CN108949203B - A biomass pyrolysis system with solid heat carrier circulation - Google Patents

Abstract

The embodiment of the invention provides a biomass pyrolysis system with a solid heat carrier circulation, which comprises a raw material drying system, a circulation reaction system and a spraying cooling system. When the biomass pyrolysis system works, the biomass raw materials are dried in the raw material drying system after being crushed, and the biomass raw materials and the solid heat carrier are subjected to fast pyrolysis reaction in a descending pyrolysis reactor of the circulating reaction system to generate pyrolysis gas and biochar, wherein the solid heat carrier is heated by a heating fluidized bed and is recycled in the descending pyrolysis reactor. According to the biomass pyrolysis system, the biomass raw material is pyrolyzed by the solid heat carrier circulating biomass pyrolysis system, and the heating, pyrolysis and separation processes of the solid heat carrier are reasonably arranged, so that the complexity problem in the circulating process of the solid heat carrier is solved, the characteristics of the solid heat carrier and the biomass raw material are fully utilized, the biomass is rapidly heated and pyrolyzed, and the pyrolysis process has the advantages of high thermal efficiency, high bio-oil yield and high oil product quality.

Description

A biomass pyrolysis system with solid heat carrier circulation

technical field

The invention belongs to the technical field of biomass energy, in particular to a biomass pyrolysis system with solid heat carrier circulation, which can be used for producing high-yield liquid fuel bio-oil, combustible gas and bio-char products from biomass.

Background technique

Biomass refers to the organic matter produced by solar photosynthesis, which can be used mainly include various agricultural and forestry wastes such as straw, sawdust, rice husks, etc. The world will produce 4 billion tons of dry matter agricultural and forestry wastes every year. With the progress of world industrialization, energy demand and environmental protection have become the top issues that many governments need to solve. Biomass energy is recognized as one of the most important alternative energy sources. The realization of efficient and clean energy utilization of biomass can provide economic and social benefits. Harmonious development provides a strong guarantee.

Biomass pyrolysis is currently an important technology for utilizing biomass as energy. Biomass pyrolysis refers to the rapid heating of biomass raw materials under the condition of complete lack of oxygen or very little oxygen content to produce solid product biochar, gas product combustible gas and liquid product bio-oil. The yield of bio-oil and combustible gas can be greater than 70%. Bio-oil is a clean and environmentally friendly liquid fuel, which can replace the use of fossil fuels such as heavy oil and diesel in industrial or civil fields, and can also extract various chemical products. It is a clean, environmentally friendly and renewable biological crude oil. Biomass pyrolysis technology can convert biomass raw materials with low bulk density into bio-oil that is easy to transport, store and utilize centrally. It has great advantages for dealing with scattered biomass resources. Therefore, extensive research and Industrialization promotion.

Biomass pyrolysis process can be divided into heat supply methods with heat carrier and without heat carrier. Due to the low efficiency of the heat carrier-free pyrolysis process system, the current research focus is mainly on processes with heat carrier, such as fluidized bed, ablation bed, Rotary cone and other types of reactors. Heat carrier can be divided into two categories: one is gas heat carrier, which mainly uses pyrolysis gas product or nitrogen, combined with the method of fluidized bed, so that biomass particles are mixed and heated by gas heat carrier to realize momentum exchange It has the advantages of less moving parts, simple structure and reliable operation, but the disadvantage is that the gas heat carrier is used, which not only increases the processing capacity of subsequent cooling of the equipment, but also needs to continue to heat the cooled gas heat carrier, resulting in the total system The thermal efficiency is not high; according to the rapid pyrolysis reaction conditions, if a gas heat carrier is used to provide a uniform reaction temperature, 10-20m ³ gas heat carrier of pyrolysis gas is required for every 1kg of material, so the equipment is bulky and the production cost is high. It brings great difficulties; the other type is solid heat carrier, generally sand or ceramic balls are used, and the solid heat carrier is heated and fully mixed with biomass particles to realize heat transfer. Due to the high heat capacity per unit volume of solid heat carrier, the reduction of The volume of the equipment is reduced, and the production cost of the equipment is controlled; the solid heat carrier is generally recycled, and the energy consumption is small, which improves the thermal efficiency of the system; in addition, no or very little additional gas is required, which reduces the process energy consumption of the cooling system and avoids Diluted pyrolysis of non-condensable gases. Therefore, in terms of thermal efficiency, equipment cost and energy consumption, the solid heat carrier pyrolysis process has great advancement and has become a hot spot of current research. The pyrolysis process using solid heat carrier involves a series of steps such as mixing, uniform distribution, reaction residence time, heating, lifting, and separation of solid heat carrier and biomass raw materials, and involves gas-solid, solid-solid under high temperature conditions. Equal separation process leads to complex design of the pyrolysis process and high failure rate, which hinders the development of this technology. Therefore, it is an urgent technical problem to develop a biomass pyrolysis process with a solid heat carrier circulation that can overcome the above-mentioned defects.

SUMMARY OF THE INVENTION

In view of the above technical problems, the present invention develops a biomass pyrolysis system with a solid heat carrier circulation. Through a specially designed pyrolysis system including a pyrolysis reactor and a solid-solid separator, the rapid heating of the solid heat carrier is realized. The circulation and separation overcome the problems of complex design and high failure rate of the current solid heat carrier biomass pyrolysis process, and ensure the long-term operation capability of the pyrolysis system.

In order to solve the above technical problems, the embodiment of the present invention provides a biomass pyrolysis system with solid heat carrier circulation, including a raw material drying system, a circulating reaction system and a spray cooling system, and the raw material drying system includes a drying hopper , a drying fluidized bed and a first cyclone separator; the circulating reaction system includes a pyrolysis hopper, a descending pyrolysis reactor, an upper solid heat carrier hopper, a lower solid heat carrier chamber, a solid-solid separator, a heating fluidized bed, primary cyclone separator, secondary cyclone separator, gas-solid separator, secondary cyclone separator, charcoal cooler and hot smoke furnace; the spray cooling system includes a forward spray tower, filter, purification tower, gas tank and oil storage tank, wherein: the drying hopper is connected to the drying fluidized bed, the drying fluidized bed is connected to the first cyclone separator, and the first cyclone separator is connected to the The pyrolysis hopper transports solids; both the pyrolysis hopper and the upper solid heat carrier hopper are connected to discharge materials to the descending pyrolysis reactor, and the descending pyrolysis reactor is connected to the first-stage cyclone separator The pyrolysis mixture is discharged; the first-stage cyclone is connected to the lower solid heat carrier chamber to discharge solids, and the second-stage cyclone is connected to discharge gas; the second-stage cyclone is connected to the forward spray tower to discharge The gas is connected to the charcoal cooler to discharge the biochar; the lower solid heat carrier chamber is connected to the solid-solid separator; the solid-solid separator is connected to the lower part of the heating fluidized bed to discharge the solid heat carrier, and is connected to the solid-solid separator. The second cyclone separator discharges gas; the second cyclone separator is connected to the solid-solid separator to discharge gas, and the second cyclone separator is connected to the charcoal cooler to discharge biochar; the heating fluidized bed The upper part is connected to the gas-solid separator; the gas-solid separator is connected to the upper solid heat carrier bucket to discharge the separated solid, and the flue gas discharged after separation is connected to the secondary cyclone separator and the primary cyclone in turn. The outer heating jacket of the separator is then passed into the drying fluidized bed; the hot smoke furnace is connected to the heating fluidized bed, and the flue gas is passed into the lower part of the heating fluidized bed; the forward spraying The spray tower is connected to the middle part of the purification tower to discharge the purified gas, and the biological oil is passed into the filter; The oil storage tank and the hot smoke furnace discharge bio-oil; the purification tower is connected to the gas tank to discharge gas, and the gas tank is connected to the hot smoke furnace to transport gas.

Preferably, the descending pyrolysis reactor is divided into a reactor inlet section, a reactor expansion section and a reactor distribution section; the reactor inlet section is provided with respectively connecting the pyrolysis hopper and the upper solid heat carrier hopper. Raw material inlet and heat carrier inlet, a baffle plate is arranged at the lower part of the heat carrier inlet; a multi-layer longitudinal distribution plate is arranged inside the expansion section of the reactor; Layer horizontal distribution plate, and the bottom is provided with a pyrolysis mixture outlet connected to the first-stage cyclone separator.

Preferably, the solid-solid separator is divided into a separator distribution section, a separator separation section and a separator expansion section from bottom to top, wherein: the separator distribution section includes a heat carrier inlet, a heat carrier uniform distribution port, and a separation tank , separation air inlet, separation air guide hole and heat carrier outlet; the heat carrier inlet is located at the upper right of the separator distribution section, connected to the lower solid heat carrier chamber, and is set at the entry point of the separator distribution section The heat carrier uniform distribution port is located at the lower part of the heat carrier inlet and is distributed at the semicircle of the heat carrier inlet; the separation groove is surrounded by the solid In the lower part of the separator, a gas distributor is arranged in the inner sleeve of the separation tank, and the gas distributor can take the shape of a hole and a slit, and the hole-shaped separation wind can be distributed in the middle and the lower part of the inner sleeve; The separation air inlet is arranged on one side of the separation tank and is connected to the gas outlet of the second cyclone separator; the heat carrier outlet arranged at the lower part of the distribution section of the separator is connected to the lower part of the heating fluidized bed; The separator separation section is located in the middle of the solid-solid separator, and above the separator separation section is the separator expansion section formed by reducing the diameter; the upper part of the separator expansion section is connected to the second The separation air outlet of the cyclone.

Preferably, the heat carrier outlet is connected to the lower part of the heating fluidized bed through an L valve or a downpipe, and the solid heat carrier separated in the solid-solid separator is input into the heating fluidized bed; the The L valve is provided with a compressed air or nitrogen inlet.

Preferably, the heating fluidized bed comprises a hot flue gas inlet, an air distribution device, a heat carrier inlet and a mixture outlet, wherein: the hot flue gas inlet is arranged at the lower part of the heating fluidized bed, and is connected with the hot flue gas furnace connection; the air distribution device is arranged at the part where the lower part of the heating fluidized bed is connected to the hot smoke furnace; the heat carrier inlet is located at the upper part of the air distribution device, and is connected to the solid-solid separator heat carrier The outlet is connected; the mixture outlet is arranged at the top of the heated fluidized bed and communicated with the gas-solid separator located above the heated fluidized bed.

Preferably, the lower part of the heat carrier inlet of the heating fluidized bed is provided with an inclined lower hopper with a collar structure, so as to realize the dispersed and uniform distribution of materials into the furnace.

Preferably, the bottom of the drying fluidized bed is provided with a raw material inlet and a hot flue gas inlet, the raw material inlet is connected to the drying hopper, and the hot flue gas inlet is sequentially connected to the first-stage cyclone separator and the second-stage cyclone separator. The outer heating jacket of the stage cyclone is connected; the outlet of the drying fluidized bed is connected to the first cyclone.

Preferably, the charcoal cooler adopts a water-cooled jacketed drum slag cooler, and the solid outlets of the secondary cyclone separator and the second cyclone separator are respectively connected to the charcoal cooler through a charcoal powder hopper.

Preferably, the forward spray tower includes a pyrolysis gas inlet, a spray medium inlet, a purified gas outlet, a safety gas outlet and a cooling medium outlet, wherein: the pyrolysis gas inlet is arranged in the forward spray tower The top center of the cyclone is connected to the gas outlet of the secondary cyclone; the spray medium inlets are evenly distributed around the pyrolysis gas inlet and are connected to the filter, each spray medium The inlets are equipped with spray heads, and the spray heads are spiral or rotary; the coking inclined plate is arranged inside the forward spray tower, and the inner cyclone structure is arranged in the middle, and the gas of the inner cyclone structure flows from all the The outlet of the purifier is discharged, and the outlet of the purifier is connected to the middle of the purification tower; the outlet of the safety gas is arranged beside the outlet of the purified gas and is connected with the safety water seal; the outlet of the cooling medium is arranged at the outlet of the The lower right part of the forward spray tower is equipped with an L-shaped or inclined slag baffle at the outlet.

Preferably, the hot smoke stove is an oil and gas dual-purpose burner, including an oil inlet, a gas inlet, an air inlet and a flue gas outlet; the oil inlet is connected to the filter; the gas inlet is connected to the gas tank ; Air is introduced from the air inlet; the flue gas outlet is connected to the lower part of the heated fluidized bed.

Preferably, the biomass pyrolysis system further includes a lower hopper, a feeder and a dust collector, the solid outlet of the first cyclone is connected to the lower hopper, and the outlet of the lower hopper passes through the lower hopper. An extractor is connected to the pyrolysis hopper; the gas outlet of the first cyclone is connected to a dust collector.

Preferably, the solid heat carrier is a ceramic ball with a particle size ranging from 1 to 2 mm, and its mass ratio is 5 to 20 times that of the biomass raw material.

In the above technical solution of the embodiment of the present invention, the biomass raw material enters the drying fluidized bed after being crushed, and is separated by a cyclone and enters the pyrolysis hopper, and then is transported into the down-flow pyrolysis reactor; The solid heat carrier separated by the solid separator is also transported to the down-flow pyrolysis reactor, where it is fully mixed with the biomass raw material for a rapid pyrolysis reaction to generate pyrolysis gas and biochar; the pyrolysis gas passes through the two-stage cyclone. The separator is sent to the forward spray tower, and then the clean gas is obtained through the purification tower, and the gas is sent to the hot smoke furnace, and the excess gas is sent to the gas tank for storage; while the bio-oil condensed from the forward spray tower is cooled by the filter and Circulating spraying, the newly generated bio-oil is sent to the oil storage tank; the solid heat carrier and part of the biochar discharged from the down-flow pyrolysis reactor are separated by the solid-solid separator, and the separated solid heat carrier re-enters the heating fluidized bed, And sent to the down-type pyrolysis reactor for recycling; the bio-char powder separated from each cyclone separation system is collected to the cold carbon machine, and after cooling, it is discharged and bagged. The beneficial effects of this technical solution are:

The biomass pyrolysis system with solid heat carrier circulation is used to pyrolyze biomass raw materials, and the heating, pyrolysis and separation processes of the solid heat carrier are reasonably set up, which solves the complexity of the solid heat carrier circulation process and makes full use of the solid heat carrier. With the characteristics of biomass raw materials, the rapid heating and pyrolysis of biomass are realized, so that the pyrolysis process has the advantages of high thermal efficiency, high bio-oil yield and high oil quality.

Description of drawings

1 is a schematic structural diagram of a biomass pyrolysis system for solid heat carrier circulation provided by an embodiment of the present invention;

2 is a schematic structural diagram of a pyrolysis reactor provided by an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a solid-solid separator provided by an embodiment of the present invention.

[Description of main component symbols]

1-drying hopper; 2-drying fluidized bed; 3a-first cyclone; 3b-second cyclone; 4-pyrolysis hopper;

5-downward pyrolysis reactor; 5a-reactor distribution section; 5b-reactor expansion section; 5c-reactor inlet section; 51-heat carrier inlet; 52-raw material inlet; 53-longitudinal distribution plate; 54-transverse Distribution plate; 55-baffle plate; 56-pyrolysis mixture outlet;

6-upper solid heat carrier bucket; 7-lower solid heat carrier chamber;

8-solid-solid separator; 8a-separator distribution section; 8b-separator separation section; 8c-separator expansion section; 81-heat carrier inlet; 82-heat carrier uniform distribution port; 83-separation air inlet; 84- Separation tank; 85-separation air all-directional hole; 86-heat carrier outlet; 87-separation air outlet;

9- Heating fluidized bed; 10a- primary cyclone separator; 10b- secondary cyclone separator; 11- gas-solid separator; 12- charcoal cooling machine; 13- hot smoke furnace; 15-filter; 16-purification tower; 17-gas tank; 18-oil storage tank; 19-lower hopper; 20-feeder; 21-exhaust induced draft fan; 22-screw conveyor; 23-separation fan; 24 - Carbon powder hopper; 25 - Combustion fan; 26 - Cooler; 27 - Circulating oil pump; 28 - Gas induced draft fan; 29 - Oil delivery pump; 30 - Safety water seal; 31 - Dust collector.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. element. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to explain the present invention and should not be construed as limiting the present invention.

In view of the existing problems, the present invention provides a biomass pyrolysis system with solid heat carrier circulation, as shown in FIG. 1, including a raw material drying system, a circulating reaction system and a spray cooling system, and the raw material drying system includes a drying system. Hopper 1, drying fluidized bed 2 and first cyclone separator 3a; the circulating reaction system includes pyrolysis hopper 4, descending pyrolysis reactor 5, upper solid heat carrier hopper 6, lower solid heat carrier chamber 7, solid solid Separator 8, heating fluidized bed 9, primary cyclone separator 10a, secondary cyclone separator 10b, gas-solid separator 11, second cyclone separator 3b, carbon cooling machine 12 and hot smoke furnace 13; spray cooling The system includes a forward spray tower 14 , a filter 15 , a purification tower 16 , a gas tank 17 and an oil storage tank 18 .

The drying hopper 1 is connected to the drying fluidized bed 2, the drying fluidized bed 2 is connected to the first cyclone separator 3a, and the first cyclone separator 3a is connected to the pyrolysis hopper 4 to transport solids;

The pyrolysis hopper 4 and the upper solid heat carrier hopper 6 are both connected and discharged to the descending pyrolysis reactor 5, and the descending pyrolysis reactor 5 is connected to the primary cyclone 10a to discharge the pyrolysis mixture; the primary cyclone 10a is connected to The lower solid heat carrier chamber 7 discharges solids, and is connected to the secondary cyclone 10b to discharge gas; the secondary cyclone 10b is connected to the forward spray tower 14 to discharge gas, and is connected to the charcoal cooler 12 to discharge biochar; the lower solid heat carrier chamber 7 Connected to the solid-solid separator 8; the solid-solid separator 8 is connected to the lower part of the heating fluidized bed 9 to discharge the solid heat carrier, and is connected to the second cyclone separator 3b to discharge gas; the second cyclone separator 3b is connected to the solid-solid separator 8 to discharge gas , the second cyclone separator 3b is connected to the cooling charcoal machine 12 to discharge the biochar; the upper part of the heating fluidized bed 9 is connected to the gas-solid separator 11; the gas-solid separator 11 is connected to the upper solid heat carrier bucket 6 to discharge the separated solid, The exhausted flue gas is connected and passed into the outer heating jacket of the secondary cyclone separator 10b and the primary cyclone separator 10a in turn, and then passed into the drying fluidized bed 2; the hot smoke furnace 13 is connected to the heating fluidized bed 9, and the smoke The gas is passed into the lower part of the heated fluidized bed 9;

The forward spray tower 14 is connected to the middle of the purification tower 16 to discharge the purified gas, and the bio-oil is passed into the filter 15; The tank 18 and the hot smoke furnace 13 discharge bio-oil; the purification tower 16 is connected to the gas tank 17 to discharge the gas, and the gas tank 17 is connected to the hot smoke furnace 13 to transport the gas.

As a specific embodiment, wherein:

The biomass pyrolysis system also includes a lower hopper 19, a feeder 20 and a dust collector 31. The solid outlet of the first cyclone 3a is connected to the lower hopper 19, and the discharge port of the lower hopper 19 is connected to the heat exchanger through the feeder 20. Decomposition hopper 4, the discharge port of the pyrolysis hopper 4 is connected to the raw material inlet of the descending pyrolysis reactor 5 through the screw conveyor 22; The separated flue gas is discharged after dust removal to meet the emission standard.

The bottom of the drying fluidized bed 2 is provided with a hot flue gas inlet and a raw material inlet, wherein the raw material inlet is connected to the drying hopper 1, and the hot flue gas inlet is connected to the primary cyclone 10a and secondary cyclone 10b of the pyrolysis reaction system The outlet of the drying fluidized bed 2 is connected to the inlet of the first cyclone separator 3a, and the solid material outlet of the lower part of the first cyclone separator 3a is connected to the input material of the lower hopper 19 through the discharge valve mouth;

As shown in FIG. 2, the descending pyrolysis reactor 5 is divided into a reactor inlet section 5c, a reactor expansion section 5b and a reactor distribution section 5a; the reactor inlet section 5c is provided with a connection to the pyrolysis hopper 4 and the upper solid heat The raw material inlet 52 and the heat carrier inlet 51 of the carrier hopper 6 are provided with a baffle plate 55 at the lower part of the heat carrier inlet 51; a multi-layer longitudinal distribution plate 53 is arranged inside the reactor expansion section 5b; The longitudinal distribution plate 53 and the multi-layer transverse distribution plate 54 are provided with a pyrolysis mixture outlet 56 connected to the first-stage cyclone 10a at the bottom; 4 is connected with the discharge port of the upper solid heat carrier hopper 6, and feeds the biomass raw material and the solid heat carrier into the reactor. More preferably, the heat carrier inlet 51 is located 100-500 mm above the raw material inlet 52, and the angle between the baffle plate 55 and the vertical centerline is 30-45 degrees. The reactor expansion section 5b can be provided with 2-5 layers of longitudinal distribution plates 53, and the reactor distribution section 5a can be provided with a total of 8-12 layers of distribution plates, including 4-6 layers of lateral distribution plates 54 and 4-6 layers of longitudinal distribution plates Plate 53; each distribution plate can be made of 90-degree angle steel or ceramic plate, and the side length can be set to 30-80mm, wherein the vertical angle is upward, the center distance between the single-layer distribution plates is 60-120mm, and the two adjacent upper and lower The distance between the layer distribution plates is 150-400mm.

The primary cyclone 10a and the secondary cyclone 10b are arranged in series; the gas outlet of the upper part of the primary cyclone 10a is connected to the inlet of the secondary cyclone 10b, and the solid outlet of the lower part is directly connected to the lower solid heat carrier chamber 7 The gas outlet of the upper part of the secondary cyclone separator 10b is connected to the forward spray tower 14, and the solid outlet of the lower part is connected to the cooling charcoal machine 12; the outer heating jacket of the primary cyclone separator 10a and the secondary cyclone separator 10b Connected to each other, the flue gas inlet of the outer heating jacket is connected to the outlet of the gas-solid separator 11 , and the flue gas outlet of the outer heating jacket is connected to the drying fluidized bed 2 .

As shown in FIG. 3 , the solid-solid separator 8 is divided into a separator distribution section 8a, a separator separation section 8b and a separator expansion section 8c from bottom to top. The separator distribution section 8a includes a heat carrier inlet 81 and a heat carrier uniform distribution port. 82. The separation air inlet 83, the separation groove 84, the separation air are all directed to the hole 85 and the heat carrier outlet 86; The heat carrier uniform distribution port 82 is set at the inlet of the separator distribution section 8a. The heat carrier uniform distribution port 82 is located at the lower part of the heat carrier inlet 81 and is distributed at the semicircle of the heat carrier inlet 81. The height of the heat carrier uniform distribution port 82 is set to 50-100mm; the separation groove 84 is surrounded by the lower part of the solid-solid separator 8 in a jacket manner. In the embodiment shown in FIG. The gas distributor, that is, the separation air direction hole 85; as an embodiment, the separation air direction hole 85 is located in the middle and lower positions of the inner sleeve of the separation tank, and the hole diameter is generally 5-20mm; Distributor, the strip slits are distributed in the semicircle position of the screw feeding port, and the general slit distance is set to 10~100mm; usually the air outlet speed from the hole and slit shape into the separation tank is required to be 8~30m/s; The inlet 83 is arranged on one side of the separation tank and is connected to the gas outlet of the second cyclone separator 3b; the separation air inlet 83 is arranged on one side of the separation tank and is connected to the gas outlet of the second cyclone separator 3b; it is arranged at the lower part of the separator distribution section 8a The heat carrier outlet 86 is connected to the lower part of the heated fluidized bed 9; the separator separation section 8b is located in the middle of the solid-solid separator 8, and the separator separation section 8b is above the separator expansion section 8c formed by changing diameter; the separator expansion section 8c The upper part of the separator is provided with a separation air outlet 87 connected to the second cyclone 3b; usually, the gas velocity in the separation section of the separator is required to be 5-10 m/s, and the upper part of the separation section becomes an expansion section after being reduced in diameter, and the gas in the expansion section of the separator is required. The speed is 3～8m/s. The heat carrier outlet 86 is connected to the lower part of the heated fluidized bed 9 through an L valve or a downpipe, and the solid heat carrier separated from the solid-solid separator 8 is input into the heated fluidized bed 9; the L valve is provided with compressed air or nitrogen Entrance.

The heated fluidized bed 9 includes a hot flue gas inlet, an air distribution device, a heat carrier inlet and a mixture outlet. The hot flue gas inlet is arranged at the lower part of the heating fluidized bed 9 and is connected to the hot smoke furnace 13; the air distribution device is arranged at the part where the lower part of the heating fluidized bed 9 is connected to the hot smoke furnace 13, and the heat carrier inlet is located at the upper part of the air distribution device , connected with the heat carrier outlet 86 of the solid-solid separator 8; when the heat carrier outlet 86 of the solid-solid separator 8 adopts an L valve, the air distribution device adopts a strip-shaped air distribution plate or a hole-shaped air distribution plate; When the heat carrier outlet 86 of 8 adopts the down pipe, the heating fluidized bed 9 can adopt the shrinkage-expansion section for material distribution, that is, the lower part of the heated fluidized bed 9 shrinks first, so that the speed of the hot flue gas is accelerated, and the solid heat carrier is fed through the down pipe. After heating the fluidized bed 9, the heat carrier is dispersed and evenly distributed under the high-speed airflow, and then the heated fluidized bed expands, and the gas velocity decreases, so that the material can achieve normal fluidization; in order to meet the process needs, the heating fluidized bed is set The fluidization speed is usually set at 10-20 m/s, and the heating fluidized bed 9 can be lined with corundum or wear-resistant castable.

A gas-solid separator 11 is connected above the heating fluidized bed 9. The gas-solid separator 11 is provided with a settling plate, the solid heat carrier outlet is connected to the inlet of the upper solid heat carrier hopper 6, and the flue gas outlet is connected to the first stage of the pyrolysis reaction system. Outer heating jacket inlets for cyclone 10a and secondary cyclone 10b;

The charcoal cooler 12 adopts a water-cooled jacketed drum slag cooler, and the solid outlets of the secondary cyclone separator 10b and the second cyclone separator 3b are respectively connected to the charcoal cooler 12 through the charcoal powder hopper 24, and the outlet of the charcoal powder hopper 24 can be conveyed by a screw. The machine transports the biochar powder into the cold carbon machine 12.

The forward spray tower 14 includes a pyrolysis gas inlet, a spray medium inlet, a purified gas outlet, a safety gas outlet and a cooling medium outlet. The pyrolysis gas inlet is set at the top center position of the forward spray tower 14 and is connected to the gas outlet of the secondary cyclone 10b; the spray medium inlets are evenly distributed around the pyrolysis gas inlet and are connected to the filter 15, generally Take 4 to 8 spray medium inlets, and install 1 to 4 spray heads at each spray medium inlet, the spray heads are spiral or rotary, and the atomization particle size is concentrated at 0.1 to 1 mm; Inside the spray tower 14 is a coking inclined plate, preferably, the angle of the coking inclined plate is 45-70 degrees, and an inspection port can be set at the bottom of the coking inclined plate; the middle of the forward spray tower 14 is provided with an inner cyclone structure, and the inner cyclone structure The gas is discharged from the purifier outlet, and the purifier outlet is connected to the middle of the purification tower 16; the safety gas outlet is arranged beside the purified gas outlet and is connected with the safety water seal 30; the cooling medium outlet is arranged at the lower right part of the forward spray tower 14 , and an L-shaped or inclined slag baffle is set at the outlet.

As shown in FIG. 1, the purified gas from the forward spray tower 14 is transported to the middle of the purification tower 16. The upper part of the purification tower 16 is provided with 2 to 4 layers of packing, and the top is provided with a gas outlet. The gas outlet can pass through the gas induced draft fan. 28 is connected to the inlet of the gas tank 17; the cooling medium outlet of the forward spray tower 14 is connected to the filter 15, the filter 15 is connected to the cooler 26, and finally connected to the circulating oil pump 27; the circulating oil pump 27 has three outlets, one is connected To the spray medium inlet of the upper part of the forward spray tower 14, the biological oil as the spray medium is transported into the forward spray tower 14, one is connected to the oil storage tank 18 through the oil pump 29, and the other is connected to the hot smoke furnace 13. ;

In the embodiment shown in FIG. 1 , since both gas and bio-oil are passed into the hot smoke furnace 13 for combustion, the hot smoke furnace 13 uses an oil and gas dual-purpose burner, and the hot smoke furnace 13 includes an oil inlet, a gas inlet, and an air inlet. and flue gas outlet, wherein: the gas inlet is connected to the gas tank 17, the air inlet is connected to the combustion fan 25, and the flue gas outlet is connected to the lower air inlet of the heating fluidized bed 9; as lining.

The solid heat carrier uses inert spherical particles, such as spherical particles selected from ceramics, quartz sand, dolomite, etc. Because ceramic balls have the advantages of high temperature resistance, wear resistance, high strength, high density, and strong heat storage capacity, as a preferred embodiment, the solid heat carrier is selected from ceramic balls, in order to facilitate fluidized heating and separation of solids. For carbon powder, the system preferably has ceramic balls with a particle size range of 1 to 2 mm. The ceramic balls are selected with a particle size range of 1 to 2 mm, and the mass ratio to the raw material to be treated is controlled at 5 to 50.

Taking a biomass pyrolysis system with solid heat carrier circulation in the above embodiment as an example, the process of the biomass pyrolysis system of the present invention will be described. As a specific embodiment, the steps of the work flow include:

1. The crushed particle size of the biomass raw material is less than 5mm, the moisture content is less than 20%, and the non-biomass impurities are less than 5%, enter the drying hopper 1, and enter the drying fluidized bed 2 through the speed regulating feeding device; the tail gas The induced draft fan 21 draws the hot flue gas with a temperature of 200-250°C from the outer heating jacket of the first-stage cyclone separator 10a, and fluidizes and dries the material through the hot flue gas, and the temperature of the hot flue gas drops to 60-120°C. ℃, and after passing through the dust collector 31, the discharge requirements are met;

2. The biomass raw material dried to moisture less than 8% enters the pyrolysis hopper 4 through the feeder 20, and enters the descending pyrolysis reactor 5 through the screw conveyor 22; the top of the descending pyrolysis reactor 5 is The high-temperature solid heat carrier with a temperature of 530-850°C conveyed by the screw conveyor 22; the solid heat carrier is dispersed by the distributor at the upper part of the descending pyrolysis reactor 5, and then fully contacts and mixes with the biomass raw material and descends, and then passes through the descending type pyrolysis reactor 5. The dispersing and mixing device inside the pyrolysis reactor 5 performs multiple mixing and reactions to produce pyrolysis steam, combustible gas and bio-char; the residence time of biomass raw materials and solid heat carrier in the reactor is 1 to 3 seconds, and the The outlet of the reactor rises from normal temperature to 450-750°C, and the temperature of the solid heat carrier drops from 530-850°C to 450-750°C;

3. The pyrolysis product discharged from the descending pyrolysis reactor 5 and the solid heat carrier enter the primary cyclone 10a together, and the solid heat carrier and biochar in the solid form are separated from the pyrolysis mixed gas, and the solid mixed material is separated It is sent to the lower solid heat carrier chamber 7; the discharged pyrolysis gas mixture is sent to the secondary cyclone separator 10b to further separate the tiny biochar contained therein;

4. The solid mixture of the solid heat carrier and biochar in the lower solid heat carrier chamber 7 is sent to the solid-solid separator 8 through the screw conveyor, and the separation air is sent from the separation air inlet 83 to the solid-solid separator 8 by the internal circulation separation fan 23. At the lower end of the feed of the separator 8, the separation air is evenly distributed through the distribution tank, and the mixed bio-char is fully separated during the falling process of the solid heat carrier; the separated bio-char powder is sent to the second cyclone separator 3b for further separation , and the clean solid heat carrier is sent to the lower part of the heating fluidized bed 9 through the L valve;

5. The hot smoke furnace 13 uses bio-oil and combustible gas for combustion to generate hot flue gas with a temperature of 600-900°C, in which the combustible gas is used as the main heating energy source, and the bio-oil is used as a supplementary fuel for temperature regulation; The flue gas enters the heating fluidized bed 9 evenly through the air distribution system. In the heating fluidized bed 9, the fixed heat carrier is carried by the hot flue gas and sent to the gas-solid separator 11 at the top. During this process, the solid heat carrier is heated. When the temperature reaches 530-850°C, it is sent to the descending pyrolysis reactor 5 again to participate in the reaction; while the temperature of the hot flue gas drops to 550-750°C, it is sent to the primary cyclone separator 10a and the secondary cyclone of the pyrolysis reaction system. In the outer heating jacket of the two-stage cyclone separation composed of the separators 10b connected in series, the temperature of the flue gas drops below 500°C, and is then introduced into the drying fluidized bed 2 to dry the biomass raw materials, and the temperature of the hot flue gas can be adjusted as required. , for example, by mixing part of the air and then reducing the flue gas temperature to 200 ~ 250 ℃;

6. The temperature of the pyrolysis mixture discharged from the secondary cyclone 10b is 400-650°C, and the pyrolysis mixture is sent to the forward spray tower 14, and is sprayed and cooled by the spray medium, so that the pyrolysis mixture can be mixed. The gas temperature drops from 400 to 650 °C to below 50 °C within 1 to 2 seconds; the spray medium is generally bio-oil, and its temperature rises from 20 to 40 °C to 30 to 50 °C during the spray cooling and pyrolysis mixed gas process. ℃, and then the sprayed bio-oil is discharged to the filter 15, and the tiny carbon powder mixed in it is filtered out; the filtered pure bio-oil enters the cooler 26, and the temperature is lowered to 20-40 ℃, and then The circulating oil pump 27 is sent to the forward spray tower 14 for circulating use as a spray medium; the newly generated bio-oil is sent to the oil storage tank 18 by the oil pump 29 for storage; the gas discharged from the forward spray tower 14 also contains some fine particles. After the oil droplets are removed in the purification tower 16, they are sent to the gas tank 17 by the gas induced draft fan 28, and most of the gas in the gas tank 17 is sent to the hot smoke furnace 13;

7. The bio-char discharged from the carbon powder hopper 24 is sent to the cold carbon machine 12 through the screw conveyor, and the cold carbon machine 12 adopts the drum water jacket for indirect heat exchange, so that the temperature of the bio-char powder is reduced from 300 to 500 ℃ to below 50 ℃, Meet the needs of direct bagging transportation.

The specific effects of the biomass pyrolysis system and method in the above embodiments of the present invention are described below through two examples of biomass pyrolysis:

1. Using rice husk as biomass raw material, the raw material of rice husk is directly crushed and transported to the factory from the rice processing plant. The particle size range of rice husk is 0～5mm, the moisture range is 11.2～14.5%, and the volatile content A _d is 65 %. The raw material enters the drying fluidized bed, the hot flue gas inlet temperature of the drying fluidized bed is 240°C, the drying gas outlet temperature is 108°C, the temperature of the raw material after drying is 57°C, and the moisture content is 4.5%; the raw material enters the pyrolysis The reactor, the solid heat carrier is made of ceramic balls, the inlet temperature is 552°C, the temperature of the pyrolysis reactor is 502°C, and the pressure is 2.5kpa; after separation, the temperature of the solid heat carrier and the solid carbon powder is 485°C, and the pyrolysis mixing The gas temperature is 473°C; the temperature in the high temperature zone of the hot smoke furnace is 850°C, and the flue gas outlet temperature is 650°C;

The material balance is calculated based on the dry basis of rice husk, the yield of bio-oil is 51.8%, the calorific value is 16.2MJ/kg, the yield of combustible gas is 19.9%, the calorific value is 17.8MJ/kg, and the yield of biochar is 28.3 %.

2. Sawdust is used as biomass raw material. The sawdust raw material is scraps from wood processing plants. When sent to the factory, the moisture is 35-45%. It needs to be dried for the first time until the moisture is less than 20%; the particle size of sawdust is in the range of 1-4.5 mm, volatile A _d was 87%. The raw material enters the drying fluidized bed, the hot flue gas inlet temperature of the drying fluidized bed is 210 °C, the drying gas outlet temperature is 86 °C, the temperature of the raw material after drying is 49 °C, and the moisture content is 5.3%; the raw material enters the pyrolysis In the reactor, the solid heat carrier is made of ceramic balls, the inlet temperature is 780°C, the temperature of the pyrolysis reactor is 690°C, and the pressure is 2.8kpa; after separation, the temperature of the solid heat carrier and the solid carbon powder is 646°C, and the pyrolysis mixing The gas temperature is 630°C; the temperature in the high temperature zone of the hot smoke furnace is 986°C, and the flue gas outlet temperature is 724°C;

The material balance is calculated based on the dry basis of sawdust. The bio-oil yield is 31.6%, the calorific value is 15.3MJ/kg, the combustible gas yield is 52.6%, the calorific value is 17.4MJ/kg, and the biochar yield is 15.8%. .

For the above-mentioned embodiments of the present invention, common knowledge such as the well-known specific structures and characteristics in the technical solutions has not been described too much; each embodiment is described in a progressive manner, and the technical features involved in each embodiment are mutually exclusive. On the premise that there is no conflict between them, they can be combined with each other, and the same and similar parts of each embodiment can be referred to each other.

In the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", " The orientation or positional relationship indicated by "back" and the like is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, so as to The particular orientation configuration and operation should not be construed as limiting the invention. Unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral body; It 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 communication between two elements or the interaction relationship between the two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. Furthermore, the terms "first", "second", "primary" and "secondary" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

The above are the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as falling within the protection scope of the present invention.

Claims (11)

1. A biomass pyrolysis system with a solid heat carrier circulation comprises a raw material drying system, a circulation reaction system and a spray cooling system, wherein the raw material drying system comprises a drying hopper, a drying fluidized bed and a first cyclone separator; the circulating reaction system comprises a pyrolysis hopper, a descending pyrolysis reactor, an upper solid heat carrier hopper, a lower solid heat carrier chamber, a solid-solid separator, a heating fluidized bed, a primary cyclone separator, a secondary cyclone separator, a gas-solid separator, a second cyclone separator, a carbon cooling machine and a hot smoke furnace; the spray cooling system comprises a forward spray tower, a filter, a purification tower, a gas tank and an oil storage tank, wherein:

the drying hopper is connected with the drying fluidized bed, the drying fluidized bed is connected with the first cyclone separator, and the first cyclone separator is connected with the pyrolysis hopper to convey solids;

the pyrolysis hopper and the upper solid heat carrier hopper are connected and discharged to the descending pyrolysis reactor, and the descending pyrolysis reactor is connected with the primary cyclone separator to discharge pyrolysis mixture; the primary cyclone separator is connected with the lower solid heat carrier chamber to discharge solids, and is connected with the secondary cyclone separator to discharge gas; the secondary cyclone separator is connected with the gas discharged by the forward spray tower and connected with the charcoal cooling machine to discharge biochar; the lower solid heat carrier chamber is connected to the solid-solid separator; the solid-solid separator is connected with the lower part of the heating fluidized bed to discharge a solid heat carrier and is connected with the second cyclone separator to discharge gas; the second cyclone separator is connected with the gas discharged by the solid-solid separator, and the second cyclone separator is connected with the charcoal cooling machine to discharge biochar; the upper part of the heating fluidized bed is communicated with the gas-solid separator; the gas-solid separator is connected with the upper solid heat carrier hopper to discharge separated solids, and the flue gas discharged after separation is sequentially connected with the external heating sleeves of the secondary cyclone separator and the primary cyclone separator and then is introduced into the drying fluidized bed; the hot smoke furnace is connected with the heating fluidized bed, and smoke is introduced into the lower part of the heating fluidized bed;

the forward spray tower is connected with the middle part of the purification tower to discharge purified gas, and biological oil is introduced into the filter; the filter is connected with the upper part of the forward spray tower to convey biological oil as a spray medium and is connected with the oil storage tank and the hot smoke grate to convey the biological oil; the purification tower is connected with the gas tank to discharge gas, and the gas tank is connected with the hot smoke furnace to convey gas; the down-flow pyrolysis reactor is characterized by being divided into a reactor inlet section, a reactor expansion section and a reactor distribution section; the reactor inlet section is provided with a raw material inlet and a heat carrier inlet which are respectively connected with the pyrolysis hopper and the upper solid heat carrier hopper, and the lower part of the heat carrier inlet is provided with a material baffle plate; a plurality of layers of longitudinal distribution plates are arranged in the expansion section of the reactor; the reactor distribution section is respectively provided with a plurality of layers of longitudinal distribution plates and a plurality of layers of transverse distribution plates, and the bottom of the reactor distribution section is provided with a pyrolysis mixture outlet connected with the primary cyclone separator; each distribution plate arranged on the distribution section of the reactor adopts 90-degree angle steel or a ceramic plate.

2. The biomass pyrolysis system of claim 1, wherein the solid-solid separator is divided from bottom to top into a separator distribution section, a separator separation section, and a separator expansion section, wherein:

the separator distribution section comprises a heat carrier inlet, a heat carrier uniform distribution port, a separation tank, a separation air inlet and a heat carrier outlet; the heat carrier inlet is positioned at the right upper part of the distribution section of the separator, is connected with the lower solid heat carrier chamber, and is provided with a heat carrier uniform distribution port at the section entering the distribution section of the separator, and the heat carrier uniform distribution port is positioned at the lower part of the heat carrier inlet and is distributed at a semicircle of the position of the heat carrier inlet; the separation tank surrounds the lower part of the solid-solid separator in an outer sleeve mode, and a separation wind uniform hole is formed in the inner sleeve of the separation tank; the separation air inlet is arranged on one side of the separation groove and is connected with the gas outlet of the second cyclone separator; the heat carrier outlet arranged at the lower part of the separator distribution section is connected to the lower part of the heating fluidized bed; the separator separation section is positioned in the middle of the solid-solid separator, and the separator expansion section formed by reducing is arranged above the separator separation section; the upper part of the separator expansion section is provided with a separated wind outlet connected to the second cyclone separator.

3. The biomass pyrolysis system according to claim 2, wherein the heat carrier outlet is connected to a lower portion of the heating fluidized bed through an L-valve or a downcomer for feeding the solid heat carrier separated in the solid separator into the heating fluidized bed; and a compressed air or nitrogen inlet is arranged on the L valve.

4. The biomass pyrolysis system of claim 1, wherein the heated fluidized bed comprises a hot flue gas inlet, an air distribution device, a heat carrier inlet, and a mixture outlet, wherein:

the hot smoke inlet is arranged at the lower part of the heating fluidized bed and is connected with the hot smoke furnace; the air distribution device is arranged at the lower part of the heating fluidized bed and connected with the hot smoke furnace; the heat carrier inlet is positioned at the upper part of the air distribution device and is connected with the heat carrier outlet of the solid-solid separator; the mixture outlet is arranged at the top of the heating fluidized bed and is communicated with the gas-solid separator positioned above the heating fluidized bed.

5. The biomass pyrolysis system of claim 4, wherein the lower part of the heat carrier inlet of the heating fluidized bed is provided with an inclined lower hopper of a collar structure.

6. The biomass pyrolysis system of claim 1, wherein a raw material inlet and a hot flue gas inlet are arranged at the bottom of the drying fluidized bed, the raw material inlet is connected with the drying hopper, and the hot flue gas inlet is sequentially connected with the external heating sleeves of the primary cyclone separator and the secondary cyclone separator; the outlet of the drying fluidized bed is connected to the first cyclone separator.

7. The biomass pyrolysis system of claim 1, wherein the cold carbon machine is a water-cooled jacket roller slag cooler or a water-cooled jacket auger, and solid outlets of the secondary cyclone separator and the second cyclone separator are respectively connected with the cold carbon machine through a carbon powder hopper.

8. The biomass pyrolysis system of claim 1, wherein the forward spray tower comprises a pyrolysis gas inlet, a spray media inlet, a purge gas outlet, a safety gas outlet, and a cooling media outlet, wherein: the pyrolysis gas inlet is arranged at the center of the top of the forward spray tower and is connected with the gas outlet of the secondary cyclone separator; the spraying medium inlets are uniformly distributed around the pyrolysis gas inlet and are connected with the filter, each spraying medium inlet is provided with a spraying head, and the spraying heads are spiral or rotary; a coking inclined plate is arranged in the forward spray tower, an inner cyclone structure is arranged in the middle of the forward spray tower, gas in the inner cyclone structure is discharged from an outlet of the purifier, and the outlet of the purifier is connected to the middle of the purification tower; the safety gas outlet is arranged beside the purified gas outlet and is connected with a safety water seal; the cooling medium outlet is arranged at the right lower part of the forward spray tower, and an L-shaped or inclined slag trap is arranged at the outlet.

9. The biomass pyrolysis system of claim 1, wherein the hot-gas stoves are dual-purpose oil and gas burners comprising an oil inlet, a gas inlet, an air inlet, and a flue gas outlet; the oil inlet is connected with the filter; the gas inlet is connected to the gas tank; air is introduced from the air inlet; the flue gas outlet is connected to the lower part of the heated fluidized bed.

10. The biomass pyrolysis system of claim 1, further comprising a lower hopper, a lifter, and a duster, the solids outlet of the first cyclone being connected to the lower hopper, the discharge outlet of the lower hopper being connected to the pyrolysis hopper through the lifter; the gas outlet of the first cyclone is connected to a dust separator.

11. The biomass pyrolysis system according to any one of claims 1 to 10, wherein the solid heat carrier is ceramic balls with a particle size range of 1-2 mm, and the mass ratio of the ceramic balls is 5-20 times of that of the biomass raw material.

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