CN112500871A - Biomass pyrolysis reaction system and method for solar light-gathering coupling heat-accumulation combustion - Google Patents

Abstract

The invention discloses a biomass pyrolysis reaction system and a biomass pyrolysis reaction method for solar energy light-gathering coupling heat-storage combustion, wherein the system adopts an auger type reactor and comprises a hollow rotating shaft, spiral fins and a light-permeable outer wall, a heat-storage combustion module is arranged in the hollow rotating shaft, and a space between the hollow rotating shaft and the light-permeable outer wall is used as a spiral feeding pyrolysis chamber; the method comprises the following steps: respectively feeding the biomass and the pyrolytic coke into a spiral feeding pyrolysis chamber, mixing the biomass and the pyrolytic coke under the rotation action of a spiral fin and moving the biomass and the pyrolytic coke to the outlet end of the spiral feeding pyrolysis chamber; the biomass is heated to the pyrolysis reaction temperature by taking focused sunlight which penetrates through the light-permeable outer wall and/or fuel gas which is sent into the heat storage combustion module for heat storage combustion as a heat source, so that the biomass is subjected to pyrolysis reaction. The invention adopts solar heating coupled heat storage combustion to realize all-weather operation of the system, and simultaneously adopts pyrolytic coke recycling to improve the solar energy utilization efficiency and the pyrolytic effect.

Description

Biomass pyrolysis reaction system and method for solar light-gathering coupling heat-accumulation combustion

Technical Field

The invention relates to a biomass pyrolysis process, in particular to a biomass pyrolysis reaction system and method for solar energy light-gathering coupling heat storage combustion.

Background

The sunlight generally irradiates the earth, whether on land or sea, and whether on mountains or islands, and can be directly developed and utilized. The development and utilization of solar energy do not pollute the environment, and therefore, the solar energy is one of the cleanest energy sources.

Biomass energy is inexhaustible, is a renewable energy source and is a unique renewable carbon source. However, because of the complex raw material components and low energy density, the fuel is generally converted into solid, liquid and gaseous fuels with higher quality and then is utilized.

Pyrolysis is a common method for realizing high-quality conversion of biomass, but the energy consumption and the cost in the treatment process are high, and intermediate link pollution is easily generated. Solar energy and biomass pyrolysis are coupled, the solar energy is used as a heat source for biomass pyrolysis, the biomass treatment cost can be reduced, the yield of biomass pyrolysis products is improved, the emission of pollutants and carbon dioxide is reduced, and stable utilization of light energy and high-quality conversion of biomass energy are realized.

Chinese patent document CN105112080A discloses a wind-light-thermal coupling pyrolysis reaction device, which comprises a main pyrolysis system, a heat supply system, a power system, a transmission system, a monitoring system and an auxiliary system, wherein the main pyrolysis system comprises a groove type solar reflector, a vacuum heat collector glass outer tube, a pyrolysis reaction device metal inner tube and an outer wall heat absorption coating of the metal inner tube. The solar pyrolysis reaction device takes the groove type paraboloid reflector to focus the direct solar light as a heat source and takes the vacuum heat collecting tube as an absorber to pyrolyze the biomass to generate biogas, biochar, pyroligneous liquor and wood tar. However, the energy source of the solar pyrolysis reaction device is only solar energy, and the solar fluctuation is large due to the change of weather, so that the solar pyrolysis reaction device is difficult to stably operate; the system is difficult to operate continuously without sunlight at night.

Chinese patent document CN109135779A discloses a device for uninterruptedly pyrolyzing biomass all day by using solar energy, which includes a condenser, a reactor, a low-temperature molten salt tank, a high-temperature molten salt tank and a product collector, wherein the condenser reflects the energy of sunlight and transfers it to the reactor to raise the temperature thereof, and the biomass to be pyrolyzed enters the reactor to perform pyrolysis reaction; a molten salt pipeline with two ends respectively connected with the low-temperature molten salt tank and the high-temperature molten salt tank is arranged on a central shaft of the reactor; the fused salt pipeline is wound with spiral blades, and the blades are driven to rotate when the fused salt pipeline rotates, so that the biomass to be pyrolyzed is conveyed from a raw material inlet to one end of the product collector in the reactor; when sunlight is sufficient, the low-temperature molten salt enters a molten salt pipeline to absorb heat in the reactor to form high-temperature molten salt so as to store solar heat; when sunlight is insufficient, the high-temperature molten salt in the high-temperature molten salt tank releases heat to pyrolyze the biomass, so that the biomass to be pyrolyzed is pyrolyzed uninterruptedly all day long. The device has effectively solved the problem that original solar energy living beings pyrolysis system can not operate when having no illumination, nevertheless has following problem: 1) the fused salt absorbs solar energy to store heat in the daytime and releases heat to heat biomass at night, and a large amount of heat is lost in the fused salt heat storage and conveying process, so that the solar energy utilization efficiency is reduced; 2) the pyrolysis temperature of the biomass is as high as hundreds of ℃, a large amount of heat is needed for continuous and stable pyrolysis, a large amount of molten salt is undoubtedly needed, and the molten salt is expensive and highly corrosive, so that the whole system is high in investment cost and high in operation risk; 3) the heat stored in the molten salt and available for pyrolysis is very limited, and after the heat release is reduced to a certain temperature, the biomass is difficult to provide enough heat, so that the pyrolysis product has the problems of high oxygen content, low energy density, reduced product quality and the like, and the continuous and stable operation is difficult.

Disclosure of Invention

The invention aims to provide a biomass pyrolysis reaction system and method capable of continuously and stably operating and high in energy utilization rate and capable of realizing solar light-gathering coupling heat storage combustion.

In order to achieve the purpose, the biomass pyrolysis reaction method for solar energy light-gathering coupling heat-storage combustion adopts an auger type reactor, which comprises a hollow rotating shaft, spiral fins and a light-permeable outer wall, wherein a heat-storage combustion module is arranged in the hollow rotating shaft, and a space between the hollow rotating shaft and the light-permeable outer wall is used as a spiral feeding pyrolysis chamber for conveying materials and carrying out pyrolysis reaction; and comprises the following steps: respectively feeding biomass and a certain amount of pyrolytic coke into the spiral feeding pyrolysis chamber from the inlet end of the spiral feeding pyrolysis chamber, and mixing the biomass and the pyrolytic coke and moving the biomass and the pyrolytic coke to the outlet end of the spiral feeding pyrolysis chamber under the rotation action of the spiral fins; the biomass in the spiral feeding pyrolysis chamber is heated to the pyrolysis reaction temperature by taking focused sunlight penetrating through the light-permeable outer wall and/or fuel gas sent into the heat storage combustion module for heat storage combustion as a heat source, so that the biomass is subjected to pyrolysis reaction, and products are treated to obtain pyrolysis gas, pyrolysis oil and pyrolysis coke.

Preferably, the weight ratio of the pyrolysis coke fed into the auger type reactor to the biomass fed into the auger type reactor is (1-3): 10.

Preferably, the waste heat of the pyrolysis product is used for preheating air entering the heat storage combustion module, and the waste heat of the flue gas discharged by the heat storage combustion module is used for drying and preheating the biomass before entering the auger-type reactor, so that the waste heat of the product and the flue gas is fully utilized.

Preferably, the temperature in the spiral feeding pyrolysis chamber is controlled to be 450-550 ℃, the pressure is controlled to be micro negative pressure (-20 Pa-50 Pa), and the micro negative pressure is favorable for reducing tar adhered to a light-transmitting component on the outer wall; the combustion temperature of the heat accumulation combustion module is controlled to be above 1000 ℃, and the temperature fluctuation interval is controlled within +/-20 ℃.

The invention also provides a solar energy light-gathering coupling heat-accumulating combustion biomass pyrolysis reaction system, which comprises a biomass feeding system, an adjustable light-gathering system, an auger type reactor and a pyrolysis product treatment system; the auger type reactor comprises a hollow rotating shaft, a spiral fin and a light-permeable outer wall; the space between the hollow rotating shaft and the light-permeable outer wall is used as a spiral feeding pyrolysis chamber for conveying materials and carrying out pyrolysis reaction; one end of the auger-type reactor is provided with a biomass inlet and a circulating pyrolytic coke inlet which are used for respectively inputting biomass and circulating pyrolytic coke into the spiral feeding pyrolytic chamber, and the other end of the auger-type reactor is provided with a pyrolytic coke outlet and a volatile matter outlet which are used for respectively outputting reaction solid-phase products and gas-phase products from the spiral feeding pyrolytic chamber; a heat accumulation combustion module is arranged in the hollow rotating shaft and is used for introducing pyrolysis gas to perform heat accumulation combustion to heat materials in the spiral feeding pyrolysis chamber; the adjustable light gathering system is used for gathering sunlight and projecting the sunlight to the inner side of the light-permeable outer wall to heat materials in the spiral feeding pyrolysis chamber; the pyrolysis product treatment system is used for treating pyrolysis reaction products to obtain pyrolysis gas, pyrolysis oil and pyrolysis coke.

Preferably, one end of the auger-type reactor is provided with the biomass inlet and the circulating pyrolytic coke inlet, the lower part and the upper part of the other end of the auger-type reactor are respectively provided with the pyrolytic coke outlet and the volatile component outlet, and the two inlets and the two outlets are both communicated with the spiral feeding pyrolysis chamber; the heat accumulation combustion module is provided with a pyrolysis gas inlet, an air inlet and a flue gas outlet; the biomass feeding system comprises a feeding bin with a feeding heat exchange assembly (the heat exchange assembly can adopt conventional heat exchange assemblies such as a coiled pipe and the like, and the lower part is the same as the conventional heat exchange assembly), and a biomass outlet of the feeding bin is connected with a biomass inlet of the auger reactor; the flue gas inlet of the feeding heat exchange assembly is connected with the flue gas outlet of the heat storage combustion module so as to preheat and dry the biomass in the feeding bin by using the waste heat of the flue gas; the pyrolysis product treatment system comprises a condensing device, a purifying device, a pyrolysis coke cooling device and a pyrolysis coke crushing device; the condensing device is provided with a volatile component inlet, a pyrolysis gas outlet and a pyrolysis liquid outlet, and is also provided with a condensing heat exchange assembly, one end of the condensing heat exchange assembly is used for inputting cold air, and the other end of the condensing heat exchange assembly is connected with an air inlet of the heat accumulation combustion module; the pyrolytic coke cooling device is provided with a high-temperature pyrolytic coke inlet and a low-temperature pyrolytic coke outlet and is also provided with a pyrolytic coke cooling heat exchange assembly; the high-temperature pyrolysis coke inlet is connected with a pyrolysis coke outlet of the auger type reactor, and the low-temperature pyrolysis coke outlet is connected with an inlet of the pyrolysis coke crushing device; one end of the pyrolytic coke cooling heat exchange assembly is used for inputting cold air, and the other end of the pyrolytic coke cooling heat exchange assembly is connected with an air inlet of the heat accumulation combustion module; the outlet of the pyrolytic coke pulverizing device is divided into two paths, one path of pyrolytic coke is output outwards, and the other path of pyrolytic coke is connected with the circulating pyrolytic coke inlet of the auger-type reactor.

Preferably, the light-permeable outer wall comprises a light-impermeable wall body and a plurality of lenses distributed on the wall body and used as sunlight introducing windows, each lens is fixed at a mounting hole formed in the wall body through an annular support, and the annular supports extend out of the wall body by a certain length to enable the lenses to protrude out of the wall body; and the annular bracket is provided with a gas blowing component for blowing a blowing gas into the space below the lens to form an isolated gas mold. The mirror surface is easily stained to a large amount of tar of living beings pyrolysis production, through spraying the air current at the peripheral malleation of lens, can form stable air film below the lens, isolated material and pyrolysis oil, reduce mirror surface and glue dirt and wearing and tearing.

Preferably, the gas purging component comprises an annular gas chamber disposed in the interlayer of the side wall of the annular support, a purge gas inlet disposed outside and/or on the upper side of the annular gas chamber for introducing a purge gas therein, and a plurality of purge gas nozzles disposed inside the annular gas chamber for dispersedly blowing the purge gas toward the space under the lens.

Preferably, the purge gas inlet is connected with the flue gas outlet of the regenerative combustion module to introduce the flue gas as purge gas; the purge gas nozzles are arranged in multiple layers, and the direction of each layer of nozzles is parallel to the lens or inclined downwards. The scheme strengthens the isolation effect through the multilayer air film and the proper air injection direction and better protects the lens.

Preferably, the regenerative combustion module comprises a regenerative body having an aperture structure; the heat accumulator is cylindrical, and the center of the heat accumulator is provided with a through hole separated from the pore passage and used as an air inlet channel; the length of the heat accumulator accounts for 1/2-2/3 of the length of the hollow rotating shaft; the section, which is not extended by the heat accumulator in the hollow rotating shaft, is used as a combustion area for heat accumulation and combustion; the heat accumulator is divided into two areas which are respectively used as a preheating area and a heat accumulation area, and the two areas and the inner end of the air inlet channel are communicated with the combustion area; the outer ends of the preheating zone and the heat storage zone are provided with pipelines for supplying heat and decomposing gas to input and outputting flue gas, and a plurality of reversing valves for alternately switching the gas inlet direction and the gas exhaust direction of the decomposing gas; and a 10-30 mm interval is reserved between the outer wall of the heat accumulator and the inner wall of the hollow rotating shaft, and the outer end of the heat accumulator is fixed on a frame at the end part of the auger type reactor, so that the whole heat accumulator does not rotate along with the hollow rotating shaft.

Preferably, the spiral fin is spirally arranged outside the hollow rotating shaft, and two adjacent circles are connected and reinforced through a reinforcing connecting rod. This arrangement mode can improve the helical fin rigidity, effectively improves the high security of system, plays the stirring effect simultaneously when rotatory, strengthens the mixed degree of pyrolysis burnt and living beings, promotes the absorption efficiency of living beings to the sunlight.

Compared with the prior art, the invention has the beneficial effects that:

1) adopt solar energy heating coupling heat accumulation burning heating method, form the two heat source heating (solar energy and burning chemical energy) to the living beings, use solar energy supply to give first place to daytime, use burning chemical energy supply to give first place to evening, can guarantee 24 hours of system incessant steady operation, adjustable reaction temperature interval is bigger simultaneously, and the product quality is higher.

2) Unlike the two-step energy supply mode of absorbing solar energy and transferring the energy to biomass through heat conduction in the prior art, the invention directly condenses the solar energy to the biomass or directly heats the biomass, does not need a molten salt energy storage system and secondary heat conduction, obviously improves the system efficiency, does not have the problem of molten salt corrosion, and greatly reduces the volume of a pyrolysis system.

3) By adopting a pyrolytic coke recycling technology, a part of pyrolytic coke is recycled to the auger type reactor and mixed with the biomass, so that the blackness of the fuel can be improved, and the solar radiation absorption capacity of the biomass can be improved, thereby improving the solar energy utilization efficiency, playing a role in catalyzing the heavy oil cracking and improving the quality of the pyrolytic oil;

4) by adopting a heat accumulation combustion technology, the heat is stored in the heat accumulator by utilizing the high-temperature flue gas, and then the pyrolysis gas is preheated by utilizing the heat stored in the heat accumulator after the direction of the air flow is switched, so that the utilization efficiency of combustion heat is effectively improved, and higher and more stable reaction temperature can be provided compared with the heating by using molten salt;

5) the solar energy reaction heat is fully utilized, and fossil energy consumption can be greatly reduced; meanwhile, the biomass products are partially combusted in a backflow mode, so that the continuous operation of the system is ensured, and the influence of weather seasons and the like on sunlight is buffered.

Drawings

Fig. 1 is a process diagram of a biomass pyrolysis reaction method of solar concentration coupling heat accumulation combustion provided in embodiment 2 of the present invention.

Fig. 2 is a schematic structural diagram of a biomass pyrolysis reaction system based on solar energy concentration and heat accumulation coupled combustion provided in embodiment 1 of the present invention.

FIG. 3 is a schematic view of the construction of the screw reactor of FIG. 2.

Fig. 4 is a schematic view of the lens and the annular frame of fig. 3.

Fig. 5 is a perspective view (partially in section) of the regenerative combustion module of fig. 3.

Fig. 6 and 7 are schematic diagrams illustrating the state of the regenerative combustion module switching between the preheating region and the regenerative region.

Wherein: the device comprises an auger-type reactor 100, a hollow rotating shaft 110, spiral fins 120, a reinforcing connecting rod 121, a light-permeable outer wall 130, a wall body 131, a lens 132, an annular bracket 133, a gas purging component 134, an annular air chamber 135, a purging gas inlet 136, a purging gas nozzle 137, a heat accumulating combustion module 140, a heat accumulator 141, an air inlet channel 142, a combustion zone 143, a preheating zone 144, a heat accumulating zone 145, a reversing valve 146, a spiral feeding pyrolysis chamber 150, a frame 160, a high-temperature bearing 170, a biomass feeding system 200, a feeding bin 210, a feeding heat exchange assembly 220, an adjustable light-gathering system 300, a pyrolysis product processing system 400, a condensing device 410, a condensing heat exchange assembly 411, a purifying device 420, a pyrolysis coke cooling device 430, a pyrolysis coke cooling heat exchange assembly 431 and a pyrolysis coke crushing device 440.

Detailed Description

The invention is described in further detail below with reference to the figures and the specific embodiments.

Example 1

As shown in fig. 1 to 7, the present embodiment provides a biomass pyrolysis reaction system for solar light-gathering coupling heat-accumulation combustion, which includes an auger-type reactor 100, a biomass feeding system 200, an adjustable light-gathering system 300, and a pyrolysis product processing system 400. Wherein:

1) auger type reactor

The auger reactor 100 includes a hollow rotating shaft 110, helical fins 120, and a light permeable outer wall 130.

Unlike the conventional auger transportation and pyrolysis integrated device, the hollow rotating shaft 110 is thickened in the embodiment, and the diameter of the thickened hollow rotating shaft occupies about 1/3 of the diameter of the whole auger type reactor 100, so that the heat transfer efficiency of the regenerative combustion module 140 is improved. Meanwhile, the black coating is arranged on the inner side of the hollow rotating shaft 110, so that the absorption capacity of combustion heat radiation is improved.

The space between the hollow rotating shaft 110 and the light permeable outer wall 130 serves as a spiral feed pyrolysis chamber 150 for transporting materials and performing pyrolysis reactions.

One end of the outer wall of the auger-type reactor 100 is provided with a biomass inlet and a circulating pyrolytic coke inlet, the lower part and the upper part of the other end are respectively provided with a pyrolytic coke outlet and a volatile component outlet, and the two inlets and the two outlets are both communicated with the spiral feeding pyrolysis chamber 150. The volatile outlet is arranged on the upper portion of the outer wall side and is perpendicular to the wall surface, the volatile outlet inclines towards the side to stagger the lenses, and when the cross section of the auger-type reactor 100 is viewed, the volatile outlet and the vertical direction form an included angle of 10-30 degrees (specifically, an included angle of 15 degrees in the embodiment).

The light-transmittable outer wall 130 includes a light-opaque wall body 131 and a plurality of quartz lenses 132 densely distributed on the wall body 131 as sunlight introduction windows. The quartz lens 132 is laid out at 1/2 not less than the entire length of the auger reactor 100 to ensure adequate absorption of sunlight by the biomass.

Each lens 132 is fixed at a mounting hole formed on the wall body 131 through a ring-shaped bracket 133, and the ring-shaped bracket 133 extends out of the wall body 131 by a certain length, so that the lens 132 protrudes 8cm outside the wall body 131. The annular bracket 133 is provided with a gas purging component 134 for blowing a small amount of purified flue gas into the space below the lens 132 to form a stable gas film and a vortex region, so that pyrolysis oil and the mirror surface are isolated, and tar is prevented from being adhered to the mirror surface.

The gas purge means 134 includes an annular gas chamber 135 provided in an interlayer (thickness 1-2 mm) of a sidewall of the annular holder 133, a purge gas inlet 136 provided outside and on an upper side of the annular gas chamber 135 for introducing a purge gas thereinto, and a plurality of purge gas nozzles 137 provided inside the annular gas chamber 135 for dispersedly blowing the purge gas toward a space below the lens 132.

The purge gas inlet 136 is connected to the flue gas outlet of the regenerative combustion module 140 to introduce the flue gas as a purge gas. The purge gas nozzles 137 on the annular bracket 133 are arranged into six layers, the upper three layers and the lower three layers are respectively a group, each group is provided with an independent inlet, the direction of the nozzles of the upper three layers is parallel to the lens 132, the lower three layers incline downwards by about 30 degrees, and the two groups of nozzle parts are not communicated with each other, so that the differential control of the two groups of gas speeds is realized.

The spiral fin 120 is spirally disposed outside the hollow rotating shaft 110, and two adjacent turns are connected and reinforced by a reinforcing connecting rod 121. The reinforcing connecting rod 121 adopts a bent pipe, the radian is about 30 degrees, the distance between the connecting points at the two ends of the reinforcing connecting rod and the outer wall is half of the distance from the hollow rotating shaft 110, the space contact surface between the reinforcing connecting rod and materials can be increased by adopting the bent pipe, and the stirring effect is enhanced. Each axial face is provided with 3 reinforcing links 121, equiangularly arranged around the hollow rotating shaft 110.

The hollow rotary shaft 110 is driven by a motor, and both ends of the hollow rotary shaft are mounted on the corresponding frame 160 through a high temperature bearing 170, so that it can rotate with respect to the frame 160. Wherein, the end connected with the output shaft of the motor adopts a high-temperature radial bearing, and the other end adopts a high-temperature thrust ball bearing. Both ends of the light permeable outer wall 130 are fixedly mounted on the corresponding frames 160 and do not rotate along with the hollow rotating shaft 110. Sealing devices are distributed near the bearings to ensure good air tightness of the spiral feeding pyrolysis chamber 150.

A heat accumulation combustion module 140 is disposed in the hollow rotating shaft 110, and is used for introducing pyrolysis gas to perform heat accumulation combustion to heat the material in the spiral feeding pyrolysis chamber 150. The main structure of the regenerative combustion module 140 is a regenerative body 141 with a pore structure, and the length of the regenerative body 1/2 occupies the length of the hollow rotating shaft 110. The heat accumulator 141 has a cylindrical shape, and a through hole is formed at the center thereof to be spaced apart from the hole, thereby forming an air inlet passage 142.

The section of the hollow rotary shaft 110 to which the heat accumulator 141 does not extend serves as a combustion region 143 for regenerative combustion. The heat accumulator 141 is divided into two regions which are respectively used as a preheating region 144 and a heat accumulation region 145, and the two regions and the inner end of the air inlet channel 142 are communicated with the combustion region 143; the outer ends of the two areas are respectively provided with a pyrolysis gas inlet and a flue gas outlet, and are provided with 3 reversing valves 146, and the periodic switching of the preheating area 144 and the heat storage area 145 can be realized by switching the passages of the reversing valves 146, so that the preheating of the inlet gas is realized.

The outer end of the heat accumulator 141 is fixed on the frame 160 at the end of the auger reactor 100, and a 20mm interval is left between the outer wall of the heat accumulator and the inner wall of the hollow rotating shaft 110, so as to provide a space for combustion and thermal expansion on the one hand, and avoid contact with the rotating hollow rotating shaft 110 on the other hand.

2) Biomass feeding system

The biomass feed system 200 includes a feed bin 210 having feed heat exchange assemblies 220 (each heat exchange assembly in the illustrated embodiment is a serpentine tube), with the biomass outlet of the feed bin 210 being connected to the biomass inlet of the auger reactor 100. The flue gas inlet of the feeding heat exchange assembly 220 is connected with the flue gas outlet of the heat accumulation combustion module 140 so as to preheat and dry the biomass in the feeding bin 210 by using the flue gas waste heat.

3) Adjustable light-focusing system

The adjustable light-gathering system 300 adopts groove type or butterfly type light gathering, the light gathering ratio is adjusted according to the current solar intensity and the temperature required by pyrolysis of different raw materials, and the adjustable range of the light gathering ratio is 4500.

4) Pyrolysis product processing system

The pyrolysis product processing system 400 is used for processing pyrolysis reaction products to obtain pyrolysis gas, pyrolysis oil and pyrolysis coke, and specifically includes a condensing device 410, a purifying device 420, a pyrolysis coke cooling device 430 and a pyrolysis coke crushing device 440 (in the embodiment, the pyrolysis coke cooling device and the pyrolysis coke crushing device adopt an integrated cooling and crushing device).

The condensing device 410 is provided with a volatile component inlet, a pyrolysis gas outlet and a pyrolysis liquid outlet, and is provided with a condensation heat exchange assembly 411, one end of the condensation heat exchange assembly 411 is used for inputting cold air, and the other end is connected with an air inlet of the heat accumulation combustion module 140.

The pyrolytic coke cooling device 430 is provided with a high-temperature pyrolytic coke inlet and a low-temperature pyrolytic coke outlet, and is provided with a pyrolytic coke cooling heat exchange assembly 431. The high-temperature pyrolysis coke inlet is connected with the pyrolysis coke outlet of the auger-type reactor 100, and the low-temperature pyrolysis coke outlet is connected with the inlet of the pyrolysis coke crushing device 440. One end of the pyrolytic coke cooling heat exchange assembly 431 is used for inputting cold air, and the other end is connected with the air inlet of the regenerative combustion module 140.

The outlet of the pyrolytic coke pulverizing device 440 is divided into two paths, one path outputs pyrolytic coke outwards, and the other path is connected with the circulating pyrolytic coke inlet of the auger-type reactor 100.

Example 2

As shown in fig. 1, the biomass pyrolysis reaction performed by the biomass pyrolysis reaction system disclosed in example 1 in this embodiment includes the following steps:

1) the biomass pulverized into particles and a certain amount of pyrolysis coke are fed into the spiral feeding pyrolysis chamber 150 from the inlet end of the spiral feeding pyrolysis chamber 150, respectively, and the biomass and the pyrolysis coke are mixed and move toward the outlet end of the spiral feeding pyrolysis chamber 150 under the rotation action of the spiral fins 120. The mass of the pyrolysis coke fed into the auger reactor 100 was 20% of the mass of the biomass fed into the auger reactor 100.

2) The biomass in the spiral feeding pyrolysis chamber 150 is heated by solar energy condensation or heat accumulation combustion.

The solar energy is condensed by the adjustable condensing system 300 to condense sunlight, and the condensed sunlight is irradiated to the biomass in the spiral feeding pyrolysis chamber 150 through the lens 132, and the biomass is mixed with high-blackness pyrolysis coke, so that the capacity of the biomass for absorbing solar radiation is increased.

The regenerative combustion carries out regenerative and preheating on the pyrolysis gas through the regenerative body 141, and the preheated pyrolysis gas meets the air preheated by the waste heat of the pyrolysis product in the combustion area 143 and is automatically ignited. By adjusting the flow rate of pyrolysis gas and air, the combustion temperature is controlled to be above 1000 ℃, and the temperature fluctuation interval is controlled to be within 10 ℃. The generated combustion heat heats the wall surface of the hollow rotating shaft 110 by various means (mainly radiation and heat conduction), and then transfers heat to the biomass through the wall surface. When solar energy fluctuates due to weather changes and the like, the reaction temperature of the auger-type reactor 100 can be stabilized by adjusting the gas quantity, and the product quality is ensured. At night or in the cloudy day when solar energy is deficient, the heat required by pyrolysis is supplied by taking combustion as a main energy source, and the uninterrupted operation of the system for 24 hours is ensured.

The regenerative combustion module 140 uses 3 directional valves 146 (A, B, C for distinction) to control the alternate operation of regenerative and preheating, and the specific pipeline valve connections are shown in fig. 6-7.

The specific operation mode of regenerative combustion is as follows: as shown in fig. 6, the direction of the reversing valve A, B is adjusted, so that the pyrolysis gas is preheated through the upper preheating zone 144, then enters the combustion zone 143 to contact with the oxygen, the pyrolysis gas has a low ignition point and is combusted immediately when meeting the oxygen to generate a large amount of high-temperature flue gas, the high-temperature flue gas is burnt out in the heat storage zone 145 and transfers the heat of the flue gas to the heat accumulator 141, and the flue gas with the reduced temperature is output through the reversing valve C. After one to two minutes of this condition, preheating zone 144 and heat storage zone 145 may be switched by switching the direction of valve A, B, C, as shown in fig. 7. The combustion mode makes full use of the residual heat of the flue gas (preheated pyrolysis gas) and the pyrolysis products (preheated air), so that the utilization efficiency of the combustion chemical energy is higher.

3) The biomass in the spiral feeding pyrolysis chamber 150 absorbs solar energy or combustion heat, and is heated to the pyrolysis reaction temperature (500 +/-10 ℃) to carry out pyrolysis reaction.

In order to reduce the adhesion of tar to the lens 132, the spiral feeding pyrolysis chamber 150 is under a slight negative pressure (controlled at about-25 Pa in this embodiment) by the suction of the induced draft fan behind the purification device 420, and a small amount of flue gas is introduced as a purge gas through the gas purge component 134, so as to form a stable gas film and a vortex region under the lens 132 and isolate the pyrolysis oil from the mirror surface. The air injection directions of the upper three layers of nozzles are parallel to the mirror surface of the lens 132, and the air injection speed is not less than 30 m/s; the air injection directions of the lower three layers of nozzles form an inclined downward inclination angle, the gas flow velocity is not less than 20m/s, and the multilayer gas film reinforced isolation effect is formed. The arrangement enables the pyrolysis oil to be contaminated on the wall surface of the auger type reactor 100 and the lens 132 as little as possible, the problems of efficiency reduction and coking caused by contamination of the pyrolysis oil are relieved to the greatest extent, and the stable and safe operation of the system is ensured.

Meanwhile, the sprayed flue gas contains a small amount of water vapor, oxygen and a large amount of carbon dioxide, can generate micro-oxidation reaction with tar and the like at high temperature, slightly releases heat, ensures that the pyrolysis temperature is in a relatively high temperature range, promotes the decomposition of heavy tar with weak volatility, reduces the coking and slagging phenomenon of tar adhered to the quartz lens 132 to the maximum extent, and effectively promotes the stable operation of the pyrolysis oil quality device while ensuring the absorption of sunlight.

4) The reaction products are divided into pyrolysis volatile components and high-temperature pyrolysis coke. The pyrolysis volatile component is condensed to obtain pyrolysis gas and pyrolysis oil, the pyrolysis oil is sold as a chemical raw material, part of the pyrolysis gas is sold as fuel gas after being purified, and part of the pyrolysis gas is burnt in the heat accumulation burning module 140 as fuel to supply heat for biomass pyrolysis.

The high-temperature pyrolysis coke (the temperature is about 500 ℃ and the diameter is within 10 cm) falls into the integrated cooling and crushing device under the action of gravity, is cooled to below 200 ℃ by cold air and is crushed to within 1cm, and a pyrolysis coke product is obtained. The purpose of cold air cooling is to avoid strong oxidation after the high-temperature coke block contacts with air, and ensure the quality of the coke block. Most of the pyrolytic coke products are directly sold as active carbon, a soil restoration agent or an agricultural fertilizer slow release agent, and the like, and a small part of the pyrolytic coke products are circulated to the auger-type reactor 100 to be mixed with the biomass.

After circulation pyrolysis coke and living beings are mixed, can effectively improve the feeding blackness, promote solar energy absorption efficiency, fresh pyrolysis coke has certain catalytic action simultaneously, can reduce living beings thermal decomposition energy barrier to reduce the required temperature of pyrolysis, further promote the whole efficiency and the economic nature of pyrolysis.

5) The cold air sent to the heat accumulation combustion module 140 is preheated to about 150 ℃ by the waste heat of the pyrolysis product through the condensation heat exchange assembly 411 and the pyrolysis coke cooling heat exchange assembly 431. In addition, the biomass before entering the auger-type reactor 100 is dried and preheated by the waste heat of the flue gas discharged from the regenerative combustion module 140 through the feeding heat exchange assembly 220, so that the overall energy efficiency is improved.

Claims (10)

1. A biomass pyrolysis reaction method of solar energy light-gathering coupling heat storage combustion is characterized in that:

an auger type reactor (100) is adopted and comprises a hollow rotating shaft (110), spiral fins (120) and a light-permeable outer wall (130), wherein a heat storage combustion module (140) is arranged in the hollow rotating shaft (110), and a space between the hollow rotating shaft (110) and the light-permeable outer wall (130) is used as a spiral feeding pyrolysis chamber (150) for conveying materials and carrying out pyrolysis reaction;

and comprises the following steps:

respectively feeding biomass and a certain amount of pyrolytic coke into the spiral feeding pyrolysis chamber (150) from the inlet end of the spiral feeding pyrolysis chamber (150), and mixing the biomass and the pyrolytic coke and moving the biomass and the pyrolytic coke to the outlet end of the spiral feeding pyrolysis chamber (150) under the rotation action of the spiral fins (120);

the biomass in the spiral feeding pyrolysis chamber (150) is heated to the pyrolysis reaction temperature by taking focused sunlight penetrating through the light-permeable outer wall (130) and/or fuel gas sent into the heat accumulation combustion module (140) for heat accumulation combustion as a heat source, so that the biomass is subjected to pyrolysis reaction, and products are treated to obtain pyrolysis gas, pyrolysis oil and pyrolysis coke.

2. The biomass pyrolysis reaction method for solar concentration coupling heat accumulation combustion as claimed in claim 1, wherein the biomass pyrolysis reaction method comprises the following steps: the weight ratio of the pyrolysis coke fed into the auger type reactor (100) to the biomass fed into the auger type reactor (100) is (1-3): 10.

3. The biomass pyrolysis reaction method for solar concentration coupling heat accumulation combustion as claimed in claim 1, wherein the biomass pyrolysis reaction method comprises the following steps: the air entering the heat storage combustion module (140) is preheated by using the waste heat of the pyrolysis product, and the biomass before entering the auger-type reactor (100) is dried and preheated by using the waste heat of the flue gas discharged by the heat storage combustion module (140).

4. The biomass pyrolysis reaction method based on solar energy concentrated coupling heat accumulation combustion as claimed in any one of claims 1 to 3, characterized in that: the temperature in the spiral feeding pyrolysis chamber (150) is controlled to be 450-550 ℃, and the pressure is controlled to be-20 to-50 Pa; the combustion temperature of the heat accumulation combustion module (140) is controlled to be above 1000 ℃, and the temperature fluctuation interval is controlled within +/-20 ℃.

5. A biomass pyrolysis reaction system for solar concentration coupling heat accumulation combustion, which is designed for realizing the method of any one of claims 1-4, and is characterized in that: comprises a biomass feeding system (200), an adjustable light gathering system (300), an auger type reactor (100) and a pyrolysis product processing system (400);

the auger reactor (100) comprises a hollow rotating shaft (110), helical fins (120) and a light-permeable outer wall (130); a spiral feeding pyrolysis chamber (150) for conveying materials and performing pyrolysis reaction is arranged in a space between the hollow rotating shaft (110) and the light-permeable outer wall (130); one end of the auger-type reactor (100) is provided with a biomass inlet and a circulating pyrolytic coke inlet which are used for respectively inputting the biomass and the circulating pyrolytic coke into the spiral feeding pyrolytic chamber (150), and the other end is provided with a pyrolytic coke outlet and a volatile matter outlet which are used for respectively outputting reaction solid-phase products and gas-phase products from the spiral feeding pyrolytic chamber (150); a heat accumulation combustion module (140) is arranged in the hollow rotating shaft (110) and is used for introducing pyrolysis gas to perform heat accumulation combustion to heat materials in the spiral feeding pyrolysis chamber (150);

the adjustable light gathering system (300) is used for gathering sunlight and projecting the sunlight to the inner side of the light-permeable outer wall (130) to heat materials in the spiral feeding pyrolysis chamber (150);

the pyrolysis product treatment system (400) is used for treating pyrolysis reaction products to obtain pyrolysis gas, pyrolysis oil and pyrolysis coke.

6. The biomass pyrolysis reaction system of claim 5, wherein:

one end of the auger type reactor (100) is provided with the biomass inlet and the circulating pyrolytic coke inlet, the lower part and the upper part of the other end are respectively provided with the pyrolytic coke outlet and the volatile component outlet, and the two inlets and the two outlets are both communicated with the spiral feeding pyrolysis chamber (150); the heat accumulation combustion module (140) is provided with a pyrolysis gas inlet, an air inlet and a flue gas outlet;

the biomass feeding system (200) comprises a feeding bin (210) with a feeding heat exchange assembly (220), wherein a biomass outlet of the feeding bin (210) is connected with a biomass inlet of the auger reactor (100); a flue gas inlet of the feeding heat exchange assembly (220) is connected with a flue gas outlet of the heat accumulation combustion module (140) so as to preheat and dry the biomass in the feeding bin (210) by using flue gas waste heat;

the pyrolysis product treatment system (400) comprises a condensing device (410), a purifying device (420), a pyrolysis coke cooling device (430) and a pyrolysis coke crushing device (440);

the condensing device (410) is provided with a volatile component inlet, a pyrolysis gas outlet and a pyrolysis liquid outlet, and is also provided with a condensation heat exchange component (411), one end of the condensation heat exchange component (411) is used for inputting cold air, and the other end of the condensation heat exchange component is connected with an air inlet of the heat accumulation combustion module (140);

the pyrolytic coke cooling device (430) is provided with a high-temperature pyrolytic coke inlet and a low-temperature pyrolytic coke outlet, and is also provided with a pyrolytic coke cooling heat exchange assembly (431); the high-temperature pyrolysis coke inlet is connected with a pyrolysis coke outlet of the auger-type reactor (100), and the low-temperature pyrolysis coke outlet is connected with an inlet of the pyrolysis coke crushing device (440); one end of the pyrolytic coke cooling heat exchange assembly (431) is used for inputting cold air, and the other end of the pyrolytic coke cooling heat exchange assembly is connected with an air inlet of the heat storage combustion module (140);

the outlet of the pyrolytic coke crushing device (440) is divided into two paths, one path of pyrolytic coke is output outwards, and the other path of pyrolytic coke is connected with the circulating pyrolytic coke inlet of the auger type reactor (100).

7. The biomass pyrolysis reaction system of claim 5, wherein: the light-permeable outer wall (130) comprises a light-impermeable wall body (131) and a plurality of lenses (132) which are distributed on the wall body (131) and used as sunlight introduction windows, each lens (132) is fixed at a mounting hole formed in the wall body (131) through an annular support (133), and the annular supports (133) extend out of the wall body (131) for a certain length to enable the lenses (132) to protrude out of the wall body (131); and a gas purging component (134) is arranged on the annular bracket (133) and used for blowing a purging gas into the space below the lens (132) to form an isolated gas mold.

8. The biomass pyrolysis reaction system of claim 7, wherein: the gas purging component (134) comprises an annular gas chamber (135) arranged in the interlayer of the side wall of the annular bracket (133), a purge gas inlet (136) arranged outside and/or on the upper side of the annular gas chamber (135) for introducing purge gas therein, and a plurality of purge gas nozzles (137) arranged inside the annular gas chamber (135) for dispersedly blowing the purge gas toward the space below the lens (132); the purge gas inlet (136) is connected with a smoke outlet of the regenerative combustion module (140) to introduce smoke as purge gas; the purge gas nozzles (137) are arranged in multiple layers, and the direction of each layer of nozzles is parallel to the lens (132) or inclined downwards.

9. The biomass pyrolysis reaction system according to any one of claims 5 to 8, wherein: the regenerative combustion module (140) comprises a regenerative body (141) with an aperture structure; the heat accumulator (141) is cylindrical, and the center of the heat accumulator is provided with a through hole separated from the pore passage to be used as an air inlet passage (142);

the length of the heat accumulator (141) accounts for 1/2-2/3 of the length of the hollow rotating shaft (110);

a section, which is not extended by the heat accumulator (141) in the hollow rotating shaft (110), is used as a combustion area (143) for heat accumulation combustion; the heat accumulator (141) is divided into two areas which are respectively used as a preheating area (144) and a heat accumulation area (145), and the two areas and the inner end of the air inlet channel (142) are communicated with the combustion area (143); the outer ends of the preheating zone (144) and the heat storage zone (145) are provided with pipelines for supplying pyrolysis gas input and flue gas output, and a plurality of reversing valves (146) for alternately switching the pyrolysis gas inlet direction and the flue gas exhaust direction;

and a 10-30 mm interval is reserved between the outer wall of the heat accumulator (141) and the inner wall of the hollow rotating shaft (110), and the outer end of the heat accumulator is fixed on a frame (160) at the end part of the auger type reactor (100) so that the whole heat accumulator does not rotate along with the hollow rotating shaft (110).

10. The biomass pyrolysis reaction system according to any one of claims 5 to 8, wherein: the spiral fin (120) is spirally arranged on the outer side of the hollow rotating shaft (110), and two adjacent circles are connected and reinforced through a reinforcing connecting rod (121).

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