Carbon-electricity co-production device system for realizing biomass utilization by coupling pyrolysis gasification furnace with boiler

Abstract

The invention provides a charcoal-electricity co-production device system for realizing biomass utilization by coupling a pyrolysis gasification furnace with a boiler. The charcoal-electricity co-production device system comprises a coal-fired boiler, the pyrolysis gasification furnace and a condensing device which are circularly connected, the coal-fired boiler comprises an economizer; the pyrolysis gasification furnace comprises a reaction inner barrel and a heating outer barrel; an inlet of the economizer is connected with the heating outer cylinder through a flue gas pipeline; and the reaction inner cylinder is connected with a pyrolysis auxiliary gas conveying pipeline. Biomass raw materials with different qualities are utilized in a graded mode, high-quality biomass charcoal, carbon-based fertilizer and high-calorific-value biomass fuel gas are generated, and economical operation of coal-fired boiler coupling biomass blending combustion is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass utilization, and in particular to a carbon-electricity cogeneration device system for realizing biomass utilization by coupling a pyrolysis gasification furnace with a boiler. Background Art

[0002] Currently, the main technology that can achieve carbon reduction in thermal power plants economically and efficiently is biomass co-firing technology. Due to the wide variety of biomass and the huge differences in the components of different biomass, it is currently difficult to find a technical route to achieve the processing of multiple biomass.

[0003] Biomass pyrolysis and gasification technology has the characteristics of high adaptability, clean products, and good environmental protection. The biomass carbon produced after biomass pyrolysis and gasification has high added value, and the generated gas has high calorific value, which can be coupled with power plant coal-fired boilers for combustion and utilization. Therefore, the coupling of biomass pyrolysis and gasification furnaces with coal-fired power plant boilers to achieve large-scale disposal of multiple biomass has obvious advantages.

[0004] Large coal-fired boilers have the characteristics of high combustion efficiency, high combustion temperature, and high emission standards. Therefore, coupling the biomass pyrolysis gasification furnace with the power station boiler can achieve partial coal substitution, reduce carbon emissions in the power generation process, and alleviate the carbon emission pressure of thermal power plants. However, on the one hand, the investment is large, and if it is coupled with the power station boiler to achieve biomass co-combustion, it is difficult to be economical. On the other hand, the products after pyrolysis and gasification are relatively single and difficult to have high added value.

[0005] CN107916142A discloses a biomass pyrolysis gasification system and a pyrolysis gasification method, wherein the system includes: a biomass pyrolysis gasification furnace, a high-temperature dust removal device and a waste heat boiler, wherein the biomass pyrolysis gasification furnace includes: a pyrolysis furnace body and a gasification furnace body formed integrally from top to bottom, wherein a plurality of heat storage radiation tubes are arranged in the pyrolysis furnace body, and a biomass inlet is provided at the top; a sandwich structure is formed at the lower part of the gasification furnace body, wherein the inner wall of the sandwich structure is composed of a funnel-shaped discharge part and a feed pipe, wherein the bottom end of the feed pipe is a solid material outlet, wherein the side wall of the funnel-shaped discharge part has a plurality of through holes, and the outer wall of the sandwich structure has an oxygen inlet and a steam inlet; a high-temperature oil and gas outlet is provided on the side wall where the pyrolysis furnace body and the gasification furnace body are connected, wherein the high-temperature dust removal device is connected to the high-temperature oil and gas outlet; and the waste heat boiler is connected to the high-temperature purified oil and gas outlet of the high-temperature dust removal device. The system is used to convert biomass into oil and gas resources to the maximum extent, and truly realizes the clean and efficient utilization of biomass.

[0006] CN109628156A discloses a biomass pyrolysis and gasification system and application, which includes a feeding device, a pyrolysis chamber and a gasification chamber. The feeding device is connected to the pyrolysis chamber and is used to feed biomass raw materials into the pyrolysis chamber; a pyrolysis gas delivery pipeline is connected to the top of the pyrolysis chamber for delivering pyrolysis gas, and a pyrolysis outlet for delivering pyrolysis coke into the gasification chamber is provided at the bottom; the gasification chamber is sleeved on the outside of the pyrolysis chamber to form a sleeve structure, a gasification gas delivery pipeline is connected to the top of the gasification chamber for delivering gasification gas, and the gasification gas delivery pipeline is sleeved on the outside of the feeding device to use the gasification gas to bake and preheat the biomass raw materials, and the baking gas generated by the baking preheating is sent to the gasification chamber, and a gasification ash outlet is opened at the bottom of the gasification chamber for delivering the gasification ash generated by gasification into an ash collector.

[0007] CN110257107A discloses a method for generating electricity by coupling a biomass pyrolysis and gasification system with a pulverized coal boiler power station, including a pretreatment unit for crushing and drying biomass for pretreatment; a pyrolysis and gasification furnace unit for pyrolyzing and gasifying the pretreated biomass into combustible gas; a metering and control unit for controlling and metering the combustible gas delivered to the pulverized coal boiler power station; and a gas storage station unit for storing the combustible gas produced by the pyrolysis and gasification furnace or releasing the combustible gas for use in the pulverized coal boiler power station. The biomass is converted into combustible gas through the pyrolysis and gasification system and delivered to the pulverized coal boiler power station for combustion and power generation, thereby realizing energy utilization.

[0008] However, the above-mentioned biomass pyrolysis system still has the problem that the generated biomass products have low calorific value and poor quality. Summary of the invention

[0009] In view of the problems existing in the prior art, the present invention provides a carbon-electricity cogeneration device system which realizes biomass utilization by coupling a pyrolysis gasification furnace with a boiler. The high-temperature flue gas generated by the coal-fired boiler is used as the heat source of the biomass pyrolysis gasification furnace to realize pyrolysis and gasification of the biomass in the furnace; the pyrolysis auxiliary gas is used as the heat source and reaction medium to realize the preparation of high-quality biomass products, and the graded utilization of biomass raw materials of different qualities is realized to produce high-quality biomass charcoal and carbon-based fertilizer as well as high calorific value biomass fuel gas, thus realizing the economical operation of the coal-fired power station boiler coupled with biomass co-combustion.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a carbon-electricity cogeneration device system that utilizes biomass by coupling a pyrolysis gasifier with a boiler. The carbon-electricity cogeneration device system includes a cyclically connected coal-fired boiler, a pyrolysis gasifier, and a condensing device;

[0012] The coal-fired boiler includes an economizer; the pyrolysis gasification furnace includes a reaction inner cylinder and a heating outer cylinder; the economizer inlet is connected to the heating outer cylinder via a flue gas duct; the reaction inner cylinder is connected to a pyrolysis auxiliary gas delivery pipeline.

[0013] The carbon-electricity cogeneration device system described in the present invention utilizes the heat source of a coal-fired boiler to couple a biomass pyrolysis gasification furnace to achieve multi-biomass pyrolysis and gasification, produce biomass fuel gas and high-quality biomass charcoal, and thus achieve the mixed combustion of different biomass with complex components in a coal-fired boiler. The inlet of the economizer is connected to the heating outer cylinder through a flue gas pipeline, and the high-temperature flue gas at the inlet of the economizer of the coal-fired boiler is used as the heat source of the biomass pyrolysis gasification furnace to achieve pyrolysis and gasification of the biomass in the furnace. The reaction inner cylinder is connected to the pyrolysis auxiliary gas delivery pipeline, and the pyrolysis auxiliary gas is introduced into the pyrolysis gasification furnace to countercurrently contact with the biomass to achieve the activation process of the biomass charcoal and improve the quality of the biomass charcoal. The carbon-electricity cogeneration device system described in the present invention can use different pyrolysis auxiliary gases for biomass of different qualities, which not only reduces the carbon emissions of coal-fired units for power generation, but also the pyrolysis and activation processes of the biomass charcoal are carried out in the same reactor, reducing the process flow and investment, and is suitable for large-scale promotion and application.

[0014] The pyrolysis gasification furnace of the present invention can be of suitable size and capacity according to actual needs. The pyrolysis auxiliary gas delivery pipeline of the present invention can be connected to the auxiliary steam of the generator set, or to the steam generator, or to the steam pressure reducing device according to actual needs.

[0015] Preferably, the tail flue of the coal-fired boiler is connected to a dust removal device.

[0016] Preferably, the reaction inner cylinder is connected to the biomass raw material input pipeline and the biomass product charcoal output pipeline respectively.

[0017] Preferably, the heating outer cylinder is also connected to the waste flue gas output pipe.

[0018] The waste flue gas in the present invention is returned to the original dust removal device of the coal-fired boiler for environmental protection treatment and then discharged in compliance with the emission standards.

[0019] Preferably, the pyrolysis auxiliary gas delivery pipeline includes an air delivery pipeline and a water vapor delivery pipeline.

[0020] Preferably, the internal structure of the pyrolysis gasification furnace includes a lifting plate turning structure or a toothed turning structure.

[0021] Preferably, the condensing device comprises a plate heat exchanger or a tube heat exchanger.

[0022] Preferably, the condensing device is connected to a condensed oil-water mixture output pipeline.

[0023] Tar and water vapor in the crude biomass gas generated by the pyrolysis reaction of the present invention are condensed and separated in a condensing device, and the obtained oil-water mixture containing wood vinegar is used as waste for professional deep processing.

[0024] In a second aspect, the present invention further provides a method for realizing carbon-electricity cogeneration by coupling a pyrolysis gasification furnace with a boiler to utilize biomass, the method being carried out using the carbon-electricity cogeneration device system for realizing biomass utilization by coupling a pyrolysis gasification furnace with a boiler as described in the first aspect; the method comprising the following steps:

[0025] (1) Biomass raw materials and pyrolysis auxiliary gas enter the reaction inner cylinder of the pyrolysis gasifier for pyrolysis reaction to produce biomass products; at the same time, the flue gas at the economizer inlet of the coal-fired boiler enters the heating outer cylinder of the pyrolysis gasifier through the flue gas pipeline to provide heat for the pyrolysis reaction;

[0026] (2) The crude biomass gas produced by the pyrolysis reaction enters the condensation device to separate and remove tar and water vapor, and then enters the coal-fired boiler for combustion.

[0027] The method for carbon-electricity cogeneration by coupling a pyrolysis gasifier with a boiler to achieve biomass utilization described in the present invention utilizes auxiliary gas as a heat source and reaction medium to achieve the preparation of high-quality biomass products, while utilizing the inlet flue gas of a coal-fired boiler economizer as a heat source for the biomass pyrolysis reaction, which not only realizes the graded processing and utilization of multi-component biomass, but also couples the high calorific value biomass gas and biomass products generated by the pyrolysis reaction for combustion in a coal-fired boiler, thereby reducing carbon emissions from thermal power generation and improving the economy of coal-fired boiler operation.

[0028] Preferably, the temperature of the pyrolysis reaction in step (1) is 600-700°C, for example, 600°C, 620°C, 650°C, 670°C, 690°C or 700°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the economizer inlet flue gas provides heat and then enters the dust removal device through the waste flue gas output pipeline for treatment and is discharged after meeting the emission standards.

[0030] Preferably, the biomass product is discharged through a biomass product output pipeline.

[0031] Preferably, when the biomass raw material is woody biomass, the feed size is less than 10 cm, for example, it can be 10 cm, 9 cm, 8 cm, 7 cm, 5 cm, 3 cm or 1 cm, etc., but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable; the pyrolysis auxiliary gas is water vapor, and the biomass product is biochar.

[0032] Preferably, the calorific value of the biochar is 3500-7000 kCal / kg, for example, 3500 kCal / kg, 4000 kCal / kg, 4500 kCal / kg, 5000 kCal / kg, 6000 kCal / kg or 7000 kCal / kg, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0033] Or biomass activated carbon with an iodine adsorption value of 500-1300 mg / g, for example, it can be 500 mg / g, 600 mg / g, 800 mg / g, 1000 mg / g, 1100 mg / g, 1200 mg / g or 1300 mg / g, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] Preferably, when the biomass raw material is straw biomass, the feed size is less than 3 cm, for example, it can be 3 cm, 2.5 cm, 2 cm, 1.5 cm, 1 cm, 0.8 cm or 0.5 cm, etc., but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable; the pyrolysis auxiliary gas is air and water vapor, and the biomass products are biomass fuel gas and biomass carbon-based fertilizer.

[0035] Preferably, the calorific value of the biomass gas is 2300-3500 kCal / Nm 3 , for example, it can be 2300kCal / Nm 3 、2500kCal / Nm 3 、2700kCal / Nm 3 、3000kCal / Nm 3 、3300kCal / Nm 3 or 3500kCal / Nm 3 The above range is not limited to the listed values, and other values ​​not listed within the above range are also applicable.

[0036] As a preferred technical solution of the present invention, the method comprises the following steps:

[0037] (1) The biomass raw material and the pyrolysis auxiliary gas enter the reaction inner cylinder of the pyrolysis gasifier to undergo a pyrolysis reaction at a temperature of 600 to 700° C. to produce biomass products; at the same time, the flue gas at the economizer inlet of the coal-fired boiler enters the heating outer cylinder of the pyrolysis gasifier through the flue gas pipeline to provide heat for the pyrolysis reaction, and then enters the dust removal device through the waste flue gas output pipeline for treatment to meet the emission standards before being discharged; the biomass products are discharged through the biomass product output pipeline;

[0038] When the biomass raw material is woody biomass, the feed size is less than 10 cm; the pyrolysis auxiliary gas is water vapor, and the biomass product is biochar with a calorific value of 3500-7000 kCal / kg or biochar activated carbon with an iodine adsorption value of 500-1300 mg / g;

[0039] When the biomass raw material is straw biomass, the feed size is less than 3 cm; the pyrolysis auxiliary gas is air and water vapor, and the biomass product has a calorific value of 2300-3500 kCal / Nm 3 biomass gas and biomass carbon-based fertilizer;

[0040] (2) The crude biomass gas produced by the pyrolysis reaction enters the condensation device to separate and remove tar and water vapor, and then enters the coal-fired boiler for combustion.

[0041] Compared with the prior art, the present invention has at least the following beneficial effects:

[0042] The carbon-electricity cogeneration device system for realizing biomass utilization by coupling a pyrolysis gasifier with a boiler provided by the present invention realizes graded processing and utilization of multiple biomass through a pyrolysis gasifier. On the one hand, the high calorific value biomass gas generated is coupled with the coal-fired boiler for combustion, thereby reducing carbon emissions from thermal power generation. On the other hand, the high-quality biomass products generated by pyrolysis and activation improve economic benefits and reduce the utilization cost of biomass co-combustion in thermal power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of a carbon-electricity cogeneration device system for realizing biomass utilization by coupling a pyrolysis gasification furnace with a boiler provided in Example 1 of the present invention.

[0044] In the figure: 1.1-coal-fired power plant boiler; 1.2-pyrolysis gasifier; 1.3-condensation device;

[0045] 2.1-Biomass raw material input pipeline; 2.2-Air delivery pipeline; 2.3-Water vapor delivery pipeline; 2.4-Biomass product output pipeline; 2.5-Raw biomass gas pipeline; 2.6-Waste flue gas output pipeline; 2.7-Purified gas pipeline; 2.8-Oil-water mixture output pipeline; 2.9-Flue gas pipeline. DETAILED DESCRIPTION

[0046] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0047] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0048] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0049] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0050] Those skilled in the art should understand that the present invention necessarily includes necessary pipelines, conventional valves and general pump equipment for realizing a complete process, but the above content does not belong to the main inventive point of the present invention. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection, and the present invention does not make special requirements and specific limitations on this.

[0051] Example 1

[0052] This embodiment provides a carbon-electricity cogeneration device system that uses a pyrolysis gasification furnace coupled with a boiler to achieve biomass utilization, and its schematic diagram is shown in FIG. Figure 1 shown.

[0053] The carbon-electricity cogeneration system comprises a cyclically connected coal-fired boiler 1.1, a pyrolysis gasifier 1.2 and a condensing device 1.3;

[0054] The coal-fired boiler 1.1 includes an economizer; the pyrolysis gasification furnace 1.2 includes a reaction inner cylinder and a heating outer cylinder; the economizer inlet is connected to the heating outer cylinder via a flue gas duct 2.9; and the reaction inner cylinder is connected to a pyrolysis auxiliary gas delivery duct.

[0055] The reaction inner cylinder is connected to the biomass raw material input pipeline 2.1 and the biomass product output pipeline 2.4 respectively;

[0056] The pyrolysis gasification furnace 1.2 and the condensation device 1.3 are connected via a crude biomass gas pipeline 2.5;

[0057] The heating outer cylinder is also connected to the waste flue gas output pipeline 2.6.

[0058] The condensing device 1.3 and the coal-fired boiler 1.1 are connected via a purified gas pipeline 2.7.

[0059] The pyrolysis auxiliary gas delivery pipeline includes an air delivery pipeline 2.2 and a water vapor delivery pipeline 2.3.

[0060] The internal structure of the pyrolysis gasification furnace 1.2 is a plate-lifting and material-turning structure.

[0061] The condensing device 1.3 is a plate heat exchanger.

[0062] The condensing device 1.3 is connected to the oil-water mixture output pipeline 2.8.

[0063] Example 2

[0064] This embodiment provides a method for realizing carbon-electricity cogeneration by coupling a pyrolysis gasification furnace with a boiler to utilize biomass. The method is performed using the carbon-electricity cogeneration device system for realizing biomass utilization by coupling a pyrolysis gasification furnace with a boiler as described in Example 1. The method comprises the following steps:

[0065] (1) Sawdust biomass raw materials with a feed size of 5 cm and pyrolysis auxiliary gas water vapor enter the reaction inner cylinder of the pyrolysis gasifier for a pyrolysis reaction at a temperature of 660° C., producing biomass charcoal with a calorific value of 7000 kCal / kg; at the same time, the flue gas at the economizer inlet of the coal-fired boiler enters the heating outer cylinder of the pyrolysis gasifier through the flue gas pipeline to provide heat for the pyrolysis reaction, and then enters the dust removal device through the waste flue gas output pipeline for treatment to meet the emission standards before being discharged; the biomass charcoal is discharged through the biomass product output pipeline;

[0066] (2) The crude biomass gas produced by the pyrolysis reaction enters the condensation device to separate and remove tar and water vapor, and then enters the coal-fired boiler for combustion.

[0067] Example 3

[0068] This embodiment provides a method for realizing carbon-electricity cogeneration by coupling a pyrolysis gasification furnace with a boiler to utilize biomass. The method is performed using the carbon-electricity cogeneration device system for realizing biomass utilization by coupling a pyrolysis gasification furnace with a boiler as described in Example 1. The method comprises the following steps:

[0069] (1) The feed size of 1 cm corn stalk biomass raw material and pyrolysis auxiliary gas air and water vapor enter the reaction inner cylinder of the pyrolysis gasifier for pyrolysis reaction at a temperature of 700 ° C, generating a calorific value of 3500 kCal / Nm 3 biomass fuel gas and biomass carbon-based fertilizer; at the same time, the flue gas at the economizer inlet of the coal-fired boiler enters the heating outer cylinder of the pyrolysis gasification furnace through the flue gas pipeline to provide heat for the pyrolysis reaction, and then enters the dust removal device through the waste flue gas output pipeline for treatment to meet the emission standards before being discharged; the biomass carbon-based fertilizer is discharged through the biomass product output pipeline;

[0070] (2) The crude biomass gas produced by the pyrolysis reaction enters the condensation device to separate and remove tar and water vapor, and then enters the coal-fired boiler for combustion.

[0071] In summary, the carbon-electricity cogeneration device system for realizing biomass utilization by coupling a pyrolysis gasifier with a boiler provided by the present invention utilizes a circularly connected coal-fired boiler, a pyrolysis gasifier and a condensing device to realize the graded processing and utilization of multiple biomass. On the one hand, the high calorific value biomass gas generated is coupled with the coal-fired boiler for combustion, thereby reducing the carbon emissions of thermal power generation. On the other hand, the high-quality biomass products generated by pyrolysis and activation improve the economic benefits and reduce the utilization cost of biomass co-combustion in thermal power plants, which has a prospect of large-scale promotion and application.

[0072] The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0073] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. A carbon-electricity cogeneration system for realizing biomass utilization by coupling a pyrolysis gasification furnace with a boiler, characterized in that: The carbon-electricity cogeneration system includes a cyclically connected coal-fired boiler, a pyrolysis gasification furnace and a condensing device; The coal-fired boiler includes an economizer; the pyrolysis gasification furnace includes a reaction inner cylinder and a heating outer cylinder; the economizer inlet is connected to the heating outer cylinder via a flue gas duct; the reaction inner cylinder is connected to a pyrolysis auxiliary gas delivery pipeline.

2. The carbon-electricity cogeneration system according to claim 1, characterized in that: The reaction inner cylinder is connected to the biomass raw material input pipeline and the biomass product output pipeline respectively; Preferably, the heating outer cylinder is also connected to the waste flue gas output pipeline; Preferably, the pyrolysis auxiliary gas delivery pipeline includes an air delivery pipeline and a water vapor delivery pipeline.

3. The carbon-electricity cogeneration system according to claim 1 or 2, characterized in that: The internal structure of the pyrolysis gasification furnace includes a lifting plate turning structure or a tooth-shaped turning structure.

4. The carbon-electricity cogeneration system according to any one of claims 1 to 3, characterized in that: The condensing device comprises a plate heat exchanger or a tube heat exchanger.

5. The carbon-electricity cogeneration system according to any one of claims 1 to 4, characterized in that: The condensing device is connected to the oil-water mixture output pipeline.

6. A method for realizing carbon-electricity cogeneration by coupling a pyrolysis gasifier with a boiler to utilize biomass, characterized in that: The method is carried out by using a carbon-electricity cogeneration device system of a pyrolysis gasification furnace coupled with a boiler to realize biomass utilization as described in any one of claims 1 to 5; the method comprises the following steps: (1) Biomass raw materials and pyrolysis auxiliary gas enter the reaction inner cylinder of the pyrolysis gasifier for pyrolysis reaction, and at the same time, the flue gas at the economizer inlet of the coal-fired boiler enters the heating outer cylinder of the pyrolysis gasifier through the flue gas pipeline to provide heat for the pyrolysis reaction; (2) The crude biomass gas produced by the pyrolysis reaction enters the condensation device to separate and remove tar and water vapor, and then enters the coal-fired boiler for combustion.

7. The method according to claim 6, characterized in that The temperature of the pyrolysis reaction in step (1) is 600-700°C; Preferably, the inlet flue gas of the economizer provides heat and then enters the dust removal device through the waste flue gas output pipeline for treatment and then is discharged after meeting the emission standards; Preferably, the biomass product is discharged through a biomass product output pipeline.

8. The method according to claim 6 or 7, characterized in that: When the biomass raw material is woody biomass, the feed size is less than 10 cm; the pyrolysis auxiliary gas is water vapor, and the biomass product is biochar or biomass activated carbon; Preferably, the calorific value of the biochar is 3500-7000 kCal / kg. Preferably, the iodine adsorption value of the biomass activated carbon is 500 to 1300 mg / g.

9. The method according to any one of claims 6 to 8, characterized in that: When the biomass raw material is straw biomass, the feed size is less than 3 cm; the pyrolysis auxiliary gas is air and water vapor, and the biomass products are biomass fuel gas and biomass carbon-based fertilizer; Preferably, the calorific value of the biomass gas is 2300-3500 kCal / Nm 3 .

10. The method according to any one of claims 6 to 9, characterized in that: The method comprises the following steps: (1) The biomass raw material and the pyrolysis auxiliary gas enter the reaction inner cylinder of the pyrolysis gasifier to undergo a pyrolysis reaction at a temperature of 600 to 700° C. to produce biomass products; at the same time, the flue gas at the economizer inlet of the coal-fired boiler enters the heating outer cylinder of the pyrolysis gasifier through the flue gas pipeline to provide heat for the pyrolysis reaction, and then enters the dust removal device through the waste flue gas output pipeline for treatment to meet the emission standards before being discharged; the biomass products are discharged through the biomass product output pipeline; When the biomass raw material is woody biomass, the feed size is less than 10 cm; the pyrolysis auxiliary gas is water vapor, and the biomass product is biochar with a calorific value of 3500-7000 kCal / kg or biochar activated carbon with an iodine adsorption value of 500-1300 mg / g; When the biomass raw material is straw biomass, the feed size is less than 3 cm; the pyrolysis auxiliary gas is air and water vapor, and the biomass product has a calorific value of 2300-3500 kCal / Nm 3 biomass gas and biomass carbon-based fertilizer; (2) The crude biomass gas produced by the pyrolysis reaction enters the condensation device to separate and remove tar and water vapor, and then enters the coal-fired boiler for combustion.

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