A production system for co-pyrolyzing bio-oil and biomass to prepare biochar

Abstract

The present invention discloses a production system for co-pyrolyzing bio-oil and biomass to prepare biochar, which comprises a pyrolysis furnace and a condensation device. Among them, the pyrolysis furnace is provided with a first feed inlet and a first gas outlet, and the first feed inlet is communicated with a first discharge outlet. The condensation device includes a hopper, a feed pipeline and an intake pipeline. One end of the feed pipeline is communicated with the hopper, and the other end is communicated with the first feed inlet. One end of the intake pipeline is communicated with the first gas outlet. The feed pipeline is horizontally disposed in the intake pipeline, and condensation holes are provided on the side wall of the feed pipeline in the intake pipeline. Thus, through this system, the present invention can utilize the co-pyrolysis effect of bio-oil and biomass to improve the biochar yield and carbon retention rate, enabling more carbon elements to be sequestered in the biochar, thereby achieving the effect of carbon sequestration. At the same time, the high retention rate of carbon elements in the biochar is conducive to increasing the calorific value of the biochar as an alternative fuel, enhancing the thermal stability of the biochar fuel, and improving the fuel performance of the biochar.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass, and in particular to a production system for co-pyrolysis to prepare biochar. Background Art

[0002] Biomass energy is a widely distributed renewable energy source with carbon neutrality, which can balance the emission and absorption of CO2. Although biomass has the potential to be directly converted into fuel, its high moisture content, low energy density, large volume, high fiber content, poor grindability and poor uniformity lead to a series of problems such as difficult biomass transportation, high cost and seasonal restrictions, which restrict its wider application.

[0003] Pyrolysis, as a biomass treatment and fuel upgrading technology, can improve the characteristics of raw materials and produce energy and chemical products. Through pyrolysis technology, biomass is usually converted into gas, liquid and solid three-phase products, and the yields of the three-phase products are regulated by changing pyrolysis process parameters, such as changing pyrolysis temperature, heating rate and carrier gas flow rate, etc. Among these three-phase products, biochar is the most potential product to replace coal combustion due to its good fuel characteristics (high energy density, high calorific value, high carbon content and low oxygen content).

[0004] In traditional biomass pyrolysis processes, most of the carbon is transferred to bio-oil and pyrolysis gas, resulting in low biochar yield, limited carbon retention rate and combustion performance of the produced biochar, and poor economy. Improving the char yield and carbon content of biomass can sequester more carbon elements in biochar, which is of great significance for achieving green and sustainable development.

[0005] Currently, there are mainly two ways of carbon sequestration in biomass pyrolysis. One is to use pressure equipment to increase the reaction pressure during biomass pyrolysis. However, pressurized pyrolysis is usually intermittent, which cannot meet the high efficiency and continuity of biomass pyrolysis carbon sequestration technology. At the same time, the safety of pressure equipment is also a technical problem that hinders the development of biomass pressurized pyrolysis carbon sequestration. The other is to use additives to co-pyrolyze with biomass. However, the use of additives will increase the industrial production cost, and adding additives will change the composition of biomass pyrolysis products, which may affect the subsequent utilization value of pyrolysis products. At the same time, some additives may cause environmental pollution. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a production system for co-pyrolyzing bio-oil and biomass to prepare biochar, which can realize continuous normal-pressure carbonization, carry out co-pyrolysis between bio-oil and biomass, so as to sequester more carbon elements in biomass into biochar.

[0007] A production system for co-pyrolyzing bio-oil and biomass to prepare biochar according to an embodiment of the present invention includes:

[0008] A pyrolysis furnace is provided with a first feed inlet, a first air inlet, a first air outlet and a first discharge outlet, and the first feed inlet is communicated with the first discharge outlet.

[0009] A condensing device includes a hopper, a feed pipeline and an air inlet pipeline. One end of the feed pipeline is communicated with the hopper, and the other end is communicated with the first feed inlet. One end of the air inlet pipeline is communicated with the first air outlet. The feed pipeline transversely penetrates through the air inlet pipeline, and condensing holes are provided on the side wall of the feed pipeline inside the air inlet pipeline. The inner diameter of the condensing holes is smaller than the particle size of the biomass particles.

[0010] In some embodiments of the present invention, the outer diameter of the feed pipeline is the same as the inner diameter of the air inlet pipeline.

[0011] In some embodiments of the present invention, the feed pipeline includes a bent section, and the bent section is in a U shape or a W shape and is arranged inside the air inlet pipeline.

[0012] In some embodiments of the present invention, it further includes: a burner, which includes an air inlet and an air outlet. The air inlet is communicated with the other end of the air inlet pipeline of the condensing device, and the air outlet is communicated with the first air inlet.

[0013] In some embodiments of the present invention, the burner further includes a fuel inlet, a slag discharge port and a mesh partition plate. The mesh partition plate is arranged above the air inlet, the fuel inlet is arranged on the side wall of the burner on one side of the mesh partition plate, and the slag discharge port is arranged on the side wall of the burner on the other side of the mesh partition plate.

[0014] In some embodiments of the present invention, the pyrolysis furnace includes: a feed box, a rotary furnace body and a discharge box. The two ends of the rotary furnace body are dynamically and sealingly connected to the feed box and the discharge box respectively. The first feed inlet and the first air outlet are both arranged on the feed box, and the first air inlet and the first discharge outlet are both arranged on the discharge box.

[0015] In some embodiments of the present invention, a condensing cavity is further arranged on the side wall of the rotary furnace body, and the condensing cavity is arranged on the side close to the first air outlet.

[0016] In some embodiments of the present invention, a material scraping plate is arranged on the inner side wall of the rotary furnace body.

[0017] In some embodiments of the present invention, it further includes: a drying furnace, which is provided with a second feed inlet, a second air inlet, a second air outlet and a second discharge outlet. The second discharge outlet is communicated with the hopper, and the air outlet is communicated with the second air inlet.

[0018] In some embodiments of the present invention, the condensation device further includes: a control valve disposed on the feed pipeline for controlling the feed rate.

[0019] Beneficial effects:

[0020] Through this system, the present invention can utilize the co-pyrolysis of bio-oil and biomass to improve the biochar yield and carbon retention rate, enabling more carbon elements to be sequestered in biochar, thereby achieving the effect of carbon sequestration. At the same time, the high carbon retention rate in biochar is conducive to increasing the calorific value of biochar as an alternative fuel, enhancing the thermal stability of biochar fuel, improving the fuel performance of biochar, and making the combustion process of biochar approach that of fossil fuels.

[0021] In the present invention, normal-temperature or low-temperature biomass is used as a cold source, thereby promoting the direct condensation and attachment of condensable volatiles in pyrolysis gas onto biomass, enabling more efficient and continuous co-pyrolysis of bio-oil and biomass to produce biochar, and thus greatly improving the efficiency of biochar production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of embodiments in conjunction with the accompanying drawings, where:

[0023] Figure 1 is a schematic diagram of a production system for co-pyrolyzing bio-oil and biomass to produce biochar according to an embodiment of the present invention;

[0024] Figure 2 is a schematic structural diagram of a condensation device according to an embodiment of the present invention;

[0025] Figure 3 is a schematic structural diagram of a burner according to an embodiment of the present invention.

[0026] Reference numerals:

[0027] 100, production system for co-pyrolyzing bio-oil and biomass to produce biochar

[0028] 1, pyrolysis furnace; 11, first feed inlet; 12, first air inlet; 13, first air outlet; 14, first discharge outlet; 15, feed box; 16, rotary furnace body; 161, condensation chamber; 162, material scraping plate; 17, discharge box;

[0029] 2, condensation device; 21, hopper; 22, feed pipeline; 221, condensation holes; 23, intake pipeline; 24, bent section; 25, control valve;

[0030] 3, burner; 31, air inlet; 32, air outlet; 33, fuel inlet; 34, slag outlet; 35, mesh partition;

[0031] 4. Drying furnace; 41. Second feed inlet; 42. Second air inlet; 43. Second air outlet; 44. Second discharge outlet. Detailed implementation mode

[0032] Combined with the accompanying drawings in the disclosed embodiments of the present application, the technical solutions in the disclosed embodiments of the present disclosure are clearly and completely described. The description of the embodiments is actually only illustrative and exemplary, and does not constitute any limitation to the present disclosure and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative work shall fall within the scope of protection of the present disclosure. In addition, well-known technologies, methods, and devices in the relevant field may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the specification.

[0033] Combined with Figures 1 to 3 As shown, a production system 100 for co-pyrolyzing bio-oil and biomass to prepare biochar according to an embodiment of the present invention at least includes a pyrolysis furnace 1 and a condensation device 2. Among them, the pyrolysis furnace 1 is provided with a first feed inlet 11, a first air inlet 12, a first air outlet 13, and a first discharge outlet 14. The first feed inlet 11 is communicated with the first discharge outlet 14. The condensation device 2 includes a hopper 21, a feed pipeline 22, and an air inlet pipeline 23. One end of the feed pipeline 22 is communicated with the hopper 21, and the other end is communicated with the first feed inlet 11. One end of the air inlet pipeline 23 is communicated with the first air outlet 13. The feed pipeline 22 is horizontally disposed in the air inlet pipeline 23. A condensation hole 221 is provided on the side wall of the feed pipeline 22 in the air inlet pipeline 23. The inner diameter of the condensation hole 221 is smaller than the particle size of the biomass particles.

[0034] During use, the biomass mixed with bio-oil is pyrolyzed in the pyrolysis furnace 1. The pyrolysis gas generated by pyrolysis will enter the air inlet pipeline 23 in the condensation device 2 through the first air outlet 13. After the biomass particles enter the feed pipeline 22 through the hopper 21, due to the condensation holes 221 provided on the feed pipeline 22, the high-temperature pyrolysis gas can pass through the condensation holes 221 into the feed pipeline 22 and contact the normal-temperature biomass particles, thereby generating a contact condensation effect so that the pyrolysis oil condenses and adheres to the biomass particles. Finally, the biomass particles attached with bio-oil enter the pyrolysis furnace 1 through the first feed inlet 11 for pyrolysis.

[0035] Among them, during the co-pyrolysis process, the bio-oil attached to the biomass particles can close the intrinsic pore structure of the biomass, form a confined space inside the biomass structure, thereby restricting the escape of the primary products of biomass pyrolysis, and then retaining them in the biomass. The free radicals (such as phenoxy groups) in these primary pyrolysis products can crosslink with hemicellulose and cellulose, and further condensation polymerization reactions occur, ultimately promoting the formation of stable biochar. At this time, the condensed bio-oil can produce the effect of a carbon sequestration agent.

[0036] Thus, through this system, the co-pyrolysis of bio-oil and biomass can be used to improve the biochar yield and carbon retention rate, so that more carbon elements are sequestered in the biochar, thereby achieving the effect of carbon sequestration. At the same time, the high retention rate of carbon elements in the biochar is beneficial to increasing the calorific value of the biochar as an alternative fuel, enhancing the thermal stability of the biochar fuel, improving the fuel performance of the biochar, and making the combustion process of the biochar approach that of fossil fuels.

[0037] Preferably, the outer diameter of the feed pipe 22 can be set to the same size as the inner diameter of the intake pipe 23, so that all the high-temperature pyrolysis gas can pass through the condensation holes 221, making the high-temperature pyrolysis gas come into full contact with the biomass particles.

[0038] Furthermore, on the basis of the above embodiments, as Figure 1 and Figure 2 shown, the feed pipe 22 includes a bent section 24, and the bent section 24 is in a U shape or a W shape. Specifically, the bent section 24 is arranged inside the intake pipe 23. When the biomass particles move along the bent feed pipe 22, they will also come into contact with the pyrolysis gas multiple times. Thus, when the biomass particles pass through a bent structure, it is equivalent to coming into contact with the pyrolysis gas twice, thereby greatly increasing the probability of bio-oil condensation and attachment to the biomass, facilitating the full condensation of the condensable volatiles in the pyrolysis gas onto the biomass, and improving the biochar yield.

[0039] In some embodiments of the present invention, as Figure 1 shown, the production system for preparing biochar by the co-pyrolysis of bio-oil and biomass further includes a burner 3. Among them, the burner 3 includes an air inlet 31 and an air outlet 32. During use, the air inlet 31 is communicated with the other end of the intake pipe 23 of the condensation device, and the air outlet 32 is communicated with the first air inlet 12.

[0040] During use, there are still some condensable volatiles and non-condensable gases in the pyrolysis gas condensed in the condensation device 2. This part of the pyrolysis gas can be introduced into the burner 3 for full combustion. The combustion generates high-temperature flue gas, and then the flue gas is introduced into the pyrolysis furnace 1. In this way, the large amount of heat contained in the flue gas can be used to supplement the energy consumption during pyrolysis, thereby achieving the effect of recovering part of the heat, reducing the energy consumption during pyrolysis, and improving the energy utilization rate.

[0041] Furthermore, since there are requirements for both the concentration and temperature of pyrolysis gas during combustion, if the method of directly igniting pyrolysis gas is used, it is easily affected by the concentration, leading to flameout, and further causing adverse chain reactions. Therefore, the stability of solid fuel combustion can be utilized to ignite pyrolysis gas, thereby achieving stable combustion of pyrolysis gas. Specifically, as Figure 3 shown, the burner 3 further includes a fuel inlet 33, a slag outlet 34, and a mesh partition 35. The mesh partition 35 is provided above the air inlet 31. The fuel inlet 33 is provided on the side wall of the burner 3 on one side of the mesh partition 35, and the slag outlet 34 is provided on the side wall of the burner 3 on the other side of the mesh partition 35.

[0042] During use, the solid fuel enters the burner 3 through the fuel inlet 33 and burns on the mesh partition 35. When the pyrolysis gas enters the burner 3 through the air inlet 31, it undergoes sufficient combustion under the action of the flame at the mesh plate. In this way, regardless of the change in the concentration of the pyrolysis gas, it will not affect the combustion of the pyrolysis gas when passing through the mesh partition 35, thus effectively ensuring the stable operation of the entire system.

[0043] In some embodiments of the present invention, as Figure 1 shown, the pyrolysis furnace 1 includes a feed box 15, a rotary furnace body 16, and a discharge box 17. Among them, both ends of the rotary furnace body 16 are dynamically and hermetically connected to the feed box 15 and the discharge box 17 respectively. The first feed port 11 and the first gas outlet 13 are both provided on the feed box 15, and the first air inlet 12 and the first discharge port 14 are both provided on the discharge box 17.

[0044] During use, the biomass wrapped or attached with bio-oil undergoes pyrolysis in the pyrolysis furnace 1. The produced pyrolytic carbon is discharged from the first discharge port 14, and the produced pyrolysis gas leaves the pyrolysis furnace 1 from the first gas outlet 13 on one side of the feed box 15. During this process, through the continuous flipping action of the rotary furnace body 16, it is beneficial to ensure that the biomass is heated more evenly and effectively improve the pyrolysis efficiency.

[0045] In addition, after the biomass enters the pyrolysis furnace 1, it gradually moves towards the discharge box 17 side in the rotary furnace body 16, while the pyrolysis gas flows towards the feed box 15 side. In this way, the pyrolysis gas to be discharged will come into preliminary contact with the newly entered biomass, thereby producing a pre-condensation effect to a certain extent. Since different volatile substances with different boiling points can be condensed in different temperature ranges, through such a setting, a hierarchical condensation effect can be formed, ultimately improving the total yield of bio-oil, and further facilitating the co-pyrolysis of bio-oil and biomass to prepare biochar and improving the yield of biochar.

[0046] Preferably, in order to facilitate the condensation effect of the pyrolysis gas with the biomass in the pyrolysis furnace 1, a condensation chamber 161 may be provided on the side wall of the rotary furnace body 16. The condensation chamber 161 is provided on the side close to the first air outlet 13. Specifically, the temperature of the condensation chamber 161 may be set in the medium-low or medium-high temperature range, for example: 80 degrees to 150 degrees, so as to condense the bio-oil within this temperature range. Then, the pre-condensed pyrolysis gas is further condensed with the room-temperature biomass in the condensation device 2, so as to condense the bio-oil within the range of 20 degrees to 30 degrees, ultimately achieving the effect of hierarchical condensation.

[0047] Further, on the basis of the above embodiments, a charging plate 162 is provided on the inner side wall of the rotary furnace body 16. Specifically, when the charging plate 162 is arranged in the area of the rotary furnace body 16 corresponding to the condensation chamber 161, the biomass can be continuously lifted and scattered by the charging plate 162, thereby increasing the contact area between the biomass and the pyrolysis gas, which is beneficial to the condensation of the condensable volatiles in the pyrolysis gas onto the biomass and improving the yield of biochar.

[0048] When the charging plate 162 is arranged in the non-condensing area, by continuously turning the biomass with the charging plate 162, the biomass can be pyrolyzed more evenly, improving the quality of the produced biochar.

[0049] In some embodiments of the present invention, as Figure 1 shown, it further includes: a drying furnace 4. The drying furnace 4 is provided with a second feed inlet 41, a second air inlet 42, a second air outlet 43 and a second discharge outlet 44. The second discharge outlet 44 is communicated with the hopper 21, and the air outlet 32 is communicated with the second air inlet 42. Before the biomass particles enter the condensation device, they are pre-dried in the drying furnace 4 to reduce the moisture in the biomass, which is beneficial to improving the carbonization efficiency during pyrolysis carbonization.

[0050] In some embodiments of the present invention, as Figure 2 shown, the condensation device 2 further includes a control valve 25. The control valve 25 is arranged on the feed pipeline 22. During use, the control valve 25 is used to control the feeding speed of the biomass particles, so that when the biomass particles move to the vicinity of the condensation holes 221, they can exhibit the characteristics of a "fluidized bed" under the action of the pyrolysis gas flow, which is beneficial to the more uniform wrapping of the condensable volatiles in the pyrolysis gas onto the biomass, thereby improving the quality of the biochar.

[0051] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. 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 should not be construed as a limitation to the present invention.

[0052] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0053] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A production system for co-pyrolyzing bio-oil and biomass to prepare biochar, characterized in that, Comprising: A pyrolysis furnace, the pyrolysis furnace comprising: a feed box, a rotary furnace body, and a discharge box. The two ends of the rotary furnace body are dynamically and sealingly connected to the feed box and the discharge box respectively. The pyrolysis furnace is provided with a first feed inlet, a first air inlet, a first air outlet, and a first discharge outlet. The first feed inlet is communicated with the first discharge outlet. The first feed inlet and the first air outlet are both provided on the feed box. The first air inlet and the first discharge outlet are both provided on the discharge box. A condensation chamber is further provided on the side wall of the rotary furnace body, and the condensation chamber is provided on one side of the first air outlet. A condensation device, the condensation device comprising: a hopper, a feed pipe, and an air inlet pipe. One end of the feed pipe is communicated with the hopper, and the other end is communicated with the first feed inlet. One end of the air inlet pipe is communicated with the first air outlet. The feed pipe transversely penetrates through the air inlet pipe. Condensation holes are provided on the side wall of the feed pipe inside the air inlet pipe. The inner diameter of the condensation holes is smaller than the particle size of the biomass particles. The feed pipe includes a bent section, and the bent section is in a U shape or a W shape, and the bent section is provided inside the air inlet pipe.

2. The production system for co-pyrolyzing bio-oil and biomass to prepare biochar according to claim 1, wherein, The outer diameter of the feed pipe is the same as the inner diameter of the air inlet pipe.

3. A production system for co-pyrolyzing bio-oil and biomass to prepare biochar according to claim 1, characterized in that, Further comprising: A burner, the burner comprising an air inlet and an air outlet. The air inlet is communicated with the other end of the air inlet pipe of the condensation device, and the air outlet is communicated with the first air inlet.

4. A production system for co-pyrolyzing bio-oil and biomass to prepare biochar according to claim 3, characterized in that, The burner further comprises a fuel inlet, a slag outlet, and a mesh partition. The mesh partition is provided above the air inlet. The fuel inlet is provided on the side wall of the burner on one side of the mesh partition, and the slag outlet is provided on the side wall of the burner on the other side of the mesh partition.

5. A production system for co-pyrolyzing bio-oil and biomass to prepare biochar according to claim 1, characterized in that, Scraping plates are provided on the inner side wall of the rotary furnace body.

6. A production system for co-pyrolyzing bio-oil and biomass to prepare biochar according to claim 3, characterized in that, Further comprising: A drying furnace, the drying furnace is provided with a second feed inlet, a second air inlet, a second air outlet, and a second discharge outlet. The second discharge outlet is communicated with the hopper, and the air outlet is communicated with the second air inlet.

7. A production system for co-pyrolyzing bio-oil and biomass to prepare biochar according to claim 1, characterized in that, The condensation device further comprises: a control valve, and the control valve is provided on the feed pipe to control the feeding speed.

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