Flue gas denitration agent and denitration process thereof

Abstract

The invention discloses a flue gas denitration agent which comprises the following components in percentage by weight: 30%-50% of organic amine, 45%-60% of polyol, 1%-5% of bio-oil, 0.2%-0.5% of an emulsifier, 0.1%-0.2% of a nanoparticle catalyst and 0.05%-0.1% of a bactericide, and relates to the technical field of flue gas treatment. According to the flue gas denitration agent and the denitration process thereof, various components such as organic amine, polyol, bio-oil, an emulsifier, a nanoparticle catalyst and a bactericide are compounded, all the components have a synergistic effect and give full play to respective advantages, the organic amine serves as a reducing agent to provide a nitrogen source, the polyol plays a role in dispersion and stabilization, and the bio-oil has a synergistic effect. The bio-oil improves the local cracking temperature and promotes the denitration reaction, the emulsifier enables all the components to form a uniform microemulsion structure, the nanoparticle catalyst provides more active sites and improves the reaction rate, the bactericide guarantees the storage stability of the denitration agent, the nano catalytic particles serve as the core, a multi-layer distributed microemulsion structure is formed, and the denitration effect is improved. And uniform distribution of liquid drops in the spraying process is ensured.

Description

Technical Field

[0001] This invention relates to the field of flue gas treatment technology, specifically to a flue gas denitrification agent and its denitrification process. Background Technology

[0002] Currently, commonly used flue gas denitrification technologies mainly include selective catalytic reduction (SCR), non-selective catalytic reduction (NSCR), and the combined SNCR + SCR process. SCR technology requires the use of a catalyst within a specific temperature range to reduce NOx by reacting it with the reducing agent. However, this method suffers from problems such as high catalyst cost and susceptibility to poisoning and deactivation. SNCR technology does not use a catalyst and directly injects the reducing agent into the high-temperature zone to react with NOx. However, its reaction temperature window is narrow, and the denitrification efficiency is greatly affected by temperature fluctuations. Furthermore, ammonia slip is a prominent issue. The combined SNCR + SCR process combines the advantages of the former two methods, but the system is complex and has high investment and operating costs.

[0003] In addition, some existing denitrification agents have many shortcomings in use. For example, some denitrification agents are mainly composed of ammonia and urea. When the dosage is low, the denitrification efficiency is low and NOx emission cannot be achieved. When the dosage is high, there is ammonia escape, causing secondary pollution. Some denitrification agents have complicated preparation processes and are prone to clogging pipelines and nozzles, affecting the stable operation of the denitrification system. Therefore, developing a high-efficiency, economical, environmentally friendly and widely adaptable flue gas denitrification agent and its denitrification process is of great practical significance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a flue gas denitrification agent and its denitrification process, solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a flue gas denitrification agent, comprising the following components by weight percentage: 30%-50% organic amine, 45%-60% polyol, 1%-5% bio-oil, 0.2%-0.5% emulsifier, 0.1%-0.2% nanoparticle catalyst, and 0.05%-0.1% bactericide.

[0006] Preferably, the organic amine includes one or more of ethylenediamine, hexamethylenediamine, triethanolamine, acetamide, and acrylamide.

[0007] Preferably, the polyol includes one or more of glycerol, ethylene glycol, butylene glycol, triethylene glycol, xylitol, and sorbitol.

[0008] Preferably, the emulsifier comprises one or more of sodium stearate, sodium dodecyl sulfonate, dodecyl dimethylamine, nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and oleic acid polyoxyethylene ester.

[0009] Preferably, the nanoparticle catalyst includes one or more of nano-activated carbon, nano-titanium dioxide, nano-vanadium pentoxide, and nano-magnesium hydroxide.

[0010] Preferably, the bactericide includes one or more of isothiazolinone, dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide, sodium trichloroisocyanurate, and glutaraldehyde.

[0011] Preferably, the preparation method of the flue gas denitrification agent includes the following steps: S1. Organic amine, polyol, and nanoparticle catalyst are added to the reactor in sequence and mixed evenly under stirring to obtain microemulsion A. The stirring speed can be adjusted according to the size of the reactor and the properties of the materials, generally 100-500 rpm, and the stirring time is 30-60 minutes to ensure that the components are fully mixed. S2. In another container, add the bio-oil and emulsifier to an appropriate amount of solvent and stir until homogeneous to obtain solution B; S3. Slowly add solution B to microemulsion A while continuing to stir at a speed of 200-600 rpm for 60-120 minutes to ensure that the components are fully mixed and form a uniform microemulsion. S4. Add bactericide to the obtained microemulsion, stir and mix evenly at a stirring speed of 100-300 rpm for 15-30 minutes to obtain a high-efficiency flue gas denitrification agent.

[0012] Preferably, in step S2, deionized water is used as the solvent, and the appropriate solvent and amount are selected according to the actual situation.

[0013] This invention also discloses a denitrification process for a flue gas denitrification agent, specifically including the following steps: A1. Preparation of denitrification agent solution: Prepare the flue gas denitrification agent prepared above into a solution containing 20-40 wt% denitrification agent, and control the temperature of the solution at 25-40℃; A2. Atomized Injection: The denitrification agent solution is atomized by an atomizing device to form fine droplets. The atomized denitrification agent solution is then quantitatively injected countercurrently into the high-temperature zone of the boiler at 750-1100℃, and then dispersed into the boiler flue gas. The countercurrent injection method can make the denitrification agent fully contact the nitrogen oxides in the flue gas, thereby improving the reaction efficiency. A3. Reactive denitrification: The denitrification agent solution undergoes a reduction reaction with nitrogen oxides in boiler flue gas under high temperature conditions, converting nitrogen oxides into nitrogen and water, thereby reducing the content of nitrogen oxides in the flue gas. During the reaction, nanoparticle catalysts provide active sites to promote the reaction, and bio-oil increases the local pyrolysis temperature, which is conducive to the rapid completion of the reaction. A4. Flue gas emissions: After denitrification treatment, the flue gas, after subsequent dust removal, demisting and other treatment processes, meets environmental emission standards and can be safely discharged into the atmosphere. Beneficial effects

[0014] This invention provides a flue gas denitrification agent and its denitrification process. Compared with existing technologies, this flue gas denitrification agent and its denitrification process have the following advantages: By using a composite of multiple components such as organic amines, polyols, bio-oils, emulsifiers, nanoparticle catalysts, and bactericides, the components work synergistically, fully leveraging their respective advantages. Organic amines act as reducing agents to provide a nitrogen source, polyols play a dispersing and stabilizing role, bio-oils increase the local pyrolysis temperature and promote the denitrification reaction, emulsifiers enable the components to form a uniform microemulsion structure, nanoparticle catalysts provide more active sites and increase the reaction rate, and bactericides ensure the storage stability of the denitrification agent. With nano-catalyst particles as the core, a multi-layered microemulsion structure is formed, ensuring uniform droplet and component distribution during injection. This allows the denitrification agent to fully contact the nitrogen oxides in the flue gas, improving the efficiency and uniformity of the denitrification reaction. The denitrification process uses a quantitative counter-current injection method after atomization, spraying the denitrification agent solution into the high-temperature zone of the boiler and then dispersing it into the boiler flue gas. This allows the denitrification agent to react with the nitrogen oxides in the flue gas under optimal reaction conditions, further improving the denitrification efficiency. Attached Figure Description

[0015] Figure 1 This is a flowchart of the steps of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1 The present invention provides two technical solutions: a flue gas denitrification agent, comprising the following components by weight percentage: 30%-50% organic amine, 45%-60% polyol, 1%-5% bio-oil, 0.2%-0.5% emulsifier, 0.1%-0.2% nanoparticle catalyst and 0.05%-0.1% bactericide.

[0018] In this invention, the organic amine includes one or more of ethylenediamine, hexamethylenediamine, triethanolamine, acetamide, and acrylamide.

[0019] In this invention, the polyol includes one or more of glycerol, ethylene glycol, butylene glycol, triethylene glycol, xylitol, and sorbitol.

[0020] In this invention, the emulsifier includes one or more of sodium stearate, sodium dodecyl sulfonate, dodecyl dimethylamine, nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and oleic acid polyoxyethylene ester.

[0021] In this invention, the nanoparticle catalyst includes one or more of nano-activated carbon, nano-titanium dioxide, nano-vanadium pentoxide, and nano-magnesium hydroxide.

[0022] In this invention, the bactericide includes one or more of isothiazolinone, dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide, sodium trichloroisocyanurate, and glutaraldehyde.

[0023] Example 1

[0024] The preparation method of flue gas denitrification agent includes the following steps: S1. Organic amine, polyol and nanoparticle catalyst are added to the reactor in sequence and mixed evenly under stirring to obtain microemulsion A. The stirring speed can be adjusted according to the size of the reactor and the properties of the materials, generally 300 rpm, and the stirring time is 45 minutes to ensure that the components are fully mixed. S2. In another container, add the bio-oil and emulsifier to an appropriate amount of solvent and stir until homogeneous to obtain solution B; S3. Slowly add solution B to microemulsion A while continuing to stir at a speed of 400 rpm for 90 minutes to ensure that the components are fully mixed and form a uniform microemulsion. S4. Add bactericide to the obtained microemulsion, stir and mix evenly at a stirring speed of 200 rpm for 20 minutes to obtain a high-efficiency flue gas denitrification agent.

[0025] Specifically, the organic amine is a mixture of ethylenediamine and triethanolamine, with ethylenediamine accounting for 30% and triethanolamine accounting for 15%; the polyol is a mixture of glycerol and ethylene glycol, with glycerol accounting for 40% and ethylene glycol accounting for 15%; the bio-oil is biodiesel, with a content of 3%; the emulsifier is sodium dodecyl sulfonate, with a content of 0.3%; the nanoparticle catalyst is nano-titanium dioxide, with a content of 0.15%; and the bactericide is isothiazolinone, with a content of 0.08%.

[0026] A denitrification process using a flue gas denitrification agent specifically includes the following steps: A1. Preparation of denitrification agent solution: Prepare the flue gas denitrification agent prepared above into a solution containing 30wt% denitrification agent, and control the temperature of the solution at 30℃; A2. Atomized Injection: The denitrification agent solution is atomized using an atomizing device to form fine droplets. The atomized denitrification agent solution is then quantitatively injected countercurrently into the high-temperature zone of the boiler at 900℃, and then dispersed into the boiler flue gas. The countercurrent injection method can ensure that the denitrification agent and nitrogen oxides in the flue gas come into full contact, thereby improving the reaction efficiency. A3. Reactive denitrification: The denitrification agent solution undergoes a reduction reaction with nitrogen oxides in boiler flue gas under high temperature conditions, converting nitrogen oxides into nitrogen and water, thereby reducing the content of nitrogen oxides in the flue gas. During the reaction, nanoparticle catalysts provide active sites to promote the reaction, and bio-oil increases the local pyrolysis temperature, which is conducive to the rapid completion of the reaction. A4. Flue gas emissions: After denitrification treatment, the flue gas, after subsequent dust removal, demisting and other treatment processes, meets environmental emission standards and can be safely discharged into the atmosphere.

[0027] Example 2

[0028] The preparation method of flue gas denitrification agent includes the following steps: S1. Organic amine, polyol and nanoparticle catalyst are added to the reactor in sequence and mixed evenly under stirring to obtain microemulsion A. The stirring speed can be adjusted according to the size of the reactor and the properties of the materials, generally 400 rpm, and the stirring time is 60 minutes to ensure that the components are fully mixed. S2. In another container, add the bio-oil and emulsifier to an appropriate amount of solvent and stir until homogeneous to obtain solution B; S3. Slowly add solution B to microemulsion A while continuing to stir at a speed of 500 rpm for 120 minutes to ensure that the components are fully mixed and form a uniform microemulsion. S4. Add bactericide to the obtained microemulsion, stir and mix evenly at a stirring speed of 250 rpm for 25 minutes to obtain a high-efficiency flue gas denitrification agent.

[0029] Specifically, the organic amine is a mixture of hexamethylenediamine and acetamide, with hexamethylenediamine accounting for 25% and acetamide accounting for 20%; the polyol is a mixture of butanediol and xylitol, with butanediol accounting for 35% and xylitol accounting for 20%; the bio-oil is lignin pyrolysis oil with a content of 2%; the emulsifier is nonylphenol polyoxyethylene ether with a content of 0.4%; the nanoparticle catalyst is nano vanadium pentoxide with a content of 0.1%; and the bactericide is dodecyl dimethyl benzyl ammonium chloride with a content of 0.06%.

[0030] A denitrification process using a flue gas denitrification agent specifically includes the following steps: A1. Preparation of denitrification agent solution: Prepare the flue gas denitrification agent prepared above into a solution containing 25wt% denitrification agent, and control the temperature of the solution at 35℃; A2. Atomized Injection: The denitrification agent solution is atomized by an atomizing device to form fine droplets. The atomized denitrification agent solution is then quantitatively injected countercurrently into the high-temperature zone of the boiler at 850°C and then dispersed into the boiler flue gas. The countercurrent injection method can ensure that the denitrification agent and nitrogen oxides in the flue gas come into full contact, thereby improving the reaction efficiency. A3. Reactive denitrification: The denitrification agent solution undergoes a reduction reaction with nitrogen oxides in boiler flue gas under high temperature conditions, converting nitrogen oxides into nitrogen and water, thereby reducing the content of nitrogen oxides in the flue gas. During the reaction, nanoparticle catalysts provide active sites to promote the reaction, and bio-oil increases the local pyrolysis temperature, which is conducive to the rapid completion of the reaction. A4. Flue gas emissions: After denitrification treatment, the flue gas, after subsequent dust removal, demisting and other treatment processes, meets environmental emission standards and can be safely discharged into the atmosphere.

[0031] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A flue gas denitrification agent, characterized by: The components include the following weight percentages: organic amine 30%-50%, polyhydric alcohol 45%-60%, bio-oil 1%-5%, emulsifier 0.2%-0.5%, nanoparticle catalyst 0.1%-0.2%, and bactericide 0.05%-0.1%.

2. The flue gas denitrification agent according to claim 1, characterized in that: The organic amine includes one or more of ethylenediamine, hexanediamine, triethanolamine, acetamide, and acrylamide.

3. The flue gas denitrification agent according to claim 1, characterized in that: The polyhydric alcohol includes one or more of glycerol, ethylene glycol, butanediol, triethylene glycol, xylitol, and sorbitol.

4. The flue gas denitrification agent according to claim 1, characterized by: The emulsifier includes one or more of sodium stearate, sodium dodecyl sulfonate, dodecyl dimethylamine, nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and oleic acid polyoxyethylene ester.

5. The flue gas denitrification agent according to claim 1, characterized in that: The nanoparticle catalyst includes one or more of nano-activated carbon, nano-titanium dioxide, nano-vanadium pentoxide, and nano-magnesium hydroxide.

6. The flue gas denitrification agent according to claim 1, characterized by: The bactericide includes one or more of isothiazolinone, dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide, sodium trichloroisocyanurate, and glutaraldehyde.

7. The flue gas denitrification agent according to claim 1, characterized by: The preparation method includes the following steps: S1. The organic amine, polyhydric alcohol, and nanoparticle catalyst are sequentially added to a reaction kettle and mixed uniformly under stirring, to obtain a microemulsion A. The stirring speed can be adjusted according to the scale of the reaction kettle and the properties of the materials, and is generally 100-500 revolutions per minute. The stirring time is 30-60 minutes, to ensure that the components are fully mixed. S2. In another container, the bio-oil and emulsifier are added to an appropriate amount of solvent and stirred uniformly, to obtain a solution B. S3. The solution B is slowly added to the microemulsion A, while continuing to stir at a speed of 200-600 revolutions per minute for 60-120 minutes, to fully integrate the components and form a uniform microemulsion. S4. The bactericide is added to the obtained microemulsion and stirred uniformly at a speed of 100-300 revolutions per minute for 15-30 minutes, to obtain the high-efficiency flue gas denitration agent.

8. The flue gas denitrification agent according to claim 7, characterized by: In S2, deionized water is selected as the solvent, and the appropriate solvent and amount are selected according to the actual situation.

9. A process for the denitration of flue gases with a denitration agent, characterized in that: Specifically, the following steps are included: A1. Preparation of a denitration agent solution: the prepared flue gas denitration agent is prepared into a solution containing 20-40 wt% denitration agent, and the temperature of the solution is controlled at 25-40℃. A2. Atomization and injection: an atomization device is used to atomize the denitration agent solution, to form fine droplets. The atomized denitration agent solution is then injected in a countercurrent manner into the high-temperature zone of a boiler at 750-1100℃, and is then dispersed into the boiler flue gas. The countercurrent injection allows the denitration agent to fully contact the nitrogen oxides in the flue gas, to improve the reaction efficiency. A3. Reaction denitration: the denitration agent solution and the nitrogen oxides in the boiler flue gas undergo a reduction reaction under high-temperature conditions, to convert the nitrogen oxides into nitrogen and water, thereby reducing the content of nitrogen oxides in the flue gas. During the reaction, the nanoparticle catalyst provides active sites to promote the reaction, and the bio-oil increases the local cracking temperature, which is conducive to the rapid completion of the reaction. A4. Flue gas emissions: After denitrification treatment, the flue gas, after subsequent dust removal, demisting and other treatment processes, meets environmental emission standards and can be safely discharged into the atmosphere.

Images