Activated carbon and silica sol supported slag melting agent for high-calcium coal gasifier

Abstract

An activated carbon and silica sol supported slag melting agent for a high-calcium coal gasifier comprises 5-10 parts of an expansion bulking agent, 10-20 parts of a catalytic slag melting agent and 40-60 parts of a high-temperature oxidant, and has the beneficial effects that substances such as activated carbon and borax in the expansion bulking agent can promote the fluffiness of an ash structure; under the cooperation action with a catalytic slag melting agent and a high-temperature oxidizing agent which are added into the raw materials, high-melting-point silicon-aluminum components and calcium-containing minerals in the ash slag are subjected to a certain chemical reaction at a low temperature to form a low-temperature eutectic melt, the fluidity is enhanced, the melting temperature of the ash slag is reduced, and the ash slag is promoted to be converted into fluidization; a proper dosage is selected according to the property of slag, the slag melting agent is sprayed into a nozzle above a slag discharging opening of a gasification furnace using high-calcium coal, liquid slag discharging can be achieved at the temperature of about 900 DEG C, and the problems that gas resources are wasted and cost is increased due to the fact that natural gas is used are effectively solved. And meanwhile, the economic loss caused by non-planned shutdown of the gasification furnace due to slag blockage is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the field of slag discharging of gasifiers, and particularly to an activated carbon and silica sol supported slagging agent for a high-calcium coal gasifier. Background Art

[0002] The Junggar Coalfield in Xinjiang is a huge open-pit coal mine with a reserve of over a hundred billion tons in China, and the predicted reserve reaches 390 billion tons. As good power coal, Junggar coal is extremely prone to serious slagging and fouling phenomena during the gasification process, which greatly limits the application of Junggar coal.

[0003] Junggar coal has a relatively high content of alkaline metals. The phase transition temperatures of these substances are relatively low, and they will gasify when the flue gas reaches a certain temperature. When gaseous alkaline metals encounter the metal heating surface, they will condense. Ca will partially precipitate at 600°C, and the precipitation rate will increase significantly after 1000°C. At about 1100°C, it will form a eutectic with minerals such as iron and silicon in the ash. When the reaction temperature is lower than the coal ash flow temperature, the ash sample shows morphological characteristics of separation, softness, and powder aggregation and does not melt, resulting in serious slagging phenomena.

[0004] In addition, in a gasifier using high-calcium coal, the content of calcium oxide in the coal ash will affect the melting point of the slag. When the content of calcium oxide is too high or too low, the melting point of the coal ash will increase. Slagging in a liquid slagging gasifier will seriously affect the gasification efficiency, reduce the heat transfer coefficient, cause problems such as blockage of the slag discharge port, and affect the production process.

[0005] In the patent with the authorization announcement number CN107084401B and the name of a pretreatment and upgrading system and method for high-sodium and high-calcium coal in oxy-fuel combustion, a method of manufacturing an acidic environment by introducing a part of the collected CO2 into a carbonic acid / coal powder acid treatment reaction chamber to remove sodium and calcium elements is proposed. This method has a certain beneficial effect on the calcium element in high-calcium coal before coal combustion, but the economic cost is relatively high and the operation is complex. According to the investigation of the production site, at present, a gasification agent nozzle is usually provided above the slag discharge outlet of a liquid slagging gasifier, and a large amount of natural gas is sprayed in to increase the temperature of the slag discharge outlet to ensure that the slag is discharged in a liquid form. However, this practice will cause a large waste of gas resources and an increase in cost. Summary of the Invention

[0006] In order to solve the defect of the existing method of using a large amount of natural gas to increase the temperature at the outlet of a liquid slagging gasifier, resulting in energy waste and economic losses, the purpose of the present invention is to provide an activated carbon and silica sol supported slagging agent for a high-calcium coal gasifier.

[0007] To achieve the above object, the present invention adopts the following technical solution: An activated carbon and silica sol supported slag agent for a high-calcium gasifier, comprising 5-10 parts of an expansion and loosening agent, 10-20 parts of a catalytic slag agent, and 40-60 parts of a high-temperature oxidant.

[0008] Further, the expansion and loosening agent includes borax, alkylaminoamine, ethanol, activated carbon, and sodium bicarbonate.

[0009] Further, the catalytic slag agent includes sodium hydroxide, piperidine, silica sol, and potassium bitartrate.

[0010] Further, the high-temperature oxidant includes vanadium oxide, sodium acetate, and sodium carbonate.

[0011] The present invention also provides a preparation method for an activated carbon and silica sol supported slag agent for a high-calcium gasifier, comprising the following steps: Add the alkylaminoamine to ethanol to prepare a solution with a concentration of 0.1-1 mol / L. Put the activated carbon into a beaker and slowly add the alkylaminoamine solution to ensure that the activated carbon is completely immersed in the solution to obtain a solid-liquid mixture. Place the solid-liquid mixture in a constant temperature water bath, control the temperature between 30-60 °C, and fully impregnate for 7-24 h. Filter the solid-liquid mixture and collect the impregnated activated carbon. Wash the activated carbon thoroughly with deionized water and dry it in a vacuum drying oven at 60-80 °C for 6-12 h to obtain the supported activated carbon.

[0012] Add borax and sodium bicarbonate to the supported activated carbon in a mass ratio of (10-20):(7-10):(5-10), and fully grind it to below 48 µm to obtain the expansion and loosening agent.

[0013] Add piperidine to deionized water, mix evenly, then add sodium hydroxide and potassium bitartrate to the solution in sequence and stir until clear, and then add silica sol. After fully stirring, add the mixed liquid to a high-pressure reaction kettle and crystallize at 150 °C for 50-60 h. The molar ratio of piperidine, sodium hydroxide, potassium bitartrate, silica sol, and deionized water is (0.3-0.4):(0.06-0.1):(0.02-0.03):1:(26-30). Take it out, wash it with deionized water, and calcine it in an argon atmosphere for 8-10 h, and fully grind it to below 48 µm to obtain the catalytic slag agent.

[0014] Mix vanadium oxide, sodium carbonate, and sodium acetate in a mass ratio of (2-5):(20-30):(10-15), and fully grind it to below 48 µm to obtain the high-temperature oxidant.

[0015] Compared with the prior art, the beneficial effects of the present invention are: ① In the present invention, activated carbon supported alkylamine is used, which has strong complexing ability under gasification conditions. It can react with metal ions in high-calcium coal slag to form relatively stable complexes, weaken the ionic bond strength of the original metal oxides, reduce the lattice energy of the slag, and thus lower the melting point of the slag. After the alkylamine molecules are adsorbed on the surface of the slag, their hydrophobic groups, the alkyl groups, stretch outwards, weakening the intermolecular attraction on the surface of the slag, thereby reducing the surface tension, decreasing the internal friction of the slag, and improving the fluidity. Borax decomposes into borate ions at high temperature and reacts with acidic oxides (such as SiO2) in the slag to form borosilicates with lower melting points than silicates, thus reducing the melting point of the slag. Sodium bicarbonate decomposes to generate CO2 gas, and the CO2 gas enters the slag loosened by alkylamine and borax, strengthening the loose structure of the slag and further reducing the slag viscosity.

[0016] ② In the present invention, a method assisted by active seeds is adopted, and piperidine is used as a template agent to prepare a catalyst. This catalyst is a weakly acidic catalyst with acidic active sites, which can generate a large number of free radicals, leading to enhanced reactions such as ion exchange and proton adsorption, thereby promoting further reactions of the slag. The potassium ion in potassium bitartrate has a relatively large radius and will undergo ion exchange with minerals in the slag to form a potassium-calcium mixed mineral structure, reducing the melting point of the slag. In addition, as an amphoteric substance, potassium bitartrate can dissociate or react appropriately according to the acidity and alkalinity of the slag, keeping the slag within an appropriate acidity and alkalinity range, thereby promoting mineral melting and transformation.

[0017] ③ In the present invention, to further promote the slag melting effect, vanadium oxide, sodium carbonate, and sodium acetate are added as oxidants. After the slag is loosened by the expansion agent, vanadium oxide enters the interior of the slag. Its active sites can adsorb reactant molecules such as hydrocarbons, enabling the reactant molecules to be enriched and approach each other on its surface, reducing the activation energy required for the slag reaction, and promoting the reaction of sodium carbonate and sodium acetate with minerals in the slag. In addition to reacting with acidic oxides, the addition of sodium carbonate and sodium acetate can also combine with calcium, magnesium, and other ions to form composite compounds with lower melting points and reduce the surface tension of the slag. An appropriate surface tension of the slag helps the slag droplets to coalesce to form larger slag droplets, which is convenient for discharging out of the furnace, further promoting liquid slag discharge. Detailed implementation manners

[0018] The various exemplary implementation manners of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention. It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention.

[0019] In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Intermediate values within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, are also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0020] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0021] Without departing from the scope or spirit of the present invention, various improvements and variations can be made to the specific embodiments of the description of the present invention, which are obvious to those skilled in the art. Other embodiments obtained from the description of the present invention are obvious to those skilled in the art. The description and examples of the present invention are merely exemplary.

[0022] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0023] In the examples of the present invention, the "parts" are all in parts by mass.

[0024] The present invention will be further described in detail below with reference to specific examples. Example

[0025] An activated carbon and silica sol supported slagging agent for a high-calcium coal gasifier, comprising the following raw materials: 8 parts of an expansion and loosening agent, 20 parts of a catalytic slagging agent, and 60 parts of a high-temperature oxidant.

[0026] A preparation method of an activated carbon and silica sol supported slagging agent for a high-calcium coal gasifier, comprising the following steps: stirring and uniformly mixing the expansion and loosening agent, the catalytic slagging agent, and the high-temperature oxidant, and drying at 120 °C for 120 min to obtain an activated carbon and silica sol supported slagging agent for a high-calcium coal gasifier. Example

[0027] An activated carbon and silica sol supported slagging agent for a high-calcium coal gasifier, comprising the following raw materials: 15 parts of an expansion and loosening agent, 20 parts of a catalytic slagging agent, and 50 parts of a high-temperature oxidant.

[0028] The preparation method of the activated carbon and silica sol supported slagging agent for the high-calcium gasifier is the same as that in Example 1. Example

[0029] An activated carbon and silica sol supported slagging agent for a high-calcium gasifier, comprising the following raw materials: 5 parts of expansion and loosening agent, 20 parts of catalytic slagging agent, and 60 parts of high-temperature oxidant.

[0030] The preparation method of the activated carbon and silica sol supported slagging agent for the high-calcium gasifier is the same as that in Example 1.

[0031] Comparative Example 1 An activated carbon and silica sol supported slagging agent for a high-calcium gasifier, which is different from Example 1 in that the high-temperature oxidant is 45 parts.

[0032] The remaining raw materials are the same as those in Example 1.

[0033] The preparation method of the activated carbon and silica sol supported slagging agent for the high-calcium gasifier is the same as that in Example 1.

[0034] Comparative Example 2 An activated carbon and silica sol supported slagging agent for a high-calcium gasifier, which is different from Example 1 in that the catalytic slagging agent is 10 parts.

[0035] The remaining raw materials are the same as those in Example 2.

[0036] The preparation method of the activated carbon and silica sol supported slagging agent for the high-calcium gasifier is the same as that in Example 1.

[0037] Performance test The activated carbon and silica sol supported slagging agent for a high-calcium gasifier prepared in the above Examples 1-3 and Comparative Examples 1-2 was sprayed into the slag discharge outlet of the gasifier for performance testing.

[0038] The above is only the preferred specific implementation manner of the present invention, and the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An activated carbon and silica sol supported slag agent for a high-calcium gasifier comprises an expansion and loosening agent, a catalytic slag agent, and a high-temperature oxidant.

2. The activated carbon and silica sol supported slag agent for a high calcium gasifier according to claim 1, characterized in that The mass parts of the raw materials are: 5 - 10 parts of the expansion and loosening agent, 10 - 20 parts of the catalytic slag agent, and 40 - 60 parts of the high-temperature oxidant.

3. The activated carbon and silica sol supported slag agent for a high calcium gasifier according to claim 1, characterized in that The expansion and loosening agent includes borax, alkylaminoamine, ethanol, activated carbon, and sodium bicarbonate.

4. The activated carbon and silica sol supported slag agent for a high-calcium gasifier according to claim 1, characterized in that The catalytic slag agent includes sodium hydroxide, piperidine, silica sol, and potassium bitartrate.

5. The activated carbon and silica sol supported slag agent for a high calcium gasifier according to claim 1, characterized in that The high-temperature oxidant includes vanadium oxide, sodium acetate, and sodium carbonate.

6. The activated carbon and silica sol supported slag agent for a high-calcium gasifier according to claim 1, wherein Prepare appropriate proportions of the expansion and loosening agent, catalytic slag agent, and high-temperature oxidant according to the gasification raw materials and slag properties.

7. A preparation method of an activated carbon and silica sol supported slag agent for a high-calcium coal gasifier, including an activated carbon and silica sol supported slag agent for a high-calcium coal gasifier according to any one of claims 1-6, characterized in that It includes the following steps: S1: Raw material selection, treatment, and weighing: Select the expansion and loosening agent, catalytic slag agent, and high-temperature oxidant in the required weight ratio, and perform grinding and screening on various raw materials, and then place them separately inside the storage tank; S2: Preparation of the expansion and loosening agent: Add alkylaminoamine to ethanol to prepare a solution with a concentration of 0.1 - 1 mol / L. Put the activated carbon into a beaker, and slowly add the alkylaminoamine solution to ensure that the activated carbon is completely immersed in the solution to obtain a solid-liquid mixture. Place the solid-liquid mixture in a constant temperature water bath, control the temperature between 30 - 60 °C, and fully impregnate for 7 - 24 h. Filter the solid-liquid mixture and collect the impregnated activated carbon. Wash the activated carbon thoroughly with deionized water and dry it in a vacuum drying oven at 60 - 80 °C for 6 - 12 h to obtain the loaded activated carbon. Add borax and sodium bicarbonate to the loaded activated carbon in a mass ratio of (10 - 20):(7 - 10):(5 - 10), and fully grind it to below 48 µm to obtain the expansion and loosening agent; S3: Preparation of the catalytic slag agent: Add piperidine to deionized water, mix evenly, then add sodium hydroxide and potassium bitartrate to the solution in sequence and stir until it is clear, and then add silica sol. After fully stirring, add the mixed liquid to a high-pressure reactor and crystallize it at 150 °C for 50 - 60 h. The molar ratio of piperidine, sodium hydroxide, potassium bitartrate, silica sol, and deionized water is (0.3 - 0.4):(0.06 - 0.1):(0.02 - 0.03):1:(26 - 30); Take it out, wash it with deionized water, and calcine it in an argon atmosphere for 8 - 10 h, and fully grind it to below 48 µm to obtain the catalytic slag agent; S4: Preparation of the high-temperature oxidant: Mix vanadium oxide, sodium carbonate, and sodium acetate in a mass ratio of (2 - 5):(20 - 30):(10 - 15), and fully grind it to below 48 µm to obtain the high-temperature oxidant; S5: Put the initiator together with the expansion and loosening agent obtained in S2, the catalytic slag agent obtained in S3, and the high-temperature oxidant obtained in S4 into an oscillating device for oscillation to make the mixture disperse and mix more evenly, and obtain an activated carbon and silica sol supported slag agent for a high-calcium gasifier.

8. The activated carbon and silica sol supported slag agent for a high calcium gasifier according to claim 7, characterized in that The alkylaminoamine in S2 is alkylaminododecylamine or alkylaminohexylamine.

9. The activated carbon and silica sol supported slag agent for a high-calcium coal gasifier according to claim 7, characterized in that The output power of the oscillating device in S5 is 300 - 400 W, and the ultrasonic oscillation time is 25 - 30 min.