阅读说明：本技术 一种农作物秸秆生产生物煤的设备及其制备工艺 (Equipment for producing biological coal by crop straws and preparation process thereof ) 是由 范嘉旖旎 张建超 王馨玉 张云飞 于 2020-07-06 设计创作，主要内容包括：本发明公开了一种农作物秸秆生产生物煤的设备及其制备工艺,涉及生物煤技术领域,包括三楼平台、低温炭化炉、二楼平台和一楼平台,所述低温炭化炉的顶部通过进料管固定连接有密闭式螺旋进料筒,所述低温炭化炉的顶部一侧固定连接有气流管,所述低温炭化炉的底部固定连接有螺旋冷却出料筒。本发明通过设置气流管,使热流中的有机酸冷却留在木酸液收集桶的内部,使冷却过的还原性气体进入燃烧室与天然气混合燃烧,达到对废气进行热量回收的目的,通过设置密闭式螺旋进料筒和螺旋冷却出料筒,能够在对低温炭化炉内部进行进料的时候利用螺旋冷却出料筒出料,并将炭化好的生物煤进行冷却,达到连续进料和连续出料的目的。(The invention discloses equipment for producing biological coal by crop straws and a preparation process thereof, and relates to the technical field of biological coal. According to the invention, the airflow pipe is arranged, so that the organic acid in the heat flow is cooled and remained in the wood acid liquid collecting barrel, the cooled reducing gas enters the combustion chamber to be mixed and combusted with natural gas, and the purpose of heat recovery of waste gas is achieved.)

1. The utility model provides an equipment of biological coal of crop straw production, includes third floor platform (4), low temperature retort (5), second floor platform (6) and first floor platform (8), its characterized in that: the top of the low-temperature carbonization furnace (5) is fixedly connected with a closed spiral feeding cylinder (2) through a feeding pipe, one side of the top of the closed spiral feeding cylinder (2) is fixedly connected with an underground hopper (1), the closed spiral feeding cylinder (2) is fixedly connected with a three-floor platform (4) through a connecting frame, one side of the top of the low-temperature carbonization furnace (5) is fixedly connected with an overflow pipe (21), the middle part of the overflow pipe (21) is fixedly connected with a safety valve (23), one end of the overflow pipe (21) is fixedly connected with a waste gas treatment box (3), the other side of the top of the low-temperature carbonization furnace (5) is fixedly connected with an airflow pipe (19), one end of the airflow pipe (19) is fixedly connected with a cooling box (18), the bottom of the cooling box (18) is fixedly connected with a wood acid liquid collecting barrel (17), one side of the top of the wood acid liquid collecting barrel, the utility model discloses a low temperature carbonization furnace, including the bottom fixedly connected with spiral cooling play feed cylinder (10) of low temperature carbonization furnace (5), the side lower part fixedly connected with cold water pipe (22) of spiral cooling play feed cylinder (10), the side top fixedly connected with cold water recovery pipe (7) of spiral cooling play feed cylinder (10), cold water pipe (22) and cold water recovery pipe (7) all communicate with outside cold water tank, heat supply pipe (11) fixedly connected with air heater (15) are passed through to bottom one side of low temperature carbonization furnace (5), air heater (15) are through connecting pipe fixedly connected with combustion chamber (12).

2. The apparatus for producing bio-coal from crop straw according to claim 1, wherein: the bottom of low temperature retort (5) is through mount and first floor platform (8) fixed connection, the middle part and the upper portion of low temperature retort (5) and second floor platform (6) and third floor platform (4) welding, the inner diapire of low temperature retort (5) is provided with vibrations grid, vibrations grid is driven by vibrating motor.

3. The apparatus for producing bio-coal from crop straw according to claim 1, wherein: the bottom of the wood acid liquid collecting barrel (17) is fixedly connected with a discharging pipe on one side, the middle of the discharging pipe is fixedly connected with a discharging valve, the bottom of the wood acid liquid collecting barrel (17) is fixedly connected with a second floor platform (6) through a supporting seat, the airflow pipe (19) penetrates through the third floor platform (4), and the tail gas pipe (16) penetrates through the second floor platform (6).

4. The apparatus for producing bio-coal from crop straw according to claim 1, wherein: the inside of exhaust-gas treatment case (3) is close to one side fixedly connected with filter screen (25) of overflow pipe (21), another side lower part fixedly connected with delivery pipe (24) of exhaust-gas treatment case (3), one side fixedly connected with active carbon adsorption layer (26) that the inside of exhaust-gas treatment case (3) is close to delivery pipe (24).

5. The apparatus for producing bio-coal from crop straw according to claim 1, wherein: a side fixedly connected with condensing engine (27) of cooler bin (18), the inside of cooler bin (18) is equipped with condenser pipe (28), the both ends of condenser pipe (28) all run through the lateral wall of cooler bin (18) and are connected with condensing engine (27), condenser pipe (28) are the distribution of multilayer S-shaped in the inside of cooler bin (18).

6. The apparatus for producing bio-coal from crop straw according to claim 1, wherein: spiral cooling goes out feed cylinder (10) and has a plurality of, a plurality of spiral cooling goes out feed cylinder (10) end-to-end connection, the bottom fixedly connected with backup pad (9) of spiral cooling play feed cylinder (10), the bottom and first floor platform (8) fixed connection of backup pad (9).

7. The apparatus for producing bio-coal from crop straw according to claim 1, wherein: the side of combustion chamber (12) fixedly connected with natural gas pipe and combustion improver pipe, the top fixedly connected with intake pipe of combustion chamber (12), the side lower part of combustion chamber (12) is through connecting pipe fixedly connected with tail gas fan (14), the top and the tail gas pipe (16) fixed connection of tail gas fan (14), the bottom and the first floor platform (8) fixed connection of tail gas fan (14).

8. The apparatus for producing bio-coal from crop straw according to claim 1, wherein: the spiral cooling discharging cylinder is characterized in that a reduction gearbox (20) is fixedly connected to one end of the spiral cooling discharging cylinder (10) and one end of the closed spiral feeding cylinder (2), a power motor is fixedly connected to one side face of the reduction gearbox (20), an input shaft of the reduction gearbox (20) is in transmission connection with an output shaft of the power motor, auger shafts are movably connected to the inner portions of the spiral cooling discharging cylinder (10) and the closed spiral feeding cylinder (2), and an output shaft of the reduction gearbox (20) is in transmission connection with the auger shafts.

9. A preparation process of biological coal produced by crop straws, which is the equipment for producing the biological coal by the crop straws according to any one of claims 1 to 8, and is characterized in that the preparation process comprises the following steps: the method comprises the steps of putting crushed crop straws into an underground hopper (1), enabling the crushed particle size of the crop straws to be less than or equal to 3cm and the water content to be less than or equal to 16%, conveying the raw materials into a low-temperature carbonization furnace (5) through a closed spiral feeding cylinder (2), enabling the raw materials to carry out pyrolysis reaction in the low-temperature carbonization furnace (5), enabling two streams of fluid to move in opposite directions on a vertical plane and form a continuous reaction area in the low-temperature carbonization furnace (5), enabling one stream to rise from the bottom to the top of the low-temperature carbonization furnace (5) through hot gas of an external heating source, enabling the other stream to fall from the top to the bottom of a pipeline through solid streams (straw particles), enabling the biomass particles (straw particles) to firstly pass through a 60-100 ℃ area with the length of 12m and consume 1.5h in the area in the process of falling from the top to the bottom of the low-temperature carbonization furnace (5), the straw pellets will first lose moisture and be dried. Then, the straw particles continuously descend to reach the area with the length of 8m and the temperature of 100-200 ℃, the time consumed in the area is 1 hour, and the straw particles begin to crack at low temperature to obtain CO and CH₄、CO₂、H₂、H₂O, and the like. The pyrolysis gas is good reducing gas, is carried to the upper part by hot gas flow to dry the subsequent raw material and finally entersAn airflow pipe (19). And then, continuously descending the straw particles to a region with the length of 4m and the temperature of 200-240 ℃, and consuming 0.5h in the region, wherein the straw particles are carbonized and further dried in the region, and at the moment, polymers of the semi-fibrous body are damaged. This phenomenon then continues to complete carbonization, and finally the straw particles reach the grid to form biomass particles. And the reducing gas pyrolyzed from the airflow pipe (19) is cooled and finally mixed with natural gas for combustion, wherein 95 percent of the reducing gas enters the ultralow-temperature carbonization furnace for heat source supplement, and 5 percent of the reducing gas is exhausted to the atmosphere after being adsorbed by activated carbon.

Technical Field

The invention relates to the technical field of biological coal, in particular to equipment for producing biological coal by crop straws and a preparation process thereof.

Background

The region of China is vast, the biomass raw materials are distributed all over the country, and the resources are rich. About 7 million tons of biomass coal can be produced per year. The 'green coal mines' with huge reserves are not only new bright spots for the development of agriculture and forestry industries, but also good methods for solving municipal refuse and building 'municipal coal mines'. The traditional energy petroleum and coal are non-renewable resources, the production cost is high, the traditional energy petroleum and coal are not clean energy, and the use of derived products causes serious pollution to the living environment of human beings. Therefore, under the dual pressure of shortage of energy resources and environmental pollution, development and utilization of renewable and more environmentally friendly new energy is pursued. The biomass coal is prepared from woody plants and herbaceous plants as raw materials, carbon in the biomass is carbon dioxide in the air and is solidified in the biomass through photosynthesis, and the biomass coal generates the same amount of carbon dioxide in the combustion process and discharges the carbon dioxide to the air, so that the biomass coal grows and the whole life cycle of the combustion process is realized, and zero emission of the carbon dioxide is realized. The fuel after briquetting has large specific gravity and small volume, is convenient for storage and transportation, is a high-quality solid fuel, has the heat value of 3200 and 4500 kilocalories, has the characteristics of flammability, low ash content, low cost and the like, can replace fuels such as firewood, raw coal and the like, and can be widely used for heating, domestic stoves, boilers, biomass power plants and the like.

At present, when crop straws are used for producing bio-coal, the preparation process of the equipment for producing bio-coal by using crop straws in the prior art needs to treat the crop straws in batches, and new crop straw raw materials are added into a carbonization furnace for preparation after a batch of bio-coal is produced, so that the efficiency for preparing the bio-coal is very low, the purpose of continuous feeding and continuous discharging cannot be achieved, and the preparation process of the existing equipment for producing bio-coal by using crop straws cannot recycle reducing gas generated in the preparation process, so that the direct discharge of the reducing gas not only causes waste gas pollution, but also causes a large amount of energy waste.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides equipment for producing bio-coal by crop straws and a preparation process thereof, which have the advantages of continuous feeding and discharging, capability of recycling waste gas and the like, and solve the problems in the background art.

(II) technical scheme

In order to realize the purposes of continuous feeding and discharging and recycling of waste gas, the invention provides the following technical scheme: an apparatus for producing bio-coal by crop straws comprises a third floor platform, a low-temperature carbonization furnace, a second floor platform and a first floor platform, wherein the top of the low-temperature carbonization furnace is fixedly connected with a closed spiral feeding cylinder through a feeding pipe, one side of the top of the closed spiral feeding cylinder is fixedly connected with an underground hopper, the closed spiral feeding cylinder is fixedly connected with the third floor platform through a connecting frame, one side of the top of the low-temperature carbonization furnace is fixedly connected with an overflow pipe, the middle part of the overflow pipe is fixedly connected with a safety valve, one end of the overflow pipe is fixedly connected with a waste gas treatment box, the other side of the top of the low-temperature carbonization furnace is fixedly connected with an airflow pipe, one end of the airflow pipe is fixedly connected with a cooling box, the bottom of the cooling box is fixedly connected with a wood acid liquid collecting barrel, one side, the bottom fixedly connected with spiral cooling of low temperature retort goes out the feed cylinder, the side lower part fixedly connected with cold water pipe of spiral cooling play feed cylinder, the side top fixedly connected with cold water recovery pipe of spiral cooling play feed cylinder, cold water pipe and cold water recovery pipe all communicate with outside cold water storage cistern, heat supply pipe fixedly connected with air heater is passed through to low temperature retort's bottom one side, the air heater passes through connecting pipe fixedly connected with combustion chamber.

Preferably, the bottom of low temperature retort is through mount and first floor platform fixed connection, the middle part and the upper portion of low temperature retort and second floor platform and third floor platform welding, the interior diapire of low temperature retort is provided with vibrations grid, vibrations grid is driven by vibrating motor.

Preferably, one side of the bottom of the wood acid liquid collecting barrel is fixedly connected with a discharging pipe, the middle of the discharging pipe is fixedly connected with a discharging valve, the bottom of the wood acid liquid collecting barrel is fixedly connected with a second floor platform through a supporting seat, the airflow pipe penetrates through the third floor platform, and the tail gas pipe penetrates through the second floor platform.

Preferably, the inside of exhaust-gas treatment case is close to one side fixedly connected with filter screen of overflow pipe, the another side lower part fixedly connected with delivery pipe of exhaust-gas treatment case, one side fixedly connected with active carbon adsorption layer that the inside of exhaust-gas treatment case is close to the delivery pipe.

Preferably, a side fixedly connected with condensing engine of cooler bin, the inside of cooler bin is equipped with the condenser pipe, the both ends of condenser pipe all run through the lateral wall of cooler bin and are connected with the condensing engine, the condenser pipe is multilayer S-shaped distribution in the inside of cooler bin.

Preferably, the spiral cooling discharge barrel is provided with a plurality of spiral cooling discharge barrels which are connected in an end-to-end manner, the bottom of the spiral cooling discharge barrel is fixedly connected with a supporting plate, and the bottom of the supporting plate is fixedly connected with a first-floor platform.

Preferably, the side surface of the combustion chamber is fixedly connected with a natural gas pipe and a combustion improver pipe, the top of the combustion chamber is fixedly connected with a gas inlet pipe, the lower part of the side surface of the combustion chamber is fixedly connected with a tail gas fan through a connecting pipe, the top of the tail gas fan is fixedly connected with the tail gas pipe, and the bottom of the tail gas fan is fixedly connected with a first-floor platform.

Preferably, one end of each of the spiral cooling discharge cylinder and the closed spiral feeding cylinder is fixedly connected with a reduction gearbox, one side face of the reduction gearbox is fixedly connected with a power motor, an input shaft of the reduction gearbox is in transmission connection with an output shaft of the power motor, auger shafts are movably connected inside the spiral cooling discharge cylinder and the closed spiral feeding cylinder, and an output shaft of the reduction gearbox is in transmission connection with the auger shafts.

A process for preparing biologic coal from the stalk of agricultural crops includes such steps as pulverizing the stalk of agricultural crops to obtain particles with size less than 3cm and water content less than 16%, loading in underground hopper, and conveying by sealed spiral feeding cylinderThe method comprises the steps of feeding raw materials into a low-temperature carbonization furnace, enabling the raw materials to be subjected to pyrolysis reaction in the low-temperature carbonization furnace, enabling two streams of fluid to move in opposite directions on a vertical plane and form a continuous reaction area in the low-temperature carbonization furnace, enabling one stream to rise from the bottom to the top of the low-temperature carbonization furnace through hot gas of an external heating source, enabling the other stream to fall from the top to the bottom of a pipeline through solid flow (straw particles), enabling the biomass particles (straw particles) to firstly pass through a 60-100 ℃ area with the length of 12m in the process of falling from the top to the bottom of the low-temperature carbonization furnace, consuming 1.5 hours in the area, and enabling the straw particles to firstly lose moisture and be dried. Then, the straw particles continuously descend to reach the area with the length of 8m and the temperature of 100-200 ℃, the time consumed in the area is 1 hour, and the straw particles begin to crack at low temperature to obtain CO and CH₄、CO₂、H₂、H₂O, and the like. The pyrolysis gas is good reducing gas and is carried to the upper part by hot gas flow to dry the subsequent raw materials, and finally enters a gas flow pipe. And then, continuously descending the straw particles to a region with the length of 4m and the temperature of 200-240 ℃, and consuming 0.5h in the region, wherein the straw particles are carbonized and further dried in the region, and at the moment, polymers of the semi-fibrous body are damaged. This phenomenon then continues to complete carbonization, and finally the straw particles reach the grid to form biomass particles. And cooling the reducing gas pyrolyzed from the airflow pipe, and mixing and combusting the reducing gas with natural gas, wherein 95 percent of the reducing gas enters the ultralow-temperature carbonization furnace for heat source supplement, and 5 percent of the reducing gas is exhausted to the atmosphere after being subjected to activated carbon adsorption treatment.

(III) advantageous effects

Compared with the prior art, the invention provides equipment for producing biological coal by crop straws and a preparation process thereof, and the equipment has the following beneficial effects:

1. this equipment of crop straw production bio-coal and preparation technology thereof through setting up the air current pipe, can follow the heat current with the inside crop straw pyrolysis of low temperature retort and discharge into the cooler bin, makes the organic acid cooling in the heat current stay in the inside of wood acid liquid collecting vessel, makes the reducing gas who cools off get into combustion chamber and natural gas mixed combustion, reaches the purpose of carrying out heat recovery to waste gas.

2. This equipment of biological coal of crop straw production and preparation technology thereof through setting up closed spiral feeding section of thick bamboo and spiral cooling play feed cylinder, can utilize spiral cooling to go out the ejection of compact of feed cylinder when carrying out the feeding to low temperature carbomorphism stove inside to cool off the biological coal that the carbomorphism is good, reach the purpose of continuous feeding and continuous ejection of compact.

Drawings

FIG. 1 is a schematic perspective view of the present invention;

FIG. 2 is a schematic rear perspective view of the present invention;

FIG. 3 is a schematic sectional view of an exhaust gas treatment tank according to the present invention;

FIG. 4 is a schematic cross-sectional view of the cooling box of the present invention.

In the figure: 1. an underground hopper; 2. a closed screw feed cylinder; 3. a waste gas treatment tank; 4. a third floor platform; 5. a low-temperature carbonization furnace; 6. a second floor platform; 7. a cold water recovery pipe; 8. a first floor platform; 9. a support plate; 10. spirally cooling the discharging barrel; 11. a heat supply pipe; 12. a combustion chamber; 14. a tail gas fan; 15. a hot air blower; 16. a tail gas pipe; 17. a wood acid liquid collecting barrel; 18. a cooling tank; 19. an airflow duct; 20. a reduction gearbox; 21. an overflow pipe; 22. a cold water pipe; 23. a safety valve; 24. a discharge pipe; 25. a filter screen; 26. an activated carbon adsorption layer; 27. a condenser; 28. a condenser tube.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-4, an apparatus for producing bio-coal from crop straws comprises a third floor platform 4, a low-temperature carbonization furnace 5, a second floor platform 6 and a first floor platform 8, wherein the bottom of the low-temperature carbonization furnace 5 is fixedly connected with the first floor platform 8 through a fixing frame, the middle part and the upper part of the low-temperature carbonization furnace 5 are welded with the second floor platform 6 and the third floor platform 4, the inner bottom wall of the low-temperature carbonization furnace 5 is provided with a vibration grid, the vibration grid is driven by a vibration motor, the top of the low-temperature carbonization furnace 5 is fixedly connected with a closed spiral feeding cylinder 2 through a feeding pipe, one side of the top of the closed spiral feeding cylinder 2 is fixedly connected with an underground hopper 1, the closed spiral feeding cylinder 2 is fixedly connected with the third floor platform 4 through a connecting frame, one side of the top of the low-temperature carbonization furnace 5 is fixedly connected with an overflow pipe 21, the middle part, one end of the overflow pipe 21 is fixedly connected with a waste gas treatment tank 3, one side of the interior of the waste gas treatment tank 3, which is close to the overflow pipe 21, is fixedly connected with a filter screen 25, the other side lower part of the waste gas treatment tank 3 is fixedly connected with a discharge pipe 24, one side of the interior of the waste gas treatment tank 3, which is close to the discharge pipe 24, is fixedly connected with an activated carbon adsorption layer 26, the other side of the top of the low-temperature carbonization furnace 5 is fixedly connected with an airflow pipe 19, one end of the airflow pipe 19 is fixedly connected with a cooling tank 18, one side of the cooling tank 18 is fixedly connected with a condenser 27, the interior of the cooling tank 18 is provided with a condenser pipe 28, two ends of the condenser pipe 28 penetrate through the side wall of the cooling tank 18 and are connected with the condenser 27, the condenser pipe 28 is distributed in a multilayer S shape in the interior of the cooling, a discharging pipe is fixedly connected to one side of the bottom of the wood acid liquid collecting barrel 17, a discharging valve is fixedly connected to the middle of the discharging pipe, the bottom of the wood acid liquid collecting barrel 17 is fixedly connected with a second floor platform 6 through a supporting seat, the airflow pipe 19 penetrates through a third floor platform 4, the tail gas pipe 16 penetrates through the second floor platform 6, the tail gas pipe 16 is fixedly connected to one side of the top of the wood acid liquid collecting barrel 17, a spiral cooling discharge barrel 10 is fixedly connected to the bottom of the low-temperature carbonization furnace 5, a plurality of spiral cooling discharge barrels 10 are provided, the spiral cooling discharge barrels 10 are in tail connection, a supporting plate 9 is fixedly connected to the bottom of the spiral cooling discharge barrel 10, the bottom of the supporting plate 9 is fixedly connected with a first floor closed platform 8, a reduction gearbox 20 is fixedly connected to one end of each of the spiral cooling discharge barrel 10 and one end of the spiral feeding barrel 2, and a power motor is fixedly connected to one side of, the input shaft of the reduction gearbox 20 is in transmission connection with the output shaft of the power motor, auger shafts are movably connected inside the spiral cooling discharge cylinder 10 and the closed spiral feeding cylinder 2, the output shaft of the reduction gearbox 20 is in transmission connection with the auger shafts, a cold water pipe 22 is fixedly connected to the lower portion of the side surface of the spiral cooling discharge cylinder 10, a cold water recovery pipe 7 is fixedly connected to the top portion of the side surface of the spiral cooling discharge cylinder 10, the cold water pipe 22 and the cold water recovery pipe 7 are both communicated with an external cold water tank, a hot air blower 15 is fixedly connected to one side of the bottom of the low-temperature carbonization furnace 5 through a heat supply pipe 11, the hot air blower 15 is fixedly connected with a combustion chamber 12 through a connecting pipe, a natural gas pipe and a combustion improver pipe are fixedly connected to the side surface of the combustion chamber 12, an air inlet pipe is fixedly connected to the top portion of the combustion chamber, the top of the tail gas fan 14 is fixedly connected with a tail gas pipe 16, and the bottom of the tail gas fan 14 is fixedly connected with the first-floor platform 8.

When in use, firstly, crushed crop straws are conveyed to an underground hopper 1 through a conveying belt, raw materials enter the interior of a low-temperature carbonization furnace 5 through the conveying of a closed spiral feeding cylinder 2, the raw materials in the low-temperature carbonization furnace 5 can undergo the processes of drying, pyrolysis and carbonization from top to bottom, the solid flow in the low-temperature carbonization furnace 5 descends, meanwhile, a hot air flow provided by a hot air blower 15 through a heat supply pipe 11 brings generated gas to the upper part of the low-temperature carbonization furnace 5, because a tail gas fan 14 continuously pumps out the gas in a pyroligneous liquor collecting barrel 17, negative pressure is generated in the pyroligneous liquor collecting barrel 17 and a cooling box 18, the hot air flow in the low-temperature carbonization furnace 5 is discharged into a cooling box 18 through an air flow pipe 19, cooled organic acid is left in the pyroligneous liquor collecting barrel 17, and cooled reducing gas is sucked away by the tail gas fan 14 through a tail gas pipe 16, then the reducing gas is sent into the combustion chamber 12 through the connecting pipe to be mixed with the natural gas, and is combusted with the natural gas under the action of the combustion improver, the hot air blower 15 sends the combustion heat into the bottom of the low-temperature carbonization furnace 5 to form thermodynamic cycle, the solid flow in the low-temperature carbonization furnace 5 descends in the low-temperature carbonization furnace 5, finally, after passing through the mesh grid, the carbonized biological coal is formed into particles by the mesh grid driven by the vibration motor, and then falls into the spiral cooling discharge cylinder 10 to be transported, and meanwhile, the cold water provided by the cold water pipe 22 is used for cooling, so that the biological coal can be directly packaged after being cooled.

The effects of the present invention will be further described below by way of specific examples.

In the embodiment, corn straws are used as raw materials for processing, wherein the raw materials are as follows: adopting the crushed corn straws with the grain diameter less than or equal to 3cm and the water content less than or equal to 16 percent.

The raw material is conveyed to an underground hopper through a conveying belt, and is conveyed to an ultralow-temperature carbonization furnace through a closed screw conveyor, and pyrolysis in the carbonization process is a continuous reaction, wherein two flows move in opposite directions on a vertical surface to form a continuous reaction area. The hot gas of the external heating source rises from the bottom to the top of the low-temperature carbonization furnace, and the solid flow (straw particles) falls from the top to the bottom of the low-temperature carbonization furnace. When biomass particles (straw particles) fall from the top to the bottom of the carbonization furnace, the biomass particles firstly pass through a 60-100 ℃ area (12m) and take 1.5 hours, and the straw particles firstly lose moisture and are dried. The straw particles continuously descend, the time for reaching the area (8m) of 100-200 ℃ is 1h, and the straw particles begin to crack at low temperature to obtain CO and CH₄、CO₂、H₂、H₂O, and the like. The pyrolysis gas is good reducing gas and is carried to the upper part by hot gas flow to dry the subsequent raw materials, and finally enters a gas circulation system. The straw particles continuously descend to reach the 200-240 ℃ area (4m) and take 0.5h, the straw particles are carbonized and further dried in the area, and at the moment, polymers of the semi-fibrous bodies are damaged. This phenomenon then continues and the straw particles reach the grid to form biomass particles. The reducing gas pyrolyzed in the gas circulation system is cooled and then mixed with natural gas for combustion, 95 percent of the reducing gas enters the ultralow-temperature carbonization furnace for heat source supplement, 5 percent of the reducing gas is adsorbed by activated carbon and then discharged to the atmosphere, and a depolymerized/dried product obtained at the bottom of the ultralow-temperature carbonization furnace is called as biological coal without being subjected to briquetting and other treatments. Then the finished product is sent into a cooling system through a closed feeding system to be cooled, and then the finished product can be bagged and put in storage. Because the structure of the biomass product is more compact, less dust is generated in the packaging process. The production process is continuous feeding and continuous discharging, the feeding speed is designed to be 7.5t/h, and 6 thousands of biomass raw materials can be processed every year, so that the project can meet the scale of producing 4 thousands of biomass briquette fuels every year (6 thousands of biomass raw materials are fed every year). The amount of waste gas generated after cooling cracked gas in the production process is about 15Nm³Pert product, gas production amount per year is 60 ten thousand Nm³The amount of supplemented natural gas combustion waste gas is 1386 ten thousand Nm³The pyrolysis gas accounts for 4.3% of the combustion waste gas, so 5% of the waste gas discharged after the gas circulation of the project can realize gas balance.

Compared with the prior art, the method can realize synchronous feeding and discharging of the production of the bio-coal, can achieve the production scale of 4 ten thousand tons of biomass briquette fuel per year, and has the annual gas production amount of 60 ten thousand Nm³The amount of supplemented natural gas combustion waste gas is 1386 ten thousand Nm³The heat energy cyclic utilization of the waste gas can be realized, and the gas balance is realized.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the use of the verb "comprise a" to define an element does not exclude the presence of another, same element in a process, method, article, or apparatus that comprises the element.

Although embodiments of the present invention have been described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.