Integrated grinding, crushing, baking and carbonizing system and method for biomass gasification raw materials

Abstract

The invention discloses a biomass gasification raw material integrated grinding, crushing, baking and carbonizing system and method.The system comprises a storage bin 10, a coal mill 20, a heating cone 21, an air pipe 30, a baking pipe 40, a dynamic and static separator 50, a powder return pipe 60, a filter 70 and a pulverized coal storage tank 80, the coal mill 20 comprises the heating cone 21, the heating cone 21 is provided with a first air inlet of the air pipe 30, and the baking cone 21 is provided with a second air inlet of the air pipe 30; the coal mill 20 comprises a heating cone 21 and an air pipe 30, hot air input by the air pipe 30 heats biomass gasification raw materials, the coal mill 20 further comprises a milling area, the biomass gasification raw materials enter the milling area under the centrifugal effect and the hot air effect at the heating cone 21, the milling area is provided with a second air inlet of the air pipe 30, and the input hot air feeds the milled biomass powder into the baking pipe 40. By adopting the system provided by the embodiment of the invention, the coupling effect of high-temperature carbonization and grinding on the biomass material in the circulating process of the system is realized, and the problem that the grinding force of the biomass is too low at the conventional operation temperature is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass gasification, and in particular to a system and method for integrated grinding, pulverizing, baking and carbonizing of biomass gasification raw materials. Background Art

[0002] Biomass gasification is the process of converting biomass (such as crop straw, forestry residues, etc.) into combustible gas or chemical raw materials, establishing a closed carbon cycle, and effectively utilizing the carbon in biomass waste. Producing chemical products such as methanol through biomass gasification can reduce carbon emissions from the source of the entire system, and even achieve zero-carbon chemical industry. At present, the main reactors are fixed-bed gasifiers, fluidized-bed gasifiers, and entrained-bed gasifiers. Among them, the entrained-bed gasifier can efficiently process biomass of various shapes and sizes (including powdered biomass) and has high gasification efficiency and synthesis gas quality. Using an entrained-bed pressurized gasifier to gasify biomass under high temperature and high pressure can greatly improve the biomass gasification efficiency and obtain high-conversion rate raw gas. It is the main direction for the large-scale industrial application of biomass gasification in the future.

[0003] The biomass milling process system is a key factor restricting the development of biomass entrained-flow gasification. The cellulose and hemicellulose in biomass are relatively hard, and the fibers of straw-based biomass are long and interwoven. This can lead to fiber clumps or knots in the milling equipment, which can easily lead to uneven texture, uneven size, and irregular shape of the milled particles. This results in low output from conventional milling equipment, and poor powder quality and stability.

[0004] Currently, biomass pulverization equipment primarily consists of hammer mills and claw mills. These use high-speed rotating hammers or claws to pulverize tough raw materials through shearing, or they utilize high-speed airflow (such as supersonic airflow) to pulverize raw material particles by collision. Existing biomass pulverization technology and processes pre-screen and dry the raw materials before producing a fine powder through a dual process of coarse and fine pulverization. The main pulverization principles can be categorized as impact pulverization, shear pulverization, grinding pulverization, and collision pulverization.

[0005] Coarse crushing methods: Hammer crushing, using high-speed rotating hammers to crush the biomass raw materials; tooth roller crushing, crushing is achieved through one or more pairs of tooth rollers rotating in opposite directions; grinding crushing, the raw materials are gradually ground under the extrusion and friction of the grinding body.

[0006] Fine grinding method: The universal grinder further grinds the coarsely ground biomass raw materials into smaller particles through the action of internal high-speed rotating cutters and fixed cutters, with particle sizes reaching millimeter level; the air flow grinder uses high-speed airflow (such as supersonic airflow) to cause the raw material particles to collide with each other and grind them. The raw materials are fed into the high-speed airflow, and as the airflow accelerates, the particles collide with each other at extremely high speeds, thereby achieving the purpose of crushing.

[0007] The raw material fineness required by biomass pressurized gasification furnace is below 120μm, and the sieve residue R 120 About 10%, and the feed rate is about 20t / h-80t / h. This requires the biomass crushing system to meet both the output requirements and the fineness requirements. However, the crushing equipment that uses the principles of high-speed impact crushing and shear crushing is subject to the influence of the high-speed rotor. The maximum output of a single unit is about 10t, which cannot meet the output requirements of large gasification furnaces. If this crushing system is used, multiple crushing equipment will be required, and the equipment and engineering investment will be extremely high. At the same time, the energy consumption is high and the economic benefits are very poor. The air flow crushing technology is used, and the equipment structure is complex, including multiple parts such as air compressors, crushing chambers, and grading devices. The equipment cost is very high, the output is limited, the equipment wear rate is high, the normal operation and maintenance costs are high, and large-scale application is relatively difficult.

[0008] Using milling technology, due to the fibrous structure of biomass raw materials, which have good toughness and low density, it is difficult to grind flexible materials into fine powder. The raw materials can be pretreated by pyrolysis and carbonization. The cellulose and hemicellulose in the biomass are pyrolyzed at high temperatures, resulting in biocarbon black particles that are then pulverized in a milling device. The grindability index of biocarbon is similar to that of ordinary coal. However, the large size of biomass raw materials and their poor thermal conductivity result in large baking and carbonization equipment, high energy consumption, and high overall investment in the two-step carbonization and grinding process, making it uneconomical. Summary of the Invention

[0009] The purpose of the present invention is to provide an integrated grinding, pulverizing, baking and carbonizing system and method for biomass gasification raw materials, so as to at least partially solve the problems of low output, insufficient fineness, large equipment investment and high energy consumption of existing pulverization processes.

[0010] The technical solution adopted by the present invention to solve its technical problems is: to provide an integrated grinding, pulverizing and baking carbonization system for biomass gasification raw materials, including a storage bin, a coal mill, a heating cone, an air duct, a baking tube, a dynamic and static separator, a powder return pipe, a filter and a pulverized coal storage tank; wherein, the storage bin is connected to the coal mill, and the biomass gasification raw materials are transmitted to the coal mill through a feeding pipe; the coal mill includes a heating cone, and the biomass gasification raw materials transmitted from the storage bin fall onto the heating cone, and the heating cone is provided with a first air inlet of the air duct, and the hot air input by the air duct heats the biomass gasification raw materials, and the coal mill also includes a grinding area, and the biomass gasification raw materials are heated in the Under the action of centrifugation and hot air from the heating cone, it enters the grinding area. The grinding area is provided with a second air inlet of the air duct, and the input hot air sends the ground biomass powder into the baking tube; the baking tube includes multiple air inlets, and the biomass powder is carbonized by the input hot air; the dynamic and static separator is connected to the baking tube, the powder return pipe and the filter to separate the received biomass powder. The biomass powder that meets the powder output requirements is sent to the filter, and the biomass powder that does not meet the powder output requirements is sent back to the coal mill through the powder return pipe; the filter filters the received gas-powder mixture, collects the biomass powder and transports it to the pulverized coal storage tank.

[0011] Preferably, the powder outlet channel of the coal mill and the powder inlet channel of the dynamic-static separator are connected through a biomass roasting pipe.

[0012] Preferably, the baking tube is 2-10 m long and 300-2000 mm in diameter.

[0013] Preferably, the powder return pipe is communicated with the end of the feed pipe.

[0014] Preferably, the powder outlet channel of the dynamic and static separator is connected to the baking tube, and the biomass powder is transported to the filter in the form of an air-powder mixture under the action of hot air introduced into the baking tube.

[0015] Preferably, the system further comprises a weighing feeder located at the lower end of the storage bin, which weighs the biomass gasification raw material output from the storage bin and delivers it to the coal mill through a feeding pipe.

[0016] Preferably, the heating cone is a hollow structure, the upper cone head is connected to the first air inlet of the air duct, and an annular groove is provided at the lower part for outputting hot air.

[0017] Preferably, the heating cone is fixedly connected to the body of the coal mill (20).

[0018] Preferably, the baking tube includes a plurality of air inlets connected to the air duct.

[0019] Preferably, the baking tube includes a plurality of air inlets connected to the baking air duct.

[0020] Preferably, the hot air temperature is between 240°C and 380°C.

[0021] Preferably, the baking tube includes a plurality of air inlets connected to the air duct.

[0022] Preferably, the baking tube includes a plurality of air inlets connected to the baking air duct.

[0023] Preferably, the system further comprises a controller for adjusting the gas ratio between the air inlets of the air duct.

[0024] The present invention also provides an integrated grinding, pulverizing and baking carbonization method for biomass gasification raw materials, which is applied to the above-mentioned system, including: drying and coarsely grinding the raw materials and then extruding and granulating them to form biomass gasification raw materials, and then conveying them to the storage bin after impurity screening, and then conveying them to the coal mill through the storage bin; heating the biomass gasification raw materials input into the coal mill through a heating cone, and then grinding the biomass gasification raw materials through the grinding area to obtain biomass powder, and conveying the biomass powder to the baking tube for carbonization treatment under the action of an entrained bed; separating the biomass powder after carbonization treatment, outputting biomass powder that meets the powder output requirements, and returning the biomass powder that does not meet the powder output requirements to the coal mill through a return pipe; filtering the biomass powder that meets the powder output requirements, and conveying the biomass powder obtained after filtration to a pulverized coal storage tank.

[0025] The beneficial effects of the present invention are:

[0026] By adopting the system provided by the embodiment of the present invention, the integrated processing of grinding, crushing and baking and carbonization of biomass gasification raw materials is realized. Through the coupling effect of grinding and carbonization, the biomass material is quickly carbonized in the baking tube, and the output of biomass powder can be increased to 3-5 times the normal output; the energy utilization efficiency is improved, the investment and operating costs are reduced, and at the same time, the quality stability of the biomass powder is guaranteed, providing stable raw materials for the subsequent gasification process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of the integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials provided by an embodiment of the present invention.

[0028] Figure 2 This is a flow chart of the integrated grinding, pulverizing, baking and carbonization method for biomass gasification raw materials provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate to facilitate understanding of the embodiments of the present invention described herein. In addition, the terms "including," "comprising," and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a product or device comprising a series of elements is not necessarily limited to those elements explicitly listed, but may include other elements not explicitly listed or inherent to the product or device.

[0031] In the present invention, terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "center," "vertical," "horizontal," "transverse," and "longitudinal" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are primarily intended to better describe the present invention and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0032] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0033] Furthermore, the terms "installed," "disposed," "provided with," "connected," "connected," and "socketed" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integral structures; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; or internal communication between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0034] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] Example 1

[0036] Embodiment 1 of the present invention provides an integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials. Figure 1 The schematic diagram of the system is shown in FIG. Figure 1 As shown, the system includes a storage bin 10, a coal mill 20, a heating cone 21, an air duct 30, a baking tube 40, a dynamic and static separator 50, a powder return pipe 60, a filter 70 and a pulverized coal storage tank 80;

[0037] The storage bin 10 is connected to the coal mill 20 and transmits the biomass gasification raw materials to the coal mill 20 through the feeding pipe;

[0038] The coal mill 20 includes a heating cone 21. The biomass gasification feedstock transported from the storage bin 10 falls into the heating cone 21. The heating cone 21 is provided with a first air inlet of an air duct 30. Hot air inputted from the air duct 30 heats the biomass gasification feedstock. The coal mill 20 also includes a grinding area. The biomass gasification feedstock enters the grinding area under the action of centrifugal force and hot air from the heating cone 21. The grinding area is provided with a second air inlet of the air duct 30. The hot air input sends the ground biomass powder into the baking tube 40.

[0039] The baking tube 40 includes multiple air inlets, through which hot air is input to carbonize the biomass powder;

[0040] The dynamic and static separator 50 is connected to the baking tube 40, the powder return pipe 60 and the filter 70 to separate the received biomass powder. The biomass powder that meets the powder output requirements is sent to the filter 70, and the biomass powder that does not meet the powder output requirements is sent back to the coal mill 20 through the powder return pipe 60.

[0041] The filter 70 filters the received gas-powder mixture, collects the biomass powder and then transports it to the pulverized coal storage tank 80 .

[0042] In a preferred embodiment, the pulverized coal outlet passage of the coal mill 20 and the pulverized coal inlet passage of the dynamic-static separator 50 are connected via a biomass roasting tube 40. The roasting tube is 2-10 m long and 300-2000 mm in diameter.

[0043] In a preferred embodiment, the powder return pipe 60 is connected to the end of the feed pipe, so that the powder entering the coal mill 20 through the powder return pipe 60 also falls into the heating cone 21. In other embodiments, the powder return pipe 60 can be independently connected to the coal mill 20. The powder return pipe 60 allows powder with larger particle size to re-enter the coal mill 20 for re-grinding, thereby improving the system's pulverization efficiency and the consistency of product quality.

[0044] In one embodiment, the powder outlet channel of the dynamic-static separator 50 is connected to the baking tube 40, and the hot air introduced into the baking tube 40 transports the biomass powder to the filter 70 in the form of an air-powder mixture. In other embodiments, the powder outlet channel of the dynamic-static separator 50 may be provided with another air inlet, and the hot air from the baking tube 40 may not be used, and the hot air from the baking tube 40 may be circulated back to the air supply device.

[0045] The dynamic-static separator 50, for example, is a cyclone separator. Its high-speed rotation generates centrifugal force, classifying the powdered material by particle size. Biomass powder that meets the required yield (smaller particle size) is pneumatically conveyed to the filter, while biomass powder that does not meet the required yield (larger particle size) is returned to the coal mill via a return pipe. This pneumatic conveying method not only ensures continuous material flow but also prevents blockage and accumulation during transportation.

[0046] In one embodiment, a weigh feeder is further included, located at the lower end of the storage bin 10, to weigh the biomass gasification feedstock output from the storage bin 10 and deliver it to the coal mill 20 through a feed pipe. The weigh feeder can precisely control the amount of biomass feedstock entering the coal mill, ensuring the stability and controllability of system operation.

[0047] In one embodiment, the heating cone 21 is a hollow structure, with the upper cone tip connected to the first air inlet of the air duct 30, and an annular groove at the lower portion for hot air output. In other embodiments, the heating cone 21 can have other structures, such as an air inlet positioned on the side of the cone, and an air outlet positioned on the side or bottom of the cone for upward air flow. Hot air input from the air duct passes through the heating cone, heating the biomass gasification feedstock, increasing its temperature, reducing its moisture content, and making it easier to pulverize.

[0048] In a preferred embodiment, the heating cone 21 is fixedly connected to the body of the coal mill 20. By fixing the heating cone and the coal mill body to form an integral structure, the heating and grinding processes are ensured to be carried out in coordination.

[0049] The grinding area features a second air inlet for the air duct, which delivers hot air to the grinding process, feeding the ground biomass into the baking tube. High-speed rotating rollers in the grinding area squeeze and shear the biomass, crushing it into fine particles. The hot air from this second inlet not only removes moisture generated during the grinding process but also blows the ground biomass into the baking tube, achieving continuous material transport.

[0050] In one embodiment, the multiple air inlets of the baking tube 40 are connected to the air duct 30. In other embodiments, the multiple air inlets of the baking tube 40 can be connected to the baking air duct. The baking air duct and the air duct 30 can be independent air inlet systems. The biomass powder in the baking tube 40 is carbonized by the input hot air, the cellulose and hemicellulose are decomposed, and the volatile matter is released. The carbonized large particles are easier to be ground after returning to the grinding area through the separator, while their calorific value is increased. The multiple air inlets enable the hot air to be evenly distributed in the baking tube, ensuring that the biomass powder is fully heat-treated. Preferably, the hot air temperature is between 240°C and 380°C.

[0051] In one embodiment, the system may further include a controller for adjusting the gas ratio between the various air inlets of the air duct 30. Adjustable valves may be provided in the air duct 30 to adjust the air volume at each inlet. By monitoring parameters such as temperature, pressure, and flow rate across the system, the controller automatically adjusts the opening of each air inlet, optimizing hot air distribution and ensuring efficient and stable system operation under various operating conditions. The controller can also adjust system operating parameters based on the characteristics of the biomass feedstock and the requirements of the target product, achieving intelligent control.

[0052] The filter filters the incoming gas-powder mixture, collecting the biomass powder for transport to the pulverized coal storage tank. Using a bag or cyclone filter, it effectively separates gas and solid particles, ensuring the purity of the collected biomass powder while preventing environmental contamination from fine particles.

[0053] By adopting the system provided by the embodiment of the present invention, the integrated processing of grinding, crushing and baking and carbonization of biomass gasification raw materials is realized. The coupling effect of grinding and carbonization enables the biomass material to be quickly carbonized in the baking tube, and the output of biomass powder can be increased to 3-5 times the normal output; energy utilization efficiency is improved, investment and operating costs are reduced, and at the same time, the quality stability of biomass powder is guaranteed, providing stable raw materials for the subsequent gasification process.

[0054] The beneficial effects of the embodiments of the present invention include:

[0055] Through the process of preheating, grinding, carbonization, and grinding, the biomass feedstock can be crushed to the required fineness and output, meeting the feed requirements of the biomass entrained-flow pressurized gasifier, thereby enabling the scale-up and expansion of chemical projects such as biomass-to-methanol. This eliminates the need for a front-end carbonization system for biomass feedstock, allowing a single system to simultaneously address both grinding and carbonization issues. This reduces the high investment cost of the carbonization process and increases the project's investment value and economic returns. This simplifies the biomass gasification process, reduces the high energy consumption and operating and maintenance costs associated with complex processes, and improves the long-term economic efficiency and stability of biomass gasification projects.

[0056] The solution provided by the present invention achieves a continuous process of preheating, grinding, carbonization, and grinding of biomass raw materials by simultaneously performing the carbonization and pulverization processes within the coal mill, thereby solving the problems of low output, insufficient fineness, large equipment investment, and high energy consumption of the biomass raw material grinding system. The carbonization process reduces the toughness of the biomass raw material and increases its brittleness, allowing the grindability index to reach the level of normal coal, further reducing its volume and facilitating grinding to the required fineness, reaching the required fineness of approximately 120 μm. The design of the heating cone ensures that the biomass raw material is fully preheated before entering the grinding area, thereby improving grinding efficiency. The design of the dynamic and static separator and the return powder pipe ensures that unqualified materials can be returned to the coal mill for secondary carbonization and grinding, thereby improving raw material utilization efficiency. The use of filter bags made of heat-resistant and oil-resistant materials for gas-powder separation solves the gas-powder separation problem caused by the precipitation of sticky substances such as tar during the biomass carbonization process. By adjusting the primary air temperature and coal mill operating parameters to control the circulation ratio, the equipment output is improved, and efficient grinding and carbonization of biomass raw materials is achieved.

[0057] Example 2

[0058] Based on the same technical concept as Example 1, this embodiment of the present invention provides a method for integrated grinding, pulverizing, baking, and carbonizing of biomass gasification feedstock, which is applicable to the system provided in Example 1 and any of its embodiments. Unless otherwise specified, the technical features of Examples 1 and 2 of the present invention may be referenced and incorporated into each other. Figure 2 A flow chart of the method is shown in FIG. Figure 2 As shown, the method includes:

[0059] In step 201 , the raw materials are dried, roughly crushed, extruded and granulated to form biomass gasification raw materials, which are then screened for impurities and transported to a storage bin, and then transported to a coal mill through the storage bin.

[0060] In step 202, the biomass gasification raw materials input into the coal mill are heated by a heating cone, and then the biomass gasification raw materials are ground into biomass powder in a grinding area. The biomass powder is transported to a baking tube for carbonization treatment under the action of an entrained flow.

[0061] In step 203 , the biomass powder after the carbonization treatment is separated, the biomass powder that meets the powder output requirement is output, and the biomass powder that does not meet the powder output requirement is sent back to the coal mill through the return pipe.

[0062] Step 204 , filtering the biomass powder that meets the powder output requirement, and delivering the biomass powder obtained after filtration to a pulverized coal storage tank.

[0063] The pulverizing principle of the method provided in the embodiment of the present invention is that the biomass raw materials undergo carbonization and pulverization processes simultaneously in the coal mill, and undergo a preheating-grinding-carbonization-grinding process through the action of a circulating fluidized bed in the coal mill until the dynamic and static separators screen the raw materials to about 120 μm, meeting the powder feeding requirements of the gasifier, and then enter the subsequent separator for gas-powder separation.

[0064] Among them, the biomass raw material crushing and carbonization system mainly includes three parts: raw material pre-screening (removing impurities such as iron filings) and transportation, biomass raw material grinding and carbonization, gas-powder separation and powder storage.

[0065] Raw material pre-screening and transportation: Biomass raw materials such as crop straw (such as corn stalks and wheat straw) and forestry waste (such as tree branches and sawdust) are dried, coarsely crushed, and then extruded into pellets to form white biomass pellets, or coarsely crushed into block-shaped wood or bamboo products. Ton bags of biomass raw materials from outside the factory are unpacked and transported via a belt conveyor to the biomass raw material storage silo. This process requires a de-ironing device to remove iron and other impurities that cannot be ground. The raw material storage silo is a conical silo. The material falls by gravity through a vibrating hopper or aerator to a weigh feeder below. The weigh feeder is weighed and conveyed to the coal mill below for grinding. A pipe chain conveyor 90, also known as a pipe chain conveyor, chain pipe conveyor, or disc chain conveyor, can also be provided. The feed pipe, as part of the pipe chain conveyor's pipeline, drives a disc or scraper via a chain to ensure that the raw material in the storage silo is transported along the pipeline to the coal mill.

[0066] Biomass raw material grinding: mainly divided into four processes:

[0067] The first step is primary heat exchange. The raw material falls through the drop pipe onto the distribution heating cone at the center of the grinding disc. The distribution heating cone is a hollow structure, with an upper portion connected to external hot air and a lower open loop groove that releases 30% of the high-temperature primary air outward through the distribution heating cone. The high-temperature hot air directly exchanges heat with the biomass material falling from the drop pipe, and then is subjected to the centrifugal force of the grinding disc to the grinding roller area.

[0068] The second step is grinding + primary carbonization. The biomass raw materials that have been preheated in the grinding area are first ground into powder with a particle size of about 2mm. After that, they are carbonized once through a baking pipeline under the action of high-temperature primary air at 200℃ to 300℃, and then enter the separator for separation. During this process, the coarsely crushed biomass powder is dried and pyrolyzed under the action of high-temperature primary air. The cellulose and hemicellulose are decomposed into small molecular gases, and the lignin structure is broken to generate aromatic compounds and carbon residues. After the primary carbonization, the biomass powder has reduced toughness, increased brittleness, increased grindability index, and further reduced volume.

[0069] The third step involves screening the recycled material, secondary carbonization, and grinding. Dynamic and static separators are used for screening, and particles 120μm or smaller that meet the discharge requirements are discharged through the powder outlet. Large particles that cannot pass through the separator, including both carbonized, large-sized black particles and uncarbonized white particles, are further carbonized by high-temperature fluidization of the primary air ejected from the distribution heating cone's jet ring groove. The airflow and centrifugal force of the grinding disc then carry the material to the roller grinding zone for secondary grinding and refinement.

[0070] Step 4: Baking, Carbonization, and Powder Separation: The ground and refined material is then carbonized in a baking pipeline to improve yield. Qualified fine powder is separated and transported through the powder outlet, while unqualified powder continues through the carbonization and grinding process. By adjusting the primary air temperature and mill operating parameters, the recirculation rate is controlled to improve equipment output.

[0071] Gas-powder separation and powder storage: The gas-powder mixture at the biomass pulverizer system's outlet is separated by a bag filter. The gas after passing through the filter bags is returned to the primary air system for circulation. Powder particles trapped on the surface of the filter bags are collected by an ash hopper and transported via a screw conveyor to a powder storage silo for storage. Because the powder temperature can reach 200°C and contains viscous substances such as tar that may precipitate during the biomass carbonization process, filter bags made of heat- and oil-resistant materials are used.

[0072] The key equipment of the biomass grinding, crushing and carbonization system is the coal mill. Unlike coal, biomass raw materials have high toughness and low brittleness, and are prone to tar precipitation during high-temperature carbonization. The coal mill must not only consider the grinding characteristics but also the carbonization process. Therefore, the coal mill needs to be specially designed, mainly including: (1) A heating cone is set on the upper part of the grinding disc, and the high-temperature primary air passes through the heating cone to perform central falling fluidization, while disturbing and heating carbonization. (2) A fluidized bed baking tube is set between the separator and the machine base to improve the carbonization effect by increasing the residence time and contact area of ​​the raw materials. (3) The angle of the nozzle ring is changed. Since biomass raw materials are softer than coal and have less wear on the machine casing, the primary air can be blown towards the machine casing to avoid blowing directly to the separator to prolong the residence time. (4) Since the grinding and crushing process requires repeated grinding-carbonization-grinding processes, large pieces of raw materials are likely to overflow from the grinding disc into the slag box, resulting in an increase in the slag discharge volume. In order to improve the efficiency of raw material utilization, a tube chain machine is set outside the slag discharge system to transport the discharged usable waste slag back to the raw material bin through the tube chain machine, thereby improving the efficiency of raw material utilization.

[0073] In the solution provided by this invention, the key equipment for gas-powder separation and powder storage is the gas-powder separation device. High-temperature carbonization in the mill easily releases tar and other precipitates, increasing the difficulty of gas-powder separation equipment. For example, PTFE is a suitable material. PTFE filter bags can withstand temperatures of 240°C, exhibit strong chemical stability and oxidation resistance, and have a smooth, self-lubricating fiber surface, making them ideal for separating powders after biomass grinding and carbonization.

[0074] By adopting the method provided by the embodiment of the present invention, the integrated processing of grinding and crushing and baking and carbonization of biomass gasification raw materials is realized. Through the coupling effect of grinding and carbonization, the biomass material is quickly carbonized in the baking tube, and the output of the biomass powder can be increased to 3-5 times the normal output; the energy utilization efficiency is improved, the investment and operating costs are reduced, and at the same time, the quality stability of the biomass powder is guaranteed, providing stable raw materials for the subsequent gasification process.

[0075] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit them. Those skilled in the art will appreciate that the technical solutions described in the aforementioned embodiments may be modified, or some of the technical features thereof may be replaced with equivalents; such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An integrated grinding, crushing, baking and carbonization system for biomass gasification raw materials, characterized in that: It includes a storage bin (10), a coal mill (20), a heating cone (21), an air duct (30), a baking tube (40), a dynamic and static separator (50), a powder return pipe (60), a filter (70) and a pulverized coal storage tank (80); The storage bin (10) is connected to the coal mill (20), and the biomass gasification raw material is transmitted to the coal mill (20) through the feeding pipe; The coal mill (20) includes a heating cone (21), and the biomass gasification raw material transmitted from the storage bin (10) falls into the heating cone (21). The heating cone (21) is provided with a first air inlet of an air duct (30), and the hot air input from the air duct (30) heats the biomass gasification raw material. The coal mill (20) also includes a grinding area. The biomass gasification raw material enters the grinding area under the action of centrifugal force and hot air from the heating cone (21). The grinding area is provided with a second air inlet of the air duct (30), and the input hot air sends the ground biomass powder into the baking tube (40); The baking tube (40) includes a plurality of air inlets, and the biomass powder is carbonized by inputting hot air; The dynamic and static separator (50) is connected to the baking tube (40), the powder return tube (60) and the filter (70), and separates the received biomass powder. The biomass powder that meets the powder output requirements is sent to the filter (70), and the biomass powder that does not meet the powder output requirements is sent back to the coal mill (20) through the powder return tube (60); The filter (70) filters the received gas-powder mixture, collects the biomass powder and then transports it to the pulverized coal storage tank (80).

2. The integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials according to claim 1 is characterized in that: The powder outlet channel of the coal mill (20) and the powder inlet channel of the dynamic and static separator (50) are connected via a biomass roasting pipe (40).

3. The integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials according to claim 1 is characterized in that: The powder return pipe (60) is communicated with the end of the feeding pipe.

4. The integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials according to claim 1 is characterized in that: The powder outlet channel of the dynamic and static separator (50) is connected to the baking tube (40), and the biomass powder is transported to the filter (70) in the form of an air-powder mixture under the action of hot air introduced from the baking tube (40).

5. The integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials according to claim 1 is characterized in that: It also includes a weighing feeder located at the lower end of the storage bin (10) for weighing the biomass gasification raw material output from the storage bin (10) and delivering it to the coal mill (20) through a feeding pipe.

6. The integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials according to claim 1 is characterized in that: The heating cone (21) is a hollow structure, the upper cone head is connected to the first air inlet of the air duct (30), and the lower part is provided with an annular groove for outputting hot air.

7. The integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials according to claim 1 or 5, characterized in that: The heating cone (21) is fixedly connected to the body of the coal mill (20).

8. The integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials according to claim 1 is characterized in that: The multiple air inlets of the baking tube (40) are connected to the air duct (30).

9. The integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials according to claim 1, characterized in that: The multiple air inlets of the baking tube (40) are connected to the baking air duct.

10. The integrated grinding, pulverizing, baking and carbonization system for biomass gasification raw materials according to claim 1 or 8, characterized in that: The system also includes a controller for adjusting the gas ratio between the air inlets of the air duct (30).

11. A method for integrated grinding, pulverizing, baking and carbonizing of biomass gasification raw materials, applied to the system according to any one of claims 1 to 10, characterized in that: include: The raw materials are dried, roughly crushed, extruded and granulated to form biomass gasification raw materials, and after impurities are screened out, they are transported to the storage bin and then transported to the coal mill through the storage bin; The biomass gasification raw materials input into the coal mill are heated by the heating cone, and then the biomass gasification raw materials are ground into biomass powder in the grinding area. The biomass powder is transported to the baking tube for carbonization treatment under the action of the entrained flow. The biomass powder after carbonization treatment is separated, and the biomass powder that meets the powder output requirements is output, and the biomass powder that does not meet the powder output requirements is sent back to the coal mill through the return pipe; The biomass powder that meets the powder output requirements is filtered, and the biomass powder obtained after filtration is transported to the pulverized coal storage tank.

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