Biomass pyrolysis and fire coal coupling utilization system and method

Abstract

The invention discloses a biomass pyrolysis and fire coal coupling utilization system and method.A raw material outlet of a biomass bin is connected to a raw material inlet of a pyrolysis reactor, a pyrolysis gas outlet of the pyrolysis reactor is connected with a raw material gas inlet of a high-temperature filter, and a purified gas outlet of the high-temperature filter is connected to a coal-fired boiler; a steam outlet of the coal-fired boiler is connected to the steam power generation system and further connected with a steam reverse blowing opening of the high-temperature filter, a flue gas inlet of the pyrolysis reactor is connected with a first flue gas outlet of the coal-fired boiler, and a flue gas outlet of the pyrolysis reactor and a second flue gas outlet of the coal-fired boiler are connected to the flue gas purification system. A steam outlet of the coal-fired boiler is connected to the steam power generation system, a steam blowback opening of the high-temperature filter and condensed water generated by the steam power generation system are connected to the coal-fired boiler. The biomass medium-temperature pyrolysis can effectively prevent volatile components such as alkali metal and chlorine from escaping, and boiler slagging corrosion is avoided.

Description

Technical Field

[0001] The present invention belongs to the field of biomass and coal coupled power generation utilization, and specifically relates to a biomass pyrolysis and coal combustion coupled utilization system and method. Background Art

[0002] Driven by the dual imperatives of energy restructuring and climate change response, the global energy sector is undergoing profound changes. With the gradual advancement of the "dual carbon" goals, reducing carbon emissions and improving energy efficiency have become core issues for development across all industries. Coal-fired power generation, as a crucial component of traditional energy supply, faces immense pressure to reduce emissions while ensuring energy security. Because coal combustion produces a significant proportion of CO2 emissions, transforming coal-fired power generation into a low-carbon power plant and achieving cleaner and more efficient combustion is a critical issue that urgently needs to be addressed in the energy sector.

[0003] Among the many low-carbon transformation technologies for coal-fired power generation, biomass co-firing has attracted considerable attention due to its unique zero-carbon properties. As a renewable energy source, biomass emits approximately the same amount of carbon dioxide as it absorbs during its growth, making it considered a near-zero-carbon energy source. By co-firing biomass with coal, the carbon intensity of coal-fired power generation can be effectively reduced without changing the existing coal-fired boiler structure. However, biomass and coal exhibit significant differences in combustion characteristics, which directly impact combustion efficiency and stability during the co-firing process.

[0004] Specifically, biomass generally has a higher volatile matter content and a lower fixed carbon content, and its combustion process is faster and more intense, while coal burns relatively slowly and steadily. This difference in combustion characteristics makes it difficult to achieve uniform mixing and sufficient combustion of biomass and coal during the blending process, thereby reducing combustion efficiency. What is more serious is that some biomass is rich in alkali metals, chlorine and other components, which easily escape in gaseous or solid form during the combustion process and deposit on the heating surface of the boiler, forming slagging and corrosion. This not only affects the thermal efficiency and service life of the boiler, but may also cause safety accidents, posing a serious threat to the stable operation of coal-fired power generation.

[0005] Therefore, in order to address the problems of low combustion efficiency and boiler slagging corrosion in the process of co-firing biomass and coal, it is particularly important to develop an efficient method for the coupled utilization of biomass and coal. This method should be able to fully utilize the zero-carbon properties of biomass, while overcoming the challenges brought about by the differences in the combustion characteristics of biomass and coal, and ensuring the stability and efficiency of the co-firing process. In addition, the method should also have the ability to effectively handle harmful components in biomass to avoid damage to the boiler. Through such technological innovations, the low-carbon transformation process of coal-fired power generation can be promoted, providing strong support for achieving the "dual carbon" goals. Summary of the Invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a system and method for the coupled utilization of biomass pyrolysis and coal combustion. By pyrolyzing biomass and purifying the high-temperature pyrolysis gas obtained by pyrolysis, it can be ensured that its incineration will not produce alkali metals, chlorine elements and other substances that are likely to cause boiler slagging and corrosion. The pyrolytic carbon enriched with components such as alkali metals and chlorine elements can be sold as a product, realizing the resource recovery of alkali metals and chlorine elements and reducing resource consumption.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a biomass pyrolysis and coal-fired coupled utilization system, comprising a biomass silo, a pyrolysis reactor, a high-temperature filter, a coal-fired boiler, a steam power generation system and a flue gas purification system, wherein the raw material outlet of the biomass silo is connected to the raw material inlet of the pyrolysis reactor, the pyrolysis gas outlet of the pyrolysis reactor is connected to the raw gas inlet of the high-temperature filter, the purified gas outlet of the high-temperature filter is connected to the coal-fired boiler, the steam outlet of the coal-fired boiler is connected to the steam power generation system, the steam outlet of the coal-fired boiler is also connected to the steam backflush port of the high-temperature filter, the flue gas inlet of the pyrolysis reactor is connected to the first flue gas outlet of the coal-fired boiler, the flue gas outlet of the pyrolysis reactor and the second flue gas outlet of the coal-fired boiler are connected to the flue gas purification system, the steam outlet of the coal-fired boiler is connected to the steam power generation system and the steam backflush port of the high-temperature filter, and the condensate generated by the steam power generation system is connected to the coal-fired boiler.

[0008] Furthermore, it also includes a pyrolytic carbon cooler, the raw material outlet of the pyrolytic carbon reactor is connected to the raw material inlet of the pyrolytic carbon cooler, and the raw material outlet of the pyrolytic carbon cooler is connected to the raw material inlet of the carbon storage bin.

[0009] Furthermore, the high temperature filter further comprises a solid outlet, and the solid outlet of the high temperature filter is connected to the raw material inlet of the pyrolytic carbon cooler.

[0010] Furthermore, it also includes a sealed feeder, the raw material outlet of the biomass silo is connected to the raw material inlet of the sealed feeder, and the raw material outlet of the sealed feeder is connected to the raw material inlet of the pyrolysis reactor.

[0011] Furthermore, the pyrolysis reactor adopts a vertical cylindrical structure with a spiral agitator inside. The furnace body of the pyrolysis reactor is made of high-temperature and corrosion-resistant stainless steel; a temperature sensor is provided on the top of the pyrolysis reactor to detect the internal temperature of the reactor.

[0012] Furthermore, the high temperature filter adopts a multi-stage filtration structure, including a coarse filtration layer, a fine filtration layer and a fine filtration layer connected in sequence, the pore size of the coarse filtration layer is 10-20μm, the pore size of the fine filtration layer is 2-5μm, and the pore size of the fine filtration layer is 0.5-2μm.

[0013] The present invention provides a method for using a biomass pyrolysis and coal combustion coupled utilization system, comprising the following steps:

[0014] Step 1: Biomass that meets the feeding requirements is loaded into the biomass silo and fed into the pyrolysis reactor under the action of a sealed feeder;

[0015] Step 2: The biomass is thermally decomposed in a pyrolysis reactor to produce high-temperature pyrolysis gas and pyrolysis char, wherein the high-temperature pyrolysis gas is fed into a high-temperature filter;

[0016] Step 3: The high-temperature filter filters and purifies the high-temperature pyrolysis gas to remove solid particles contained in the gas. The purified pyrolysis gas is then fed into a coal-fired boiler for combustion.

[0017] Step 4: The coal-fired boiler burns the purified pyrolysis gas and coal to generate high-temperature flue gas, part of which is fed into the pyrolysis reactor to provide heat for the pyrolysis process, and the rest is used to produce steam. Part of the generated steam is used for backwashing of the high-temperature filter, and the rest is fed into the steam power generation system to produce electricity. The condensate generated by the steam power generation system is again fed into the coal-fired boiler to produce steam;

[0018] Step 5: The flue gas after heating by the coal-fired boiler and the pyrolysis reactor is uniformly sent to the flue gas purification system for purification before being discharged.

[0019] Furthermore, in step 1, meeting the feed requirements means that the biomass particles have a particle size of ≤20 mm and a moisture content of ≤20%; and the temperature of thermal decomposition in the pyrolysis reactor is 400-600°C.

[0020] Furthermore, in step 2 and step 3, the biomass is thermally decomposed in the pyrolysis reactor to produce pyrolytic char and the solid produced by filtration through the high-temperature filter is sent to a pyrolytic char cooler, cooled to below 50° C., and then sent to a charcoal storage bin.

[0021] Furthermore, in step 4, high temperature flue gas refers to flue gas temperature ≥ 700°C.

[0022] Compared with the prior art, the present invention has at least the following beneficial effects:

[0023] The present invention provides a biomass pyrolysis and coal combustion coupled utilization system. By coupling a coal-fired boiler with a pyrolysis reactor, biomass pyrolysis and coal combustion are coupled. The biomass pyrolysis process fixes volatile components such as alkali metals and chlorine in the biomass into pyrolytic charcoal, where they are enriched. This prevents these substances from entering the gas phase during high-temperature combustion, thereby effectively preventing boiler slagging and corrosion. Simultaneously, the high-temperature flue gas generated by the coal-fired boiler is used to heat the pyrolysis reactor, ensuring sufficient pyrolysis of the biomass, achieving cascaded heat utilization within the system, and improving energy efficiency.

[0024] Furthermore, the present invention uses a pyrolytic carbon cooler to cool the high-temperature pyrolytic carbon and then sends it to a charcoal storage bin, which facilitates storage and transportation while ensuring the quality of the pyrolytic carbon. Pyrolytic carbon is rich in carbon and has many high-value applications, such as fuel carbon, activated carbon substrate, electrode material, etc. For pyrolytic carbon that is particularly rich in alkali metals, such as straw pyrolytic carbon, it can also be used as a soil conditioner, carbon-based organic fertilizer, etc., realizing the resource recovery of alkali metals and chlorine elements.

[0025] Furthermore, flue gas from the coal-fired boiler and pyrolysis reactor is fed into a flue gas purification system for purification before discharge, avoiding direct emissions and polluting the environment, thus meeting environmental protection requirements. This design not only achieves efficient biomass utilization, but also promotes resource recycling and environmental protection.

[0026] Furthermore, a portion of the high-temperature flue gas generated by the coal-fired boiler is used to heat the pyrolysis reactor, ensuring the required temperature for the pyrolysis process and sufficient decomposition of the material. Another portion is used to produce steam, which is then used for backwashing the high-temperature filter and the steam power generation system, achieving a cascaded utilization of heat within the system. This design not only improves the system's thermal efficiency, but also enhances its operational stability and extends the equipment's service life.

[0027] Furthermore, the pyrolysis reactor adopts a vertical cylindrical structure with an internal spiral agitator to ensure sufficient mixing and uniform heating of the biomass feedstock, further improving pyrolysis efficiency. Furthermore, the furnace body of the pyrolysis reactor is made of high-temperature and corrosion-resistant stainless steel, and a temperature sensor is installed on the top to monitor the internal temperature of the reactor in real time, ensuring the stability and safety of the pyrolysis process.

[0028] Furthermore, the system of the present invention utilizes a high-temperature filter with a multi-stage filtration structure to effectively filter and purify the high-temperature pyrolysis gas, removing solid particles contained in the gas, improving the operational stability of the coal-fired boiler, and reducing the risk of boiler slagging and corrosion. Simultaneously, the flue gas from the coal-fired boiler and pyrolysis reactor is uniformly fed into the flue gas purification system for purification, avoiding direct emissions and environmental pollution. This multi-stage filtration and purification design ensures the effective purification and utilization of flue gas, meets environmental protection requirements, and provides strong support for the company's sustainable development.

[0029] The present invention provides a method for using a biomass pyrolysis and coal-fired coupling utilization system, which realizes the efficient coupling utilization of biomass pyrolysis and coal-fired. First, by controlling the particle size and moisture content of the biomass particles, the sufficient decomposition and efficient pyrolysis of the biomass in the pyrolysis reactor are ensured. Secondly, the high-temperature pyrolysis gas is purified by a multi-stage filter to remove solid particles in the gas, thereby improving the combustion efficiency and operational stability of the coal-fired boiler. At the same time, the high-temperature flue gas and steam generated by the coal-fired boiler are fully utilized, providing the necessary energy for heating the pyrolysis reactor and back-flushing the high-temperature filter, thereby realizing the cascade utilization of heat within the system. In addition, the pyrolysis carbon is sent to a carbon storage bin for storage after cooling treatment, which is convenient for subsequent high-value utilization. The entire method of use has a clear process and is easy to operate. It not only improves energy utilization efficiency, but also reduces environmental pollution and equipment loss, with significant economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 1 is a process flow chart of the system of the present invention. DETAILED DESCRIPTION

[0031] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0034] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0035] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0036] The present invention aims to address the shortcomings of existing coal-fired power plants in biomass-coupled low-carbon transformation, such as easy slagging and corrosion of boilers and poor operating stability. It provides a biomass pyrolysis and coal-fired coupled utilization system and method. By coupling the combustion of biomass pyrolysis gas and coal, pyrolytic carbon is produced as another product, which effectively avoids the escape of volatile components such as alkali metals and chlorine elements into the boiler, thereby realizing the low-carbon transformation of coal-fired power plants.

[0037] In order to implement the above technical solution, Figure 1 As shown, the present invention provides a biomass pyrolysis and coal combustion coupled utilization system, including a biomass silo, a sealed feeder, a pyrolysis reactor, a pyrolysis carbon cooler, a carbon storage silo, a high-temperature filter, a coal-fired boiler, a steam power generation system and a flue gas purification system.

[0038] The biomass silo, sealed feeder, pyrolysis reactor and pyrolysis carbon cooler are all provided with a raw material inlet and a raw material outlet. The raw material outlet of the biomass silo is connected to the raw material inlet of the sealed feeder, the raw material outlet of the sealed feeder is connected to the raw material inlet of the pyrolysis reactor, the raw material outlet of the pyrolysis reactor is connected to the raw material inlet of the pyrolysis carbon cooler, and the raw material outlet of the pyrolysis carbon cooler is connected to the raw material inlet of the carbon storage silo.

[0039] The pyrolysis reactor is also provided with a pyrolysis gas outlet, the high-temperature filter is provided with a raw gas inlet, a purified gas outlet and a solid outlet, the pyrolysis gas outlet is connected to the raw gas inlet of the high-temperature filter, the solid outlet of the high-temperature filter is connected to the raw material inlet of the pyrolysis carbon cooler, and the purified gas outlet is connected to the coal-fired boiler.

[0040] The pyrolysis reactor is also provided with a flue gas inlet and a flue gas outlet, and the high-temperature filter is also provided with a steam backflush port. The flue gas inlet of the pyrolysis reactor is connected to the first flue gas outlet of the coal-fired boiler, the flue gas outlet of the pyrolysis reactor and the second flue gas outlet of the coal-fired boiler are connected to the flue gas purification system, the steam outlet of the coal-fired boiler is connected to the steam power generation system and the steam backflush port of the high-temperature filter, and the condensate generated by the steam power generation system is connected to the coal-fired boiler.

[0041] The working method of the above system includes the following steps:

[0042] Step 1: biomass that meets the feeding requirements is loaded into the biomass silo and fed into the pyrolysis reactor under the action of a sealed feeder. The feeding requirements are that the biomass particle size is ≤20mm and the moisture content is ≤20%;

[0043] Step 2: The biomass is decomposed in a pyrolysis reactor at 400-600°C to produce high-temperature pyrolysis gas and pyrolysis carbon. The pyrolysis gas is sent to a high-temperature filter, and the pyrolysis carbon is sent to a pyrolysis carbon cooler. The pyrolysis carbon cooler cools the pyrolysis carbon to below 50°C and then sends it to a carbon storage bin.

[0044] Step 3: The high-temperature filter filters and purifies the high-temperature pyrolysis gas to remove solid particles contained in the gas. The purified gas is sent to the coal-fired boiler for combustion, and the solids produced by the filtration are sent to the pyrolysis carbon cooler for cooling and recovery along with the pyrolysis carbon.

[0045] Step 4: The coal-fired boiler burns pyrolysis gas and coal to generate high-temperature flue gas (flue gas temperature ≥ 700°C). Part of the flue gas is fed into the pyrolysis reactor to provide heat for the pyrolysis process, and the rest is used to produce steam. Part of the steam is used for backwashing of the high-temperature filter, and the rest is fed into the steam power generation system to produce electricity. The condensate generated by the steam power generation system is fed back into the coal-fired boiler to produce steam.

[0046] In step 5, the flue gas from the coal-fired boiler and pyrolysis reactor is fed into a flue gas purification system for purification before discharge. The system can also adjust various parameters based on actual needs: increasing the coal blending ratio for higher power output; reducing the reactor temperature and residence time for higher pyrolysis efficiency; and lowering the oil-gas separation temperature for higher bio-oil recovery.

[0047] Preferably, the biomass silo is also provided with a moisture content detection device for detecting the moisture content of the biomass. When the moisture content exceeds 15%, desiccant is added to the biomass silo for drying. The biomass silo is also provided with a particle size detection device for detecting the particle size of the biomass particles.

[0048] Preferably, the pyrolysis reactor adopts a vertical cylindrical structure with a spiral agitator inside to ensure sufficient mixing and uniform heating of the biomass raw materials; the furnace body of the pyrolysis reactor is made of high-temperature and corrosion-resistant stainless steel; a temperature sensor is provided on the top of the pyrolysis reactor to detect the internal temperature of the reactor.

[0049] Preferably, the outer walls of the biomass silo, the pyrolysis reactor and the pyrolysis char cooler are all provided with an insulation layer.

[0050] Preferably, the pyrolytic carbon cooler adopts a circulating fluidized bed cooling method; the carbon storage bin adopts a closed design and is equipped with a ventilation system to maintain a dry and ventilated storage environment.

[0051] Preferably, the high temperature filter adopts a multi-stage filtration structure, including a coarse filtration layer, a fine filtration layer and a fine filtration layer connected in sequence, the pore size of the coarse filtration layer is 10-20μm, the pore size of the fine filtration layer is 2-5μm, and the pore size of the fine filtration layer is 0.5-2μm.

[0052] Preferably, the coal-fired boiler adopts a dual-circuit design, including a main combustion chamber and an auxiliary combustion chamber. The main combustion chamber is used to burn pyrolysis gas and coal, and the auxiliary combustion chamber is used to burn coal to generate steam. The furnace of the coal-fired boiler adopts a water-cooled wall structure and uses low-temperature superheated steam as the heat source of the boiler.

[0053] Preferably, the steam power generation system is designed with high pressure parameters, with a steam pressure of 12-16 MPa and a temperature of 450-480°C;

[0054] Preferably, the flue gas purification system includes a cyclone separator, an electrostatic precipitator and an activated carbon filter connected in sequence, the cyclone separator is used to remove particulate impurities, the electrostatic precipitator is used to remove electrostatic impurities, and the activated carbon filter is used to remove organic impurities.

[0055] Preferably, the control system of the system of the present invention adopts Siemens S7-300 series PLC controller to realize automatic operation control, including functions such as material level control, temperature control, pressure control and intelligent monitoring.

[0056] Example 1

[0057] Step 1: biomass with a particle size of 18 mm and a moisture content of 18% is loaded into a biomass silo and fed into a pyrolysis reactor by a sealed feeder.

[0058] In step 2, the biomass is decomposed at 600°C in a pyrolysis reactor, producing high-temperature pyrolysis gas and pyrolysis char. The pyrolysis gas is fed into a high-temperature filter, and the pyrolysis char is fed into a pyrolysis char cooler. The pyrolysis char cooler cools the pyrolysis char to 30°C before transferring it to a charcoal storage bin.

[0059] Step 3: A high-temperature filter filters and purifies the high-temperature pyrolysis gas to remove solid particles. The purified gas is then fed into a coal-fired boiler for combustion, while the solids produced by the filtration are fed into a pyrolysis carbon cooler for cooling and recovery along with the pyrolysis carbon.

[0060] In step 4, the coal-fired boiler combusts the pyrolysis gas and coal, feeding a portion of the flue gas at 650°C into the pyrolysis reactor to provide heat for the pyrolysis process. The remaining flue gas is used to produce steam. A portion of the steam is used to backflush the high-temperature filter, while the remainder is fed into the steam power generation system to generate electricity. The condensate from the steam power generation system is fed back into the coal-fired boiler to produce steam.

[0061] Step 5: The flue gas after heating by the coal-fired boiler and the pyrolysis reactor is uniformly sent to the flue gas purification system for purification before being discharged.

[0062] Example 2:

[0063] The present invention provides a method for using a biomass pyrolysis and coal combustion coupled utilization system, comprising the following steps:

[0064] Step 1: biomass with a particle size of less than 10 mm and a moisture content of 15% is loaded into a biomass silo and fed into a pyrolysis reactor by a sealed feeder;

[0065] Step 2: The biomass is decomposed in a pyrolysis reactor at 500°C to produce high-temperature pyrolysis gas and pyrolysis carbon. The pyrolysis gas is sent to a high-temperature filter, and the pyrolysis carbon is sent to a pyrolysis carbon cooler. The pyrolysis carbon cooler cools the pyrolysis carbon to 45°C and then sends it to a carbon storage bin.

[0066] Step 3: The high-temperature filter filters and purifies the high-temperature pyrolysis gas to remove solid particles contained in the gas. The purified gas is sent to the coal-fired boiler for combustion, and the solids produced by the filtration are sent to the pyrolysis carbon cooler for cooling and recovery along with the pyrolysis carbon.

[0067] Step 4: The coal-fired boiler combusts the pyrolysis gas and coal, sending part of the 700°C flue gas to the pyrolysis reactor to provide heat for the pyrolysis process, and the rest is used to produce steam. Part of the generated steam is used for backwashing of the high-temperature filter, and the rest is sent to the steam power generation system to produce electricity. The condensate generated by the steam power generation system is again sent to the coal-fired boiler to produce steam;

[0068] Step 5: The flue gas after heating by the coal-fired boiler and the pyrolysis reactor is uniformly sent to the flue gas purification system for purification before being discharged.

[0069] Example 3:

[0070] The present invention provides a method for using a biomass pyrolysis and coal combustion coupled utilization system, comprising the following steps:

[0071] Step 1: biomass with a particle size of less than 5 mm and a moisture content of 10% is loaded into a biomass silo and fed into a pyrolysis reactor by a sealed feeder;

[0072] Step 2: The biomass is decomposed at 400°C in a pyrolysis reactor to produce high-temperature pyrolysis gas and pyrolysis carbon. The pyrolysis gas is sent to a high-temperature filter, and the pyrolysis carbon is sent to a pyrolysis carbon cooler. The pyrolysis carbon cooler cools the pyrolysis carbon to 50°C and then sends it to a carbon storage bin.

[0073] Step 3: The high-temperature filter filters and purifies the high-temperature pyrolysis gas to remove solid particles contained in the gas. The purified gas is sent to the coal-fired boiler for combustion, and the solids produced by the filtration are sent to the pyrolysis carbon cooler for cooling and recovery along with the pyrolysis carbon.

[0074] Step 4: The coal-fired boiler combusts the pyrolysis gas and coal, sending part of the 500°C flue gas to the pyrolysis reactor to provide heat for the pyrolysis process, and the rest is used to produce steam. Part of the generated steam is used for backwashing of the high-temperature filter, and the rest is sent to the steam power generation system to produce electricity. The condensate generated by the steam power generation system is again sent to the coal-fired boiler to produce steam;

[0075] Step 5: The flue gas after heating by the coal-fired boiler and the pyrolysis reactor is uniformly sent to the flue gas purification system for purification before being discharged.

[0076] Example 4:

[0077] The present invention provides an improved implementation of a biomass pyrolysis and coal combustion coupled utilization system, including the following features:

[0078] 1. The biomass silo is also equipped with a magnetic separation device to remove metal impurities in the biomass raw materials and improve pyrolysis efficiency;

[0079] 2. The furnace body of the pyrolysis reactor is made of high temperature and corrosion resistant ceramic fiber felt, and the internal wall is provided with an aluminum silicate fiber insulation layer;

[0080] 3. The pyrolytic carbon cooler adopts a circulating fluidized bed cooling method. The cooling temperature can be adjusted between 30-50℃ and the cooling wind speed is 3-4m / s.

[0081] 4. The high temperature filter adopts a four-stage filtration structure, the first stage is grid filtration, the second stage is boiler slag filtration, the third stage is bacterial filtration, and the fourth stage is activated carbon filtration;

[0082] 5. The coal-fired boiler adopts a three-circuit design, including a main combustion chamber, an auxiliary combustion chamber and a steam generation chamber. The main combustion chamber is used to burn pyrolysis gas and coal, the auxiliary combustion chamber is used to burn coal to generate steam, and the steam generation chamber is used to heat boiler water;

[0083] 6. The steam power generation system adopts ultra-high pressure parameter design, with steam pressure of 15-20MPa and temperature of 460-500℃;

[0084] 7. The flue gas purification system adopts a multi-stage dust removal device, including an electrostatic precipitator, an activated carbon filter and a wet electrode dust collector.

[0085] 8. The control system of the present invention adopts Siemens S7-400 series PLC controller to achieve fully automatic operation control, including material level control, temperature control, pressure control, intelligent monitoring and fault diagnosis functions.

[0086] 9. The system of the present invention is also equipped with a gas analyzer for real-time monitoring of the gas composition generated during the operation of the system, timely adjustment of system parameters, and ensuring stable operation of the system.

[0087] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all points of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and range of equivalents of the claims are included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0088] In addition, it should be understood that although this specification describes the embodiments, not every embodiment contains only one independent technical solution. This description is for clarity only. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for the purpose of illustrating the technical concept of the present invention and cannot be used to limit the scope of protection of the present invention. Any changes made based on the technical solution in accordance with the technical concept proposed by the present invention fall within the scope of protection of the claims of the present invention.

Claims

1. A biomass pyrolysis and coal combustion coupled utilization system, characterized in that: It includes a biomass silo, a pyrolysis reactor, a high-temperature filter, a coal-fired boiler, a steam power generation system and a flue gas purification system, wherein the raw material outlet of the biomass silo is connected to the raw material inlet of the pyrolysis reactor, the pyrolysis gas outlet of the pyrolysis reactor is connected to the raw gas inlet of the high-temperature filter, the purified gas outlet of the high-temperature filter is connected to the coal-fired boiler, the steam outlet of the coal-fired boiler is connected to the steam power generation system, the steam outlet of the coal-fired boiler is also connected to the steam backflush port of the high-temperature filter, the flue gas inlet of the pyrolysis reactor is connected to the first flue gas outlet of the coal-fired boiler, the flue gas outlet of the pyrolysis reactor and the second flue gas outlet of the coal-fired boiler are connected to the flue gas purification system, the steam outlet of the coal-fired boiler is connected to the steam power generation system and the steam backflush port of the high-temperature filter, and the condensate generated by the steam power generation system is connected to the coal-fired boiler.

2. The biomass pyrolysis and coal combustion coupled utilization system according to claim 1, characterized in that: It also includes a pyrolytic carbon cooler, the raw material outlet of the pyrolytic carbon reactor is connected to the raw material inlet of the pyrolytic carbon cooler, and the raw material outlet of the pyrolytic carbon cooler is connected to the raw material inlet of the carbon storage bin.

3. The biomass pyrolysis and coal combustion coupled utilization system according to claim 2, characterized in that: The high temperature filter further comprises a solid outlet, and the solid outlet of the high temperature filter is connected to the raw material inlet of the pyrolytic carbon cooler.

4. The biomass pyrolysis and coal combustion coupled utilization system according to claim 1, characterized in that: The invention also comprises a sealed feeder, wherein the raw material outlet of the biomass silo is connected to the raw material inlet of the sealed feeder, and the raw material outlet of the sealed feeder is connected to the raw material inlet of the pyrolysis reactor.

5. The biomass pyrolysis and coal combustion coupled utilization system according to claim 1, characterized in that: The pyrolysis reactor adopts a vertical cylindrical structure with a spiral stirrer inside. The furnace body of the pyrolysis reactor is made of high-temperature and corrosion-resistant stainless steel. A temperature sensor is provided on the top of the pyrolysis reactor to detect the internal temperature of the reactor.

6. The biomass pyrolysis and coal combustion coupled utilization system according to claim 1, characterized in that: The high temperature filter adopts a multi-stage filtration structure, including a coarse filtration layer, a fine filtration layer and a fine filtration layer connected in sequence. The pore size of the coarse filtration layer is 10-20 μm, the pore size of the fine filtration layer is 2-5 μm, and the pore size of the fine filtration layer is 0.5-2 μm.

7. The method for using the biomass pyrolysis and coal combustion coupled utilization system according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Biomass that meets the feeding requirements is loaded into the biomass silo and fed into the pyrolysis reactor under the action of a sealed feeder; Step 2: The biomass is thermally decomposed in a pyrolysis reactor to produce high-temperature pyrolysis gas and pyrolysis char, wherein the high-temperature pyrolysis gas is fed into a high-temperature filter; Step 3: The high-temperature filter filters and purifies the high-temperature pyrolysis gas to remove solid particles contained in the gas. The purified pyrolysis gas is then fed into a coal-fired boiler for combustion. Step 4: The coal-fired boiler burns the purified pyrolysis gas and coal to generate high-temperature flue gas, part of which is fed into the pyrolysis reactor to provide heat for the pyrolysis process, and the rest is used to produce steam. Part of the generated steam is used for backwashing of the high-temperature filter, and the rest is fed into the steam power generation system to produce electricity. The condensate generated by the steam power generation system is again fed into the coal-fired boiler to produce steam; Step 5: The flue gas after heating by the coal-fired boiler and the pyrolysis reactor is uniformly sent to the flue gas purification system for purification before being discharged.

8. The method for using the biomass pyrolysis and coal combustion coupled utilization system according to claim 7, characterized in that: In step 1, meeting the feed requirements means that the biomass particles have a particle size of ≤20 mm and a moisture content of ≤20%; and the temperature of thermal decomposition in the pyrolysis reactor is 400-600°C.

9. The method for using the biomass pyrolysis and coal combustion coupled utilization system according to claim 7, characterized in that: In step 2 and step 3, the biomass is thermally decomposed in the pyrolysis reactor to produce pyrolytic carbon, and the solid produced by filtration through the high-temperature filter is sent to the pyrolytic carbon cooler, cooled to below 50° C., and then sent to the carbon storage bin.

10. The method for using the biomass pyrolysis and coal combustion coupled utilization system according to claim 7, characterized in that: In step 4, high temperature flue gas refers to flue gas temperature ≥ 700°C.

Images