Pyrolysis coke recycling biomass pyrolysis system and method based on secondary reflection condensation

Abstract

The invention provides a pyrolysis coke recycling biomass pyrolysis system and method based on secondary reflection condensation, the system comprises a heliostat field, a secondary reflector, a pyrolysis coke heat collector and a pyrolysis furnace, the heliostat field and the pyrolysis coke heat collector are both installed on the ground, the secondary reflector is arranged above the pyrolysis coke heat collector, and the pyrolysis furnace is arranged above the pyrolysis coke heat collector. The pyrolysis coke heat collector is connected with the pyrolysis furnace; the heliostat field is used for reflecting sunlight to the secondary reflector for condensation, the secondary reflector is used for reflecting the condensed sunlight to the pyrolytic coke heat collector, and the pyrolytic coke heat collector is used for heating pyrolytic coke and transmitting the pyrolytic coke absorbing heat to the pyrolysis furnace; the pyrolyzing furnace is used for taking the heat-absorbed pyrolytic coke as a heat source to generate pyrolytic reaction with biomass, so as to obtain high-temperature pyrolytic coke, flue gas and pyrolytic gas. According to the invention, the height from the pyrolytic coke heat collector to the ground can be reduced, the safety of the system and the operability of maintenance during failure can be improved, the system structure is more compact, and the construction cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of concentrated solar energy biomass pyrolysis, and in particular to a pyrolysis and recycling biomass pyrolysis system and method based on secondary reflection and concentration. Background Art

[0002] my country has abundant solar energy resources. More than two-thirds of the country's total area has more than 2,200 hours of sunshine per year, and the total annual solar radiation across the country can reach 3,340 to 8,400 MJ / m 2 Above, the median value is 5852MJ / m 2 , and the annual sunshine hours in most areas can reach more than 3,300 hours, and the development potential of solar energy resources is huge.

[0003] At the same time, as a large agricultural country, my country has a huge amount of biomass energy resources. The currently available biomass energy resources are equivalent to about 5 billion tons of standard coal, which is about 4 times the current total energy consumption of my country and accounts for 54.5% of the total amount of exploitable clean energy.

[0004] Biomass pyrolysis technology is a high-quality waste conversion technology, but it requires external heat sources during the treatment process. It is a high-energy consumption process and usually produces high carbon emissions. Concentrated solar energy has the advantages of high heating rate and no pollutant emissions during the heating process, which can well match the energy requirements of biomass pyrolysis technology.

[0005] Chinese patent document CN114540054A discloses a polygeneration system for concentrated solar pyrolysis of biomass, which is mainly composed of a batching pretreatment device, a pyrolysis reaction device, a concentrated solar heat collection device, a heat storage device, a catalytic reforming reaction device, a waste heat boiler, an organic Rankine cycle system and a control terminal, wherein the batching pretreatment device includes a biomass crusher, a screw feeder and a flat-plate solar collector, the biomass crusher is connected to the input end of the screw feeder, and the flat-plate solar collector is used to heat the material in the screw feeder. The concentrated solar heat collection device includes a reflector array and a compound parabolic concentrator, the compound parabolic concentrator is arranged around the periphery of the pyrolysis reaction device, and the reflector array is used to reflect solar radiation to the compound parabolic concentrator. The system reasonably matches the energy grades of different processes and reduces the irreversible loss of the system. However, in actual operation, since biomass has a high volatile matter content, the heavy components precipitated during pyrolysis adhere to the light-transmitting outer wall, causing light window pollution and reducing system efficiency. Moreover, as the pyrolysis reaction proceeds, most of the concentrated solar energy is absorbed by the volatile matter adhered to the light-transmitting outer wall, causing the temperature of the light-transmitting outer wall to rise sharply, which may cause high-temperature damage to it.

[0006] Chinese patent document CN216786051U discloses a novel solar biochar preparation device, which includes a chassis and a horizontal steering device arranged on the chassis, a bracket is arranged on the horizontal steering device, a butterfly-shaped concentrator is rotatably arranged on the top of the bracket, and a biomass thermal decomposition furnace is arranged on the butterfly-shaped concentrator. The device combines biomass thermal decomposition and solar thermal decomposition technologies, uses the heat generated by solar energy to provide energy at the reactor, promotes biomass thermal decomposition, effectively reduces the dependence of the biomass carbonization process on external heat source heating, and thus solves the problem of high pollution and high energy consumption during the thermal decomposition process. However, the device uses a dish-type concentrator, and the biomass thermal decomposition furnace is located at the focus of the dish-type concentrator, which is placed at a relatively high position, making it inconvenient to feed and overhaul and maintain the equipment during actual operation, and it is difficult to ensure the long-term stable operation and safety of the system. Summary of the invention

[0007] The purpose of the present invention is to provide a thermal decomposition and recycling biomass pyrolysis system and method based on secondary reflection and focusing, which is used to solve the problems of light window pollution and reduced system efficiency in the pyrolysis process of the biomass pyrolysis system in the prior art, and it is difficult to ensure the stable operation and safety of the system. The system safety and the operability of maintenance in case of failure can be improved, the structure of the entire system can be more compact, the construction cost can be reduced, and the influence of light window pollution on the operation of the system can be reduced.

[0008] According to a first aspect of the present invention, a pyrolysis and recycling biomass pyrolysis system based on secondary reflection and concentration is provided, comprising a heliostat field, a secondary reflector, a pyrolysis and recycling collector, and a pyrolysis furnace, wherein the heliostat field and the pyrolysis and recycling collector are both installed on the ground, the secondary reflector is arranged above the pyrolysis and recycling collector, and the pyrolysis and recycling collector is arranged at the focus of the secondary reflector; the pyrolysis and recycling collector is connected to the pyrolysis furnace;

[0009] The heliostat field is used to reflect sunlight to the secondary reflector for concentration, and the secondary reflector is used to reflect the concentrated sunlight to the pyrolysis coke collector, and the pyrolysis coke collector is used to heat the pyrolysis coke and transmit the pyrolysis coke after absorbing heat to the pyrolysis furnace, and the pyrolysis furnace is used to use the pyrolysis coke after absorbing heat as a heat source to react with biomass to produce high-temperature pyrolysis coke, flue gas and pyrolysis gas; the temperature of the high-temperature pyrolysis coke reaches above 600°C;

[0010] It also includes a discharge auger and a biomass dryer; the discharge auger is connected to the pyrolysis furnace, the discharge auger is used to send the high-temperature pyrolysis coke obtained by the pyrolysis reaction to the biomass dryer, and the biomass dryer is used to use the high-temperature pyrolysis coke to dry the biomass.

[0011] Preferably, the pyrolysis furnace is a drum heat storage pyrolysis furnace or an auger type continuous pyrolysis furnace.

[0012] Preferably, the outer wall of the thermal decoking collector is a light-transmitting outer wall.

[0013] Preferably, the pyrolysis coke collector comprises a pyrolysis coke outlet, which is used to output the pyrolysis coke after absorbing heat to the pyrolysis furnace; the pyrolysis furnace comprises a feeder, which is used to transport biomass to the pyrolysis furnace; the pyrolysis coke outlet is connected to the feeder.

[0014] Preferably, it also includes a burner and an air preheater; the air preheater is used to utilize the waste heat of the flue gas to heat the external air and send the heated air into the burner; the burner is used to use the pyrolysis gas as fuel for combustion when the energy of the concentrated sunlight is insufficient, so as to heat the pyrolysis furnace.

[0015] Preferably, a dynamic airflow isolation device is further included; the dynamic airflow isolation device is used to blow inert gas into the furnace wall of the pyrolysis furnace to form a protective atmosphere on the surface of the furnace wall.

[0016] According to another aspect of the present invention, a method for pyrolysis of recycled biomass based on secondary reflection and focusing is provided, comprising the following steps:

[0017] S1: Reflecting sunlight to a secondary reflector through a heliostat field for concentration, and then reflecting the concentrated sunlight to a thermal decoking collector through the secondary reflector;

[0018] S2: sending the pyrolysis coke to the pyrolysis coke heat collector, heating the pyrolysis coke through the pyrolysis coke heat collector, and transmitting the pyrolysis coke after absorbing heat to the pyrolysis furnace;

[0019] S3: feeding the biomass into the pyrolysis furnace, and the pyrolysis coke after absorbing heat is used as a heat source to react with the biomass in the pyrolysis furnace to produce high-temperature pyrolysis coke, flue gas and pyrolysis gas; the temperature of the high-temperature pyrolysis coke reaches above 600°C;

[0020] S4: The unloading auger delivers the high-temperature pyrolysis coke obtained by the pyrolysis reaction into the biomass dryer. The biomass dryer uses the high-temperature pyrolysis coke to dry the biomass, and then the biomass enters the pyrolysis furnace from the feeder.

[0021] Preferably, after step S4, after heating the biomass, the high-temperature thermal decomposition adds part of the high-temperature thermal decomposition that has been cooled down into the thermal decomposition collector for heating, thereby realizing the recycling of the thermal decomposition.

[0022] Preferably, the ratio of the mass flow rate of the pyrolysis coke entering the pyrolysis furnace to the mass flow rate of the biomass is (0.5-3):1.

[0023] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0024] (1) The pyrolysis and recycling biomass pyrolysis system and method based on secondary reflection and concentration provided by the present invention can overcome the problems of difficult operation and light window pollution in the actual operation of the biomass pyrolysis system in the prior art. The pyrolysis and recycling biomass pyrolysis system based on secondary reflection and concentration provided by the present invention adopts a combination of a heliostat field and a secondary reflector to fully concentrate light and provide it to a pyrolysis collector. Therefore, the pyrolysis collector can be directly fixed on the ground, which can reduce the height of the pyrolysis collector from the ground, improve the system safety and the operability of maintenance in case of failure, make the whole system structure more compact, and reduce the construction cost. In addition, the pyrolysis cycle is used as the heat absorbing medium of the pyrolysis collector to reduce the influence of light window pollution on the operation of the system.

[0025] (2) A pyrolysis coke recycling biomass pyrolysis system and method based on secondary reflection and concentration provided by the present invention comprises a heliostat field, a secondary reflector, a pyrolysis coke collector, and a pyrolysis furnace. The heliostat field and the pyrolysis coke collector are both installed on the ground, the secondary reflector is arranged above the pyrolysis coke collector, and the pyrolysis coke collector is connected to the pyrolysis furnace; the heliostat field is used to reflect sunlight to the secondary reflector for focusing, the secondary reflector is used to reflect the concentrated sunlight to the pyrolysis coke collector, the pyrolysis coke collector is used to heat the pyrolysis coke, and transmit the pyrolysis coke after absorbing heat to the pyrolysis furnace, and the pyrolysis furnace is used to use the pyrolysis coke after absorbing heat as a heat source to react with biomass to obtain high-temperature pyrolysis coke, flue gas, and pyrolysis gas. The present invention can reduce the height of the pyrolysis coke collector from the ground, improve the system safety and the operability of maintenance in case of failure, and the system structure is more compact and the construction cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of a pyrolysis and recycling biomass pyrolysis system based on secondary reflection and focusing according to an embodiment of the present invention;

[0027] Figure 2 This is a principle structural block diagram of a pyrolysis and recycling biomass pyrolysis system based on secondary reflection and focusing according to an embodiment of the present invention;

[0028] Figure 3 The present invention is a flowchart of a method for pyrolysis and recycling biomass pyrolysis based on secondary reflection and focusing according to an embodiment of the present invention.

[0029] In all the drawings, the same reference numerals are used to represent the same elements or structures, wherein: 1 - pyrolysis coke collector, 2 - feeder, 3 - pyrolysis furnace, 4 - unloading dragon, 5 - biomass dryer, 6 - heliostat field, 7 - secondary reflector. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Some embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0032] See also Figure 1 and Figure 2 The embodiment of the present invention provides a pyrolysis and recycling biomass pyrolysis system based on secondary reflection and concentration, comprising a heliostat field 6, a secondary reflector 7, a pyrolysis and coking collector 1, and a pyrolysis furnace 3. The heliostat field 6 and the pyrolysis and coking collector 1 are both installed on the ground. The heliostat field 6 comprises a plurality of heliostats, and the plurality of heliostats surround the pyrolysis and coking collector 1. The secondary reflector 7 is arranged above the pyrolysis and coking collector 1, and the pyrolysis and coking collector 1 is connected to the pyrolysis furnace 3.

[0033] The heliostat field 6 is used to reflect sunlight to the secondary reflector 7 for focusing. The secondary reflector 7 is used to reflect the focused sunlight to the pyrolysis coke collector 1. The pyrolysis coke collector 1 is used to heat the pyrolysis coke and transfer the pyrolysis coke b after absorbing heat to the pyrolysis furnace 3. The pyrolysis furnace 3 is used to use the pyrolysis coke b after absorbing heat as a high-temperature heat source to react with the dried biomass a' to obtain pyrolysis coke, flue gas and pyrolysis gas.

[0034] Specifically, the pyrolysis furnace 3 is a drum heat storage pyrolysis furnace or an auger type continuous pyrolysis furnace. Figure 1 The pyrolysis furnace 3 shown in FIG. 1 is a drum heat storage pyrolysis furnace.

[0035] Specifically, the thermal decoking collector 1 is arranged at the focus of the secondary reflector 7 , so that the concentrated solar radiation obtained by the secondary concentration is directly projected downward to the thermal decoking collector 1 .

[0036] The pyrolysis decoking collector 1 includes a light-permeable outer wall. Therefore, the concentrated solar energy obtained by secondary concentration can pass through the light-permeable outer wall and project into the interior of the pyrolysis decoking collector 1, thereby fully utilizing the energy of sunlight to heat the pyrolysis decoking b inside the pyrolysis decoking collector 1.

[0037] The pyrolysis coke collector 1 includes a pyrolysis coke outlet, and the pyrolysis coke b after absorbing heat enters the pyrolysis furnace 3 from the pyrolysis coke outlet; the pyrolysis furnace 3 includes a feeder 2, and the dried biomass a' enters the pyrolysis furnace 3 from the feeder 2; the pyrolysis coke outlet is connected to the feeder 2. The high-temperature heat dissipation loss of the pyrolysis coke b at the pyrolysis coke outlet before mixing with the dried biomass a' is reduced as much as possible.

[0038] The pyrolysis coke recycling biomass pyrolysis system also includes a discharge auger 4 and a biomass dryer 5; the discharge auger 4 is used to feed the high-temperature pyrolysis coke obtained by the pyrolysis reaction into the biomass dryer 5, and the biomass dryer 5 uses the high-temperature pyrolysis coke to dry the biomass a, and then enters the pyrolysis furnace 3 from the feeder 2. Therefore, under the action of the discharge auger 4, the sensible heat of the high-temperature pyrolysis coke obtained by the pyrolysis furnace 3 is used to dry and preheat the biomass a, so as to fully realize the waste heat recovery of the pyrolysis product.

[0039] The mass flow ratio of the pyrolysis coke b and the biomass a entering the pyrolysis furnace 3 is (0.5-3):1.

[0040] The pyrolysis coke recycling biomass pyrolysis system also includes a burner and an air preheater; the air preheater is used to use the waste heat of the flue gas to preheat the external air to obtain high-temperature air, and send the high-temperature air to the burner; the burner is used to use the pyrolysis gas as fuel for combustion when the energy of the concentrated sunlight is insufficient to heat the pyrolysis furnace 3. The waste heat of the flue gas discharged from the pyrolysis furnace 3 and the use of the pyrolysis gas can be fully utilized.

[0041] The pyrolysis coke recycling biomass pyrolysis system also includes a dynamic airflow isolation device; the dynamic airflow isolation device is used to blow inert gas into the furnace wall of the pyrolysis furnace 3 to form a protective atmosphere on the surface of the furnace wall. The protective atmosphere can have a role similar to a protective film, which can prevent heavy components generated during the pyrolysis reaction from adhering to the furnace wall surface of the pyrolysis furnace, reduce the adhesion of heavy components such as pyrolysis oil, and ensure long-term and efficient operation of the system.

[0042] It should be noted that the pyrolysis and recycling biomass pyrolysis system based on secondary reflection and concentration provided by the present invention reflects solar energy once through the heliostat field 6. Since the outer wall of the pyrolysis and coke collector 1 is light-transmissive, the secondary reflector 7 can project the focused solar energy into the interior of the pyrolysis and coke collector 1. The heliostat field 6 has a solar energy tracking function, which can ensure the operating temperature of the pyrolysis and coke collector 1. The high-temperature pyrolysis coke obtained by pyrolysis in the pyrolysis furnace 3 is sent to the biomass dryer 5 by the unloading auger 4 to dry the biomass a. After drying, a part of the pyrolysis coke b is sent to the pyrolysis and coke collector 1 for heat absorption, and the other part of the pyrolysis and coke product b' is output as a solid product. In addition, the pyrolysis coke b after heat absorption is sent to the pyrolysis furnace 3 as a heat source to react with the biomass a for pyrolysis. Since the pyrolysis coke b has lower volatility than the biomass a, the use of pyrolysis coke b as the heat-absorbing working medium of the pyrolysis and coke collector 1 can greatly reduce the impact of light window pollution on the pyrolysis and coke collector 1. A portion of the pyrolysis gas obtained by the pyrolysis reaction is sent to the burner for combustion as fuel, which can provide the pyrolysis furnace 3 with the heat required for the pyrolysis reaction. Therefore, the pyrolysis furnace can be heated when the concentrated radiation energy is low, the pyrolysis products can be fully utilized and the normal operation of the system can be maintained.

[0043] like Figure 3 As shown, another embodiment of the present invention provides a pyrolysis method for recycling biomass based on secondary reflection and focusing, using the pyrolysis system for recycling biomass based on secondary reflection and focusing of the above embodiment, the method comprises:

[0044] Step 1: The sunlight is reflected by the heliostat field 6 to the secondary reflector 7 for focusing, and then the focused sunlight is reflected by the secondary reflector 7 to the thermal decoking collector 1;

[0045] Step 2, feeding the pyrolysis coke b into the pyrolysis coke collector 1, heating the pyrolysis coke b through the pyrolysis coke collector 1, and transmitting the pyrolysis coke b after absorbing heat to the pyrolysis furnace 3;

[0046] Step 3: The biomass a is fed into the pyrolysis furnace 3. The pyrolysis coke b after absorbing heat acts as a heat source to react with the biomass a in the pyrolysis furnace 3 to obtain high-temperature pyrolysis coke, flue gas and pyrolysis gas.

[0047] In summary, the pyrolysis and recycling biomass pyrolysis system and method based on secondary reflection and concentration provided by the present invention can overcome the problems of difficult operation and light window pollution in the actual operation of the biomass pyrolysis system in the prior art. The pyrolysis and recycling biomass pyrolysis system based on secondary reflection and concentration provided by the present invention adopts a combination of a heliostat field and a secondary reflector to fully concentrate light and provide it to a pyrolysis collector. Therefore, the pyrolysis collector can be directly fixed on the ground, which can reduce the height of the pyrolysis collector from the ground, improve the system safety and the operability of maintenance in case of failure, make the whole system structure more compact, and reduce the construction cost. In addition, the pyrolysis cycle is used as the heat absorbing medium of the pyrolysis collector to reduce the influence of light window pollution on the operation of the system, providing new ideas for the technical field of complementary utilization of multiple renewable energy sources.

[0048] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A pyrolysis and recycling biomass pyrolysis system based on secondary reflection and focusing, characterized in that: It includes a heliostat field, a secondary reflector, a pyrolysis coke collector, and a pyrolysis furnace. The heliostat field and the pyrolysis coke collector are both installed on the ground. The secondary reflector is arranged above the pyrolysis coke collector, and the pyrolysis coke collector is arranged at the focus of the secondary reflector. The pyrolysis coke collector is connected to the pyrolysis furnace. The heliostat field is used to reflect sunlight to the secondary reflector for concentration, and the secondary reflector is used to reflect the concentrated sunlight to the pyrolysis coke collector, and the pyrolysis coke collector is used to heat the pyrolysis coke and transmit the pyrolysis coke after absorbing heat to the pyrolysis furnace, and the pyrolysis furnace is used to use the pyrolysis coke after absorbing heat as a heat source to react with biomass to produce high-temperature pyrolysis coke, flue gas and pyrolysis gas; the temperature of the high-temperature pyrolysis coke reaches above 600°C; It also includes a discharge auger and a biomass dryer; the discharge auger is connected to the pyrolysis furnace, the discharge auger is used to send the high-temperature pyrolysis coke obtained by the pyrolysis reaction to the biomass dryer, and the biomass dryer is used to use the high-temperature pyrolysis coke to dry the biomass.

2. The pyrolysis and recycling biomass pyrolysis system based on secondary reflection and focusing according to claim 1 is characterized in that: The pyrolysis furnace is a drum heat storage pyrolysis furnace or an auger type continuous pyrolysis furnace.

3. The pyrolysis and recycling biomass pyrolysis system based on secondary reflection and focusing according to claim 1 is characterized in that: The outer wall of the thermal decoking collector is a light-transmitting outer wall.

4. The pyrolysis and recycling biomass pyrolysis system based on secondary reflection and focusing according to claim 1 is characterized in that: The pyrolysis coke collector comprises a pyrolysis coke outlet, which is used to output the pyrolysis coke after absorbing heat to the pyrolysis furnace; the pyrolysis furnace comprises a feeder, which is used to transport biomass to the pyrolysis furnace; The thermal decoking outlet is connected to the feeder.

5. The pyrolysis and recycling biomass pyrolysis system based on secondary reflection and focusing according to claim 1 is characterized in that: It also includes a burner and an air preheater; the air preheater is used to use the waste heat of the flue gas to heat the external air and send the heated air into the burner; the burner is used to use the pyrolysis gas as fuel for combustion when the energy of the concentrated sunlight is insufficient, so as to heat the pyrolysis furnace.

6. The pyrolysis and recycling biomass pyrolysis system based on secondary reflection and focusing according to claim 1 is characterized in that: It also includes a dynamic airflow isolation device; the dynamic airflow isolation device is used to blow inert gas into the furnace wall of the pyrolysis furnace to form a protective atmosphere on the surface of the furnace wall.

7. A pyrolysis method for recycling biomass based on secondary reflection and focusing, characterized in that: The following steps are involved: S1: Reflecting sunlight to a secondary reflector through a heliostat field for concentration, and then reflecting the concentrated sunlight to a thermal decoking collector through the secondary reflector; S2: sending the pyrolysis coke to the pyrolysis coke heat collector, heating the pyrolysis coke through the pyrolysis coke heat collector, and transmitting the pyrolysis coke after absorbing heat to the pyrolysis furnace; S3: feeding the biomass into the pyrolysis furnace, and the pyrolysis coke after absorbing heat is used as a heat source to react with the biomass in the pyrolysis furnace to produce high-temperature pyrolysis coke, flue gas and pyrolysis gas; the temperature of the high-temperature pyrolysis coke reaches above 600°C; S4: The unloading auger delivers the high-temperature pyrolysis coke obtained by the pyrolysis reaction into the biomass dryer. The biomass dryer uses the high-temperature pyrolysis coke to dry the biomass, and then the biomass enters the pyrolysis furnace from the feeder.

8. The pyrolysis method for recycling biomass based on secondary reflection and focusing according to claim 7 is characterized in that: After step S4, after heating the biomass, the high-temperature thermal pyrolysis adds part of the high-temperature pyrolysis that has been cooled down into the pyrolysis collector for heating, thereby realizing the recycling of the pyrolysis.

9. The pyrolysis method for recycling biomass by pyrolysis based on secondary reflection and focusing according to claim 7, characterized in that: The ratio of the mass flow rate of the pyrolysis coke entering the pyrolysis furnace to the mass flow rate of the biomass is (0.5-3):1.

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