Biomass pyrolysis pressure stabilization system and method

Abstract

The present invention provides a biomass pyrolysis pressure stabilization system and method thereof, the biomass pyrolysis pressure stabilization system includes a pyrolysis reaction device, a water seal tank, a valve group and a pyrolysis gas utilization device; the pyrolysis gas outlet of the pyrolysis reaction device and the feed inlet of the pyrolysis gas utilization device are connected by a first pipeline, and the first pipeline is provided with the valve group; the pyrolysis gas outlet of the pyrolysis reaction device is also provided with a second pipeline, and the second pipeline is connected to the water seal tank for achieving water seal pressure stabilization; wherein the valve group includes a number of flow regulating valves connected in series. The biomass pyrolysis pressure stabilization system of the present invention can meet the pressure stabilization requirements of the dust-containing and tar-containing pyrolysis gas of the organic solid waste micro-positive pressure pyrolysis system; effectively realize the pressure difference distribution between upstream and downstream, thereby realizing the anti-backmixing function of the pyrolysis gas; the equipment cost is low and the operation is simple; the biomass pyrolysis pressure stabilization method of the present invention can stabilize the operating pressure, prevent backmixing, prevent tar condensation and precipitation, and take into account the emergency discharge of the system.

Description

Technical Field

[0001] The invention relates to a biomass pyrolysis pressure stabilization system and method. Background Art

[0002] Organic solid waste mainly includes agricultural and forestry biomass, domestic waste and its derivatives, oily sludge, water treatment sludge, etc. The main disposal options for organic solid waste are: incineration, landfill, pyrolysis gasification, etc. The landfill option is costly and cannot fundamentally achieve the harmlessness and resource utilization of organic solid waste. In most cases, it is used as a temporary storage option for solid waste and hazardous waste that cannot be temporarily disposed of. Current incineration technology has the following bottlenecks on a small and medium scale: (1) The flue gas volume is large, and the cost of flue gas treatment is particularly high on a small scale; (2) It is difficult to achieve resource utilization of solid waste. The flue gas heat energy generated by incineration is low-grade energy with low parameters, making it difficult to achieve high-value utilization; (3) Incineration must have a scale effect, but currently a large amount of solid waste, especially single bulk hazardous waste, cannot be treated in a centralized and large-scale manner.

[0003] Pyrolysis technology refers to the use of temperature to heat organic solid waste under oxygen-free conditions, causing the organic matter components in the organic solid waste to undergo thermal cracking reactions and be converted into pyrolysis gas and solid residue, thereby reducing the organic impurity content of the solid residue to below the regulatory requirements. This method is currently the way to harmlessly dispose of organic solid wastes such as sludge, dry garbage, and industrial waste salt. The main components of pyrolysis gas are hydrogen, carbon monoxide, carbon dioxide, water vapor, and gaseous hydrocarbons, and may also contain a small amount of tar and dust. The presence of tar and dust makes the scheme of condensing the pyrolysis gas and then reusing it prone to problems such as pipeline blockage. In addition, the process scheme of directly gasifying or incinerating the pyrolysis gas without condensation also has the advantage of higher thermal efficiency, and is being increasingly used in the field of resource utilization of organic solid waste.

[0004] Organic solid waste is often fed using plunger pumps, which exhibit pulsed feeding characteristics. Pyrolysis of organic solid waste often utilizes rotary or spiral reactors, where the material undergoes periodic tumbling and agitation. This results in a certain degree of volatility in the pyrolysis gas produced by the pyrolysis equipment. To ensure tumbling of the material within the reactor and complete organic matter removal, these reactors often have large rotating components. The solid-phase feed and discharge components of the reactor are relatively stationary, and large dynamic seals connect the stationary and rotating components, making gas leaks more likely. Using a slight negative pressure makes it difficult for on-site operators to detect these leaks. Therefore, in actual production, pyrolysis reactors typically operate at a slight positive pressure range of +20 to +500 Pa to ensure system and personnel safety. The pulsed feeding characteristics of organic solid waste with plunger pumps further contribute to the volatility of the pyrolysis gas produced by the pyrolysis equipment. When the pyrolysis gas volume is low, the operating pressure of the pyrolysis reactor changes from a slight positive pressure to a negative pressure, which can easily cause high-temperature air from downstream equipment or ambient air to be drawn into the pyrolysis reactor, leading to explosions.

[0005] To stabilize the operating pressure within the organic solid waste pyrolysis reactor and increase the system's tolerance to fluctuations in pyrolysis gas volume, a corresponding pressure stabilization subsystem is required to ensure the stability of the pyrolysis reactor's operating conditions. However, pyrolysis gas cooling is prone to tar condensation and coking, placing high demands on the pressure stabilization solution.

[0006] In the prior art, organic solid waste or biomass pyrolysis and gasification systems often employ a buffer tank as a pressure stabilization solution to ensure a stable gas supply to subsequent utilization systems due to system fluctuations in the generated gas flow rate. For example, in CN 102559289 A (Biomass Synthesis Gas Cooling and Scrubbing Process and System), a pressure stabilization tank is installed for high-temperature, dusty, and tar-containing biomass synthesis gas exceeding 1000°C after a series of purification processes, including quenching, waste heat utilization, dust removal, and electric coke capture. Another example is CN 108728143 A (Biomass Ex-Situ Catalytic Pyrolysis and Liquefaction System), where a pressure stabilization tank is employed to ensure stable gas flow during the biomass gasification and liquefaction process. The advantage of using a buffer tank as a pressure stabilization solution is its maturity and suitability for processes involving purified gas prior to utilization. For unpurified, high-temperature, dusty, and tar-containing gas, this solution is prone to tar and coke precipitation.

[0007] Another common pressure stabilization solution involves a gas pressure-stabilizing valve, which is used in situations where there is a certain pressure differential between upstream and downstream. For relevant examples, see CN 204420240 U and CN 206637072 U. These gas pressure-stabilizing valves all involve relatively complex structures, making them only suitable for relatively clean gas. Furthermore, these valves have a large pressure drop, making them suitable for scenarios with a certain pressure differential between upstream and downstream. They are also less suitable for organic solid waste pyrolysis devices, which often operate at a slightly positive pressure and have relatively poor pyrolysis gas cleanliness. Summary of the Invention

[0008] The present invention aims to provide a biomass pyrolysis pressure stabilization system and method thereof, which has the advantages of low equipment cost, simple operation, low coking, and low cost, as the organic solid waste pyrolysis utilization system has high requirements for the stability of the pyrolysis gas pressure. However, the pyrolysis reactor has a slightly positive operating pressure, the pyrolysis gas has a high dust content, and tar condensation and coking easily occur during cooling. As a result, existing pressure stabilizing tanks, pressure stabilizing valves and other solutions are unable to effectively solve the defect of the direct utilization scenario of organic solid waste pyrolysis gas.

[0009] A biomass pyrolysis pressure stabilization system comprises a pyrolysis reaction device, a water seal tank, a valve group and a pyrolysis gas utilization device; the pyrolysis gas outlet of the pyrolysis reaction device and the feed inlet of the pyrolysis gas utilization device are connected via a first pipe, on which the valve group is provided; the pyrolysis gas outlet of the pyrolysis reaction device is further provided with a second pipe, which is connected to the water seal tank for achieving water seal pressure stabilization; wherein the valve group comprises a plurality of flow regulating valves connected in series.

[0010] Preferably, the number of the flow regulating valves is 2 to 4.

[0011] Preferably, the flow regulating valve is a butterfly valve, a ball valve or a sleeve regulating valve, more preferably a butterfly valve.

[0012] Preferably, the pyrolysis reaction device is a rotary reactor or a spiral reactor.

[0013] Preferably, the pyrolysis gas utilization device is a gasification furnace or a hot air furnace.

[0014] Preferably, the biomass pyrolysis pressure stabilization system further includes a blower, and the air inlet of the pyrolysis gas utilization device is connected to the blower through a pipeline.

[0015] Preferably, the biomass pyrolysis and pressure stabilization system further comprises a heat utilization unit, the feed port of the heat utilization unit is connected to the discharge port of the pyrolysis gas utilization device, and the heat utilization unit is used to burn the product in the pyrolysis gas utilization device to provide energy to the outside world; the heat utilization unit is preferably an incinerator or a boiler;

[0016] Wherein, the biomass pyrolysis and pressure stabilization system further includes an induced draft fan, and the discharge port of the heat utilization unit is connected to the induced draft fan.

[0017] A biomass pyrolysis and pressure stabilization method is performed using the biomass pyrolysis and pressure stabilization system described above, under the following conditions:

[0018] The starting stage of biomass pyrolysis: the water seal level of the water seal tank is established, the pyrolysis reaction device and the water seal tank are connected and in operation; the flow regulating valve of the valve group is opened and the valve opening is set; the pyrolysis reaction device and the pyrolysis gas utilization device are heated;

[0019] During the load increase phase of biomass pyrolysis, the pyrolysis reaction device and the pyrolysis gas utilization device are maintained in a slightly negative pressure operation; the feeding device of the pyrolysis reaction device is opened at a starting load, and the feeding load of the feeding device is increased, and the valve opening of the flow control valve is adjusted in coordination, so that the pyrolysis reaction device operates at a positive pressure; and the pyrolysis gas utilization device operates at a negative pressure;

[0020] Biomass pyrolysis operation stage: when the feed load of the feed device is at the standard feed load, the valve opening of the flow control valve is adjusted, and the operating pressure of the pyrolysis reaction device is positive pressure operation; the operating pressure of the pyrolysis gas utilization device is negative pressure operation;

[0021] Shutdown stage of biomass pyrolysis: stop feeding the pyrolysis reaction device, wait until the raw materials in the pyrolysis reaction device are completely emptied, reduce the operating temperature of the pyrolysis reaction device and the pyrolysis gas utilization device to below the shutdown temperature, and shut down the pyrolysis reaction device and the pyrolysis gas utilization device.

[0022] In the present invention, during the furnace startup stage, the water seal level can be established according to the pressure requirement of the pyrolysis reaction device. The water seal level is the distance from the water seal pipe to the water surface. Preferably, the water seal level is 20mm to 200mm, for example 40mm.

[0023] Preferably, during the start-up phase, the pyrolysis reaction device is heated to 450-650°C, for example, 500°C.

[0024] Preferably, during the furnace start-up stage, the pyrolysis gas is heated to 650-1050°C, for example, 750°C, by a device.

[0025] Preferably, during the operation phase, the operating pressure of the pyrolysis reaction device is 20-400 Pa.

[0026] Preferably, during the operation stage, the operating pressure of the pyrolysis gas utilization device is -50 to -550 Pa.

[0027] In the present invention, in the load increasing stage, before the starting load is turned on, the method of maintaining the pyrolysis reaction device and the pyrolysis gas utilization device to operate at a slightly negative pressure can be maintained by starting an induced draft fan.

[0028] In a preferred embodiment of the present invention, the biomass pyrolysis and pressure stabilization method can be carried out according to the following conditions:

[0029] In the startup phase, the flow regulating valves of the biomass pyrolysis and pressure stabilization system are butterfly valves, and the valve openings of the two butterfly valves are set between 40° and 60°; the biomass pyrolysis and pressure stabilization system further includes an induced draft fan, which is started and has an operating frequency of 8 to 12 Hz;

[0030] In the load increase stage: maintaining the pyrolysis reaction device and the pyrolysis gas utilization device in a slightly negative pressure operation; opening the feed device of the pyrolysis reaction device at a load of 30% to 70%;

[0031] Then, the feed load of the feed device is increased, the operating pressure of the pyrolysis reaction device is 100-200 Pa; the operating pressure of the pyrolysis gas utilization device is -250--500 Pa; the valve opening of the two butterfly valves is adjusted to between 50° and 60°; and the frequency of the induced draft fan is adjusted to 12-20 Hz according to the above pressure;

[0032] During the operation phase, when the feed load of the feed device is at the standard feed load, the pyrolysis reaction device operates at a pressure of 150 to 250 Pa; the pyrolysis gas utilization device operates at a pressure of -550 to -300 Pa, the valve openings of the two butterfly valves are adjusted to between 55 and 70 degrees, and the frequency of the induced draft fan is adjusted to 20 to 35 Hz according to the above pressures;

[0033] The shutdown stage: stop feeding the pyrolysis reaction device, wait until the raw materials in the pyrolysis reaction device are completely emptied, reduce the operating temperature of the pyrolysis reaction device and the pyrolysis gas utilization device to below the shutdown temperature, shut down the pyrolysis reaction device and the pyrolysis gas utilization device, and shut down the induced draft fan.

[0034] In the present invention, in order to achieve stable operating pressure and prevent back-mixing of downstream gases, the system of the present invention is configured with the valve group. When the pyrolysis gas passes through the flow control valve with a certain valve opening, a local pressure resistance will be formed, which will in turn form a certain resistance to the flow of the pyrolysis gas, so that the operating pressure difference between the pyrolysis reaction device and the pyrolysis gas utilization device is greater than a certain value, thereby achieving anti-back-mixing between the two through the pressure difference. Since the valve opening of the flow control valve is more sensitive to the local assist coefficient, and the relationship between the valve opening of the flow control valve and the local resistance coefficient of the airflow has been clarified, when conventional physical properties such as airflow density and viscosity are known, the operating pressure of the pyrolysis reaction device and the pyrolysis gas utilization device can be accurately controlled by adjusting the valve opening and the downstream fan.

[0035] In the present invention, when the pipeline of the valve group is equipped with only one flow regulating valve, the flow regulating valve often needs to maintain a relatively low opening to achieve upstream and downstream pressure differential distribution. At this time, the valve opening is very sensitive to the local resistance of the pipeline, and it is easy to have difficulty adjusting the valve opening to the required pressure resistance. Moreover, when the system pyrolysis gas volume fluctuates, the pressure differential changes greatly, which easily leads to fluctuations in the system operating pressure. By configuring multiple flow regulating valves in series, the valve can be maintained at a relatively high opening. At this time, the impact of the system pyrolysis gas volume fluctuation on the pressure differential will also be maintained at a relatively low level, achieving the goal of maintaining the micro-positive operating pressure of the pyrolysis reactor. In addition, a relatively high valve opening can avoid blockage caused by dust settling and gathering at these locations. Of course, an excessive number of flow regulating valves will also lead to an increase in system cost and operational control complexity.

[0036] In the present invention, when the amount of pyrolysis gas fluctuates too much, the system pressure change may exceed the adjustment range of the valve group. To solve this problem, the system of the present invention is configured with the water seal tank. When the system is operating normally, the water seal tank is configured with a certain water seal liquid level height (the static liquid column pressure formed by the water seal height is consistent with the maximum operating pressure of the pyrolysis reaction device). If the operating pressure of the pyrolysis reaction device is higher than the set maximum operating pressure, the pyrolysis gas will automatically bubble out to reduce the operating pressure of the pyrolysis reaction device.

[0037] In the present invention, pyrolysis gas tends to contain a high amount of tar, which may condense and precipitate when flowing through the pyrolysis gas pipeline. This can be achieved by providing a dense insulation layer on the pyrolysis gas pipeline, ensuring that the pyrolysis gas does not significantly cool down in the pipeline, thereby effectively preventing tar precipitation.

[0038] In the present invention, the pyrolysis reaction device typically has a large dynamic seal connection between the stationary and rotating components, resulting in poor airtightness. To ensure the safety of the pyrolysis reaction device during operation, the pyrolysis reaction device often operates at a slight positive pressure of approximately +20 to +400 Pa. Fluctuations in pyrolysis gas production can easily lead to excessive fluctuations in the operating pressure of the pyrolysis reaction device, which can cause the operating pressure of the pyrolysis reaction device to exceed the design value of the dynamic seal device or cause the flue gas / gasification gas from the downstream pyrolysis gas utilization device to re-mix and enter the pyrolysis reaction device.

[0039] On the basis of conforming to the common sense in this field, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0040] The reagents and raw materials used in the present invention are commercially available.

[0041] The positive progress effect of the present invention is:

[0042] (1) The biomass pyrolysis pressure stabilization system of the present invention, relying on equipment such as a valve group and a water seal tank, can meet the pressure stabilization requirements of the dust- and tar-containing pyrolysis gas of the organic solid waste micro-positive pressure pyrolysis system; when achieving pressure stabilization, the pressure distribution of multiple valves is effectively achieved to realize the pressure difference distribution between upstream and downstream, thereby realizing the anti-backmixing function of the pyrolysis gas; the system realizes low equipment cost and simple operation;

[0043] (2) The biomass pyrolysis pressure stabilization system method of the present invention can stabilize the operating pressure, prevent back mixing, prevent tar condensation and precipitation, and take into account the emergency discharge of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the biomass pyrolysis and pressure stabilization system of Example 1 of the present invention.

[0045] Description of reference numerals:

[0046] Rotary reactor 1

[0047] Valve group 2

[0048] Hot air stove 3

[0049] Heat utilization unit 4

[0050] Water seal tank 5

[0051] Blower K101

[0052] Induced draft fan K102 DETAILED DESCRIPTION

[0053] The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. Experimental methods in the following examples without specifying specific conditions were performed according to conventional methods and conditions, or selected according to the product specifications.

[0054] Example 1

[0055] A biomass pyrolysis pressure stabilization system, such as Figure 1 As shown, it includes a rotary reactor 1, a water seal tank 5, a valve group 2, a hot air furnace 3, a heat utilization unit 4, a blower K101, and an induced draft fan K102. The pyrolysis gas outlet of the rotary reactor 1 and the feed inlet of the hot air furnace 3 are connected via a first pipeline, on which a valve group 2 is provided. The pyrolysis gas outlet of the rotary reactor 1 is also provided with a second pipeline, which is connected to the water seal tank 5 for achieving water seal pressure stabilization. The valve group 2 includes two butterfly valves connected in series.

[0056] The air inlet of the hot blast furnace 3 is connected to the blower K101 through a pipeline.

[0057] The feed port of the heat utilization unit 4 is connected to the discharge port of the hot blast furnace 3. The heat utilization unit 4 is used to burn the product in the hot blast furnace 3 to provide energy to the outside world;

[0058] The biomass pyrolysis and pressure stabilization system further includes an induced draft fan K102 , and the discharge port of the heat utilization unit 4 is connected to the induced draft fan K102 .

[0059] Biomass pyrolysis pressure stabilization method

[0060] The above-mentioned biomass pyrolysis pressure stabilization system targets the oversize of dry garbage. The system has a processing capacity of 200 kg / h. The downstream pyrolysis gas utilization device is a hot air furnace 3. The inner diameter of the pyrolysis gas pipeline is 100 mm and the length of the pipeline is 3 m. When running at full load, the pyrolysis gas volume is 562 m 3 / h, after the hot air furnace 3 flue gas is heat utilized and sprayed, the volume flow rate is 2200m 3 / h (after spraying flue gas at 40℃), gas density is 0.445kg / m 3 The gas viscosity is 0.000043Pas, the induced draft fan K102 has a rated wind pressure of 3.0kPa and a rated flow rate of 4000m 3 / h, the maximum operating pressure of the rotary reactor 1 is 400Pa.

[0061] (1) Start-up stage

[0062] Start-up stage: establish the water seal level of water seal tank 5 to 40mm;

[0063] The rotary reactor 1 and the water seal tank 5 are connected and in operation; the rotary reactor 1 is heated to 500°C and the rotary reactor 2 is heated to 750°C; the two butterfly valves are opened and the valve openings are set to 50° and 60° respectively; the induced draft fan K102 is started and the operating frequency is adjusted to 10Hz;

[0064] (2) Load increase stage:

[0065] The rotary reactor 1 and the hot air furnace 3 operate at a slightly negative pressure;

[0066] Start the feeding device of the rotary reactor 1 at 50% load, and start the blower K101 at the same time. Increase the operating frequency of the induced draft fan K102 according to the thermocouple reading of the hot blast stove 3, so that the operating temperature of the hot blast stove 3 gradually rises to the designed operating temperature of 1100°C.

[0067] According to the pressure reading change of the rotary reactor 1, the operating frequency of the induced draft fan K102 is gradually increased to 15Hz. The operating pressure of the rotary reactor 1 is about 50-150Pa slightly positive pressure, and the hot air furnace 3 is operated at a slightly negative pressure of -50--150Pa;

[0068] After the inlet and outlet of the rotary reactor 1 are stable, the operation of the rotary reactor 1 is maintained stable. At this time, the pipeline and local resistance is 300 Pa, the operating pressure of the hot blast furnace 3 is maintained at -150 Pa, and the operating pressure of the rotary reactor 1 is 150 Pa. When the amount of pyrolysis gas generated in the rotary reactor 1 fluctuates within the range of 85% to 115%, the slightly positive operating pressure of the rotary reactor 1 can be maintained at 67 to 247 Pa;

[0069] Set the openings of the two butterfly valves of valve group 2 to 55° and 60° respectively, adjust the operating frequency of the induced draft fan K102 to 13 Hz, and stabilize the operating pressure of the rotary reactor 1 to a slightly positive pressure of about 50-200 Pa;

[0070] Increase the feed load of the feed system, and according to the pressure reading change of the rotary reactor 1, increase the valve opening of the valve group 2, and coordinate the valve opening of the two butterfly valves to 60°;

[0071] Gradually increase the operating frequency of the induced draft fan K102 to 25 Hz to ensure that the rotary reactor 1 is operated at a slightly positive pressure of about 100 to 200 Pa, and the operating pressure of the hot blast furnace 3 is at a slightly negative pressure of about -250 to -500 Pa;

[0072] During the above process, the blower K101 is adjusted and increased to make the operating temperature of the hot blast furnace 3 above the target temperature.

[0073] (4) Operation phase

[0074] Stabilize the operating load and fine-tune the operating frequency of the induced draft fan K102. At this time, the pipeline and local resistance is 708 Pa, the operating pressure of the hot air furnace 3 is maintained at -550 Pa, the operating pressure of the rotary reactor 1 is maintained at 158 ​​Pa, and the valve opening of the two butterfly valves is 60°;

[0075] When the amount of pyrolysis gas in the rotary reactor 1 fluctuates within the range of 90 to 110%, the slightly positive operating pressure of the rotary reactor 1 can be maintained at 23 to 306 Pa.

[0076] (5) Shutdown stage

[0077] Stop feeding the rotary reactor 1 feed plunger pump;

[0078] As the material in the rotary reactor 1 decreases (according to the temperature change of the thermocouple of the hot blast stove 3), the operating frequency of the blower K101 is gradually reduced to make the operating temperature of the hot blast stove 3 above the design target temperature of 1100°C;

[0079] According to the operating pressure of the rotary reactor 1 and the hot blast furnace 3, gradually reduce the operating frequency of the induced draft fan K102 and simultaneously reduce the valve opening of the valve group 2;

[0080] After stopping feeding for 2 hours, the material in the rotary reactor 1 is completely emptied and the cooling process is started;

[0081] When the operating temperature of the rotary reactor 1 and the hot blast furnace 3 drops to the shutdown temperature, turn off the fan blower K101 and the induced draft fan K102, and turn off the rotating motor of the rotary reactor 1 and the hot blast furnace 3.

[0082] The biomass pyrolysis pressure stabilization system of Example 1 is systematically designed. During the biomass pyrolysis process, while ensuring sufficient pyrolysis, combustion, and utilization of the biomass, it also achieves accurate control of the operating pressure and temperature regulation of the rotary reactor 1 and the hot blast furnace 3. There is no backmixing or tar condensation and precipitation during system operation.

Claims

1. A biomass pyrolysis pressure stabilization system, characterized in that: It includes a pyrolysis reaction device, a water seal tank, a valve group and a pyrolysis gas utilization device; the pyrolysis gas outlet of the pyrolysis reaction device and the feed inlet of the pyrolysis gas utilization device are connected through a first pipeline, and the valve group is provided on the first pipeline; the pyrolysis gas outlet of the pyrolysis reaction device is also provided with a second pipeline, and the second pipeline is connected to the water seal tank for achieving water seal pressure stabilization; wherein the valve group includes a plurality of flow regulating valves connected in series; The biomass pyrolysis and pressure stabilization system further includes a heat utilization unit, the feed port of which is connected to the discharge port of the pyrolysis gas utilization device, and is used to burn the product in the pyrolysis gas utilization device to provide energy to the outside world; The biomass pyrolysis and pressure stabilization system further includes an induced draft fan, which is connected to the discharge port of the heat utilization unit.

2. The biomass pyrolysis and pressure stabilization system according to claim 1, characterized in that: The number of the flow regulating valves is 2 to 4; And / or, the flow regulating valve is a butterfly valve, a ball valve or a sleeve regulating valve.

3. The biomass pyrolysis and pressure stabilization system according to claim 2, characterized in that: The flow regulating valve is a butterfly valve.

4. The biomass pyrolysis and pressure stabilization system according to claim 1, characterized in that: The pyrolysis reaction device is a rotary reactor or a spiral reactor; And / or, the pyrolysis gas utilization device is a gasification furnace or a hot air furnace.

5. The biomass pyrolysis and pressure stabilization system according to claim 1, characterized in that: The biomass pyrolysis and pressure stabilization system further includes a blower, and the air inlet of the pyrolysis gas utilization device is connected to the blower through a pipeline.

6. The biomass pyrolysis and pressure stabilization system according to claim 1, characterized in that: The heat utilization unit is an incinerator or a boiler.

7. A biomass pyrolysis and pressure stabilization method, characterized in that: The process is carried out using the biomass pyrolysis and pressure stabilization system according to any one of claims 1 to 6, under the following conditions: The starting stage of biomass pyrolysis: the water seal level of the water seal tank is established, the pyrolysis reaction device and the water seal tank are connected and in operation; the flow regulating valve of the valve group is opened and the valve opening is set; the pyrolysis reaction device and the pyrolysis gas utilization device are heated; During the load increase phase of biomass pyrolysis, the pyrolysis reaction device and the pyrolysis gas utilization device are maintained in a slightly negative pressure operation; the feeding device of the pyrolysis reaction device is opened at a starting load, and the feeding load of the feeding device is increased, and the valve opening of the flow control valve is adjusted in coordination, so that the pyrolysis reaction device operates at a positive pressure; and the pyrolysis gas utilization device operates at a negative pressure; Biomass pyrolysis operation stage: when the feed load of the feed device is at the standard feed load, the valve opening of the flow control valve is adjusted, and the operating pressure of the pyrolysis reaction device is positive pressure operation; the operating pressure of the pyrolysis gas utilization device is negative pressure operation; Shutdown stage of biomass pyrolysis: stop feeding the pyrolysis reaction device, wait until the raw materials in the pyrolysis reaction device are completely emptied, reduce the operating temperature of the pyrolysis reaction device and the pyrolysis gas utilization device to below the shutdown temperature, and shut down the pyrolysis reaction device and the pyrolysis gas utilization device.

8. The biomass pyrolysis and pressure stabilization method according to claim 7, characterized in that: During the furnace starting stage, the water seal level is the distance from the water seal pipe to the water surface, which is 20mm to 200mm; and / or, the pyrolysis reaction device is heated to 450-650° C.; And / or, the pyrolysis gas is heated to 650-1050° C. by a device.

9. The biomass pyrolysis and pressure stabilization method according to claim 8, characterized in that: During the furnace start-up phase, the water seal level is the distance from the water seal pipe to the water surface, which is 40 mm. and / or, the pyrolysis reaction device is heated to 500° C.; And / or, the pyrolysis gas is heated to 750° C. using a device.

10. The biomass pyrolysis and pressure stabilization method according to claim 7, characterized in that: During the operation phase, the operating pressure of the pyrolysis reaction device is 20-400 Pa; And / or, the operating pressure of the pyrolysis gas utilization device is -50 to -550 Pa.

11. The biomass pyrolysis and pressure stabilization method according to any one of claims 7 to 10, characterized in that: In the startup phase, the flow regulating valves of the biomass pyrolysis and pressure stabilization system are butterfly valves, and the valve openings of the two butterfly valves are set between 40° and 60°; the biomass pyrolysis and pressure stabilization system further includes an induced draft fan, which is started and has an operating frequency of 8 to 12 Hz; The load increasing stage: maintaining the pyrolysis reaction device and the pyrolysis gas utilization device in a slightly negative pressure operation; Opening the feeding device of the pyrolysis reaction device at a load of 30% to 70%; Then, the feed load of the feed device is increased, the operating pressure of the pyrolysis reaction device is 100-200 Pa; the operating pressure of the pyrolysis gas utilization device is -250--500 Pa; the valve opening of the two butterfly valves is adjusted to between 50° and 60°, and the frequency of the induced draft fan is adjusted to 12-20 Hz according to the above pressure; During the operation phase, when the feed load of the feed device is at the standard feed load, the pyrolysis reaction device operates at a pressure of 150 to 250 Pa; the pyrolysis gas utilization device operates at a pressure of -550 to -300 Pa, the valve openings of the two butterfly valves are adjusted to between 55 and 70 degrees, and the frequency of the induced draft fan is adjusted to 20 to 35 Hz according to the above pressures; The shutdown stage: stop feeding the pyrolysis reaction device, wait until the raw materials in the pyrolysis reaction device are completely emptied, reduce the operating temperature of the pyrolysis reaction device and the pyrolysis gas utilization device to below the shutdown temperature, shut down the pyrolysis reaction device and the pyrolysis gas utilization device, and shut down the induced draft fan.

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