A system for co-production of oil, heat and white carbon black by biomass thermal conversion

Abstract

The present application relates to the field of biomass energy utilization, and particularly relates to a biomass thermal conversion cogeneration oil, heat and white carbon black system, which comprises an acid washing pool, a drying machine, a feeding bin, a rice hull feeding screw, a pyrolysis reactor, a condenser, a chemical chain combustor, a molten salt heat preservation system, an oxygen carrier separator, an oxygen carrier feeding screw, a separator, a cloth bag collector and an oxidation riser. In the technical scheme of the present application, the non-condensable gas is combusted to provide heat for the system, the pyrolysis carbon is combusted by the chemical chain, the oxygen carrier provides the oxygen element required for combustion, the molten salt heat preservation system timely takes away the heat generated by combustion and produces steam, and the combustion over-temperature is prevented. By providing the oxygen element required for combustion by the oxygen carrier and cooperating with the molten salt heat preservation system, the problem that the combustion temperature needs to be strictly controlled in the preparation of white carbon black by the rice hull carbon combustion method is solved, meanwhile, the oxygen carrier and the molten salt are used as the heat carrier for circulation, the heat efficiency is high, and the efficient cogeneration of the bio-oil, steam and white carbon black is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biomass energy utilization, and particularly relates to a biomass thermal conversion system for co-production of oil, heat and white carbon black. BACKGROUND

[0002] The simplest way to treat rice husk is direct combustion to supply energy, but unfortunately, rice husk combustion produces a large amount of rice husk ash, which is difficult to effectively utilize and is prone to secondary pollution. Studies have shown that rice husk contains 15-20wt% of amorphous silicon dioxide (also known as white carbon black), and if the amorphous silicon dioxide can be extracted without destroying its structure to prepare white carbon black, it will be a waste into treasure, and greatly improve the utilization value of rice husk.

[0003] Therefore, scholars have carried out research on comprehensive utilization of rice husk, and have proposed a large number of methods for comprehensive disposal and utilization of rice husk. At present, the mainstream methods include two categories, the first category is to burn the organic components of rice husk for heat, and the inorganic ash is prepared into white carbon black products through a series of means such as alkali dissolution, acid precipitation and granulation; the other category is to pyrolyze the rice husk to convert it into high-quality oil, gas and carbon products, and then deeply utilize the primary products, including burning pyrolysis gas for heat, extracting chemical products and refined fuel oil from pyrolysis oil, and further preparing activated carbon and white carbon black from pyrolysis carbon. Compared with the first category, the first category only realizes the energy utilization of the organic components of rice husk, and produces a large amount of carbon dioxide emissions during combustion, which does not play a role in carbon sequestration and emission reduction, and the preparation of white carbon black from rice husk ash requires the use of a large amount of acid and alkali chemicals, the process is long, and the environmental protection performance is poor. The second category is to first convert rice husk into oil, gas and carbon products, and then deeply utilize them, which has high resource output rate and great development potential, but unfortunately, there is currently a lack of mature comprehensive utilization system for rice husk pyrolysis.

[0004] To this end, Chinese patent application 201520812750.9 proposes a device for simultaneously preparing bio-oil and white carbon black by coupling hydrolysis, baking, pyrolysis and calcination. The device realizes efficient co-production of bio-oil and white carbon black by designing a hydrolysis, baking, pyrolysis and calcination process. However, the process has some shortcomings. First, the calcination temperature is 600-800℃, and research shows that amorphous silicon dioxide, i.e. white carbon black, in rice husk carbon can crystallize at a temperature higher than 650℃, which reduces its quality. Second, the process burns a large amount of rice husk carbon, which produces a large amount of carbon dioxide emissions, which does not comply with the carbon emission reduction policy. In recent years, some scholars have proposed a chemical looping combustion method. Compared with air oxygen supply, chemical looping combustion supplies oxygen through solid oxygen carriers, does not introduce nitrogen during combustion, and the flue gas produced during combustion is almost entirely carbon dioxide, which is easy to capture and collect without carbon dioxide emissions. The solid-solid reaction rate is slow, easy to control and stable, and the combustion temperature distribution is uniform, which is very suitable for temperature-controlled preparation of high-quality white carbon black from rice husk carbon. However, there is currently a lack of a corresponding rice husk disposal system. Therefore, it is urgent to develop an efficient rice husk comprehensive disposal and utilization system to realize efficient utilization of all components of rice husk. SUMMARY

[0005] (I) Technical problems to be solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present application provides a biomass thermal conversion co-production of oil, heat and white carbon black system for realizing efficient utilization of all components of rice husk.

[0007] (II) Technical solutions

[0008] In order to achieve the above-mentioned purpose, the biomass thermal conversion co-production of oil, heat and white carbon black system of the present application comprises: an acid pickling tank, a dryer, a feed bin, a rice husk feeding screw, a pyrolysis reactor, a condenser, a chemical looping combustor, a molten salt heat preservation system, an oxygen carrier separator, an oxygen carrier feeding screw, a separator, a bag collector and an oxidation riser;

[0009] The acid pickling tank, the material channel of the dryer, the feed bin, the rice husk feeding screw and the pyrolysis reactor are connected in sequence to transport and process the rice husk;

[0010] The pyrolysis gas outlet of the pyrolysis reactor is connected to the condenser, the condenser cools the condensable components in the pyrolysis gas to bio-oil, and the non-condensable gas is transported to the oxidation riser through a gas outlet pipeline, and the solid outlet of the pyrolysis reactor is connected to the feeding port of the chemical looping combustor;

[0011] The feed inlet of the chemical looping combustor is also connected with the discharge outlet of the oxygen carrier feed screw, the discharge outlet of the chemical looping combustor is connected with the feed inlet of the separator, the chemical looping combustor can sufficiently mix and heat the rice husk char and the oxygen carrier, so that the rice husk char generates white carbon black through combustion reaction; the molten salt heat preservation system is connected with the molten salt channel of the chemical looping combustor to take away the heat generated by the combustion of the rice husk char and generate steam;

[0012] The separator separates the oxygen carrier and the white carbon black, the oxygen carrier can be discharged to the gas outlet pipeline through the solid outlet of the separator and carried to the oxidation riser by the non-condensable gas discharged from the condenser; the white carbon black can be discharged through the outlet at the upper end of the separator and enter the bag collector;

[0013] The lower end of the oxidation riser is also provided with an air inlet channel, the flue gas generated by combustion carries the oxygen carrier to rise to the oxygen carrier separator, and the outlet at the lower end of the oxygen carrier separator is connected with the feed inlet of the oxygen carrier feed screw.

[0014] Optionally, the flue gas outlet at the upper end of the oxygen carrier separator is connected with the air inlet of the pyrolysis reactor, the flue gas outlet of the pyrolysis reactor is connected with the flue duct in the dryer, and the flue gas outlet of the dryer is connected with the feed inlet of the separator.

[0015] Optionally, the pyrolysis reactor is a rotary furnace, a spiral pyrolysis reactor or a down-flow bed reactor, and the pyrolysis temperature is controlled to be 400-600°C.

[0016] Optionally, the working temperature of the molten salt of the molten salt heat preservation system is 350-550°C.

[0017] Optionally, the oxygen carrier is an oxide of one of iron-based, nickel-based, manganese-based and copper-based or a composite oxide of several of them; the oxygen carrier is in a granular form and the particle size distribution is 0.5-2mm.

[0018] Optionally, the chemical looping combustor is a spiral reactor, a moving bed reactor or a rotary kiln reactor.

[0019] Optionally, the spiral reactor comprises a driving motor, a sealing joint, a furnace body, a heat preservation sleeve and a sealing end head.

[0020] The furnace body comprises a cylindrical furnace wall and a spiral shaft with spiral blades rotatably arranged in the furnace wall; the upper part close to the first end of the furnace wall is sequentially provided with an oxygen carrier inlet and a rice husk char inlet, the lower part close to the second end of the furnace wall is provided with a discharge outlet, the position close to the rice husk char inlet to the upper part of the second end of the furnace wall protrudes upward to form a flue gas channel with the spiral blades, and a plurality of flue gas outlets are arranged on the flue gas channel.

[0021] The heat preservation sleeve is arranged outside the furnace wall, and a spiral guide vane is arranged in an annular space between the heat preservation sleeve and the furnace wall, a molten salt inlet is formed at a second end of the annular space, and a molten salt outlet is formed at a first end of the annular space;

[0022] A sealing joint is arranged at a first end of the furnace wall, and a sealing end head is arranged at a second end of the furnace wall, and the sealing joint and the sealing end head jointly support rotation of the spiral shaft;

[0023] The driving motor is connected with the spiral shaft through the sealing joint, so as to drive the spiral shaft to rotate.

[0024] Optionally, the molten salt inlet is located at a lower part of the second end of the annular space, and an extension direction of the molten salt inlet is perpendicular to an axis direction of the annular space;

[0025] The molten salt outlet is located at an upper part of the first end of the annular space, and an extension direction of the molten salt outlet is perpendicular to an axis direction of the annular space.

[0026] Optionally, a reverse blade with 0.5-1.0 pitch is arranged on the spiral shaft close to the second end, the reverse blade is opposite to the spiral blade in rotation direction and has equal pitch, and the discharge port is located between the spiral blade and the reverse blade.

[0027] And / or, the pitch of the spiral blade is 0.8-2.0 times of the diameter of the spiral shaft.

[0028] Optionally, the oxygen carrier inlet is away from the rice hull carbon inlet by 3-6 pitches.

[0029] And / or, the rice hull carbon inlet is away from the flue gas passage by 1-2 pitches.

[0030] (Three) beneficial effects

[0031] The biomass thermal conversion co-production oil, heat and white carbon black system of the application first performs acid pickling and ash removal on the rice hull, and then further pyrolyzes and converts the rice hull into oil, gas and carbon products, and then respectively disposes the pyrolysis oil, gas and carbon, that is, condenses and collects the pyrolysis oil, burns the pyrolysis gas to supply heat, and chemically chains and burns the pyrolysis carbon to obtain white carbon black, and the heat generated by the burning is used for producing steam, so as to realize efficient comprehensive utilization of the rice hull. Specifically, by coupling the pyrolysis and chemical chain combustion methods, the rice hull is converted into high-quality pyrolysis oil, steam and white carbon black products, and efficient full-component utilization of the rice hull is realized.

[0032] And the system designs the chemical chain combustor and the molten salt heat preservation system coupling utilization, realizes the accurate temperature control through the chemical chain combustor, guarantees the white carbon black quality, and the oxygen carrier is used as the oxygen supply agent, does not introduce the additional impurity in the flue gas, and the flue gas is almost all CO2, is convenient for subsequent capture, and does not produce carbon emission; energy produced during combustion is taken away in time through the molten salt heat preservation system, and the temperature stability of the chemical chain combustor is further ensured by utilizing the characteristics of the molten salt, such as large specific heat and small temperature change of heat absorption / heat release.In addition, the oxygen carrier and the molten salt can be recycled in the system, steam is produced by using the molten salt heat preservation system, energy waste is not caused, the system has high energy efficiency, and the steam quality is good.

[0033] In addition, the system is designed to react with the non-condensable gas and the oxygen carrier in the oxidation riser, which can ensure that the oxidation riser maintains a high temperature, improve the activity of the oxygen carrier and oxygen, and ensure that the two fully react to restore the oxygen supply capacity of the oxygen carrier; the flue gas generated by the combustion of non-condensable gas can further be used as energy for the pyrolysis and drying process to realize self-heating operation of the system; and the flue gas after heat exchange can also be used as a power source for the separation of the oxygen carrier and white carbon black, further playing a role.

[0034] In summary, in the technical scheme of the present application, the non-condensable gas is combusted to provide heat for the system, the pyrolysis carbon is combusted by chemical chain combustion, the oxygen carrier provides the oxygen elements required for combustion, the molten salt heat preservation system takes away the heat generated by combustion in time to produce steam and prevent overtemperature combustion. By providing the oxygen elements required for combustion through the oxygen carrier and using the molten salt heat preservation system, the problem of needing to strictly control the combustion temperature in the preparation of white carbon black by the rice husk carbon combustion method is solved, and the oxygen carrier and the molten salt are recycled as heat carriers, so the system has high thermal efficiency and realizes the efficient co-production of bio-oil, steam and white carbon black. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is a structure schematic diagram of the biomass thermal conversion cogeneration oil, heat and white carbon black system of the present application.

[0036] Figure 2 It is a structure schematic diagram of the chemical chain combustor of the present application.

[0037]

Explanation of reference numerals

[0038] 1: acid washing tank; 2: drying machine; 3: feeding bin; 4: rice husk feeding screw; 5: pyrolysis reactor; 6: condenser; 7: chemical chain combustor; 8: molten salt heat preservation system; 9: oxygen carrier separator; 10: oxygen carrier feeding screw; 11: separator; 12: bag collector; 13: oxidation riser.

[0039] 7-1: drive motor; 7-2: sealing joint; 7-3: furnace body; 7-4: heat preservation sleeve; 7-5: sealing end; 7-31: spiral shaft; 7-32: spiral blade; 7-33: flue gas passage; 7-34: reverse blade; 7-35: oxygen carrier inlet; 7-36: rice husk charcoal inlet; 7-37: flue gas outlet; 7-38: discharge port; 7-41: spiral guide vane; 7-42: molten salt inlet; 7-43: molten salt outlet. DETAILED DESCRIPTION

[0040] In order to better explain the present application, so as to be understood, the present application is described in detail below by specific embodiments, combined with the accompanying drawings.

[0041] It should be noted that all directional directions (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), if the specific posture changes, the directional directions also change accordingly.

[0042] In addition, in the present application, the description such as "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0043] In the present application, unless otherwise specifically defined and limited, the terms "connection", "fixing" and the like should be understood broadly, for example, "fixing" can be fixed connection, or detachable connection, or integral; "connection" can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] Reference Figure 1 The present application provides a biomass thermal conversion co-production oil, heat, white carbon black system, which comprises: an acid washing pool 1, a drying machine 2, a feeding bin 3, a rice husk feeding screw 4, a pyrolysis reactor 5, a condenser 6, a chemical chain combustor 7, a molten salt heat preservation system 8, an oxygen carrier separator 9, an oxygen carrier feeding screw 10, a separator 11, a bag collector 12 and an oxidation riser 13.

[0045] The acid washing tank 1, the material channel of the drying machine 2, the feeding bin 3, the rice husk feeding screw 4 and the pyrolysis reactor 5 are sequentially connected to transfer and process the rice husks. The rice husks are cleaned and deashed in the acid washing tank 1, then dehydrated mechanically and fed into the drying machine 2. The material outlet of the drying machine 2 is connected with the feeding bin 3. The lower end of the feeding bin 3 is connected with the rice husk feeding screw 4. The rice husk feeding screw 4 delivers the material to the pyrolysis reactor 5.

[0046] The pyrolysis reactor 5 can adopt a spiral pyrolysis reactor, which is externally provided with a flue gas heating jacket. The flue gas required for heating is separated from the flue gas by the oxygen carrier separator 9. The pyrolysis gas outlet of the pyrolysis reactor 5 is connected with the condenser 6. The condenser 6 cools the condensable components in the pyrolysis gas into bio-oil, and delivers the non-condensable gas to the oxidation riser 13 through a gas outlet pipeline. The solid outlet of the pyrolysis reactor 5 is connected with the feeding port of the chemical looping combustor 7. The feeding port of the chemical looping combustor 7 is described in detail in the following. Figure 2 The pyrolysis reactor 5 can adopt a spiral pyrolysis reactor, which is externally provided with a flue gas heating jacket. The flue gas required for heating is separated from the flue gas by the oxygen carrier separator 9. The pyrolysis gas outlet of the pyrolysis reactor 5 is connected with the condenser 6. The condenser 6 cools the condensable components in the pyrolysis gas into bio-oil, and delivers the non-condensable gas to the oxidation riser 13 through a gas outlet pipeline. The solid outlet of the pyrolysis reactor 5 is connected with the feeding port of the chemical looping combustor 7. The feeding port of the chemical looping combustor 7 is described in detail in the following.

[0047] The chemical looping combustor 7 can also adopt a spiral form, which is externally provided with a heat preservation sleeve 7-4 connected with the molten salt heat preservation system 8. The feeding port of the chemical looping combustor 7 (herein, the oxygen carrier inlet 7-35) is also connected with the discharge port of the oxygen carrier feeding screw 10. The discharge port 7-38 of the chemical looping combustor 7 is connected with the feeding port of the separator 11. The chemical looping combustor 7 can fully mix and heat the rice husk carbon and the oxygen carrier entering the interior, so that the rice husk carbon is combusted to generate white carbon black. The molten salt heat preservation system 8 is connected with the molten salt channel of the chemical looping combustor 7 (specifically, the channel formed by the heat preservation sleeve 7-4) to take away the heat generated by the combustion of the rice husk carbon and generate steam. The working temperature of the molten salt of the molten salt heat preservation system 8 can be preferably 350-550℃. The molten salt heat preservation system 8 can adopt the mature molten salt energy storage system at present. The molten salt can be circulated between the chemical looping combustor 7 and the molten salt heat preservation system 8. The chemical looping combustor 7 and the molten salt heat preservation system 8 are coupled and utilized. The precise temperature control of the rice husk carbon combustion process is realized by the chemical looping combustor 7 to ensure the quality of the white carbon black. The oxygen carrier serves as an oxygen supplier and does not introduce additional impurities into the flue gas. The flue gas is almost CO2, which is convenient for subsequent capture and does not produce carbon emissions. The energy generated by the combustion is taken away in time by the molten salt heat preservation system 8. The specific heat of the molten salt is large, and the temperature change of the molten salt during heat absorption / heat release is small, which further ensures the stable and uniform temperature of the chemical looping combustor 7. In addition, the oxygen carrier and the molten salt can be recycled in the system. The molten salt heat preservation system is used to produce steam, which does not cause energy waste. The system has high energy efficiency and good steam quality.

[0048] The separator 11 separates the oxygen carrier from the white carbon black, the oxygen carrier can be discharged to the gas outlet pipeline through the solid outlet at the lower end of the separator 11 and is carried to the oxidation riser 13 by the non-condensable gas discharged from the condenser 6; the white carbon black can be discharged through the outlet at the upper end of the separator 11 and enter the bag collector 12; the bag collector 12 captures and collects the white carbon black entering the bag collector 12, while discharging the flue gas for conveying solids.

[0049] The lower end of the oxidation riser 13 is also provided with an air inlet channel, which can provide combustion-supporting air for non-condensable gas combustion and can also provide combustion-supporting air for the re-oxidation of the oxygen carrier. The flue gas generated by combustion carries the oxygen carrier upward to the oxygen carrier separator 9, and the outlet at the lower end of the oxygen carrier separator 9 is connected to the inlet of the oxygen carrier feeding screw 10, so that the oxygen carrier is recycled during the operation of the system. By making the non-condensable gas and the oxygen carrier react simultaneously in the oxidation riser, the non-condensable gas combustion can ensure that the oxidation riser maintains a high temperature, improves the activity of the oxygen carrier and oxygen, and ensures that the two fully react to restore the oxygen supply capacity of the oxygen carrier; the flue gas generated by the non-condensable gas combustion can further be used as energy for the pyrolysis and drying process to realize self-heating operation of the system; and the flue gas after heat exchange can also be used as a power source for the separation of the oxygen carrier and the white carbon black, and further play a role.

[0050] The biomass thermal conversion system for co-production of oil, heat and white carbon black of the application first performs acid pickling and deashing on rice husks, then further converts the rice husks into oil, gas and carbon products by pyrolysis, and then disposes the pyrolysis oil, gas and carbon respectively, i.e. condenses and collects the pyrolysis oil, burns the pyrolysis gas for heat supply, and obtains white carbon black by chemical looping combustion of the pyrolysis carbon, and the heat generated by combustion is used for steam production, thereby realizing efficient comprehensive utilization of rice husks. Specifically, by coupling pyrolysis and chemical looping combustion methods, the rice husks are converted into high-quality pyrolysis oil, steam and white carbon black products, realizing efficient full-component utilization of rice husks.

[0051] In order to further improve the thermal efficiency, the flue gas outlet at the upper end of the oxygen carrier separator 9 is connected to the gas inlet of the pyrolysis reactor 5, the flue gas outlet of the pyrolysis reactor 5 is connected to the flue duct in the drying machine 2, and the flue gas outlet of the drying machine 2 is connected to the feeding inlet of the separator 11. The high-temperature flue gas discharged from the oxygen carrier separator 9 first enters the pyrolysis reactor 5 to provide energy for the pyrolysis process, then enters the drying machine 2 to further recover the waste heat of the flue gas, and finally enters the separator 11 as a power source for the separation of the oxygen carrier and the white carbon black. The oxygen carrier is an oxide of one of iron-based, nickel-based, manganese-based and copper-based or a composite oxide of several of them; the oxygen carrier is in a granular form and has a particle size distribution of 0.5-2 mm.

[0052] In addition, in the preferred embodiment, the pyrolysis reactor 5 can be a rotary furnace, a spiral pyrolysis reactor or a down-flow bed reactor, and the pyrolysis temperature is controlled to be 400-600℃.

[0053] Further, the chemical looping combustor 7 can be a screw reactor, a moving bed reactor, or a rotary kiln reactor, etc. In a preferred embodiment, as shown in Figure 2 The chemical looping combustor 7 can include a driving motor 7-1, a sealing joint 7-2, a furnace body 7-3, a heat preservation sleeve 7-4, and a sealing end 7-5.

[0054] The furnace body 7-3 includes a cylindrical furnace wall and a screw shaft 7-31 with screw blades 7-32 rotatably arranged in the furnace wall, wherein the screw blades 7-32 can be welded on the screw shaft 7-31. The upper part of the furnace wall near the first end is sequentially provided with an oxygen carrier inlet 7-35 and a rice husk char inlet 7-36. The oxygen carrier is first put into the furnace body 7-3, then moves along the screw blades 7-32 to heat up, and then contacts and collides with the rice husk char to ensure the temperature control effect. At the same time, the oxygen carrier and the rice husk char collide and grind with each other in the furnace, which can reduce the particle size of the white carbon black and improve its quality. In addition, the lower part of the furnace wall near the second end is provided with a discharge port 7-38, and the position of the furnace wall near the rice husk char inlet 7-36 to the upper part of the second end protrudes upward to form a flue gas passage 7-33 between the screw blades 7-32. The flue gas passage 7-33 can be a rectangular passage, so that the cross section of the furnace wall is approximately U-shaped. The upper part of the flue gas passage 7-33 is provided with a plurality of flue gas outlets 7-37 for discharging flue gas, which can help to quickly discharge flue gas.

[0055] Further, the furnace wall is provided with a heat preservation sleeve 7-4, and a spiral guide vane 7-41 is arranged in the annular space between the heat preservation sleeve 7-4 and the furnace wall. Specifically, the spiral guide vane 7-41 can be welded on the outer surface of the furnace body 7-3, and the inner shape of the spiral guide vane 7-41 is matched with the shape of the furnace wall. The second end of the annular space is formed with a molten salt inlet 7-42, and the first end of the annular space is formed with a molten salt outlet 7-43. The first end of the furnace wall is provided with a sealing joint 7-2, and the second end of the furnace wall is provided with a sealing end 7-5. The sealing joint 7-2 and the sealing end 7-5 jointly support the rotation of the screw shaft 7-31. The driving motor 7-1 is connected with the screw shaft 7-31 through the sealing joint 7-2, so as to drive the screw shaft 7-31 to rotate. The first end of the furnace wall and the first end of the annular space are both the end close to the driving motor 7-1.

[0056] The rice hull charcoal and the oxygen carrier enter the furnace body 7-3 from different inlets respectively, are fully mixed under the stirring of the helical blade 7-32, the rice hull charcoal generates combustion reaction to generate white carbon black, and moves to the discharge port 7-38 under the driving of the helical blade 7-32 to be discharged, the heat preservation sleeve 7-4 outside the furnace body 7-3 is connected to the molten salt at 350-450 DEG C, so as to prevent the furnace body 7-3 from being overheated or hypothermic due to too fast or too slow combustion of the rice hull charcoal. The above-mentioned rice hull charcoal chemical chain combustion preparation white carbon black device adopts a helical combustion device, controls the residence time of the material in the furnace, controls the combustion rate by controlling the proportion of the oxygen carrier and the rice hull charcoal, and combines the external molten salt heat preservation system to control the temperature, so as to realize accurate temperature control of the combustion process, ensure that the rice hull charcoal is completely burned, and at the same time, the amorphous silicon dioxide structure is not damaged. At the same time, the oxygen carrier and the rice hull charcoal collide and grind in the furnace, so as to reduce the particle size of the white carbon black and improve the quality thereof. Compared with the conventional combustion gas-solid reaction preparation white carbon black of the rice hull charcoal, the chemical chain combustion is a solid-solid reaction, the reaction rate control is more stable, the temperature control is more uniform, local overheating is prevented, and the quality of the white carbon black is better.

[0057] Furthermore, the helical combustion device is ingeniously designed in the above-mentioned scheme, the driving motor 7-1 is used to control the helical rotation speed, so as to control the residence time of the material in the furnace, ensure the full combustion of the material, and the operation is simple; the oxygen carrier inlet 7-35 and the rice hull charcoal inlet 7-36 are separately arranged, so as to facilitate the adjustment of the proportion of the two, control the combustion rate by controlling the proportion of the oxygen carrier and the rice hull charcoal, and control the temperature by combining the molten salt heat preservation system, so as to realize the efficient preparation of the rice hull source white carbon black. The flue gas channel 7-33 is designed to timely guide out the combustion generated gas, so as to solve the problem that the device operation is affected due to the fact that the combustion flue gas cannot be timely guided out and the pressure in the furnace is too large, and the stability of the equipment operation is improved. The external molten salt heat preservation system is connected through the molten salt inlet 7-42 and the molten salt outlet 7-43, the molten salt has the characteristics of large specific heat capacity and small temperature change amplitude during heat absorption / heat release, the temperature in the furnace is uniform, the temperature in the furnace is prevented from being too low to cause the carbon to be incompletely pyrolyzed, and the temperature in the furnace is prevented from being too high to damage the amorphous silicon dioxide structure, and the quality of the white carbon black is further ensured.

[0058] In the preferred embodiment, the molten salt inlet 7-42 is located at the lower part of the second end of the annular space, and the extension direction of the molten salt inlet 7-42 is perpendicular to the axis direction of the annular space; the molten salt outlet 7-43 is located at the upper part of the first end of the annular space, and the extension direction of the molten salt outlet 7-43 is perpendicular to the axis direction of the annular space. In this way, the extension direction of the molten salt inlet 7-42 or the molten salt outlet 7-43 is the same as the tangent direction of the helical guide vane 7-41, so that the flow of the molten salt feeding and discharging is smooth.

[0059] Further, referring again to Figure 1In a more preferable embodiment, a reverse blade 7-34 is arranged on the spiral shaft 7-31 near the second end, and the reverse blade 7-34 is opposite to the spiral blade 7-32 in rotation direction and has the same pitch. The discharge port 7-38 is located between the spiral blade 7-32 and the reverse blade 7-34, i.e. no spiral blade 7-32 and reverse blade 7-34 are arranged on the spiral shaft 7-31 opposite to the discharge port 7-38, so as to ensure that the solid is completely discharged. And / or, the pitch of the spiral blade 7-32 is 0.8-2.0 times the diameter of the spiral shaft 7-31, so as to control the feeding speed.

[0060] In addition, the oxygen carrier inlet 7-35 is 3-6 pitches away from the rice husk carbon inlet 7-36, so as to ensure that the oxygen carrier has enough time to warm up. And / or, the rice husk carbon inlet 7-36 is 1-2 pitches away from the flue gas passage 7-33, so as to ensure that the oxygen carrier and the rice husk carbon can smoothly discharge the flue gas when starting to react after mixing. The top of the flue gas passage 7-33 is 50-100 mm higher than the top of the spiral blade 7-32, so as to form a large enough flue gas expansion space, so as to prevent the pressure of the flue gas from being too large, and a plurality of flue gas outlets 7-37 are arranged correspondingly, so as to minimize the residence time of the flue gas.

[0061] It should be understood that the above description of the specific embodiments of the present application is only for the purpose of illustrating the technical route and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, but the present application is not limited to the above specific embodiments. Any changes or modifications made within the scope of the claims of the present application shall be covered within the protection scope of the present application.

Claims

1. A biomass thermal conversion system for the co-production of oil, heat, and silica, characterized in that, The system comprises an acid washing tank (1), a dryer (2), a feeding bin (3), a rice husk feeding screw (4), a pyrolysis reactor (5), a condenser (6), a chemical looping combustor (7), a molten salt heat preservation system (8), an oxygen carrier separator (9), an oxygen carrier feeding screw (10), a separator (11), a bag collector (12) and an oxidation riser (13); The acid washing tank (1), the material channel of the dryer (2), the feeding bin (3), the rice husk feeding screw (4) and the pyrolysis reactor (5) are sequentially connected to transfer and process the rice husk; The pyrolysis gas outlet of the pyrolysis reactor (5) is connected with the condenser (6), the condenser (6) cools the condensable components in the pyrolysis gas into bio-oil, and the non-condensable gas is transported to the oxidation riser (13) through a gas outlet pipeline, and the solid outlet of the pyrolysis reactor (5) is connected with the feeding inlet of the chemical looping combustor (7); The feeding inlet of the chemical looping combustor (7) is also connected with the discharging outlet of the oxygen carrier feeding screw (10), the discharging outlet (7-38) of the chemical looping combustor (7) is connected with the feeding inlet of the separator (11), the chemical looping combustor (7) can fully mix the rice husk char and the oxygen carrier and heat them to make the rice husk char generate white carbon black through combustion reaction; the molten salt heat preservation system (8) is connected with the molten salt channel of the chemical looping combustor (7) to take away the heat generated by the combustion of the rice husk char and generate steam; The separator (11) separates the oxygen carrier from the white carbon black, the oxygen carrier is discharged to the gas outlet pipeline through the solid outlet of the separator (11) and is carried to the oxidation riser (13) by the non-condensable gas discharged from the condenser (6); the white carbon black is discharged through the outlet at the upper end of the separator (11) and enters the bag collector (12); The lower end of the oxidation riser (13) is also provided with an air inlet channel, the flue gas generated by combustion carries the oxygen carrier to rise to the oxygen carrier separator (9), and the outlet at the lower end of the oxygen carrier separator (9) is connected with the feeding inlet of the oxygen carrier feeding screw (10); The chemical looping combustor (7) is a spiral reactor, wherein the spiral reactor comprises a driving motor (7-1), a sealing joint (7-2), a furnace body (7-3), a heat preservation sleeve (7-4) and a sealing end head (7-5); The furnace body (7-3) comprises a cylindrical furnace wall and a spiral shaft (7-31) with spiral blades (7-32) rotatably arranged in the furnace wall; the upper part close to the first end of the furnace wall is sequentially provided with an oxygen carrier inlet (7-35) and a rice husk char inlet (7-36), the lower part close to the second end of the furnace wall is provided with a discharging outlet (7-38), and the position close to the rice husk char inlet (7-36) to the upper part of the second end of the furnace wall protrudes upward to form a flue gas channel (7-33) with the spiral blades (7-32), and a plurality of flue gas outlets (7-37) are arranged on the flue gas channel (7-33); The heat preservation sleeve (7-4) is arranged outside the furnace wall, and helical guide vanes (7-41) are arranged in an annular space between the heat preservation sleeve (7-4) and the furnace wall; a molten salt inlet (7-42) is formed at a second end of the annular space; and a molten salt outlet (7-43) is formed at a first end of the annular space; The first end of the furnace wall is provided with the sealing joint (7-2), and the second end of the furnace wall is provided with the sealing end (7-5); and the sealing joint (7-2) and the sealing end (7-5) jointly support rotation of the helical shaft (7-31); The driving motor (7-1) is connected with the helical shaft (7-31) through the sealing joint (7-2) to drive the helical shaft (7-31) to rotate.

2. The biomass thermal conversion co-production of oil, heat, white carbon black system according to claim 1, characterized in that, The flue gas outlet at the upper end of the oxygen carrier separator (9) is connected with the gas inlet of the pyrolysis reactor (5); the flue gas outlet of the pyrolysis reactor (5) is connected with a flue in the dryer (2); and the flue gas outlet of the dryer (2) is connected with the feed inlet of the separator (11).

3. The biomass thermal conversion co-production of oil, heat, and white carbon black system of claim 1, wherein, The pyrolysis reactor (5) is a rotary furnace, a helical pyrolysis reactor or a down-flow bed reactor, and the pyrolysis temperature is controlled to be 400-600 ℃.

4. The biomass thermal conversion co-production of oil, heat, and white carbon black system of claim 1, wherein, The working temperature of the molten salt in the molten salt heat preservation system (8) is 350-550 ℃.

5. The biomass thermal conversion co-production of oil, heat, and white carbon black system of claim 1, wherein, The oxygen carrier is an oxide of one of iron-based, nickel-based, manganese-based and copper-based or a composite oxide of several of them; and the oxygen carrier is in a granular form with a particle size distribution of 0.5-2 mm.

6. The system for co-production of oil, heat and white carbon black from biomass thermal conversion according to any one of claims 1-5, wherein, The molten salt inlet (7-42) is located at the lower part of the second end of the annular space, and the extension direction of the molten salt inlet (7-42) is perpendicular to the axial direction of the annular space; The molten salt outlet (7-43) is located at the upper part of the first end of the annular space, and the extension direction of the molten salt outlet (7-43) is perpendicular to the axial direction of the annular space.

7. The system for co-production of oil, heat and white carbon black from biomass thermal conversion according to any one of claims 1-5, wherein, The reverse blade (7-34) is arranged on the helical shaft (7-31) near the second end, and has 0.5-1.0 pitch; the reverse blade (7-34) is opposite to the helical blade (7-32) in the rotation direction and has the same pitch; and the discharge port (7-38) is located between the helical blade (7-32) and the reverse blade (7-34); And / or, the pitch of the helical blade (7-32) is 0.8-2.0 times the diameter of the helical shaft (7-31).

8. The system for co-production of oil, heat and white carbon black from biomass thermal conversion according to any one of claims 1-5, wherein, The oxygen carrier inlet (7-35) is spaced apart from the rice hull charcoal inlet (7-36) by 3-6 pitches; And / or, the rice hull charcoal inlet (7-36) is spaced apart from the flue gas passage (7-33) by 1-2 pitches.

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