Device and method for performing desulfurization and denitrification on pulverized coal before entering boiler

Abstract

The invention relates to a device and a method for desulfurization and denitrification of pulverized coal before entering a boiler, and the device comprises a reaction kettle which is a reaction container of the pulverized coal; the pulverized coal supply mechanism is used for feeding pulverized coal into the reaction kettle; the gas supply mechanism supplies oxygen to the pulverized coal inlet of the reaction kettle to form oxygen pulverized coal jet flow; the long open fire mechanism is used for continuously igniting the oxygen pulverized coal jet flow; the monitoring and adjusting mechanism comprises a temperature sensor for monitoring the temperature in the reaction kettle; the two-phase separator is used for carrying out solid-gas separation on a reaction product; a high-temperature powder conveying mechanism; the distributors are used for uniformly distributing the solid-phase powder among the corresponding combustors; a gas processing mechanism; and a sulfur recovery mechanism. According to the device for desulfurizing and denitrifying the pulverized coal before entering the boiler, the pulverized coal can be efficiently desulfurized and denitrified before entering the boiler, so that the content of sulfur and nitrogen carried by fire coal entering the boiler is greatly reduced, flue gas generated by the pulverized coal boiler does not need to be desulfurized, and high-quality bituminous coal does not need to be denitrated.

Description

Technical Field

[0001] The present invention relates to pulverized coal fuel for pulverized coal boilers, and in particular to a device and method for desulfurizing and denitrifying pulverized coal before entering a boiler, which realizes furnace desulfurization and denitrification in a coal chemical industry manner. Background Art

[0002] To improve coal combustion efficiency, large pulverized coal boilers typically pulverize raw coal into pulverized coal, which is then blown into the furnace with primary air for efficient combustion. This approach does address combustion efficiency issues. However, chemical elements such as sulfur and nitrogen contained in coal generate sulfur oxides and nitrogen oxides during combustion, which are emitted into the atmosphere with the flue gas and contribute significantly to flue gas pollution. To combat these pollutants, the government introduced FGD technology to remove sulfur oxides from flue gas, and SNCR+SCR technology to remove nitrogen oxides during the combustion process and flue gas. Neither FGD technology for desulfurization nor SNCR or SCR technology for denitrification were mature technologies at the time, nor are they mature technologies today. While they successfully removed sulfur oxides and nitrogen oxides during operation, they also created new environmental problems and severe secondary pollution. Furthermore, these technologies required significant equipment investment—over 100 million yuan for the desulfurization and denitrification equipment of a 600MW generator unit—and high operating costs, requiring a government subsidy of 0.03 cents per kilowatt-hour of electricity generated. Consequently, a 600MW generator operating for 6,000 hours per year (8,760 hours per year) would require over 100 million yuan in government subsidies. Existing desulfurization (FGD) technologies consume large amounts of lime or limestone powder. Limestone mining destroys mountains, and lime burning increases carbon emissions. Pulverizing and slurrying limestone is not only expensive but also severely corrodes pipelines, pumps, and valves. Small droplets of lime / gypsum formed during the desulfurization process drift with the flue gas, eventually settling back to the ground and contaminating the soil. Desulfurization gypsum from coal-fired power plants far from urban areas, unable to be recycled, is abandoned and decomposes into sulfur oxides and lime over time, polluting the atmosphere and soil and water. Existing denitrification technologies, namely SNCR and SCR, use ammonia-based denitrification, using ammonia or urea to produce ammonia. Ammonia and urea are both flammable, explosive, and toxic. Ammonia injected into the furnace or flue cannot fully react, and a certain percentage will escape. This escaping ammonia forms aerogels in the atmosphere, severely hindering the deposition of dust pollution and the dispersion of other pollutants. The SCR's ammonia injection point is located just above the air preheater, where it reacts with sulfur oxides in the flue gas to form compounds such as ammonium sulfite, ammonium sulfate, and ammonium bisulfate. These compounds are a thick, sticky liquid that adheres firmly to air preheater components, damaging seals, reducing heat exchange efficiency, increasing operating resistance, and forcing premature overhauls. Ammonia, urea, and catalysts also represent significant costs.

[0003] To address this issue, patent document No. 201320053287.5, entitled "A Pre-Reaction Device for a Pulverized Coal Boiler," discloses a pre-reaction device for a pulverized coal boiler. This device denitrifies the pulverized coal before it enters the boiler, thereby reducing the production of nitrogen oxides during the combustion process within the boiler. However, due to equipment limitations and a short reaction time, the reaction cannot proceed fully, and therefore can only achieve a very limited effect in reducing nitrogen oxides in flue gas. Furthermore, this device does not address the issue of desulfurization. Summary of the Invention

[0004] The present invention provides a device for desulfurizing and denitrifying pulverized coal before it enters the boiler. The device can efficiently desulfurize and denitrify the pulverized coal before it enters the boiler, greatly reducing the sulfur and nitrogen content carried by the coal when it enters the boiler, so that the flue gas generated by the pulverized coal boiler does not need to be desulfurized, and high-quality bituminous coal does not need flue gas denitrification.

[0005] The device for desulfurizing and denitrifying pulverized coal before entering the boiler of the present invention comprises:

[0006] The reactor is a reaction vessel for pulverized coal, having a pulverized coal inlet and a pulverized coal outlet. The pulverized coal is continuously heated in the reactor to produce coal gasification, escaping volatile matter, sulfur and nitrogen;

[0007] A pulverized coal feeding mechanism, which continuously feeds pulverized coal into the reactor through dense phase pneumatic force using CO2 or N2 gas;

[0008] An air supply mechanism continuously supplies oxygen to the pulverized coal inlet of the reactor to form an oxygen-pulverized coal jet;

[0009] The pilot flame mechanism is located at the coal inlet of the reactor to continuously ignite the oxygen coal jet;

[0010] A monitoring and adjustment mechanism, comprising a temperature sensor for monitoring the temperature in the reactor, the monitoring and adjustment mechanism being connected to the gas supply mechanism and being capable of adjusting the gas supply of the gas supply mechanism according to the detected data so as to keep the temperature within a set range;

[0011] The two-phase separator is connected to the outlet of the reactor to continuously separate the solid and gas of the reaction products to obtain high-temperature solid phase powder and gas;

[0012] High-temperature powder conveying mechanism, which conveys the high-temperature solid phase powder obtained from the two-phase separator into the distributor using dense phase pneumatic conveying of CO2 or N2 gas;

[0013] The distributor evenly distributes the solid phase powder between the corresponding burners, and the burners spray the solid phase powder into the boiler for combustion;

[0014] A gas processing mechanism for cooling and desulfurizing the gas separated by the two-phase separator, or for cooling, desulfurizing and denitrifying the gas;

[0015] The sulfur recovery mechanism processes the sulfur removed by the gas processing mechanism into sulfur.

[0016] Preferably, the powder supply mechanism is a central storage type powder supply mechanism.

[0017] Preferably, the gas supply mechanism can also supply water vapor into the reactor.

[0018] Preferably, the monitoring and adjustment mechanism also includes an atmosphere detection component for monitoring the hydrogen concentration in the reactor. The atmosphere detection component is connected to the monitoring and adjustment mechanism to send the detected hydrogen concentration to the monitoring and adjustment mechanism. When the hydrogen concentration is lower than the set concentration, the monitoring and adjustment mechanism controls the gas supply mechanism to increase the amount of water vapor supplied. When the hydrogen concentration is higher than the set concentration, the monitoring and adjustment mechanism controls the gas supply mechanism to reduce the amount of water vapor supplied.

[0019] Preferably, the two-phase separator includes a high-temperature cyclone separator for separating coarser particles and a bag separator for separating finer particles, and the high-temperature cyclone separator and the bag separator are connected in series.

[0020] Preferably, the high-temperature powder feeding mechanism feeds the solid phase powder into the distributor via CO2 or N2 gas.

[0021] Preferably, the excess CO2 gas can be flue gas discharged from a boiler.

[0022] Preferably, the pre-furnace desulfurization and desulfurization device also includes a gas recovery and utilization system for recovering the gas processed by the gas processing mechanism for use as a chemical raw material.

[0023] Preferably, the outer walls of the reactor, two-phase separator, high-temperature powder conveying and gas conveying pipelines are provided with insulation devices, and the inner walls are covered with refractory and insulation linings or water-cooled walls.

[0024] The present invention also provides a method for desulfurizing and denitrifying pulverized coal before entering a boiler, wherein the pulverized coal is desulfurized and denitrified by the device for desulfurizing and denitrifying pulverized coal before entering a boiler as described above, comprising the following steps:

[0025] S1, the pulverized coal is delivered into the reactor by dense phase pneumatic conveying of CO2 or N2 gas. At the same time, oxygen is quantitatively delivered to the pulverized coal inlet according to the amount of pulverized coal delivered to form a mixed jet of oxygen and pulverized coal. At the same time, the pilot flame of the pilot flame mechanism ignites the pulverized coal, and the input oxygen causes part of the pulverized coal to react with CO.

[0026] S2, monitors the temperature in the reactor and adjusts the oxygen supply according to the detected data to keep the temperature 50°C-100°C below the ash melting point, so that water and volatile matter in the pulverized coal escape, and the iron sulfide and organic sulfur in the pulverized coal undergo a decomposition reaction to release elemental sulfur or hydrogen sulfide, and nitrogen in the pulverized coal escapes in the form of NH3 and HCN and further decomposes into H2, N2 and carbon black;

[0027] S3, after the reaction of step S2 is completed, the gas content in the reactor increases sharply, and the gas-solid mixture leaves the reactor and enters the two-phase separator, which separates the solid and gas products of the reactor;

[0028] S4, delivering the solid phase powder obtained by solid-gas separation into a distributor through a high-temperature conveying mechanism;

[0029] S5, the distributor evenly distributes the solid powder among the corresponding burners;

[0030] S6, cooling and desulfurizing the gas obtained by solid-gas separation or cooling and desulfurizing and denitrifying the gas through a gas processing mechanism;

[0031] S7, processing the sulfur obtained from the gas processing unit into sulfur through the sulfur recovery unit;

[0032] Preferably, the method further includes step S8, wherein the gas processed in step S6 is recovered by a gas recovery and utilization system for use as a chemical raw material, or is introduced into a pulverized coal boiler for combustion.

[0033] Compared with existing technologies, the present invention offers the following advantages: The pre-furnace desulfurization and denitrification device of the present invention can maintain the temperature within the reactor at a set temperature by controlling the oxygen supply, typically 50°C to 100°C below the ash melting point. At this temperature, water and volatile matter in the pulverized coal escape, and the iron sulfide (pyrite) and organic sulfur contained in the pulverized coal undergo a decomposition reaction, releasing elemental sulfur or hydrogen sulfide. NH3 or HCN also escapes. The released NH3 and HCN further decompose into H2, N2, and carbon black at 1000°C, rendering them harmless. A two-phase separator separates the solid phase powder and gas produced in the reactor. The separated solid phase is red-hot blue charcoal. Using carbon dioxide or nitrogen as a carrier, the carbon powder is transported in a dense phase through a distributor and burner, then blown into a boiler for combustion and power generation. The separated gas is cooled and desulfurized by a processing unit, and then fed into a boiler for combustion and power generation. It can also be used as a chemical raw material after separation and purification, increasing the value of the coal. The removed sulfur can be processed into sulfur for resource utilization. When CO2 gas is used to pneumatically convey pulverized coal into the reactor through dense phase, the pulverized coal and CO2 gas in the reactor are heated and react to generate CO, forming a severely oxygen-deficient and strongly reducing atmosphere in the reactor. At the same time, the CO generated by the CO2 gas can be recovered and utilized. In the scheme of using N2 to convey pulverized coal or solid-phase powder, N2 does not react and does not generate useful substances. When the gas is recycled and utilized, a large amount of N2 needs to be removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic structural diagram of a pre-furnace desulfurization and denitrification device for a pulverized coal boiler according to an embodiment of the present invention.

[0035] 1 reactor;

[0036] 2 pulverized coal supply mechanism, 21 pulverized coal bin, 22 buffer mechanism, 23 pulverized coal feeding mechanism;

[0037] 3. Gas supply mechanism;

[0038] 4. Eternal flame mechanism;

[0039] 5 two-phase separator;

[0040] 6. High temperature powder conveying mechanism;

[0041] 7 gas processing mechanism, 71 cooling mechanism, 72 desulfurization mechanism;

[0042] 8 dispensers.

[0043] 9 burners;

[0044] 10. Pulverized coal boiler. DETAILED DESCRIPTION

[0045] The present invention provides a device for desulfurizing and denitrifying pulverized coal before it enters the boiler. Figure 1 As shown, the reactor comprises: a reactor 1, a pulverized coal supply mechanism 2, a gas supply mechanism 3, a pilot flame mechanism 4, a monitoring and adjustment mechanism (not shown), a two-phase separator 5, a high-temperature pulverized coal conveying mechanism 6, a gas processing mechanism 7, a distributor 8, and a sulfur recovery mechanism (not shown). Reactor 1 has a pulverized coal inlet and outlet, serving as a reaction vessel for the pulverized coal. Within reactor 1, the pulverized coal and oxygen undergo a continuous gasification reaction, releasing heat, causing the pulverized coal to heat up and release volatile matter, sulfur, and nitrogen. The inner wall of reactor 1 is lined with a fire-resistant and heat-insulating lining. The pulverized coal supply mechanism 2 uses CO2 or N2 gas to pneumatically blow the pulverized coal into reactor 1 via dense phase pneumatic blowing. The gas supply mechanism 3 supplies oxygen into reactor 1, forming an oxygen-pulverized coal jet. The pilot flame mechanism 4 continuously ignites the oxygen-pulverized coal jet within reactor 1, causing the pulverized coal to burn, producing CO gas and releasing heat. The monitoring and adjustment mechanism includes a temperature sensor that monitors the temperature within the reactor 1. This mechanism is connected to the gas supply mechanism 3 and adjusts the amount of oxygen supplied by the gas supply mechanism 3 based on the detected data to maintain the temperature within a set range. Specifically, when the temperature falls below the set value, the gas supply from the gas supply mechanism 3 is increased; when the temperature rises above the set value, the oxygen supply from the gas supply mechanism 3 is reduced. A two-phase separator 5 continuously separates the product from the reactor 1 into a high-temperature solid-phase powder and gas. A high-temperature powder conveying mechanism 6 conveys the high-temperature solid-phase powder obtained from the two-phase separator 5 via dense-phase pneumatic conveying of CO2 or N2 gas into a distributor 8. The distributor 8 evenly distributes the solid-phase powder between corresponding burners 9, which then spray the solid-phase powder into a boiler for combustion. A gas processing mechanism 7 cools and desulfurizes the gas separated by the two-phase separator 5. The desulfurized gas can be fed into a furnace for combustion to generate electricity, or purified and separated for use as a chemical raw material. The sulfur recovery mechanism processes the removed sulfur into sulfur.

[0046] The pre-furnace desulfurization and denitrification device of the present invention separates the solid-phase powder and gas within the reactor 1 via a two-phase separator 5. Since the oxidizable sulfur and most of the nitrogen are separated and discharged in the gas phase, the flue gas generated by the combustion of the solid-phase powder within the pulverized coal boiler 10 no longer requires desulfurization, significantly reducing the denitrification burden. Simultaneously, the separated gas is cooled and desulfurized by a gas processing unit 7. The desulfurized gas can then be fed into the pulverized coal boiler 10 for combustion, while a sulfur recovery unit processes the removed sulfur for sulfur recovery. By controlling the oxygen supply, the temperature can be maintained at a set level, typically approximately 50°C to 100°C below the ash melting point. In this embodiment, the ash melting point refers to the temperature at which the pulverized coal completely melts. At this temperature, water and volatiles in the pulverized coal escape, and the iron sulfide (pyrite) and organic sulfur contained in the pulverized coal decompose to release elemental sulfur or hydrogen sulfide. NH3 or HCN also escapes. The released NH3 and HCN will be further decomposed into H2, N2 and carbon black at 1000℃ and become harmless.

[0047] When the pulverized coal is transported into the reactor 1 through dense phase pneumatic conveying using CO2 gas, the pulverized coal in the reactor 1 and the CO2 gas are heated and reacted to generate CO, which can be recovered and utilized.

[0048] like Figure 1 As shown, the pulverized coal supply mechanism 2 includes a pulverized coal bin 21, a buffer mechanism 22 and a pulverized coal feeding mechanism 23. The pulverized coal bin 21 is used to store pulverized coal, the buffer mechanism 22 ensures a steady supply of pulverized coal, and the pulverized coal feeding mechanism 23 feeds pulverized coal into the reactor 1 through CO2 or N2 gas.

[0049] In addition to supplying oxygen to reactor 1, gas supply mechanism 3 also supplies water vapor. This water vapor reacts with the carbon in the pulverized coal to form CO and H₂ (also known as the water-gas reaction). An appropriate concentration of hydrogen in the system facilitates the decomposition of FeS in the coal and the release of nitrogen from coal functional groups. Furthermore, the gasification reaction consumes some heat, helping to control the temperature within the combustion chamber.

[0050] The pilot flame mechanism 4 can obtain a fire source by using fuel oil, gas or arc plasma, thereby providing a stable and reliable ignition source for the interior of the reactor 1 .

[0051] The two-phase separator 5 comprises a series-connected high-temperature cyclone and bag filter. The high-temperature cyclone separates coarser particles, while the bag filter separates finer particles. The products in the reactor pass through the high-temperature cyclone and bag filter in sequence. The two-phase separator 5 undergoes multi-stage separation, effectively separating the solid phase powder (red-hot semi-coke powder) from the gas (including coal volatiles, primarily CO and methane, with trace amounts of H2 and N2, and sulfur vapor).

[0052] In this embodiment, the CO2 gas used by the powder supply mechanism 2 and the high-temperature powder conveying mechanism 6 can be derived from boiler flue gas. The outer walls of the reactor 1, two-phase separator 5, and the high-temperature powder and gas conveying pipelines are insulated, while the inner walls are coated with refractory and thermal insulation linings or water-cooled walls.

[0053] In this embodiment, the pre-furnace desulfurization and denitrification device also includes an atmosphere detection component (not shown in the figure), which monitors the concentration of hydrogen in the reactor 1 and sends the detected hydrogen concentration to the monitoring and adjustment mechanism. When the concentration of hydrogen is lower than the set concentration, the monitoring and adjustment mechanism controls the gas supply mechanism 3 to increase the amount of water vapor supplied. When the concentration of hydrogen is higher than the set concentration, the monitoring and adjustment mechanism controls the gas supply mechanism 3 to reduce the amount of water vapor supplied.

[0054] The gas processing mechanism 7 includes a cooling mechanism 71 and a desulfurization mechanism 72. The gas separated by the two-phase separator 5 is first cooled by the cooling mechanism 71, and then the gas is transported to the desulfurization mechanism 72 for desulfurization treatment.

[0055] The pre-furnace desulfurization and denitrification device can also be configured to further separate the gas treated by the gas processing unit 7, including CO, tar, volatile matter, and hydrogen, through a gas recovery system for use as a chemical raw material. Alternatively, the desulfurized gas can be fed into the pulverized coal boiler 10 for combustion and power generation.

[0056] The present invention also provides a method for desulfurizing and denitrifying pulverized coal before entering a boiler. The method can be used to desulfurize and denitrify pulverized coal by using the above-mentioned device for desulfurizing and denitrifying pulverized coal before entering a boiler, and the method comprises the following steps:

[0057] S1: Pulverized coal is continuously fed into the reactor 1 using dense-phase CO2 or N2 gas. Simultaneously, oxygen is quantitatively and continuously delivered to the coal inlet based on the amount of pulverized coal delivered, creating a turbulent and agitated state with the oxygen and coal, forming a mixed jet of oxygen and coal. Simultaneously, the pilot flame of the pilot flame mechanism 4 ignites the coal, causing some of the coal to react with CO. In addition, in the scheme where the pulverized coal is fed into the reactor 1 using N2 gas, the N2 gas does not participate in the reaction and constitutes an impurity. In the scheme where the pulverized coal is fed into the reactor 1 using CO2 gas, the CO2 gas reacts with some of the coal to produce CO.

[0058] S2, monitor the temperature in the reactor 1 through the monitoring and adjustment mechanism and adjust the oxygen supply according to the detected data to keep the temperature within the set range, which is 50℃ below the ash melting point

[0059] -100℃, at such a temperature, the coal powder will instantly react with water and volatile matter to escape, and the iron sulfide and organic sulfur in the coal powder will undergo thermal decomposition reaction, 2FeS→2Fe+S2， Sulfur vapor escapes, or the following reaction occurs with the participation of water vapor: FeS + 2H2O → Fe(OH)2 + H2S. Organic sulfur undergoes thermal decomposition as CS2 → C + S2, escaping sulfur vapor, or generating H2S with the participation of H. Simultaneously, at this temperature, NH3 and HCN also escape, decomposing the released NH3 and HCN into H2, N2, and carbon black. The reaction formula is:

[0060] The ash melting point of coal with different components is different, which can be measured in the laboratory. Generally, the temperature setting range is usually 900℃-1300℃;

[0061] S3, after the reaction of step S2 is completed, the gas content in the reactor 1 increases sharply, and the gas-solid two-phase flow leaves the reactor 1 and enters the two-phase separator 5, which separates the solid and gas products of the reactor 1;

[0062] S4, the solid phase powder obtained by solid-gas separation is delivered to the distributor 8 through the high-temperature conveying mechanism;

[0063] S5, the distributor 8 evenly distributes the solid phase powder between the corresponding burners 9;

[0064] S6, cooling and desulfurizing the gas obtained by solid-gas separation or cooling and desulfurizing and denitrifying the gas by the gas processing mechanism 7;

[0065] S7, processing the sulfur obtained from the gas processing unit 7 into sulfur through a sulfur recovery unit;

[0066] In step S8, the gas recovery system recycles the gas processed in step S6 for use as a chemical raw material. Specifically, when using CO2 gas to transport pulverized coal and solid-phase powder, the gas separated by the two-phase separator 5 must first be cooled and desulfurized and denitrified by the gas processing mechanism 7. Alternatively, the gas separated by the two-phase separator 5 can be cooled and desulfurized without denitrification before being introduced into the pulverized coal boiler 10 for combustion. This solution does not distinguish between using CO2 or N2 gas to transport pulverized coal and solid-phase powder.

[0067] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention is defined by the claims. Various modifications or equivalent substitutions made by those skilled in the art within the spirit and scope of protection of the present invention also fall within the scope of protection of the present invention.

Claims

1. A device for desulfurizing and denitrifying pulverized coal before entering a boiler, characterized in that: include: The reactor is a reaction vessel for pulverized coal, having a pulverized coal inlet and a pulverized coal outlet. The pulverized coal is continuously heated in the reactor to produce coal gasification, escaping volatile matter, sulfur and nitrogen; A pulverized coal feeding mechanism, which continuously feeds pulverized coal into the reactor through dense phase pneumatic force using CO2 or N2 gas; An air supply mechanism continuously supplies oxygen to the pulverized coal inlet of the reactor to form an oxygen pulverized coal jet; The pilot flame mechanism is located at the coal inlet of the reactor to continuously ignite the oxygen coal jet; A monitoring and adjustment mechanism, comprising a temperature sensor for monitoring the temperature in the reactor, the monitoring and adjustment mechanism being connected to the gas supply mechanism and being capable of adjusting the gas supply of the gas supply mechanism according to the detected data so as to keep the temperature within a set range; The two-phase separator is connected to the outlet of the reactor to continuously separate the solid and gas of the reaction products to obtain high-temperature solid phase powder and gas; High-temperature powder conveying mechanism, which conveys the high-temperature solid phase powder obtained from the two-phase separator into the distributor using dense phase pneumatic conveying of CO2 or N2 gas; The distributor evenly distributes the solid phase powder between the corresponding burners, and the burners spray the solid phase powder into the boiler for combustion; A gas processing mechanism for cooling and desulfurizing the gas separated by the two-phase separator, or for cooling, desulfurizing and denitrifying the gas; The sulfur recovery mechanism processes the sulfur removed by the gas processing mechanism into sulfur.

2. The device according to claim 1, characterized in that The powder supply mechanism is a central storage type powder supply mechanism.

3. The device according to claim 1, characterized in that The gas supply mechanism can also supply water vapor into the reactor.

4. The device according to claim 1, characterized in that The monitoring and adjustment mechanism also includes an atmosphere detection component for monitoring the hydrogen concentration in the reactor. The atmosphere detection component is connected to the monitoring and adjustment mechanism and sends the detected hydrogen concentration to the monitoring and adjustment mechanism. When the hydrogen concentration is lower than the set concentration, the monitoring and adjustment mechanism controls the gas supply mechanism to increase the amount of water vapor supplied. When the hydrogen concentration is higher than the set concentration, the monitoring and adjustment mechanism controls the gas supply mechanism to reduce the amount of water vapor supplied.

5. The device according to claim 1, characterized in that The two-phase separator includes a high-temperature cyclone separator for separating coarser particles and a bag separator for separating finer particles. The high-temperature cyclone separator is connected in series with the bag separator.

6. The device according to claim 1, characterized in that The high-temperature powder conveying mechanism delivers the solid phase powder into the distributor through CO2 or N2 gas.

7. The device according to claim 1 or 6, characterized in that The CO2 gas may be flue gas discharged from a boiler.

8. The device according to claim 1, characterized in that The furnace-front desulfurization and desulfurization device also includes a gas recovery and utilization system for recovering the gas processed by the gas processing mechanism to use as a chemical raw material.

9. The device according to claim 1, characterized in that The outer walls of the reactor, two-phase separator, high-temperature powder conveying and gas conveying pipelines are provided with heat-insulating devices, and the inner walls are provided with fire-resistant and heat-insulating linings or water-cooled walls.

10. A method for desulfurizing and denitrifying pulverized coal before entering a boiler, characterized in that: Desulfurization and denitrification of pulverized coal by the pre-furnace desulfurization and denitrification device according to any one of claims 1 to 9 comprises the following steps: S1, using CO2 or N2 gas in dense phase pneumatic conveying to deliver pulverized coal into the reactor, and at the same time, according to the amount of pulverized coal delivered, quantitatively deliver oxygen to the pulverized coal inlet to form a mixed jet of oxygen and pulverized coal. At the same time, the pilot flame generated by the pilot flame mechanism ignites the oxygen and pulverized coal mixed jet, causing part of the pulverized coal to react with CO; S2, monitors the temperature in the reactor and adjusts the oxygen supply according to the detected data to keep the temperature 50°C-100°C below the ash melting point, so that water and volatile matter in the pulverized coal escape, and the iron sulfide and organic sulfur in the pulverized coal undergo a decomposition reaction to release elemental sulfur or hydrogen sulfide, and nitrogen in the pulverized coal escapes in the form of NH3 and HCN and further decomposes into H2, N2 and carbon black; S3, after the reaction of step S2 is completed, the gas content in the reactor increases sharply, and the gas-solid mixture leaves the reactor and enters the two-phase separator, which separates the solid and gas products of the reactor; S4, delivering the solid phase powder obtained by solid-gas separation into a distributor through a high-temperature conveying mechanism; S5, the distributor evenly distributes the solid phase powder among the corresponding burners; S6, cooling and desulfurizing the gas obtained by solid-gas separation or cooling and desulfurizing and denitrifying the gas through a gas processing mechanism; S7, processing the sulfur obtained from the gas processing mechanism into sulfur through the sulfur recovery mechanism.

11. The method according to claim 10, characterized in that: The method further includes step S8, wherein the gas processed in step S6 is recovered by a gas recovery system for use as a chemical raw material, or introduced into a pulverized coal boiler for combustion.

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