Biomass pyrolysis poly-generation device with pretreatment system and method

Abstract

The invention relates to the field of high-value utilization of organic solid wastes, in particular to a biomass pyrolysis poly-generation device with a pretreatment system, which comprises a pretreatment furnace, a low-temperature pyrolysis furnace and a high-temperature carbonization furnace. In addition, the invention further provides a pyrolysis poly-generation method, raw materials pass through the pretreatment furnace and then enter the low-temperature pyrolysis furnace to be pyrolyzed, pyrolysis gas and pyrolysis carbon are generated, the pyrolysis gas is collected through a channel and discharged, follow-up separation and condensation treatment are carried out, high-value chemicals are obtained, the pyrolysis carbon enters the high-temperature carbonization furnace to be further carbonized into activated carbon, and the activated carbon is recycled. And the waste heat is recycled for the pretreatment process. The pretreatment, low-temperature pyrolysis and high-temperature carbonization are coupled in one system, the pretreatment is used for upgrading low-temperature pyrolysis and high-temperature carbonization products, the waste heat generated in the high-temperature carbonization process is used for providing heat required by the pretreatment, efficient pyrolysis and carbonization co-production is realized, and the system has the advantages of efficient energy utilization, energy conservation and environmental protection.

Description

Technical Field

[0001] The invention relates to the field of high-value utilization of organic solid waste, and in particular to a biomass pyrolysis polygeneration device and method with a pretreatment system. Background Art

[0002] With the gradual depletion of fossil energy and the intensification of environmental pollution, the development and utilization of renewable energy has become an urgent need for the world. Biomass, as a widely existing renewable resource, is green, pollution-free and has low carbon dioxide emissions. Pyrolysis technology is a very important means of biomass utilization, which can transform low-grade biomass resources into products with higher added value, which not only improves the utilization quality of biomass energy but also improves its utilization efficiency.

[0003] Among them, biochar, as an important solid phase product in the pyrolysis process, is regarded as an environmentally friendly multifunctional material, which is characterized by not only a large specific surface area and pore size. However, compared with activated carbon, the processing efficiency and stability of biochar are still relatively low, resulting in great limitations in the application of biochar. In order to improve the quality of biochar, physical and chemical activation is an important biochar activation method. Physical activation usually uses steam, air or CO2, while chemical activation usually uses ZnCl2, K2SO4, H3PO4, etc. as activators. The physical and chemical combined activation method can achieve a larger specific surface area, more complex pore structure and surface chemical properties by combining the advantages of the two activation methods. Compared with single physical activation or chemical activation, this method is more flexible and adaptable. It can be customized according to specific needs and has a wider application potential. It is worth noting that acidic liquids such as H3PO4 are not only raw materials for activating biomass, but also one of the important catalysts for biomass pyrolysis. Chinese patent CN201910962271.8 discloses a biomass pretreatment method for improving the selectivity of high-value chemicals in pyrolysis oil. The bio-oil component obtained by pyrolysis of biomass treated with phosphoric acid is significantly improved, and a liquid product with L-glucose ketone (LGO) as the main product is obtained. At the same time, the excess water removed during the impregnation process will exist in the form of steam, which can be used for subsequent carbon activation in combination with the active components in the pretreatment.

[0004] At present, separate reaction devices are generally used for biomass pretreatment and biochar activation, and they are carried out in independent processes. It is impossible to achieve coordinated regulation in the same reaction process. At the same time, both pretreatment and pyrolysis require a certain temperature, which greatly increases the power consumption of the entire process route and has poor technical and economic efficiency.

[0005] Therefore, it is urgent to develop simple and efficient biomass pyrolysis equipment for the co-production of activated carbon and high-value chemicals, avoid complex pretreatment, pyrolysis and carbonization equipment, and at the same time improve energy utilization efficiency to achieve high-value utilization and resource utilization of biomass. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a biomass pyrolysis polygeneration device and method with a pretreatment system to solve the problem of low utilization efficiency of biomass in the prior art.

[0008] (II) Technical solution

[0009] In order to achieve the above-mentioned object, the biomass pyrolysis polygeneration device with a pretreatment system of the present invention comprises:

[0010] A pretreatment furnace, wherein the pretreatment furnace is a hollow tube arranged obliquely, the head end of the pretreatment furnace is lower than the tail end, a feed port is provided at the top of the head end of the pretreatment furnace, a circulating feeder is provided inside the pretreatment furnace, and a plurality of feeding baffles are spaced apart on the circulating feeder; a spray port is provided at the top of the tail end of the pretreatment furnace, a steam outlet is provided at the bottom of the tail end of the pretreatment furnace, and a waste heat flue gas recovery port is also provided at the head end of the pretreatment furnace;

[0011] A low-temperature pyrolysis furnace, wherein the low-temperature pyrolysis furnace is a hollow tube arranged obliquely, the end of the low-temperature pyrolysis furnace is lower than the head end, and the end of the pretreatment furnace is butt-jointed with and connected to the head end of the low-temperature pyrolysis furnace; a pyrolysis screw feeder is arranged inside the low-temperature pyrolysis furnace, a pyrolysis gas outlet is arranged at the top of the end of the low-temperature pyrolysis furnace, and a pyrolysis charcoal outlet is arranged at the bottom of the end of the low-temperature pyrolysis furnace;

[0012] A high-temperature carbonization furnace, which is a horizontally arranged hollow tube, a carbonization screw feeder is arranged inside the high-temperature carbonization furnace, the pyrolytic charcoal outlet is connected to the head end of the high-temperature carbonization furnace, an activated carbon outlet is arranged at the bottom of the end of the high-temperature carbonization furnace, a waste heat flue gas outlet is arranged at the end of the high-temperature carbonization furnace, and the waste heat flue gas outlet is connected to the waste heat flue gas recovery port; a steam inlet is arranged at the top of the high-temperature carbonization furnace, and the steam outlet is connected to the steam inlet through a one-way air pump.

[0013] Optionally, a smoke baffle is provided at the position of the steam inlet in the high-temperature carbonization furnace, and the smoke baffle is arranged on the side of the steam inlet close to the front end of the high-temperature carbonization furnace, and the free end of the smoke baffle extends toward the rear end of the high-temperature carbonization furnace to guide the gas to diffuse from the front end to the rear end of the high-temperature carbonization furnace.

[0014] Optionally, the angle formed by the axis of the pretreatment furnace and the axis of the low-temperature pyrolysis furnace is 90° to 120°.

[0015] Optionally, an upwardly protruding material blocking baffle is provided at the bottom of the joint between the end of the pretreatment furnace and the head end of the low-temperature pyrolysis furnace; the feeding baffle is a soft plate, and the material blocking baffle is arranged parallel to the feeding baffle; the gap between the material blocking baffle and the wall of the circulating loader is 1 to 3 mm.

[0016] Optionally, the interval between adjacent feeding baffles is 20 to 50 mm; the angle between the circulating feeder and the feeding baffle is 45° to 135°; and the gap between the feeding baffle and the inner wall of the pretreatment furnace is 1 to 3 mm.

[0017] Optionally, the outer diameter of the spiral blade of the pyrolysis screw feeder is 0.5 to 0.8 times the outer diameter of the spiral blade of the carbonization screw feeder; the pitch of the spiral blade of the pyrolysis screw feeder is 2 to 5 times the pitch of the spiral blade of the carbonization screw feeder.

[0018] Optionally, the pretreatment furnace is a hollow square tube;

[0019] The low-temperature pyrolysis furnace and the high-temperature carbonization furnace are both hollow tubes with a D-shaped cross-section. The tops of the low-temperature pyrolysis furnace and the high-temperature carbonization furnace are both flat walls, and a smoke exhaust channel is formed between the flat wall and the corresponding pyrolysis screw feeder or the carbonization screw feeder.

[0020] Optionally, the circulating loader is a conveyor belt.

[0021] Furthermore, the present invention also provides a pyrolysis polygeneration method, which is implemented based on the above-mentioned biomass pyrolysis polygeneration device with a pretreatment system, and comprises:

[0022] S1, the circulating feeder rotates clockwise, driving the feeding baffle to move, and the pyrolysis screw feeder and the carbonization screw feeder rotate at a set speed; at the same time, the low-temperature pyrolysis furnace and the high-temperature carbonization furnace are heated to the set temperature respectively;

[0023] S2, adding raw materials from the feed port, the feed baffle drives the raw materials to move in the pretreatment furnace, spraying pretreatment liquid from the spray port, the pretreatment liquid and the raw materials are mixed and pretreated, and the pretreated raw materials are sent to the low-temperature pyrolysis furnace;

[0024] S3, the raw material is heated in the low-temperature pyrolysis furnace, and catalytic pyrolysis occurs under the catalytic action of the pretreatment liquid to produce pyrolysis char and pyrolysis gas; the pyrolysis gas is discharged through the pyrolysis gas outlet, and then condensed and separated to obtain pyrolysis oil; the pyrolysis char enters the high-temperature carbonization furnace through the pyrolysis char outlet;

[0025] S4. The water vapor generated by the pretreatment furnace enters the high-temperature carbonization furnace through the one-way air pump, and the pyrolytic carbon is further heated in the high-temperature carbonization furnace, and a carbonization reaction occurs under the combined activation of water vapor and pretreatment liquid, thereby generating waste heat flue gas and activated carbon; the activated carbon is discharged through the activated carbon outlet and collected, and the waste heat flue gas is sent back to the pretreatment furnace through the waste heat flue gas outlet.

[0026] Optionally, the temperature of the pretreatment furnace is provided by the waste heat flue gas from the high-temperature carbonization furnace, and the temperature of the pretreatment furnace is 150-200°C; the temperature of the low-temperature pyrolysis furnace and the high-temperature carbonization furnace is electrically heated, the temperature of the low-temperature pyrolysis furnace is 300-500°C, and the temperature of the high-temperature carbonization furnace is 600-800°C;

[0027] And / or, the pretreatment solution is a ZnCl2 solution, a K2SO4 solution or a H3PO4 solution with a concentration of 50-80%.

[0028] (III) Beneficial effects

[0029] The technical solution of the present invention provides a biomass pyrolysis multi-generation device and method with a pretreatment system, which couples pretreatment, low-temperature pyrolysis and high-temperature carbonization in one device, utilizes the waste heat generated in the high-temperature carbonization process to provide the required heat for the pretreatment stage, and the water evaporated in the pretreatment process provides an activator for the subsequent activation of activated carbon, effectively improving the energy utilization efficiency. The biomass raw material first enters the pretreatment furnace, and the preliminary pretreatment of the raw material is achieved by spraying the pretreatment liquid in the pretreatment furnace, the squeezing effect of the feeding baffle on the circulating feeder, and the heat provided by the waste heat flue gas. Then it enters the low-temperature pyrolysis furnace for pyrolysis reaction to generate pyrolysis gas and pyrolysis charcoal. The pyrolysis gas is collected and discharged from the pyrolysis gas outlet, and is subsequently separated and condensed to obtain a liquid product with L-glucose ketone and furfural as the main products. The pyrolytic carbon then enters the high-temperature carbonization furnace, and under the activation of the water vapor discharged from the pretreatment furnace, it is further carbonized into activated carbon with a mainly mesoporous structure, a higher specific surface area, greater stability and adsorption capacity. At the same time, the waste heat is recycled into the pretreatment process to form a multi-product system that jointly generates a variety of high-value products, thereby improving the utilization rate of waste heat and the comprehensive utilization efficiency of energy, and also improving the utilization efficiency of biomass resources.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) High space utilization: No additional auxiliary equipment is required, and the raw material pretreatment, pyrolysis and carbonization reaction sections are arranged in the same furnace body. The device structure is compact and the space utilization is improved.

[0032] (2) High energy utilization rate: The waste heat flue gas recovery method can recycle the pyrolysis gas generated during the pyrolysis process, which not only reduces dependence on external energy, but also improves the overall energy efficiency of the system, further reduces energy waste, and reduces operating costs.

[0033] (3) Flexible process control: The pretreatment furnace, low-temperature pyrolysis furnace and high-temperature carbonization furnace operate independently, and by adjusting the operating parameters of different furnaces, efficient processing of different biomass materials can be achieved, which has good process flexibility.

[0034] (4) Cogeneration of high-value products: The device couples the pretreatment, pyrolysis and carbonization processes. It can simultaneously obtain a variety of valuable products, including liquid products rich in high-value chemicals and activated carbon. The biomass raw materials can be converted into a variety of usable resources to the maximum extent, thereby improving the overall economic benefits.

[0035] (5) Environmentally friendly: The pyrolysis and carbonization of biomass reduces the pollution emissions caused by traditional combustion. At the same time, the recycling of pyrolysis gas also reduces waste gas emissions, helps reduce carbon footprint, meets environmental protection requirements, and is significantly environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of a biomass pyrolysis polygeneration device with a pretreatment system according to the present invention.

[0037] [Description of Reference Numerals]

[0038] 1: pretreatment furnace; 11: feed port; 12: circulating feeder; 13: feed baffle; 14: spray port; 15: steam outlet;

[0039] 2: low temperature pyrolysis furnace; 21: pyrolysis screw feeder; 22: pyrolysis gas outlet; 23: pyrolysis carbon outlet; 24: material blocking baffle;

[0040] 3: high temperature carbonization furnace; 31: carbonization screw feeder; 32: activated carbon outlet; 33: waste heat flue gas outlet; 34: steam inlet; 35: flue gas baffle;

[0041] 4: One-way air pump. DETAILED DESCRIPTION

[0042] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0043] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0044] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; "connection" can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] See also Figure 1 The present invention provides a biomass pyrolysis polygeneration device with a pretreatment system, which includes a pretreatment furnace 1, a low-temperature pyrolysis furnace 2 and a high-temperature carbonization furnace 3.

[0047] The pretreatment furnace 1 is a hollow tube arranged at an angle. The head end of the pretreatment furnace 1 is lower than the tail end. A feed port 11 is provided at the top of the head end of the pretreatment furnace 1. A circulating feeder 12 is provided inside the pretreatment furnace 1. A plurality of feeding baffles 13 are spaced apart on the circulating feeder 12. A spray port 14 is provided at the top of the tail end of the pretreatment furnace 1. A steam outlet 15 is provided at the bottom of the tail end of the pretreatment furnace 1. A waste heat flue gas recovery port is also provided at the head end of the pretreatment furnace 1. The raw material enters from the head end of the pretreatment furnace 1, and the spray liquid enters from the tail end of the pretreatment furnace 1. The spray liquid is sprayed from a high position on the moving raw material. The raw material and the spray liquid have a longer contact time and path. At the same time, under the pushing action of gravity and the feeding baffle 13, the raw material enhances the full contact between the liquid and the raw material, improves the pretreatment effect, and makes the subsequent pyrolysis process more uniform and efficient.

[0048] Among them, the pretreatment furnace 1 can be preferably a hollow square tube. The circulating feeder 12 is preferably a conveyor belt, which is supported by a pair of rollers rotatably installed on the side wall of the pretreatment furnace 1. When the rotating direction of the circulating feeder 12 is clockwise, the upper side of the circulating feeder 12 moves from the head end to the end of the pretreatment furnace 1. The conveyor belt feeder can smoothly convey the raw materials, avoiding the material stirring and compression caused by the screw feeder, and ensuring that the raw materials remain loose when in contact with the pretreatment liquid entering from the spray port 14, thereby improving the penetration effect of the impregnation liquid. Moreover, the feeding baffle 13 is arranged on the conveyor belt, and the raw materials can be evenly transported in layers, so that the sprayed liquid can more widely and evenly cover the surface of each layer of raw materials, enhance the contact efficiency between the raw materials and the liquid, and improve the pretreatment effect.

[0049] The low-temperature pyrolysis furnace 2 is a hollow tube arranged obliquely, the end of the low-temperature pyrolysis furnace 2 is lower than the head end, and the end of the pretreatment furnace 1 is connected to and connected with the head end of the low-temperature pyrolysis furnace 2; a pyrolysis screw feeder 21 is arranged inside the low-temperature pyrolysis furnace 2, a pyrolysis gas outlet 22 is arranged at the top of the end of the low-temperature pyrolysis furnace 2, and a pyrolysis charcoal outlet 23 is arranged at the bottom of the end of the low-temperature pyrolysis furnace 2. The end of the pyrolysis screw feeder 21 is stably supported for rotation by a double bearing structure.

[0050] The high temperature carbonization furnace 3 is a horizontally arranged hollow tube, a carbonization screw feeder 31 is arranged inside the high temperature carbonization furnace 3, the pyrolytic carbon outlet 23 is connected to the head end of the high temperature carbonization furnace 3, an activated carbon outlet 32 ​​is arranged at the bottom of the end of the high temperature carbonization furnace 3, a waste heat flue gas outlet 33 is arranged at the end of the high temperature carbonization furnace 3, and the waste heat flue gas outlet 33 is connected to the waste heat flue gas recovery port; a steam inlet 34 is arranged at the top of the high temperature carbonization furnace 3, and the steam outlet 15 is connected to the steam inlet 34 through a one-way air pump 4. The pyrolytic carbon is further heated and carbonized in the high temperature carbonization furnace 3 based on the physical and chemical combined activation method, and the pore size distribution of the generated activated carbon is mainly mesopores.

[0051] Among them, in a preferred embodiment, the low-temperature pyrolysis furnace 2 and the high-temperature carbonization furnace 3 are both hollow tubes with a D-shaped cross-section, which include an arc wall and a plurality of flat walls (specifically, three flat walls form a square tube with a notch on one side), and the arc wall is connected to the notch of the square tube to form a hollow tube with a D-shaped cross-section. After installation, the flat wall is located at the top, and a smoke exhaust channel is formed between the flat wall and the corresponding pyrolysis screw feeder 21 or the carbonization screw feeder 31. Among them, the pyrolysis gas outlet 22 and the waste heat flue gas outlet 33 are respectively connected to the corresponding smoke exhaust channels. The screw feeder is located in the corresponding arc wall, and there is an independent space extended by the flat wall above the screw feeder. The large amount of flue gas generated by pyrolysis will not accumulate and stay, thereby reducing the possibility of coking and blockage, and at the same time reducing the secondary reaction of the pyrolysis gas.

[0052] The present invention docks the pretreatment furnace 1 and the low-temperature pyrolysis furnace 2, and then cooperates with the horizontally arranged high-temperature carbonization furnace 3 to form a triangular structure, which has the following advantages: First, the head end of the pretreatment furnace 1 is lower than the tail end, which can give full play to the gravity of the raw materials and the pushing effect of the feeding baffle 13, which is conducive to the full contact and reaction between the spray liquid and the raw materials. Secondly, the tail end of the low-temperature pyrolysis furnace 2 is lower than the head end and is tilted. The gravity is used to make the raw materials slide down naturally, which reduces the dependence on mechanical conveying equipment and reduces energy consumption. Thirdly, the raw materials go through the pretreatment, pyrolysis and carbonization stages in sequence, which helps to better control the temperature and reaction time of each stage, and can also maximize the use of waste heat, improve thermal efficiency, and at the same time reduce the floor space of the equipment and improve space utilization.

[0053] The present invention couples pretreatment, low-temperature pyrolysis and high-temperature carbonization in one device, and utilizes the waste heat generated in the high-temperature carbonization process to provide the required heat for the pretreatment stage, effectively saving energy consumption. The water evaporated in the pretreatment process provides an activator for the subsequent activation of activated carbon, effectively improving the energy utilization efficiency. The biomass raw material first enters the pretreatment furnace 1, and the preliminary pretreatment of the raw material is achieved by spraying the pretreatment liquid in the pretreatment furnace 1, the squeezing effect of the feeding baffle 13 on the circulating feeder 12, and the heat provided by the waste heat flue gas. Then it enters the low-temperature pyrolysis furnace 2 for pyrolysis reaction to generate pyrolysis gas and pyrolysis charcoal. The pyrolysis gas is collected and discharged from the pyrolysis gas outlet 22, and is subsequently separated and condensed to obtain a liquid product with L-glucose ketone and furfural as the main products. The pyrolysis char then enters the high-temperature carbonization furnace 3, and under the activation of the water vapor discharged from the pretreatment furnace 1, it is further carbonized into activated carbon with a mesoporous structure, a higher specific surface area, and stronger stability and adsorption capacity. At the same time, the waste heat is recycled to the pretreatment process to form a multi-product system that jointly generates a variety of high-value products, improve the waste heat utilization rate and the comprehensive energy utilization efficiency, and also improve the utilization efficiency of biomass resources. In summary, by coupling pretreatment, low-temperature pyrolysis and high-temperature carbonization in one system, using pretreatment to improve the quality of low-temperature pyrolysis and high-temperature carbonization products, and using the waste heat generated by the high-temperature carbonization process to provide the required heat for pretreatment, efficient pyrolysis and carbonization co-production is achieved, which has the advantages of efficient energy utilization, energy saving and environmental protection.

[0054] See again Figure 1 A smoke damper 35 is provided at the position of the steam inlet 34 in the high-temperature carbonization furnace 3. The smoke damper 35 is provided at the side of the steam inlet 34 close to the head end of the high-temperature carbonization furnace 3. The free end of the smoke damper 35 extends toward the end end of the high-temperature carbonization furnace 3 to guide the gas to diffuse from the head end to the end end of the high-temperature carbonization furnace 3. The smoke damper 35 for guiding the flow of smoke at the steam inlet 34 can prevent the high-temperature smoke from flowing back, reduce the pressure of the steam outlet 15, and allow water vapor to smoothly enter the high-temperature carbonization furnace 3, thereby enhancing the effect of the physical and chemical combined activation.

[0055] In a preferred embodiment, a plurality of feed baffles 13 located on the same side of the circulating feeder 12 are parallel to each other and evenly spaced, and the interval between adjacent feed baffles 13 can be preferably 20-50 mm; the angle between the circulating feeder 12 and the feed baffle 13 can be preferably 45°-135°; the gap between each edge (two side edges and one top edge) of the feed baffle 13 and the inner wall surface corresponding to the pretreatment furnace 1 can be preferably 1-3 mm. The angle formed by the axis of the pretreatment furnace 1 and the axis of the low-temperature pyrolysis furnace 2 can be preferably 90°-120°.

[0056] In addition, a material blocking baffle 24 protruding upward is provided at the bottom of the joint between the end of the pretreatment furnace 1 and the head end of the low-temperature pyrolysis furnace 2; the material blocking baffle 24 is a hard plate (made of rigid material), and the feeding baffle 13 is a soft plate (made of flexible material and elastically deformable), and the material blocking baffle 24 is arranged in parallel with the feeding baffle 13; the gap between the material blocking baffle 24 and the wall of the circulating feeder 12 can preferably be 1 to 3 mm. When the circulating feeder 12 rotates, if the feeding baffle 13 hits the material blocking baffle 24, the feeding baffle 13 will be squeezed to elastic deformation and can pass through the gap between the material blocking baffle 24 and the circulating feeder 12, and the feeding baffle 13 can restore its original shape after passing through the gap. Moreover, since the material blocking baffle 24 is located at the bottom of the docking point, and the raw materials are transported from the head end to the end on the upper side of the circulating loader 12, when the raw materials reach the end of the pretreatment furnace 1, they will be blocked by the material blocking baffle 24 and can only enter the head end of the low-temperature pyrolysis furnace 2, and can no longer return to the head end of the pretreatment furnace 1. The material blocking baffle 24 greatly improves the efficiency of raw material transportation.

[0057] In addition, in a preferred embodiment, the outer diameter of the spiral blade of the pyrolysis screw feeder 21 is 0.5 to 0.8 times the outer diameter of the spiral blade of the carbonization screw feeder 31; the pitch of the spiral blade of the pyrolysis screw feeder 21 is 2 to 5 times the pitch of the spiral blade of the carbonization screw feeder 31. The larger pitch of the pyrolysis screw feeder 21 helps to reduce the residence time of the material in the equipment and avoid excessive reaction or secondary reaction of the material during the pyrolysis process. The smaller pitch of the carbonization screw feeder 31 can extend the residence time of the material in the equipment. This is particularly important for the activation process of activated carbon. Extending the residence time can enable the material to fully contact the reaction atmosphere, improve the carbonization and activation efficiency, and thus obtain a more active activated carbon product. At the same time, in order to maintain the smoothness of the material flow in the equipment and avoid material accumulation, the outer diameter of the spiral blade needs to be appropriately adjusted. When the pitch increases, the outer diameter is smaller, and when the pitch decreases, the outer diameter is larger to ensure fast and uniform material delivery.

[0058] Furthermore, the present invention also provides a pyrolysis polygeneration method, which is implemented based on the above-mentioned biomass pyrolysis polygeneration device with a pretreatment system, and comprises:

[0059] S1, the circulating feeder 12 rotates clockwise, driving the feeding baffle 13 to move, and the pyrolysis screw feeder 21 and the carbonization screw feeder 31 rotate at a set speed driven by the corresponding motors; at the same time, the low-temperature pyrolysis furnace 2 and the high-temperature carbonization furnace 3 are heated to the set temperature respectively;

[0060] S2, adding raw materials from the feed port 11, the feed baffle 13 drives the raw materials to move in the pretreatment furnace 1, spraying pretreatment liquid from the spray port 14, the pretreatment liquid and the raw materials are mixed and pretreated, and the pretreated raw materials (under the combined effect of low-temperature baking in the pretreatment furnace 1 and extrusion by the flexible feed baffle 13, the pretreatment effect is enhanced, and after evaporating excess water, the rigid material blocking baffle 24 blocks the raw materials) are sent to the low-temperature pyrolysis furnace 2;

[0061] S3, the raw material is heated in the low-temperature pyrolysis furnace 2, and catalytic pyrolysis occurs under the catalytic action of the pretreatment liquid to produce pyrolytic carbon and pyrolytic gas; the pyrolytic gas is discharged through the pyrolytic gas outlet 22, and then condensed and separated to obtain pyrolytic oil rich in high-value chemicals; the pyrolytic carbon enters the high-temperature carbonization furnace 3 through the pyrolytic carbon outlet 23;

[0062] S4. The water vapor generated by the pretreatment furnace 1 enters the high-temperature carbonization furnace 3 under the action of the one-way air pump 4. The pyrolytic carbon is further heated in the high-temperature carbonization furnace 3, and a carbonization reaction occurs under the combined activation of water vapor and pretreatment liquid, generating waste heat flue gas and activated carbon; the activated carbon is discharged and collected through the activated carbon outlet 32, and the waste heat flue gas is sent back to the pretreatment furnace 1 through the waste heat flue gas outlet 33.

[0063] The temperature of the pretreatment furnace 1 is provided by the waste heat flue gas from the high-temperature carbonization furnace 3, and the temperature is 150-200°C; the temperature of the low-temperature pyrolysis furnace 2 and the high-temperature carbonization furnace 3 is electrically heated, the temperature of the low-temperature pyrolysis furnace 2 is 300-500°C, and the temperature of the high-temperature carbonization furnace 3 is 600-800°C. The pretreatment liquid is a ZnCl2 solution, a K2SO4 solution or a H3PO4 solution with a concentration of 50-80%.

[0064] The following is a detailed description of a method for pyrolysis polygeneration using a biomass pyrolysis polygeneration device with a pretreatment system through specific embodiments, wherein each embodiment uses a device with a substantially same structure.

[0065] Example 1

[0066] The inner cross-section of the pretreatment furnace 1 is a 300mm×300mm square and a length of 800mm; the circulating feeder 12 is placed in the pretreatment furnace 1, and the feeding baffles 13 are evenly distributed. The interval between adjacent feeding baffles 13 is 20mm, the angle between the feeding baffle 13 and the circulating feeder 12 is 45°, and the gap between the feeding baffle 13 and the inner wall of the pretreatment furnace 1 is 2mm; the inner diameter of the inner cross-section of the arc wall of the low-temperature pyrolysis furnace 2 is 300mm, the outer diameter is 420mm, and the length is 100 0mm; the low-temperature pyrolysis furnace 2 is connected to the pretreatment furnace 1 at an angle of 90°, and a material blocking baffle 24 is arranged in the middle; the shaft diameter of the pyrolysis screw feeder 21 is 100mm, the outer diameter of the spiral blade is 296m, and the pitch is 20mm; the inner diameter of the inner section of the arc wall of the high-temperature carbonization furnace 3 is 400mm, the outer diameter is 560mm, and the length is 1200mm; the shaft diameter of the carbonization screw feeder 31 is 150mm, the outer diameter of the spiral blade is 396mm, and the pitch is 5mm.

[0067] 50% H3PO4 is used as the pretreatment liquid, and walnut shells are fed as raw materials into the pretreatment furnace 1, the average temperature in the furnace is 120°C, and the rotation speed of the circulating feeder 12 is 1r / min. Under the interaction of the feeding baffle 13 and the material blocking baffle 24, the raw materials pretreated by the pretreatment liquid are fed into the low-temperature pyrolysis furnace 2 with a temperature set at 400°C, and the rotation speed of the pyrolysis screw feeder 21 is 10r / min. Under the promotion of the pyrolysis screw feeder 21, the raw materials are rapidly heated and pyrolysis reaction occurs. The pyrolysis gas is collected and rapidly separated and condensed, with a liquid phase yield of 39.8wt%. Dehydrated sugars and furans in the bio-oil account for 65.5% of the detectable organic components, of which levulinic acid accounts for 38.8% and furfural accounts for 20.1%. The pyrolysis char enters the high-temperature carbonization furnace 3 with a temperature set at 800°C through the pyrolysis char outlet 23. The speed of the carbonization screw feeder 31 is 5r / min. The raw material is further heated under the push of the carbonization screw feeder 31, and activated carbon is formed under the combined action of physical activation of water vapor from the pretreatment furnace 1 and chemical activation of the pretreatment liquid from the pretreatment furnace 1. The waste heat flue gas enters the pretreatment furnace 1 through the waste heat flue gas outlet 33 to provide the heat required for pretreatment.

[0068] The final specific surface area is 577.9 cm 2 / g, and mesoporous activated carbon with an average pore size of 30.5nm, realizes the multi-product utilization of pyrolysis of biomass waste.

[0069] Example 2

[0070] The difference between this embodiment and the embodiment 1 is that the distribution of the circulating feeder 12 and the structure of the connection with the pretreatment furnace 1 and the low-temperature pyrolysis furnace 2 are changed. The feeding baffles 13 are evenly distributed on the circulating feeder 12, the interval between adjacent feeding baffles 13 is 15 mm, the angle between the feeding baffles 13 and the circulating feeder 12 is 60°, the low-temperature pyrolysis furnace 2 is connected to the pretreatment furnace 1 through the middle, the angle is 120°, and a material blocking baffle 24 is arranged in the middle.

[0071] 60% H3PO4 was used as the pretreatment liquid, and pine wood was fed into the pretreatment furnace 1 as the raw material. The average temperature in the furnace was 150°C, and the rotation speed of the circulating feeder 12 was 0.5r / min. Under the interaction of the feeding baffle 13 and the material blocking baffle 24, the raw material after being pretreated by the pretreatment liquid was fed into the low-temperature pyrolysis furnace 2 with the temperature set at 350°C. The rotation speed of the pyrolysis screw feeder 21 was 15r / min. Under the push of the pyrolysis screw feeder 21, the raw material was rapidly heated and a pyrolysis reaction occurred. The pyrolysis gas is collected and rapidly separated and condensed, with a liquid phase yield of 31.9wt%. Dehydrated sugars and furans in the bio-oil account for 68.8% of the detectable organic components, of which levulinic acid accounts for 42.7% and furfural accounts for 15.1%. The pyrolysis char enters the high-temperature carbonization furnace 3 with a temperature set at 600°C through the pyrolysis char outlet 23. The speed of the carbonization screw feeder 31 is 3r / min. The raw material is further heated up under the push of the carbonization screw feeder 31, and activated carbon is formed under the combined action of physical activation of water vapor from the pretreatment furnace 1 and chemical activation of the pretreatment liquid from the pretreatment furnace 1. The waste heat flue gas enters the pretreatment furnace 1 through the waste heat flue gas outlet 33 to provide the heat required for pretreatment.

[0072] The final specific surface area is 621.2 cm 2 / g, and mesoporous activated carbon with an average pore size of 12.7nm, realizes the multi-product utilization of pyrolysis of biomass waste.

[0073] Example 3

[0074] The present embodiment differs from the first embodiment in that the feeding baffles 13 are evenly distributed on the circulating feeder 12, and the interval between adjacent feeding baffles 13 is 30 mm.

[0075] Using 50% ZnCl2 as the pretreatment liquid, pine wood is fed into the pretreatment furnace 1 as the raw material, the average temperature in the furnace is 200°C, and the rotation speed of the circulating feeder 12 is 0.6r / min. Under the interaction of the feeding baffle 13 and the material blocking baffle 24, the raw material after being pretreated by the pretreatment liquid is fed into the low-temperature pyrolysis furnace 2 with the temperature set at 380°C, and the rotation speed of the pyrolysis screw feeder 21 is 17r / min. Under the push of the pyrolysis screw feeder 21, the raw material is rapidly heated and a pyrolysis reaction occurs. The pyrolysis gas is collected and rapidly separated and condensed, with a liquid phase yield of 35.4wt%. Dehydrated sugars and furans in the bio-oil account for 59.1% of the detectable organic components, of which levulinic acid accounts for 20.8% and furfural accounts for 35.9%. The pyrolysis char enters the high-temperature carbonization furnace 3 with a temperature set at 650°C through the pyrolysis char outlet 23. The speed of the carbonization screw feeder 31 is 2.5r / min. The raw material is further heated up under the push of the carbonization screw feeder 31, and activated carbon is formed under the combined action of physical activation of water vapor from the pretreatment furnace 1 and chemical activation of the pretreatment liquid from the pretreatment furnace 1. The waste heat flue gas enters the pretreatment furnace 1 through the waste heat flue gas outlet 33 to provide the heat required for pretreatment.

[0076] The final specific surface area is 743.2 cm 2 / g, and the mesoporous activated carbon with an average pore size of 15.9nm realizes the multi-product utilization of pyrolysis of biomass waste.

[0077] Example 4

[0078] The present embodiment differs from the first embodiment in that the angle between the feed baffle 13 and the circulating loader 12 is 135°, the low-temperature pyrolysis furnace 2 is connected to the pretreatment furnace 1 through a central passage at an angle of 110°, and a material blocking baffle 24 is provided in the middle.

[0079] 55% ZnCl2 was used as the pretreatment liquid, and pine wood was fed into the pretreatment furnace 1 as the raw material. The average temperature in the furnace was 180°C, and the rotation speed of the circulating feeder 12 was 0.4r / min. Under the interaction of the feeding baffle 13 and the material blocking baffle 24, the raw material after being pretreated by the pretreatment liquid was fed into the low-temperature pyrolysis furnace 2 with the temperature set at 450°C. The rotation speed of the pyrolysis screw feeder 21 was 19r / min. Under the push of the pyrolysis screw feeder 21, the raw material was rapidly heated and a pyrolysis reaction occurred. The pyrolysis gas is collected and rapidly separated and condensed, with a liquid phase yield of 40.3wt%. Dehydrated sugars and furans in the bio-oil account for 58.8% of the detectable organic components, of which 15.0% are L-glucose ketone and 38.2% are furfural. The pyrolysis char enters the high-temperature carbonization furnace 3 with a temperature set at 650°C through the pyrolysis char outlet 23. The speed of the carbonization screw feeder 31 is 3r / min. The raw material is further heated up under the push of the carbonization screw feeder 31. Activated carbon is formed under the combined action of physical activation of water vapor from the pretreatment furnace 1 and chemical activation of the pretreatment liquid from the pretreatment furnace 1. The waste heat flue gas enters the pretreatment furnace 1 through the waste heat flue gas outlet 33 to provide the heat required for pretreatment.

[0080] The final specific surface area is 688.1 cm 2 / g, and mesoporous activated carbon with an average pore size of 16.8nm, realizes the multi-product utilization of pyrolysis of biomass waste.

[0081] It should be understood that the above description of the specific embodiments of the present invention is only for illustrating the technical route and features of the present invention, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, but the present invention is not limited to the above specific implementation methods. Any changes or modifications made within the scope of the claims of the present invention should be included in the protection scope of the present invention.

Claims

1. A biomass pyrolysis polygeneration device with a pretreatment system, characterized in that: include: A pretreatment furnace (1), wherein the pretreatment furnace (1) is a hollow tube arranged at an angle, the head end of the pretreatment furnace (1) is lower than the tail end, a feed port (11) is provided at the top of the head end of the pretreatment furnace (1), a circulating feeder (12) is provided inside the pretreatment furnace (1), and a plurality of feed baffles (13) are spaced apart on the circulating feeder (12); a spray port (14) is provided at the top of the tail end of the pretreatment furnace (1), a steam outlet (15) is provided at the bottom of the tail end of the pretreatment furnace (1), and a waste heat flue gas recovery port is also provided at the head end of the pretreatment furnace (1); A low-temperature pyrolysis furnace (2), wherein the low-temperature pyrolysis furnace (2) is a hollow tube arranged obliquely, the end of the low-temperature pyrolysis furnace (2) is lower than the head end, and the end of the pretreatment furnace (1) is butt-jointed with and connected to the head end of the low-temperature pyrolysis furnace (2); a pyrolysis screw feeder (21) is arranged inside the low-temperature pyrolysis furnace (2), a pyrolysis gas outlet (22) is arranged at the top of the end of the low-temperature pyrolysis furnace (2), and a pyrolysis charcoal outlet (23) is arranged at the bottom of the end of the low-temperature pyrolysis furnace (2); A high-temperature carbonization furnace (3), wherein the high-temperature carbonization furnace (3) is a horizontally arranged hollow tube, a carbonization screw feeder (31) is arranged inside the high-temperature carbonization furnace (3), the pyrolytic carbon outlet (23) is connected to the head end of the high-temperature carbonization furnace (3), an activated carbon outlet (32) is arranged at the bottom of the end of the high-temperature carbonization furnace (3), a waste heat flue gas outlet (33) is arranged at the end of the high-temperature carbonization furnace (3), and the waste heat flue gas outlet (33) is connected to the waste heat flue gas recovery port; a steam inlet (34) is arranged at the top of the high-temperature carbonization furnace (3), and the steam outlet (15) is connected to the steam inlet (34) via a one-way air pump (4).

2. The biomass pyrolysis polygeneration device with a pretreatment system according to claim 1, characterized in that: A smoke baffle (35) is provided at the position of the steam inlet (34) in the high-temperature carbonization furnace (3). The smoke baffle (35) is arranged on the side of the steam inlet (34) close to the head end of the high-temperature carbonization furnace (3). The free end of the smoke baffle (35) extends toward the end end of the high-temperature carbonization furnace (3) to guide the gas to diffuse from the head end to the end end of the high-temperature carbonization furnace (3).

3. The biomass pyrolysis polygeneration device with a pretreatment system according to claim 1, characterized in that: The angle formed by the axis of the pretreatment furnace (1) and the axis of the low-temperature pyrolysis furnace (2) is 90° to 120°.

4. The biomass pyrolysis polygeneration device with a pretreatment system according to claim 1, characterized in that: A material blocking baffle (24) protruding upward is provided at the bottom of the joint between the end of the pretreatment furnace (1) and the head end of the low-temperature pyrolysis furnace (2); the feed baffle (13) is a soft plate, and the material blocking baffle (24) is arranged parallel to the feed baffle (13); the gap between the material blocking baffle (24) and the wall of the circulation feeder (12) is 1 to 3 mm.

5. The biomass pyrolysis polygeneration device with a pretreatment system according to claim 1, characterized in that: The interval between adjacent feeding baffles (13) is 20 to 50 mm; the angle between the circulating feeder (12) and the feeding baffle (13) is 45° to 135°; and the gap between the feeding baffle (13) and the inner wall of the pretreatment furnace (1) is 1 to 3 mm.

6. The biomass pyrolysis polygeneration device with a pretreatment system according to claim 1, characterized in that: The outer diameter of the spiral blade of the pyrolysis screw feeder (21) is 0.5 to 0.8 times the outer diameter of the spiral blade of the carbonization screw feeder (31); and the pitch of the spiral blade of the pyrolysis screw feeder (21) is 2N5 times the pitch of the spiral blade of the carbonization screw feeder (31).

7. The biomass pyrolysis polygeneration device with a pretreatment system according to claim 1, characterized in that: The pretreatment furnace (1) is a hollow square tube; The low-temperature pyrolysis furnace (2) and the high-temperature carbonization furnace (3) are both hollow tubes with a D-shaped cross-section. The tops of the low-temperature pyrolysis furnace (2) and the high-temperature carbonization furnace (3) are both flat walls, and a smoke exhaust channel is formed between the flat wall and the corresponding pyrolysis screw feeder (21) or the carbonization screw feeder (31).

8. The biomass pyrolysis polygeneration device with a pretreatment system according to claim 1, characterized in that: The circulating feeder (12) is a conveyor belt.

9. A pyrolysis polygeneration method, which is implemented based on the biomass pyrolysis polygeneration device with a pretreatment system according to any one of claims 1 to 8, characterized in that: The pyrolysis polygeneration method comprises: S1, the circulating feeder (12) rotates clockwise, driving the feeding baffle (13) to move, and the pyrolysis screw feeder (21) and the carbonization screw feeder (31) rotate at a set speed; at the same time, the low-temperature pyrolysis furnace (2) and the high-temperature carbonization furnace (3) are heated to the set temperature respectively; S2, adding raw materials from the feed port (11), the feed baffle (13) drives the raw materials to move in the pretreatment furnace (1), spraying pretreatment liquid from the spray port (14), the pretreatment liquid and the raw materials are mixed and pretreated, and the pretreated raw materials are sent to the low-temperature pyrolysis furnace (2); S3, the raw material is heated in the low-temperature pyrolysis furnace (2), and catalytic pyrolysis occurs under the catalytic action of the pretreatment liquid, thereby generating pyrolysis char and pyrolysis gas; the pyrolysis gas is discharged through the pyrolysis gas outlet (22), and then condensed and separated to obtain pyrolysis oil; the pyrolysis char enters the high-temperature carbonization furnace (3) through the pyrolysis char outlet (23); S4. The water vapor generated by the pretreatment furnace (1) enters the high-temperature carbonization furnace (3) through the one-way air pump (4), and the pyrolytic carbon is further heated in the high-temperature carbonization furnace (3). A carbonization reaction occurs under the combined activation of the water vapor and the pretreatment liquid, thereby generating waste heat flue gas and activated carbon; the activated carbon is discharged through the activated carbon outlet (32) and collected, and the waste heat flue gas is sent back to the pretreatment furnace (1) through the waste heat flue gas outlet (33).

10. The pyrolysis polygeneration method according to claim 9, characterized in that: The temperature of the pretreatment furnace (1) is provided by the waste heat flue gas from the high-temperature carbonization furnace (3), and the temperature of the pretreatment furnace (1) is 150-200° C.; the temperature of the low-temperature pyrolysis furnace (2) and the high-temperature carbonization furnace (3) is electrically heated, and the temperature of the low-temperature pyrolysis furnace (2) is 300-500° C., and the temperature of the high-temperature carbonization furnace (3) is 600-800° C.; And / or, the pretreatment solution is a ZnCl2 solution, a K2SO4 solution or a H3PO4 solution with a concentration of 50-80%.

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