CN114736701B - A biomass pyrolysis furnace, a biomass pyrolysis system and a pyrolysis process - Google Patents

Abstract

The present invention relates to the technical field of biomass pyrolysis equipment, specifically a biomass pyrolysis furnace and a biomass pyrolysis system and a pyrolysis process, wherein the biomass pyrolysis furnace comprises an outer shell and a heating body, the heating body is sleeved and connected in the outer shell, and a combustion chamber is reserved between the two, the combustion chamber is divided into a pyrolysis chamber and a catalytic cracking chamber from top to bottom by a partition, and a hot air blower is also connected to the catalytic cracking chamber: a plurality of openings are provided on the heating body, and a plurality of flame stabilizing bodies are embedded in the openings; a full premixing blower is provided on the outer shell; a reaction chamber is provided in the heating body, and the reaction chamber is composed of a spirally arranged combustion tube; a silo is provided at the top of the combustion tube, and a hot nitrogen air duct is connected to the silo; a receiving bin is provided at the bottom of the combustion tube. The present invention provides a biomass pyrolysis furnace and a biomass pyrolysis system used in conjunction with the biomass pyrolysis furnace, which is intended to prepare biomass carbon by biomass and tar, and to achieve catalytic decomposition of tar.

Description

A biomass pyrolysis furnace, a biomass pyrolysis system and a pyrolysis process

Technical Field

The invention relates to the technical field of biomass pyrolysis equipment, in particular to a biomass pyrolysis furnace and a biomass pyrolysis system and a pyrolysis process.

Background technique

The excessive exploitation and utilization of non-renewable fossil energy such as coal and oil have made the energy and environmental problems on the earth more and more serious. The search for efficient and clean energy has become a hot topic of world concern. Biomass resources are the fourth largest resource on the earth, and its reserves are second only to coal, oil and natural gas. It is also the clean renewable energy with the largest reserves and is one of the most suitable alternative energy sources to fossil energy. Biomass energy has the characteristics of abundant resources, low cost, renewable and clean. Therefore, the development and application of biomass has become a hot topic of widespread concern.

Biomass pyrolysis is the process of converting biomass into combustible gases and natural resources through pyrolysis. Biomass pyrolysis is the process of heating biomass raw materials under anaerobic or oxygen-limited conditions to achieve pyrolysis reaction and obtain biochar, bio-oil and gas. At present, the design of biomass pyrolysis process and thermal cleaning furnace has received extensive attention, but the current biomass pyrolysis process still has many problems to be solved. One of the problems is the conversion and removal of tar. Tar is mainly produced when the molecular bonds of cellulose, lignin, hemicellulose and other components of biomass are broken. During the breaking process, small gaseous molecules such as _CO , CO2, _H2O , _CH4 , and large molecules such as coke, pyroacetic acid, and tar are produced. The composition of tar is complex, containing hundreds of compounds of different types and properties. The main component is polynuclear aromatic components. Tar contains high concentrations of PAH substances. PAH substances are highly toxic. After the tar condensed into fine droplets is incompletely burned, PAH substances and coke will be produced. PAH substances are carcinogenic. If the tar is purified, the tar wastewater produced contains phenol and phenolic compounds, benzene series, heterocyclic rings, aromatic compounds and other organic matter. Its COD concentration is high and it also emits a strong irritating odor, which pollutes the environment and endangers human health.

Summary of the invention

In view of the deficiencies in the prior art, the purpose of the present invention is to provide a biomass pyrolysis furnace, a biomass pyrolysis system and a pyrolysis process. The present invention provides a biomass pyrolysis furnace, and a biomass pyrolysis system used in conjunction with the biomass pyrolysis furnace, aiming to prepare biomass carbon from biomass and tar, and to achieve catalytic decomposition of tar.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

A biomass pyrolysis furnace, characterized in that it comprises an outer shell and a heating body, the heating body is sleeved and connected in the outer shell, and a combustion chamber is reserved between the two, the combustion chamber is divided into a pyrolysis chamber and a catalytic cracking chamber from top to bottom by a partition, and a hot air blower is also connected to the catalytic cracking chamber:

The heating body is provided with a plurality of openings, and the openings are provided with a plurality of flame stabilizing bodies;

The outer shell is provided with a full premixing fan, and the full premixing fan is respectively connected with the pyrolysis chamber and the catalytic cracking chamber through a connecting pipe;

A reaction chamber is arranged in the heating body, and the reaction chamber is composed of a spirally arranged combustion tube; a material bin is arranged through the top of the combustion tube, and a hot nitrogen air duct is connected to the material bin; a receiving bin is arranged through the bottom of the combustion tube;

The combustion tube is also connected with an air supply tube.

Preferably, the silo is also connected to a buffer silo for storing granular biomass via a material elevator.

Preferably, a discharge pipe is provided between the combustion pipe and the receiving bin, and a pyrolysis gas discharge pipe is connected through the discharge pipe. An opening and closing assembly is also provided on the discharge pipe, and the opening and closing assembly includes a servo and a rotary plate. The output shaft of the servo transversely passes through the side wall of the discharge pipe and is fixedly connected to the rotary plate at the end. The rotary plate rotates to a horizontal direction to block the interior of the discharge pipe.

Preferably, valves are respectively provided on the hot nitrogen duct, the air supply pipe and the connecting pipe.

The present invention also provides a biomass pyrolysis system based on a biomass pyrolysis furnace, comprising:

Drying and crushing equipment, used for drying and crushing biomass;

A mixing and granulating device, used for mixing and granulating tar and biomass, wherein the mixing and granulating device is connected to the buffer bin;

Biomass pyrolysis furnace, used for preparing biomass charcoal;

A sedimentation tank, used to collect a mixture of tar vapor, pyrolysis gas and dust generated by pyrolysis, wherein the sedimentation tank is in continuous connection with the pyrolysis gas exhaust pipe;

Cyclone separators, used for centrifugal separation of gas and dust;

The primary detarring tower is used to separate the tar vapor from the pyrolysis gas;

A secondary detarring tower, used for secondary separation of tar vapor, wherein the primary detarring tower and the secondary detarring tower are respectively connected to the mixing granulation equipment;

A gas-acid separation tower is used to separate wood vinegar from the pyrolysis gas;

A purification device, used for purifying the pyrolysis gas and obtaining combustible gas;

The drying and crushing equipment, the mixing and granulating equipment, the biomass pyrolysis furnace, the sedimentation tank, the cyclone separator, the primary detarring tower, the secondary detarring tower, the gas-acid separation tower, and the purification device are sequentially connected;

The primary detarring tower and the secondary detarring tower are connected to the mixing granulation equipment.

Preferably, the biomass pyrolysis furnace and the drying and crushing equipment are also connected to the purification device respectively, and the purification device is connected to the full premix blower and the air supply pipe respectively.

The present invention also protects a process for pyrolyzing biomass using a biomass pyrolysis system, comprising the following steps:

Step 1, using the drying and pulverizing equipment to dry and pulverize the biomass, the pulverized length is 2-4 cm, and the biomass is dried to a moisture content of less than 10%;

Step 2: using the mixing and granulating equipment to mix and granulate the tar and biomass to obtain a material to be processed, wherein the mass ratio of the tar to the biomass is 1:7-10;

Step 3, using the biomass pyrolysis furnace to pyrolyze biomass to prepare biochar, wherein the biochar is prepared under the conditions of pyrolysis at 250-400° C. for 1-1.5 h;

Step 4: using the sedimentation tank to collect the mixture of tar vapor, pyrolysis gas and dust;

Step 5, using the cyclone separator for centrifugal separation to obtain gas and dust;

Step 6, using the primary detarring tower to separate tar vapor;

Step 7, using the secondary detarring tower to separate the tar vapor again;

Step 8, using the gas-acid separation tower to separate the pyrolysis gas from the wood acetic acid;

Step 9: purify, collect and process the pyrolysis gas using the purification device to obtain combustible gas.

Preferably, the specific method of biomass pyrolysis is:

After the biomass is processed by the drying and crushing equipment, tar and biomass are blended in the mixing and granulating equipment to obtain a material to be processed. The material to be processed is stored in the buffer bin and enters the silo under the action of the material elevator. The material to be processed enters the combustion tube driven by the exhaust gas of the hot nitrogen air duct, and biomass carbon is prepared in the combustion tube. The prepared biomass carbon is collected in the receiving bin; the mixture of tar vapor, pyrolysis gas and dust generated by combustion is first discharged into the sedimentation tank through the pyrolysis gas exhaust pipe, and then discharged into the cyclone separation machine for dust removal operation, and then the mixed gas is discharged into the primary detarring tower to perform a primary separation operation of tar vapor, and the remaining pyrolysis gas is discharged into the secondary detarring tower to perform a secondary separation operation of tar vapor, and the remaining pyrolysis gas after separation is discharged into the gas-acid separation tower to separate wood acetic acid from pyrolysis gas, and the pyrolysis gas after final separation is treated in a purification device to obtain combustible gas;

The tar separated by the primary detarring tower and the secondary detarring tower is then discharged into the mixing granulation equipment to realize the utilization of the tar;

The purification device is connected to the drying and crushing equipment, and the combustible gas provides a thermal environment for the drying and crushing equipment;

The purification device is connected to the biomass pyrolysis furnace, and the purification device is connected to the full premixing fan on the biomass pyrolysis furnace to achieve mixing of air and combustible gas and provide combustible gas to the flame stabilizing body;

The purification device is also connected to the gas supply pipe on the biomass pyrolysis furnace to achieve catalytic cracking of tar in the combustion pipe.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention provides a biomass pyrolysis furnace, which is divided into a pyrolysis chamber and a catalytic cracking chamber by a partition. The pyrolysis chamber and the catalytic cracking chamber can be used together for the pyrolysis reaction of biomass, and realize the high-temperature carbonization of the material to be treated, and the obtained biomass carbon is collected through a receiving bin; when the catalytic cracking chamber can be used alone after the pyrolysis is completed, the high temperature provided by the catalytic cracking chamber is used to realize the final catalytic cracking of the tar in the combustion tube, at which time the tar and the catalyst are mixed in the mixing granulation device, and then discharged into the combustion tube, and the catalyst and the tar are made to slide down at the catalytic cracking chamber, at which time a mixed gas containing water is discharged into the combustion tube through the mixed gas pipe, and the mixed gas includes pyrolysis gas and air, and the tar is cracked at 750-900°C at a high temperature;

By using the biomass pyrolysis furnace of the present application, not only the preparation of biomass carbon is achieved, but also the catalytic cracking of tar is achieved, so the amount of tar produced by biomass combustion is effectively reduced.

2. In the present invention, a hot nitrogen duct and an air supply pipe are respectively connected to the combustion tube. The air supply pipe can flow nitrogen or pyrolysis gas. When nitrogen is circulated in the air supply pipe, nitrogen is introduced into the top and bottom ends of the combustion tube respectively. The position of the material in the combustion tube is regulated by adjusting the air supply volume of the two nitrogen gases, and the material to be treated is placed in a suspended state, which is convenient for achieving a better carbonization operation. When pyrolysis gas is circulated in the air supply pipe, combustible gas is provided into the combustion tube, which is convenient for high-temperature catalytic cracking of tar.

3. The biomass carbon preparation method of the present invention is: after mixing, crushing and granulating the biomass and tar, the pyrolysis operation is carried out in a biomass pyrolysis furnace to realize the preparation of biomass carbon in an oxygen-free environment or a low-oxygen environment; the tar cracking operation of the present invention is: mixing the tar and the catalyst, carrying out a catalytic cracking operation in a biomass pyrolysis furnace, and realizing the catalytic cracking of the tar under the conditions of pyrolysis gas, oxygen and water.

4. The present invention also designs a biomass pyrolysis system for use with a biomass pyrolysis furnace. The biomass pyrolysis system is used to separate pyrolysis gas, wood acetic acid, tar, and biochar, and to recycle tar and pyrolysis gas. Excess pyrolysis gas can be purified and reused as fuel gas for secondary use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a system diagram of a biomass pyrolysis furnace for pyrolysis of biomass according to the present invention;

FIG. 2 is a schematic diagram of the internal structure of a biomass pyrolysis furnace of the present invention.

Description of reference numerals:

1. Outer shell; 2. Heating body; 3. Purification device; 4. Partition; 5. Pyrolysis chamber; 6. Catalytic cracking chamber; 7. Hot air blower; 8. Flame stabilizing body; 9. Full premixing fan; 10. Connecting pipe; 11. Combustion pipe; 12. Silo; 13. Hot nitrogen air duct; 14. Receiving bin; 15. Air supply pipe; 16. Primary detarring tower; 17. Secondary detarring tower; 18. Gas-acid separation tower; 19. Valve; 20. Material elevator; 21. Buffer bin; 22. Discharge pipe; 23. Gas discharge pipe; 24. Steering gear; 25. Rotary plate; 26. Drying and crushing equipment; 27. Mixing and granulating equipment; 28. Sedimentation tank; 29. Cyclone separator.

Detailed ways

The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention. The experimental methods in the embodiments of the present invention are conventional methods unless otherwise specified.

The equipment for pyrolyzing biomass using a biomass pyrolysis furnace, as shown in Figure 1-2, includes:

Drying and crushing equipment 26, used for drying and crushing biomass;

A mixing and granulating device 27, used for mixing and granulating tar and biomass, wherein the mixing and granulating device 27 is connected to the buffer bin 21;

A biomass pyrolysis furnace, used for pyrolysis of biomass to prepare biochar, wherein the biochar is prepared under the conditions of pyrolysis at 250-400°C for 1-1.5h;

A sedimentation tank 28 is used to collect a mixture of tar vapor, pyrolysis gas and dust generated by pyrolysis, and the sedimentation tank 28 is connected to the pyrolysis gas exhaust pipe 23;

A cyclone separator 29, for centrifugally separating gas and dust;

The primary detarring tower 16 is used to separate the tar vapor from the pyrolysis gas;

The secondary detarring tower 17 is used for secondary separation of tar vapor, and the primary detarring tower 16 and the secondary detarring tower 17 are respectively connected to the mixing granulation equipment 27;

A gas-acid separation tower 18 is used to separate wood vinegar from the pyrolysis gas;

Purification device 3, used for purifying the pyrolysis gas and obtaining combustible gas;

The drying and crushing equipment 26, the mixing and granulating equipment 27, the biomass pyrolysis furnace, the sedimentation tank 28, the cyclone separator 29, the primary detarring tower 16, the secondary detarring tower 17, the gas-acid separation tower 18, and the purification device 3 are sequentially connected;

The primary detarring tower 16 and the secondary detarring tower 17 are connected to the mixing granulation equipment 27;

The biomass pyrolysis furnace and the drying and crushing equipment 26 are also connected to the purification device 3 respectively, and the purification device 3 is connected to the full premixing fan 9 and the air supply pipe 15 respectively.

The structure of the biomass pyrolysis furnace is shown in FIG2 , and includes an outer shell 1 and a heating body 2. The heating body 2 is sleeved and connected in the outer shell 1, and a combustion chamber is reserved between the two. The combustion chamber is used for the circulation of combustible gas, so that the flames on all flame stabilizing bodies 8 can burn continuously. The combustion chamber is divided from top to bottom into a pyrolysis chamber 5 and a catalytic cracking chamber 6 by a partition 4. The pyrolysis reaction of biomass is jointly realized in the pyrolysis chamber 5 and the catalytic cracking chamber 6, and the high-temperature carbonization of the material to be treated is realized to obtain biomass carbon. When the catalytic cracking chamber is used alone, the high temperature provided by the catalytic cracking chamber is used to realize the final catalytic cracking of tar in the combustion tube. The catalytic cracking chamber 6 is also connected with a hot air blower 7, which is convenient for providing hot air into the hot air blower 7 to increase the combustion temperature of the flame stabilizing body 8 in the catalytic cracking chamber 6:

The heating body 2 is provided with a plurality of openings, and a plurality of flame stabilizing bodies 8 are embedded in the openings;

The outer shell 1 is provided with a full premixing fan 9, which realizes the mixing of air and combustible gas, discharges the mixture into the combustion chamber, and provides combustion gas to the flame on the flame stabilizing body 8. The full premixing fan 9 is respectively connected with the pyrolysis chamber 5 and the catalytic cracking chamber 6 through a connecting pipe 10. The connecting pipe 10 is provided with a valve, which controls the flow direction of the gas, and then regulates and controls according to the requirements of the pyrolysis reaction and the catalytic cracking reaction.

A reaction chamber is arranged in the heating body 2, and the reaction chamber is composed of a spirally arranged combustion tube 11; a silo 12 is arranged through the top of the combustion tube 11, and a hot nitrogen air duct 13 is connected to the silo 12; a receiving bin is arranged through the bottom of the combustion tube 11; the hot nitrogen air duct 13 discharges hot nitrogen, and the air in the combustion tube 11 is discharged through the hot nitrogen, and the pyrolysis of the object to be treated to produce biomass carbon is performed in the combustion tube 11;

The combustion tube 11 is also connected with an air supply tube 15, and the air supply tube 15 can be fed with pyrolysis gas or nitrogen. When connected with pyrolysis gas, it is convenient to realize catalytic cracking of tar; when connected with nitrogen, it is convenient to control the position of the object to be treated in the combustion tube 11.

The embodiments of the present invention all rely on a device for pyrolyzing biomass using a biomass pyrolysis furnace, which is specifically as follows:

Example 1

The process of using the equipment to perform biomass pyrolysis is specifically as follows:

After the biomass is processed by the drying and crushing equipment 26, the tar and the biomass are mixed in the mixing and granulating equipment 27 to obtain the material to be processed, which is stored in the buffer bin 21 and enters the silo 12 under the action of the material elevator 20. The material to be processed enters the combustion tube 11 driven by the exhaust gas of the hot nitrogen air duct 13, and the biomass carbon is prepared in the combustion tube 11. The prepared biomass carbon is collected in the receiving bin; the tar vapor, pyrolysis gas and dust generated by the combustion are collected. The mixture is first discharged into the sedimentation tank 28 through the pyrolysis gas discharge pipe 23, and then discharged into the cyclone separation machine 29 for dust removal operation, and then the mixed gas is discharged into the primary detarring tower 16 to perform a primary separation operation of tar vapor, and the remaining pyrolysis gas is discharged into the secondary detarring tower 17 to perform a secondary separation operation of tar vapor, and the remaining pyrolysis gas after separation is discharged into the gas-acid separation tower 18 to achieve separation of wood acetic acid and pyrolysis gas, and finally the separated pyrolysis gas is treated in a purification device to obtain combustible gas;

The tar separated by the primary detarring tower 16 and the secondary detarring tower 17 is then discharged into the mixing granulation device 27 to realize the utilization of the tar;

The purification device 3 is connected to the drying and crushing equipment 26, and the combustible gas provides a thermal environment for the drying and crushing equipment 26;

The purification device 3 is connected to the biomass pyrolysis furnace, and the purification device 3 is connected to the full premixing fan 9 on the biomass pyrolysis furnace to achieve mixing of air and combustible gas and provide combustible gas to the flame stabilizing body 8;

Nitrogen is introduced into the gas supply pipe 15 , and the position of the object to be processed in the combustion tube 11 is regulated by adjusting the flow rate of the nitrogen gas up and down.

Example 2

The process of using the equipment to carry out catalytic cracking of tar is specifically as follows:

The tar and the catalyst are mixed in the mixing and granulating device 27 to obtain the material to be processed I, which is stored in the buffer bin 21 and enters the material bin 12 under the action of the material elevator 20. The material to be processed I enters the combustion tube 11, and the hot air blower 7 is operated to control the temperature of the combustion tube 11, and the catalytic cracking of the tar is carried out at 750-900°C, and the catalyst is collected in the receiving bin; the mixture of pyrolysis gas and dust generated by the combustion is passed through the hot air blower 7 to the combustion tube 11. The degassing pipe 23 is first discharged into the sedimentation tank 28, and then discharged into the cyclone separation machine 29 for dust removal operation, and then the mixed gas is discharged into the primary detarring tower 16 to perform a primary separation operation of tar vapor, and the remaining pyrolysis gas is discharged into the secondary detarring tower 17 to perform a secondary separation operation of tar vapor, and the remaining pyrolysis gas after separation is discharged into the gas-acid separation tower 18 to achieve the separation of wood acetic acid and pyrolysis gas, and finally the separated pyrolysis gas is treated in a purification device to obtain combustible gas;

The tar separated by the primary detarring tower 16 and the secondary detarring tower 17 is then discharged into the mixing granulation device 27 to realize the utilization of the tar;

The purification device 3 is connected to the biomass pyrolysis furnace, and the purification device 3 is connected to the full premixing fan 9 on the biomass pyrolysis furnace to achieve mixing of air and combustible gas and provide combustible gas to the flame stabilizing body 8;

The purification device 3 is also connected to the gas supply pipe 15 on the biomass pyrolysis furnace to achieve catalytic cracking of tar in the combustion pipe 11. At this time, a mixture of pyrolysis gas, air and water is introduced into the gas supply pipe 15 to facilitate the cracking of tar.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (1)

1. A biomass pyrolysis system, comprising:

A drying and pulverizing device (26) for drying and pulverizing biomass;

The mixing granulation equipment (27) is used for mixing and granulating the tar and the biomass, and the mixing granulation equipment (27) is communicated with the buffer bin (21);

The biomass pyrolysis furnace is used for preparing biomass charcoal;

A sedimentation tank (28) for collecting a mixture of tar vapor, pyrolysis gas and dust produced by pyrolysis, the sedimentation tank (28) being in through connection with the pyrolysis gas discharge pipe (23);

A cyclone separator (29) for centrifugally separating gas and dust;

a primary tar removal tower (16) for separating tar vapor from pyrolysis gas once;

The secondary tar removal tower (17) is used for carrying out secondary separation on tar steam, and the primary tar removal tower (16) and the secondary tar removal tower (17) are respectively connected with the mixing granulation equipment (27) in a penetrating way;

a gas-acid separation tower (18) for separating pyroligneous liquor in the pyrolysis gas;

the purifying device (3) is used for purifying the pyrolysis gas and obtaining combustible gas;

The drying and crushing equipment (26), the mixing and granulating equipment (27), the biomass pyrolysis furnace, the sedimentation tank (28), the cyclone separator (29), the primary tar removal tower (16), the secondary tar removal tower (17), the gas-acid separation tower (18) and the purification device (3) are sequentially connected in a penetrating manner;

The biomass pyrolysis furnace comprises an outer shell (1) and a heat supply body (2), wherein the heat supply body (2) is sleeved and connected in the outer shell (1), a combustion cavity is reserved between the heat supply body and the outer shell, the combustion cavity is divided into a pyrolysis chamber (5) and a catalytic pyrolysis chamber (6) from top to bottom by a partition plate (4), and a hot air blower (7) is further connected to the catalytic pyrolysis chamber (6) in a penetrating manner;

a plurality of openings are formed in the heat supply body (2), and a plurality of flame stabilizing bodies (8) are embedded in the openings;

the full-premix fan (9) is arranged on the outer shell (1), and the full-premix fan (9) is respectively in through connection with the pyrolysis chamber (5) and the catalytic pyrolysis chamber (6) through a communicating pipe (10);

A reaction chamber is arranged in the heat supply body (2), and the reaction chamber consists of a spirally arranged combustion tube (11); a bin (12) is arranged at the top end of the combustion tube (11) in a penetrating way, and a hot nitrogen air pipe (13) is connected to the bin (12) in a penetrating way; the bottom of the combustion tube (11) is provided with a receiving bin (14) in a penetrating way;

An air supply pipe (15) is also connected to the combustion pipe (11) in a penetrating way;

the bin (12) is also connected with a buffer bin (21) for storing granular biomass through a material lifting machine (20);

A discharge pipe (22) is arranged between the combustion pipe (11) and the receiving bin (14), a pyrolysis gas discharge pipe (23) is connected to the discharge pipe (22) in a penetrating way, an opening and closing assembly is further arranged on the discharge pipe (22), the opening and closing assembly comprises a steering engine (24) and a rotating plate (25), an output shaft of the steering engine (24) transversely penetrates through the side wall of the discharge pipe (22) and is fixedly connected with the rotating plate (25) at the end part, and the rotating plate (25) rotates to the horizontal direction to block the inside of the discharge pipe (22);

valves (19) are respectively arranged on the hot nitrogen air pipe (13), the air supply pipe (15) and the communicating pipe (10), the drying and crushing equipment (26) is in through connection with the purification device (3), and the purification device (3) is in through connection with the full premix fan (9);

the biomass pyrolysis process by using the biomass pyrolysis system comprises the following steps:

Step 1, drying and crushing biomass by using the drying and crushing equipment (26), wherein the crushing length is 2-4cm, and drying until the water content of the biomass is below 10%;

Step 2, mixing and granulating the tar and the biomass by using the mixing and granulating equipment (27) to obtain a to-be-treated substance, wherein the mass ratio of the tar to the biomass is 1:7-10;

step 3, pyrolyzing the to-be-treated matters by using the biomass pyrolysis furnace to prepare biomass charcoal, wherein the preparation condition of the biomass charcoal is pyrolysis for 1-1.5h at 250-400 ℃;

Step 4, collecting a mixture of tar steam, pyrolysis gas and dust by using the sedimentation tank (28);

step 5, centrifugally separating by utilizing the cyclone separator (29) to obtain gas and dust;

Step 6, utilizing the primary tar removal tower (16) to separate tar steam;

Step 7, utilizing the secondary tar removal tower (17) to separate tar steam again;

Step 8, separating the pyroligneous acid in the pyrolysis gas by using the gas-acid separation tower (18);

step 9, purifying and collecting pyrolysis gas by using the purifying device (3) to obtain combustible gas

The specific method for biomass pyrolysis comprises the following steps:

After biomass is processed by adopting the drying and crushing equipment (26), blending and granulating of tar and biomass are realized in the mixing and granulating equipment (27), a to-be-processed object is obtained, the to-be-processed object is stored in the buffer bin (21) and enters the bin (12) under the action of the material lifting machine (20), the to-be-processed object enters the combustion pipe (11) under the driving of the exhaust gas of the hot nitrogen air pipe (13), the preparation of biomass charcoal is carried out in the combustion pipe (11), and the prepared biomass charcoal is collected in the receiving bin (14); the mixture of tar steam, pyrolysis gas and dust generated by combustion is discharged into the sedimentation tank (28) through the pyrolysis gas discharge pipe (23) firstly, then is discharged into the cyclone separator (29) for dust removal operation, then the mixed gas is discharged into the primary tar removal tower (16) for primary separation operation of the tar steam, the residual pyrolysis gas is discharged into the secondary tar removal tower (17) for secondary separation operation of the tar steam, the residual pyrolysis gas after separation is discharged into the gas-acid separation tower (18), the separation of wood acetic acid and pyrolysis gas is realized, and finally the pyrolysis gas after separation is treated in the purification device to obtain combustible gas;

the tar separated by the primary tar removal tower (16) and the secondary tar removal tower (17) is discharged into the mixing granulation equipment (27) again, so that the utilization of the tar is realized;

-the combustible gas of the purification device (3) provides a thermal environment to the drying and pulverizing apparatus (26);

The purification device (3) provides combustible gas for the full premix fan (9) to realize the mixing of air and the combustible gas and provides the combustible gas for the flame stabilizing body (8);

nitrogen is introduced into the air supply pipe (15), and the position of the object to be treated in the combustion pipe (11) is regulated and controlled by the flow of the nitrogen.