with a flow rate of 0.5-1.0 m / s to ensure uniform fluidization of the material. The residence time is 20-30 minutes, and the gas flow rate is adjusted by a variable frequency fan.

[0034] In this process, the biochar generated in reactor 1 is mainly collected by the bottom screw conveyor (i.e., bottom discharge module) (ash content <5%). Figure 2 As shown, the remaining products (bio-oil and initial syngas) are separated by cyclone separator 3 and transported to secondary gasification reactor 2.

[0035] In one possible implementation, the system further includes a cyclone separator for separating the bio-oil and the initial syngas produced in the initial pyrolysis reaction and conveying them to the secondary fluidized bed gasification reactor.

[0036] like Figure 2 As shown, cyclone separator 3 is connected to the outlet pipe of reactor 1. The core function of the cyclone separator is to separate solid particles and gaseous products in a gas-solid two-phase flow. The solid particles include biochar (unreacted carbonaceous solids) and ash (inorganic impurities in biomass) generated by reactor 1, preventing solids from entering the secondary reactor and causing blockage, while simultaneously recovering the biochar (which can be used as a soil conditioner or fuel). The gaseous products include bio-oil vapor (containing tar), initial syngas (H2, CO, CH4, etc.), and the fluidizing medium (N2). The gas-solid mixture enters the cyclone separator at high tangential speed, forming a rotating vortex inside. Due to its lower density, the gas flows from the solid phase... Figure 2 As shown, the solid particles are discharged from the top central tube. Due to their high density, they are thrown against the wall of the container and fall down the wall to the bottom collection port, where they are discharged from the system through the bottom discharge module.

[0037] The cyclone separator transports the separated gaseous products through a top pipe to a secondary fluidized bed gasification reactor 2. The secondary fluidized bed gasification reactor 2 utilizes various gasifying agents to gasify the pyrolysis reactants, yielding the target syngas. Specifically, reactor 2 decomposes large-molecule tar into smaller-molecule gases (such as H2 and CO) through high-temperature pyrolysis. The gasifying agent reactions include: using steam to promote the water-gas reaction, using oxygen to partially burn the tar to provide heat, and CO2 participating in the reforming reaction.

[0038] In one possible implementation, the secondary fluidized bed gasification reactor includes: The second temperature control module is used to jointly regulate the temperature using the burner and the waste heat recovery module to maintain the reaction temperature of 700-800°C in the secondary fluidized bed gasification reactor. The pressure control module is used to maintain a slightly positive pressure environment of 0.1-0.3 MPa in the secondary fluidized bed gasification reactor; The gasifying agent flow control module is used to independently control the gas flow rate of each gasifying agent, including at least: an oxygen flow control module, a water vapor flow control module, and a carbon dioxide flow control module.

[0039] Specifically, the secondary fluidized bed gasification reactor 2 further gasifies the pyrolysis reactants (bio-oil and syngas) to generate high-purity H2 / CO syngas. During this process, the temperature is controlled at 700-800℃ (±10℃) through a second temperature control module in conjunction with the burner and waste heat recovery system. A slightly positive pressure environment (0.1-0.3MPa) is maintained by a pressure control module to prevent external air infiltration. Furthermore, a gasifying agent flow control module independently controls the gas flow rate of each gasifying agent in reactor 2; specifically, the gas flow rate can be adjusted by regulating the opening of the gas valves. Since this embodiment employs multiple gasifying agents working synergistically, the corresponding gasifying agent flow control module needs to perform independent intelligent control for each gasifying agent.

[0040] During the biomass gas synthesis process of the system, a sensor monitoring module is also used to monitor the real-time status data of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and to store the collected real-time status data.

[0041] In one possible implementation, the real-time status data includes: temperature status data, concentrations of various gases in the reactor, and tar concentration; the sensor monitoring module includes: The temperature monitoring unit is used to monitor the reaction temperature in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and to collect temperature status data. The gas composition analysis unit is used to collect the concentration of each gas in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, as well as the actual molar ratio of H2 and CO in the target synthesis gas generated at the current moment; A tar monitoring unit is used to monitor the concentration of tar in the bio-oil.

[0042] Specifically, the sensor monitoring module can collect reactor status data in real time, providing input for the control algorithm (central control module). The sensor monitoring module includes a temperature sensor array composed of multiple K-type thermocouples (accuracy ±1℃), capable of acquiring real-time temperature data every 30 seconds. The gas composition analysis unit can consist of an online gas chromatograph (GC) and an infrared sensor (CO / CO2 detection), installed in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, as well as at the reactor outlet. The sampling frequency can be once every 30 seconds, acquiring H2, CO, CO2 concentrations, and the H2 / CO ratio. The tar monitoring device (i.e., the tar monitoring unit) can employ laser-induced fluorescence (LIF), installed at the outlet of the primary fluidized bed pyrolysis reactor or at the outlet pipe at the top of the cyclone separator, to detect the tar concentration (ppm level) in the bio-oil generated in reactor 1 in real time. Correspondingly, the real-time status data includes: the real-time temperature at various locations in the reactor, the concentration of various gases in the reactor, the actual molar ratio of H2 and CO in the target syngas generated at the current moment, and the tar concentration in the bio-oil generated in reactor 1.

[0043] In one possible implementation, the temperature monitoring unit includes a plurality of K-type thermocouples; the plurality of K-type thermocouples are respectively located at one or more of the following monitoring points in the system: The feed inlet location of the primary fluidized bed pyrolysis reactor; The fluidized bed in the primary fluidized bed pyrolysis reactor is located in the middle position. The reactant outlet location of the primary fluidized bed pyrolysis reactor; The location of the supply port for each gasifying agent in the secondary fluidized bed gasification reactor; The fluidized bed in the secondary fluidized bed gasification reactor is located in the middle position. The outlet position of the fluidized bed in the secondary fluidized bed gasification reactor.

[0044] Specifically, the system is equipped with multiple temperature monitoring points, including at least three temperature measurement points within reactor 1 (inlet, middle, and outlet). The inlet refers to the raw material inlet location, typically located at the bottom of the reactor where the biomass raw material mixes with the fluidizing medium (nitrogen), i.e., the initial point where material and gas are injected into the reactor together. This ensures initial temperature stability: ensuring that the biomass reaches the preset pyrolysis temperature (400-500℃) upon entry, avoiding incomplete pyrolysis due to low temperatures. It also monitors the preheating of the fluidizing medium and detects whether the nitrogen has been preheated to a suitable temperature. The middle position of the fluidized bed, located at the midpoint of the reactor's fluidized bed layer, represents the active region where the biomass particles are fully fluidized and undergo pyrolysis. This position often represents the core reaction temperature, reflecting the real-time intensity of the pyrolysis reaction, ensuring temperature fluctuations are within ±5℃. Abnormal temperatures in the middle (such as localized overheating or low temperatures) may indicate uneven fluidization or material accumulation. The reactant outlet is located in the gas-solid separation zone at the top of the reactor, specifically where the gaseous products (bio-oil vapor, syngas, and a small amount of tar) are discharged after separation from the unreacted biochar / ash. The temperature at this location indicates the product gas temperature, ensuring the pyrolysis products are at a suitable temperature before entering the cyclone separator (to prevent tar condensation and pipe blockage). It also reflects the degree of reaction completion; comparing the outlet temperature with the inlet / middle temperature indirectly indicates whether the pyrolysis reaction is complete (a sudden drop in outlet temperature may indicate incomplete reaction). Corresponding temperature measuring points can also be installed at the inlet, middle, and outlet of reactor 2. Furthermore, a corresponding temperature measuring device is installed at the supply port of each gasifying agent in reactor 2 to monitor the initial temperature of each gasifying agent.

[0045] Therefore, the central control module (PLC) dynamically adjusts the electric heating power or flue gas circulation volume by comparing temperature data at various points. For example, if the inlet temperature is low, bottom heating needs to be increased; if the middle temperature is high but the outlet temperature is low, the fluidization rate may need to be reduced to prolong the residence time; if the outlet temperature is too high, it may indicate excessive pyrolysis, requiring an alarm to be triggered or the heating power to be reduced.

[0046] The collected real-time status data is input to the central control module, which employs an industrial-grade programmable logic controller (PLC). Using a fuzzy PID algorithm, it dynamically adjusts the gasifying agent flow rate, fan speed, and temperature to ensure H2 / CO≈2. Alternatively, a neural network (such as the BP algorithm) can be used to replace the fuzzy PID algorithm, training a model based on historical data to predict the optimal gasifying agent ratio to adapt to more complex changes in biomass composition. Or, a reinforcement learning algorithm can be introduced to dynamically adjust control parameters based on real-time gas production quality, further improving system robustness.

[0047] In one possible implementation, the real-time status data includes at least: the actual molar ratio of H2 to CO in the target syngas generated at the current moment; the central control module issues the adjustment command based on the real-time status data according to the following steps: Step 1: Based on the real-time status data, determine the ratio deviation value of H2 and CO, and the rate of change of deviation. The ratio deviation value represents the difference between the actual molar ratio of H2 and CO and the target molar ratio, where the target molar ratio is 2. Specifically, the ratio deviation value (e) represents the difference between the current actual ratio (actual molar ratio) of H2 / CO in the syngas and the target ratio (set value, such as H2 / CO = 2.0). The deviation change value (Δe) represents the trend of the deviation value (e) per unit time, reflecting the dynamic response speed of the system.

[0048] Step 2: Map the proportional deviation value and the deviation change value to fuzzy variables. The fuzzy set of the proportional deviation value (e) includes: {negative large (NB), negative small (NS), zero (ZO), positive small (PS), positive large (PB)}. The fuzzy set of the deviation change value (Δe) includes: {negative fast (NF), negative slow (NS), zero (ZO), positive slow (PS), positive fast (PF)}. The corresponding elements from these fuzzy sets are determined as fuzzy variables, that is, the H2 / CO proportional deviation (e) and its rate of change (Δe) are mapped to fuzzy variables (such as "positive large" and "negative small").

[0049] Step 3: Based on the fuzzy rule base built from operational experience, the fuzzy variables are mapped to fuzzy outputs.

[0050] The fuzzy rule base may include 50 control rules defined based on expert experience, such as: IF e = negative large AND Δe = positive small THEN Increase A2 water vapor flow rate by 10%. In this embodiment, the specific content of the rules is not limited.

[0051] Step 4: The fuzzy output is converted into adjustment commands using the center-of-gravity method. These commands include at least: commands to adjust the opening degree of each gasifying agent valve, commands to adjust the fan frequency of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and commands to adjust the electric heating power of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor. Specifically, the membership functions of the fuzzy rule output are weighted and averaged to convert them into precise control commands. For example, the output might be "increase steam flow rate by 15%" or "decrease CO2 valve opening by 5%", thereby adjusting the gasifying agent valve opening, fan frequency (0-100Hz), and electric heating power (0-50kW) via the PLC, ultimately stabilizing the H2 / CO ratio within the range of 2.0±0.1.

[0052] Reference Figure 3 , Figure 3 A schematic diagram of the control logic of a central control module is shown, such as... Figure 3 As shown, during the gasification reaction in reactors 1 and 2, sensors (sensor monitoring modules) collect real-time data (i.e., real-time status data) and send it to the central control module. Based on the real-time collected temperature data and gas composition data (H2, CO, CO2 concentrations and H2 / CO ratio), the central control module dynamically issues control commands using a fuzzy PID algorithm to regulate: the injection flow rate ratio of each gasifying agent; the frequency conversion speed regulation of the blower to control the gas residence time; and the precise adjustment of the reaction temperature. This achieves precise control of the H2 / CO ratio.

[0053] The control system proposed in this application boasts high energy utilization efficiency. Through a two-stage reaction unit thermal coupling design, energy efficiency is enhanced. The temperature gradient optimizes the reaction path: the primary fluidized bed (400-500℃) focuses on biomass pyrolysis, achieving efficient separation of biochar, bio-oil, and syngas through low-temperature pyrolysis (biochar ash content <5%, fixed carbon >60%); the secondary fluidized bed (700-800℃) focuses on gasification, with the high-temperature environment promoting the water-gas reaction (C+H2O→CO+H2) and CO2 reforming (CO2+C→2CO), improving the biomass pyrolysis gasification effect and resulting in high calorific value syngas. Methanol synthesis requires H2 / CO≈2; by injecting different gasifying agents, dynamic matching and precise H2 / CO control eliminate the need for additional conversion reaction units in traditional processes, saving on additional equipment investment. Furthermore, the versatility of raw materials is enhanced. For different biomass materials such as straw (C / H≈0.6) and sawdust (C / H≈0.8), by adjusting the proportion of the gasifying agent (e.g., increasing the steam flow rate by 10%-15% for sawdust), the H2 / CO ratio can be stably controlled at 2.0±0.1, solving the problem of large ratio fluctuations (±15%) during traditional single-agent (e.g., steam) gasification. This makes it particularly suitable for large-scale processing of various agricultural and forestry wastes. A portion of the captured CO2 is used for gasifying agent recycling, reducing carbon emissions by 30%. Through the triple innovation of "staged reaction - multi-agent regulation - energy closed loop," it not only solves the problems of large fluctuations in syngas ratio, difficult tar treatment, and low energy efficiency in traditional biomass gasification, but also achieves full-process greening from raw material processing to by-product utilization, providing an efficient and environmentally friendly technical path for large-scale production of green methanol and replacement of fossil energy.

[0054] The second aspect of this application also provides a biomass gasification control method, applied to the biomass gasification control system described in the first aspect of this application, with reference to... Figure 4 , Figure 4 A flowchart illustrating the steps of a biomass gasification control method is shown, such as... Figure 4 As shown, the method includes: Step S101: In a primary fluidized bed pyrolysis reactor, biomass raw materials are fed into the fluidized bed for preliminary pyrolysis reaction to obtain pyrolysis reactants, which include: bio-oil and initial syngas. Step S102: In a two-stage fluidized bed gasification reactor, the pyrolysis reactants are gasified using a variety of gasifying agents to obtain target syngas, which includes H2 and CO; wherein the various gasifying agents include at least: oxygen, water vapor, and carbon dioxide. Step S103: Monitor the real-time status data of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor; Step S104: Based on the real-time status data, an adjustment command is issued. The adjustment command is used to regulate the flow rate of the various gasifying agents, as well as the fan speed and reaction temperature in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, so that the molar ratio of H2 to CO in the generated target syngas is within a first threshold range.

[0055] In one possible implementation, the real-time status data includes at least: the actual molar ratio of H2 to CO in the target synthesis gas generated at the current moment; the step of issuing an adjustment command based on the real-time status data includes: Based on the real-time status data, the ratio deviation value of H2 and CO, as well as the rate of change of the deviation, are determined; the ratio deviation value represents the difference between the actual molar ratio of H2 and CO and the target molar ratio, where the target molar ratio is 2; The proportional deviation value and the deviation change value are mapped to fuzzy variables; A fuzzy rule library built based on operational experience maps the fuzzy variables to fuzzy outputs. The fuzzy output is converted into adjustment instructions using the center of gravity method. The adjustment instructions include at least: instructions to adjust the opening degree of each gasifying agent valve, instructions to adjust the fan frequency of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and instructions to adjust the electric heating power of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor.

[0056] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0057] Finally, 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 a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] The above provides a detailed description of the biomass gasification control system and biomass gasification control method provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

[0059] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0060] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

[0061] The terms "an embodiment," "embodiment," or "one or more embodiments" as used herein mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of this application. Furthermore, please note that the examples of the phrase "in one embodiment" do not necessarily all refer to the same embodiment.

[0062] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0063] In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This application can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A biomass gasification control system, characterized in that, The system includes: A primary fluidized bed pyrolysis reactor is used to feed biomass raw materials into a fluidized bed for preliminary pyrolysis reaction to obtain pyrolysis reactants, which include: bio-oil and initial syngas; A two-stage fluidized bed gasification reactor is used to gasify the pyrolysis reactants using a variety of gasifying agents to obtain a target syngas, wherein the target syngas includes H2 and CO; wherein the various gasifying agents include at least: oxygen, water vapor, and carbon dioxide; Sensor monitoring module: used to monitor real-time status data in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor; Central control module: Used to issue adjustment commands based on the real-time status data. The adjustment commands are used to regulate the flow rate of the various gasifying agents, as well as the fan speed and reaction temperature in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, so that the molar ratio of H2 to CO in the generated target syngas is within a first threshold range.

2. The biomass gasification control system according to claim 1, characterized in that, The real-time status data includes at least: the actual molar ratio of H2 and CO in the target synthesis gas generated at the current moment; the central control module issues the adjustment command based on the real-time status data according to the following steps: Based on the real-time status data, the ratio deviation value of H2 and CO, as well as the rate of change of the deviation, are determined; the ratio deviation value represents the difference between the actual molar ratio of H2 and CO and the target molar ratio, where the target molar ratio is 2; The proportional deviation value and the deviation change value are mapped to fuzzy variables; A fuzzy rule library built based on operational experience maps the fuzzy variables to fuzzy outputs. The fuzzy output is converted into adjustment instructions using the center of gravity method. The adjustment instructions include at least: instructions to adjust the opening degree of each gasifying agent valve, instructions to adjust the fan frequency of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and instructions to adjust the electric heating power of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor.

3. The biomass gasification control system according to claim 1, characterized in that, The real-time status data includes: temperature status data, concentrations of various gases in the reactor, and tar concentration; the sensor monitoring module includes: The temperature monitoring unit is used to monitor the reaction temperature in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and to collect temperature status data. The gas composition analysis unit is used to collect the concentration of each gas in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, as well as the actual molar ratio of H2 and CO in the target synthesis gas generated at the current moment; A tar monitoring unit is used to monitor the concentration of tar in the bio-oil.

4. The biomass gasification control system according to claim 3, characterized in that, The temperature monitoring unit includes multiple K-type thermocouples; the multiple K-type thermocouples are respectively located at one or more of the following monitoring points in the system: The feed inlet location of the primary fluidized bed pyrolysis reactor; The fluidized bed in the primary fluidized bed pyrolysis reactor is located in the middle position. The reactant outlet location of the primary fluidized bed pyrolysis reactor; The location of the supply port for each gasifying agent in the secondary fluidized bed gasification reactor; The fluidized bed in the secondary fluidized bed gasification reactor is located in the middle position. The outlet position of the fluidized bed in the secondary fluidized bed gasification reactor.

5. The biomass gasification control system according to claim 1, characterized in that, The primary fluidized bed pyrolysis reactor includes: The first temperature control module is used to control the temperature by combining electric heating and flue gas circulation to maintain the reaction temperature of the primary fluidized bed pyrolysis reactor at 400-500℃. A fluidizing medium control module is used to adjust the gas flow rate of the fluidizing medium to 0.5-1.0 m / s using a variable frequency fan, wherein the fluidizing medium is nitrogen. The bottom discharge module is used to discharge the biochar produced by the reaction from the bottom of the primary fluidized bed pyrolysis reactor.

6. The biomass gasification control system according to claim 5, characterized in that, The system also includes a cyclone separator for separating the bio-oil and the initial syngas produced in the initial pyrolysis reaction and conveying them to the secondary fluidized bed gasification reactor.

7. The biomass gasification control system according to claim 1, characterized in that, The secondary fluidized bed gasification reactor includes: The second temperature control module is used to jointly regulate the temperature using the burner and the waste heat recovery module to maintain the reaction temperature of 700-800°C in the secondary fluidized bed gasification reactor. The pressure control module is used to maintain a slightly positive pressure environment of 0.1-0.3 MPa in the secondary fluidized bed gasification reactor; The gasifying agent flow control module is used to independently control the gas flow rate of each gasifying agent, including at least: an oxygen flow control module, a water vapor flow control module, and a carbon dioxide flow control module.

8. The biomass gasification control system according to claim 1, characterized in that, The system further includes: a raw material pretreatment module, the raw material pretreatment module comprising: A pulverizing device is used to pulverize biomass raw materials so that the particle size of the biomass raw materials is 3-5 mm; A rotary dryer is used to control the moisture content of the biomass raw material to 10-15% at 80-100℃.

9. A method for controlling biomass gasification, characterized in that, The biomass gasification control system applied to any one of claims 1-8, the method comprising: In a primary fluidized bed pyrolysis reactor, biomass feedstock is fed into the fluidized bed for preliminary pyrolysis reaction to obtain pyrolysis reactants, which include: bio-oil and initial syngas; In a two-stage fluidized bed gasification reactor, the pyrolysis reactants are gasified using a variety of gasifying agents to obtain target syngas, which includes H2 and CO; wherein the various gasifying agents include at least: oxygen, water vapor, and carbon dioxide; Monitor the real-time status data of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor; Based on the real-time status data, an adjustment command is issued to regulate the flow rate of the various gasifying agents, as well as the fan speed and reaction temperature in the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, so that the molar ratio of H2 to CO in the generated target syngas is within a first threshold range.

10. The biomass gasification control method according to claim 9, characterized in that, The real-time status data includes at least: the actual molar ratio of H2 and CO in the target synthesis gas generated at the current moment; the step of issuing adjustment commands based on the real-time status data includes: Based on the real-time status data, the ratio deviation value of H2 and CO, as well as the rate of change of the deviation, are determined; the ratio deviation value represents the difference between the actual molar ratio of H2 and CO and the target molar ratio, where the target molar ratio is 2; The proportional deviation value and the deviation change value are mapped to fuzzy variables; A fuzzy rule library built based on operational experience maps the fuzzy variables to fuzzy outputs. The fuzzy output is converted into adjustment instructions using the center of gravity method. The adjustment instructions include at least: instructions to adjust the opening degree of each gasifying agent valve, instructions to adjust the fan frequency of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor, and instructions to adjust the electric heating power of the primary fluidized bed pyrolysis reactor and the secondary fluidized bed gasification reactor.

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