Biochar-based gasification process system

Abstract

The invention relates to a gasification process system taking charcoal as a main material, and relates to the technical field of clean energy biomass. Comprising a gasification bin, a gasification furnace, a first-stage inertia separator, a moving bed cracking furnace, a carbon production bin, a second-stage cyclone separator and a return feeder, the gasification bin is communicated with one side of the bottom of the gasification furnace through a second-stage screw feeder arranged at the bottom of the gasification bin, and the first-stage inertia separator is communicated with one side of the top of the gasification furnace; the bottom of the first-stage inertia separator is communicated with the top of the moving bed cracking furnace, and the carbon production bin is communicated with the top of the moving bed cracking furnace through a third-stage screw feeder; one side of the secondary cyclone separator is communicated with the top of the primary inertia separator, the bottom of the secondary cyclone separator is communicated with the top of the return feeder, and one side of the return feeder is communicated with one side of the gasification furnace. The invention provides a process system capable of producing high-quality charcoal and gasified gas without tar, and the gasification reaction efficiency can be greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of clean energy biomass, and specifically to a gasification process system mainly based on biochar. Background Art

[0002] Biomass gasification mainly uses biomass (wood chips, agricultural and forestry wastes, etc.) as raw materials and air as a gasifying agent. Without any external energy, additives, auxiliaries and other chemical drugs, through thermochemical reactions, the cellulose, hemicellulose and lignin macromolecules in biomass are converted into small-molecule biomass combustible gas, small-molecule biomass char and small-molecule liquid. The main combustible components of biomass combustible gas are CO, H 2 , CH 4 , and there is also a very small amount of CnHm (n>1). It can be widely used in various fields of industrial and agricultural production, such as power generation, gas supply, heating (replacing coal combustion), etc. At the same time, the obtained biomass char has a developed pore structure. For biomass char with less ash content such as fruit tree waste and fruit shells, activated carbon series products can be made, and its uses are extensive. Biomass with high ash content such as straw can be used as carbon-based fertilizers; currently, the quality of fixed-bed gasification biochar is good, but the tar problem cannot be solved, while the tar problem of circulating fluidized bed gasification can be solved, but the obtained biochar particles are small, the dust content is high, and the quality is poor.

[0003] Therefore, how to provide a gasification process system mainly based on biochar has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0004] To solve at least one technical problem in the background art, the present invention provides a gasification process system mainly based on biochar, a process system that can produce high-quality biochar and the gasified gas is tar-free, and can greatly improve the gasification reaction efficiency.

[0005] To achieve the above object, the present invention provides a gasification process system mainly based on biochar, including: a gasification silo, a gasification furnace, a primary inertial separator, a moving bed cracking furnace, a carbon production silo, a secondary cyclone separator and a return feeder; the gasification silo is connected to one side of the bottom of the gasification furnace through a secondary screw feeder provided at its bottom, and the primary inertial separator is connected to one side of the top of the gasification furnace; the bottom of the primary inertial separator is connected to the top of the moving bed cracking furnace, and the carbon production silo is connected to the top of the moving bed cracking furnace through a tertiary screw feeder provided at its bottom; one side of the secondary cyclone separator is connected to the top of the primary inertial separator, the bottom of the secondary cyclone separator is connected to the top of the return feeder, and one side of the return feeder is connected to one side of the gasification furnace.

[0006] Further, it further includes a high-temperature air preheater, a steam generator, a economizer, a bag filter, and a pressurized blower; the top of the high-temperature air preheater is connected to the top of the secondary cyclone separator, and the bottom of the high-temperature air preheater is sequentially connected to the steam generator and the economizer; the air inlet of the bag filter is connected to one side of the bottom of the economizer, and the air outlet of the bag filter is connected to the pressurized blower.

[0007] Further, it further includes a gasification blower, the gasification blower is connected to the high-temperature air preheater, and the high-temperature air preheater is also connected to the gasification furnace through a gasifying agent inlet pipe.

[0008] Further, it further includes a bottom material bin, and the bottom material bin is connected to one side of the gasification furnace through a primary screw feeder provided at its bottom.

[0009] Further, a gasifying agent inlet pipe is connected to the bottom end of the gasification furnace.

[0010] Further, the bottom end of the gasification furnace is connected to a slag cooler through a slag discharge pipe.

[0011] Further, it further includes a return air blower, and the return air blower is connected to the bottom of the return feeder for introducing return air into the return feeder.

[0012] Further, it further includes a biochar storage tank and a biochar cooling conveyor, the biochar storage tank is connected to the bottom end of the moving bed pyrolysis furnace, and the bottom end of the biochar storage tank is connected to the biochar cooling conveyor for sending the biochar to the biochar storage bin.

[0013] The beneficial effects of the present invention are as follows:

[0014] (1) By adding a moving bed pyrolysis furnace in the circulating fluidized bed, it is ensured that the added biomass fuel can produce high-quality biochar.

[0015] (2) By adding a primary inertial separator at the outlet of the gasification furnace, it is ensured that the ash separated at the primary stage has larger particles, and the small-particle ash is carried by the gasifying gas into the secondary cyclone separator.

[0016] (3) By adding a secondary cyclone separator, the separation efficiency of the circulating fluidized bed is improved, and the circulation ratio of the circulating fluidized bed is increased.

[0017] (4) By reducing the separation efficiency of the primary inertial separator, the dust content of large particles entering the moving bed pyrolysis furnace is reduced, which is the key to improving the quality of biochar.

[0018] (5) The feed for producing biochar directly enters the furnace at the top of the moving bed pyrolysis furnace, and only pyrolysis reactions occur, ensuring the production of pure biochar. Brief Description of the Drawings

[0019] Figure 1 is the overall structural view of the present invention;

[0020] Figure 2 is the graph showing the change of temperature of the gasifier and the moving bed pyrolysis furnace of the present invention over time;

[0021] Figure 3 is the graph showing the change of pressure of the gasifier and the moving bed pyrolysis furnace of the present invention over time.

[0022] In the figure: 1. bottom material bin; 2. primary screw feeder; 3. gasification material bin; 4. secondary screw feeder; 5. gasifier; 6. gasifying agent inlet pipeline; 7. slag cooler; 8. primary inertial separator; 9. carbon product bin; 10. tertiary screw feeder; 11. secondary cyclone separator; 12. return feeder; 13. return air blower; 14. high-temperature air preheater; 15. steam generator; 16. economizer; 17. bag filter; 18. pressurizing blower; 19. gasification blower; 20. moving bed pyrolysis furnace; 21. biochar storage tank; 22. biochar cooling conveyor. Detailed Embodiments

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances for the embodiments of the present invention described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] In the present invention, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation.

[0026] Moreover, in addition to being used to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0027] In addition, the terms "mounted", "arranged", "provided with", "connected", "linked", "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there is an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] To achieve the above object, as Figure 1 shown, the present invention provides a gasification process system mainly composed of biochar, including: a gasification silo 3, a gasification furnace 5, a primary inertial separator 8, a moving bed cracking furnace 20, a carbon production silo 9, a secondary cyclone separator 11 and a return feeder 12; the gasification silo 3 is connected to one side of the bottom of the gasification furnace 5 through a secondary screw feeder 4 provided at its bottom, and the primary inertial separator 8 is connected to one side of the top of the gasification furnace 5; the bottom of the primary inertial separator 8 is connected to the top of the moving bed cracking furnace 20, and the carbon production silo 9 is connected to the top of the moving bed cracking furnace 20 through a tertiary screw feeder 10 provided at its bottom; one side of the secondary cyclone separator 11 is connected to the top of the primary inertial separator 8, the bottom of the secondary cyclone separator 11 is connected to the top of the return feeder 12, and one side of the return feeder 12 is connected to one side of the gasification furnace 5. The temperature change curves of the gasification furnace and the moving bed cracking furnace in the present invention are as Figure 2 shown; the pressure change curves of the gasification furnace and the moving bed cracking furnace of the present invention are as Figure 3 shown.

[0029] The present invention further includes a high-temperature air preheater 14, a steam generator 15, a economizer 16, a bag filter 17 and a pressurizing fan 18; the top of the high-temperature air preheater 14 is connected to the top of the secondary cyclone separator 11, and the bottom of the high-temperature air preheater 14 is sequentially connected to the steam generator 15 and the economizer 16; the inlet of the bag filter 17 is connected to one side of the bottom of the economizer 16, and the outlet of the bag filter 17 is connected to the pressurizing fan 18. The bag filter 17 can capture fine ash particles, and the qualified gasified gas is sent to the gas users through the pressurization of the pressurizing fan 18.

[0030] The present invention further includes a gasification fan 19, the gasification fan 19 is connected to the high-temperature air preheater 14, and the high-temperature air preheater 14 is also connected to the gasification furnace 5 through a gasifying agent inlet pipe to send hot air into the gasification furnace 5 to participate in the gasification reaction.

[0031] The present invention further includes a bottom material bin 1, the bottom material bin 1 is connected to one side of the gasification furnace 5 through a primary screw feeder 2 provided at its bottom for sending the bottom material into the gasification furnace 5.

[0032] To further optimize the technical solution, the bottom end of the gasification furnace 5 is connected to a gasifying agent inlet pipe 6, and the gasifying agent can be introduced into the gasification furnace 5 through the gasifying agent inlet pipe 6.

[0033] To further optimize the technical solution, the bottom end of the gasification furnace 5 is connected to a slag cooler 7 through a slag discharge pipe, and the large slag particles generated in the gasification furnace 5 enter the slag cooler 7 through the slag discharge pipe and are sent out of the gasification furnace.

[0034] The present invention further includes a return air fan 13, the return air fan 13 is connected to the bottom of the return feeder 12, and is used to introduce return air into the return feeder 12, so that the ash particles separated by the secondary cyclone separator 11 can smoothly return to the gasification furnace 5.

[0035] The present invention further includes a biochar storage tank 21 and a biochar cooling conveyor 22, the biochar storage tank 21 is connected to the bottom end of the moving bed pyrolysis furnace 20, and the bottom end of the biochar storage tank 21 is connected to the biochar cooling conveyor 22 for sending the biochar to the biochar storage bin.

[0036] By adding a moving bed pyrolysis furnace in the circulating fluidized bed, the present invention ensures that the added biomass fuel can produce high-quality biochar. By adding a primary inertial separator at the outlet of the gasifier, it is ensured that the ash separated at the primary stage has larger particles, and the small-particle ash is carried by the gasified gas into the secondary cyclone separator. By adding a secondary cyclone separator, the separation efficiency of the circulating fluidized bed is improved, and the circulation ratio of the circulating fluidized bed is increased. By reducing the separation efficiency of the primary inertial separator, the dust content of large particles entering the moving bed pyrolysis furnace is reduced, which is the key to improving the quality of biochar. The feed for producing biochar directly enters the furnace at the top of the moving bed pyrolysis furnace, and only pyrolysis reactions occur, ensuring the production of pure biochar.

[0037] The working principle of the present invention is as follows:

[0038] The biomass material enters the gasification bin 3 through the feeding system, and then enters the gasifier 5 through the secondary screw feeder 4. The gasifying agent entering the gasifier 5 through the gasifying agent inlet pipe 6 reacts with the biomass to produce gasified gas. The gasified gas carries ash particles of different sizes and undergoes gas-solid rough separation by the primary inertial separator 8. The separated large-particle ash particles enter the moving bed pyrolysis furnace 20, providing high temperature for the moving bed pyrolysis furnace 20, causing the biomass material entering the moving bed pyrolysis furnace 20 from the carbon-producing bin 9 through the tertiary screw feeder 10 to undergo pyrolysis reactions, releasing volatile components to produce biochar. The biochar is stored in the biochar storage tank 21 and sent to the biochar storage bin through the biochar cooling conveyor 22. The small-particle ash particles not separated by the primary inertial separator 8 are carried by the gasified gas into the secondary cyclone separator 11. Through the efficient centrifugal action, most of the ash particles are separated and enter the gasifier 5 through the action of the return feeder 12 for re-gasification reactions. Such a cycle ensures a high circulation ratio of the entire system and improves the gasification efficiency. The gasified gas is cooled by the high-temperature air preheater 14, the steam generator 15, and the economizer 16, enters the bag filter 17 to capture fine ash particles, and the qualified gasified gas is pressurized by the booster fan 18 and sent to the gas users.

[0039] Since the ash content in the biomass is relatively low, and the circulating fluidized bed requires a large amount of circulating material to maintain the material pressure in the gasifier 5, a bottom material bin 1 is provided in front of the gasifier 5. Through the action of the primary screw feeder 2, the bottom material is sent into the gasifier 5.

[0040] The large slag particles generated in the gasifier 5 enter the slag cooler 7 through the slag discharge pipe and are sent out of the furnace.

[0041] The gasification blower 19 sends air into the high-temperature air preheater 14 to be heated by the gasified gas, and the hot air enters the gasifying agent inlet pipe and then is sent into the gasifier 5 to participate in the gasification reaction.

[0042] The return air enters the return feeder 12 through the return air blower 13 with a high head, ensuring that the ash particles separated by the secondary cyclone separator 11 can smoothly return to the gasifier 5.

[0043] The above are only preferred embodiments of the present invention, and do not impose any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and decorations made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A biochar-based gasification process system, characterized in that: include: A gasification silo (3), a gasification furnace (5), a primary inertial separator (8), a moving bed cracking furnace (20), a charcoal-producing silo (9), a secondary cyclone separator (11) and a return device (12); the gasification silo (3) is connected to one side of the bottom of the gasification furnace (5) via a secondary screw feeder (4) arranged at the bottom thereof, and the primary inertial separator (8) is connected to one side of the top of the gasification furnace (5); the bottom of the primary inertial separator (8) is connected to the top of the moving bed cracking furnace (20), and the charcoal-producing silo (9) is connected to the top of the moving bed cracking furnace (20) via a tertiary screw feeder (10) arranged at the bottom thereof; one side of the secondary cyclone separator (11) is connected to the top of the primary inertial separator (8), the bottom of the secondary cyclone separator (11) is connected to the top of the return device (12), and one side of the return device (12) is connected to one side of the gasification furnace (5).

2. A biochar-based gasification process system as claimed in claim 1, characterized in that: It also includes a high-temperature air preheater (14), a steam generator (15), an economizer (16), a bag dust collector (17) and a pressurized fan (18); the top of the high-temperature air preheater (14) is connected to the top of the secondary cyclone separator (11), and the bottom of the high-temperature air preheater (14) is connected to the steam generator (15) and the economizer (16) in sequence; the air inlet of the bag dust collector (17) is connected to one side of the bottom of the economizer (16), and the air outlet of the bag dust collector (17) is connected to the pressurized fan (18).

3. A biochar-based gasification process system as claimed in claim 2, characterized in that: It also includes a gasification fan (19), which is connected to the high-temperature air preheater (14), and the high-temperature air preheater (14) is also connected to the gasification furnace (5) through a gasification agent inlet pipeline.

4. A biochar-based gasification process system as claimed in claim 1 or 3, characterized in that: It also comprises a bottom material bin (1), wherein the bottom material bin (1) is connected to one side of the gasification furnace (5) via a primary screw feeder (2) arranged at the bottom thereof.

5. The biochar-based gasification process system according to claim 1, characterized in that: The bottom end of the gasification furnace (5) is connected to a gasification agent inlet pipeline (6).

6. A biochar-based gasification process system as claimed in claim 5, characterized in that: The bottom end of the gasification furnace (5) is connected to a slag cooler (7) via a slag discharge pipe.

7. The biochar-based gasification process system according to claim 1, characterized in that: It also comprises a return material fan (13), which is connected to the bottom of the return material device (12) and is used to pass the return material air into the return material device (12).

8. The biochar-based gasification process system according to claim 1, characterized in that: It also includes a biochar storage tank (21) and a biochar cooling conveyor (22), wherein the biochar storage tank (21) is connected to the bottom end of the moving bed pyrolysis furnace (20), and the bottom end of the biochar storage tank (21) is connected to the biochar cooling conveyor (22) for conveying the biochar to the biochar storage bin.

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