Denitration combustion-supporting acid mist removal auxiliary agent

Abstract

The invention discloses a denitration combustion-supporting acid mist removal auxiliary agent, and belongs to the technical field of catalytic cracking flue gas sulfur transfer agents, and the method comprises the following steps: reacting ferric chloride, magnesium chloride, aluminum chloride and a sodium hydroxide aqueous solution according to an accurate ratio to generate a cross-linking agent solution, mixing the cross-linking agent solution with modified magnesium saponite, and carrying out heating and heat preservation treatment to form a cross-linked structure. And then, dipping the cross-linked magnesium saponite in a solution containing a plurality of metal salts, and roasting to obtain the final auxiliary agent. Polyethylene glycol ether and sodium aluminosilicate are adopted in the preparation of the modified magnesium saponite, so that the pore structure and the thermal stability are optimized. Compared with the prior art, the assistant effectively reduces the emission of SOX and NOX in the catalytic cracking process, especially the emission of sulfur trioxide, improves the combustion efficiency, reduces the generation of pollutants, avoids the use of toxic substances, reduces the environmental pollution, and has remarkable environmental protection benefits and economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of catalytic cracking flue gas sulfur transfer agents, in particular to a denitration, combustion-supporting, and acid mist removal auxiliary agent. Background Art

[0002] With the acceleration of industrialization, emissions of acidic substances such as sulfides and nitrides are increasing. Sulfide emissions, in particular, have had a serious impact on the environment, leading to the annual expansion of acid rain areas. To meet this challenge, investment in environmental monitoring and law enforcement capacity building has been increased, and effective emission reduction technologies are urgently needed.

[0003] In the oil refining industry, catalytic cracking units are the primary source of sulfur oxide emissions. Faced with the increasing use of heavier crude oil and the increasing proportion of high-sulfur crude oil, traditional sulfur oxide reduction technologies such as hydrodesulfurization and scrubbing desulfurization face challenges such as high investment, high operating costs, and the generation of secondary pollution. Therefore, the development of an economical, efficient, and environmentally friendly sulfur oxide reduction technology has become a top priority.

[0004] Currently, there are three main methods for controlling sulfur oxide emissions from catalytic cracking unit flue gas: hydrodesulfurization pretreatment, scrubbing desulfurization, and the addition of sulfur transfer agents. While hydrodesulfurization can improve product properties and reduce sulfur content, it suffers from high investment and operating costs, as well as complex equipment. While scrubbing desulfurization offers high desulfurization efficiency, it also suffers from high investment, large footprint, and wastewater generation. In contrast, the addition of sulfur transfer agents, with its low cost, lack of additional equipment, and ease of operation, has become the most economical solution.

[0005] The working principle of sulfur transfer agent is to realize SO X The absorption-release process. In the regenerator, the sulfur transfer agent and SO X The reaction generates metal sulfate, which is then reduced in the reactor to release H2S, completing the transfer of sulfur. The sulfur is then recovered in the form of sulfur through the downstream sulfur recovery device, realizing the resource utilization of sulfur.

[0006] Chinese invention patent CN102755809B discloses a method for preparing a pillared magnesium saponite-type catalytic cracking flue gas sulfur transfer agent. The method comprises the following steps: mixing magnesium saponite with water to obtain a magnesium saponite dispersion; mixing an iron source, a magnesium source, an aluminum source, and / or a cerium source with water or oxalic acid, and adding a NaOH solution to prepare a crosslinker solution; mixing the magnesium saponite dispersion and the crosslinker solution, maintaining the mixture at 10-80°C for 5-30 hours, and then maintaining the mixture at 90-130°C for 1-40 hours to obtain a crosslinked magnesium saponite; impregnating cerium nitrate on the crosslinked magnesium saponite, and calcining the mixture to obtain the pillared magnesium saponite-type catalytic cracking flue gas sulfur transfer agent. The pillared magnesium saponite-type catalytic cracking flue gas sulfur transfer agent prepared by the above method provided by the invention has good desulfurization activity. However, the sulfur transfer agent of the invention has problems with insufficient desulfurization efficiency and stability, which limits its wide application and adaptability under different operating conditions. Summary of the Invention

[0007] In response to the defects of the prior art, the present invention provides a method for preparing a denitrification, combustion-supporting and acid mist removal auxiliary agent. The method achieves efficient desulfurization activity by finely controlling the raw material mixing, cross-linking reaction and roasting process. At the same time, it may reduce the stringent requirements for equipment and operating conditions, improve the feasibility of the preparation process and the economy of the desulfurizer, and help solve the problems of high cost, complex operation or insufficient desulfurization efficiency in the prior art.

[0008] In the field of industrial emission control, "acid mist removal" refers to compounds or mixtures that can neutralize or convert acidic substances. These substances are used to reduce acid gases such as SO in industrial processes, especially in petroleum refining and chemical production. X and NO X During the catalytic cracking process, acid mist removal additives capture and convert acidic oxides such as SO3 through chemical reactions, thereby reducing their corrosive effects on the environment and equipment.

[0009] "Acid mist" generally refers to substances with acidic properties that can release hydrogen ions (H+) or react with water to form acidic solutions. SO₃ is a typical example of acid mist in catalytic cracking flue gas because it easily reacts with water to form sulfuric acid, increasing the acidity of the flue gas. SO₃ emissions not only contribute to the formation of acid rain but also pose serious risks to human health and ecosystems.

[0010] Acid mist removal additive is a chemical additive specially designed to reduce the emission of acidic substances in industrial processes. In the catalytic cracking process, sulfur and nitrogen oxides (such as SO X and NO X) are major pollutants that not only cause serious environmental pollution but can also corrode equipment. Sulfur trioxide (SO3) is particularly strong, as it reacts with water to form sulfuric acid, further exacerbating the damage to the environment and equipment.

[0011] The denitrification combustion-supporting and acid mist removal additive of the present invention effectively captures and transforms these acidic substances through a series of actions. X The reaction generates metal sulfate, which is then reduced in the reactor to release H2S, completing the sulfur transfer. This process not only reduces SO3 emissions but also realizes the resource utilization of sulfur, converting the original pollutant into recyclable sulfur.

[0012] In addition, this additive also has a combustion-supporting effect, improving combustion efficiency and reducing carbon monoxide (CO) emissions, further enhancing the environmental performance of the industrial process. By using this additive, efficient desulfurization and combustion-supporting effects can be achieved at low investment and operating costs without adding new equipment, resulting in significant economic and environmental benefits.

[0013] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0014] A method for preparing a denitrification combustion-supporting and acid mist removal additive is as follows:

[0015] Step 1: Mix ferric chloride, magnesium chloride, aluminum chloride and water, and add sodium hydroxide aqueous solution to prepare a crosslinking agent solution;

[0016] Step 2: mixing the modified magnesium saponite with the crosslinker solution prepared in step 1, heating and preserving the mixture to obtain crosslinked magnesium saponite;

[0017] Step 3, immersing the cross-linked magnesium saponite in a metal salt solution to obtain the impregnated magnesium saponite;

[0018] Step 4: calcining the impregnated magnesium soapstone to obtain a denitrification, combustion-supporting, and acid mist removal additive.

[0019] The weight proportions of the substances in step 1 are: 120-180 parts of ferric chloride, 80-120 parts of magnesium chloride, 80-100 parts of aluminum chloride, 1800-2200 parts of water, and 400-600 parts of 0.5-2 mol / L sodium hydroxide aqueous solution.

[0020] The mass ratio of the modified magnesium soapstone to the cross-linking agent solution prepared in step 1 is 1:2-4.

[0021] The mass ratio of the cross-linked magnesium soapstone to the metal salt solution is 1:8-12.

[0022] The temperature-raising and heat-insulating treatment is to maintain the temperature at 40-60° C. for 10-30 hours, and then maintain the temperature at 80-110° C. for 10-30 hours.

[0023] The metal salt solution contains 0.01-0.03 mol / L silver chloride, 0.005-0.02 mol / L chloroplatinic acid, 0.005-0.02 mol / L palladium chloride, 0.02-0.04 mol / L cobalt chloride, 0.04-0.06 mol / L nickel chloride, 0.03-0.05 mol / L bismuth acetate, 0.05-0.07 mol / L zinc chloride, 0.07-0.09 mol / L titanium tetrachloride, 0.02-0.04 mol / L zirconium chloride, and 0.01-0.03 mol / L sodium tungstate.

[0024] The calcination temperature is 400-800° C., and the calcination time is 3-8 hours.

[0025] The preparation method of the modified magnesium soapstone is as follows, in parts by weight:

[0026] S1. Dissolve sodium hydroxide and sodium bicarbonate in water to prepare alkali solution; the mass ratio of sodium hydroxide, sodium bicarbonate and water is 0.5-2:1-2:12-18;

[0027] S2. Dissolve magnesium chloride and aluminum chloride in water to prepare a magnesium-aluminum aqueous solution, wherein the mass ratio of magnesium chloride to aluminum chloride to water is 0.5-2:15-25:300-500;

[0028] S3, dissolving the polyethylene glycol ether in water to prepare an aqueous solution containing the polyethylene glycol ether, wherein the mass ratio of the polyethylene glycol ether to water is 0.5-2:4-6;

[0029] S4. Under a constant temperature of 80-90° C. and stirring conditions, first add 80-120 parts of sodium aluminosilicate to 500-700 parts of alkali solution to obtain a silicon-containing liquid, and then dropwise add 150-250 parts of a magnesium aluminum aqueous solution and 150-250 parts of a polyethylene glycol ether aqueous solution to the silicon-containing liquid. After the dropwise addition, continue stirring for 2-4 hours to obtain a reaction solution;

[0030] S5. Add the reaction solution to a crystallization kettle, seal it, and crystallize it at a constant temperature of 150-180° C. for 10-20 hours. After the crystallization is completed, cool it to room temperature, and then centrifuge, wash it with water, vacuum dry it at 30-50° C. for 5-15 hours, crush it, and pass it through a 50-200 mesh sieve to obtain modified magnesium soapstone.

[0031] In the preparation method of the denitration combustion-supporting and acid mist removal auxiliary agent of the present invention, each substance has the following functions:

[0032] Ferric chloride, magnesium chloride, and aluminum chloride serve as metal sources, which react with sodium hydroxide to generate corresponding hydroxides. These hydroxides are the basis for preparing a crosslinker solution, which is then used to react with magnesium saponite to form a crosslinked structure.

[0033] Sodium hydroxide, as a strong base, is used to adjust the pH value of the solution, promote the hydrolysis of metal chloride to form hydroxide, and also play a cross-linking role.

[0034] Modified magnesium saponite serves as a catalyst support, providing specific pore structure and surface characteristics, which helps to improve catalytic efficiency and selectivity.

[0035] Polyethylene glycol ether, polypropylene glycol and polyethylene glycol are used as organic treatment agents to improve the pore structure and surface properties of magnesium soapstone, enhance its dispersibility and stability, and contribute to improving catalytic performance.

[0036] Sodium aluminosilicate, silica sol and sodium silicate, as silicon sources, participate in the formation of the skeleton structure of the modified magnesium soapstone and affect the porosity and thermal stability of the material.

[0037] Metal salt solution (including silver chloride, chloroplatinic acid, palladium chloride) is used as a precious metal source. These metal ions are fixed on magnesium saponite during the impregnation process to form active components, which catalyze reactions such as denitrification, combustion support, and acid removal.

[0038] Cobalt chloride, nickel chloride, bismuth acetate, zinc chloride, titanium tetrachloride, zirconium chloride, and sodium tungstate may serve as co-catalysts or promoters to improve the activity and stability of the catalyst.

[0039] Through the combined effects of these substances, the denitrification, combustion-supporting, and acid mist removal additive of the present invention can effectively reduce SO X and NO X emissions, improve combustion efficiency and reduce the generation of pollutants.

[0040] Compared with the existing technology, it has the following beneficial effects:

[0041] 1) The denitrification, combustion-supporting, and acid mist removal additive of the present invention shows excellent desulfurization efficiency. Adding 2% of the denitrification, combustion-supporting, and acid mist removal additive can significantly reduce the SO2 concentration in the flue gas, and after 216 hours of continuous operation, it can still maintain a desulfurization rate of more than 85%, which is higher than the desulfurization rate of about 70% of general products.

[0042] 2) Compared with hydrodesulfurization and washing desulfurization methods, the denitrification combustion-supporting and acid mist removal additive of the present invention does not require the addition of new equipment and has lower investment and operating costs. x A device containing no more than 1500 μg / g is particularly economical as it provides a cost-effective solution.

[0043] 3) The present invention's denitrification, combustion-supporting, and acid mist removal additive features an optimized composition, avoiding the use of toxic vanadium species and reducing the use of nitrates, thereby mitigating potential harm to workers and the environment. Furthermore, its use in catalytic cracking units does not adversely affect the main catalyst's heavy oil conversion capacity, or the yields and properties of various products, demonstrating excellent process compatibility. DETAILED DESCRIPTION

[0044] Main sources of substances:

[0045] Polyethylene glycol: Guangzhou Tongyang Chemical Co., Ltd., model: OEG6000.

[0046] Polypropylene glycol: Tianjin Zhonghe Shengtai Chemical Co., Ltd., product number: DL-2000D.

[0047] Polyethylene glycol ether: Wuhan Lanabai Pharmaceutical Chemical Co., Ltd., product number: 19052713.

[0048] Sodium silicate: CAS number: 1344-09-8.

[0049] Silica sol: Shandong Xinrongxin Chemical Technology Co., Ltd., product number: 20231011001.

[0050] Sodium aluminosilicate: CAS number: 1344-00-9.

[0051] Example 1

[0052] A method for preparing a denitrification combustion-supporting and acid mist removal additive is as follows:

[0053] Step 1: 150 g of ferric chloride, 100 g of magnesium chloride, 90 g of aluminum chloride and 2 kg of water were mixed, and 500 g of 1 mol / L sodium hydroxide aqueous solution was added to prepare a crosslinker solution;

[0054] Step 2: mixing the modified magnesium saponite with the crosslinker solution prepared in step 1 in a mass ratio of 1:3, maintaining the mixture at 50° C. for 20 hours, and then maintaining the mixture at 100° C. for 20 hours to obtain crosslinked magnesium saponite;

[0055] Step 3, impregnating the cross-linked magnesium saponite in a metal salt solution, the mass ratio of the cross-linked magnesium saponite to the metal salt solution is 1:10, and the metal salt solution contains 0.02 mol / L silver chloride, 0.01 mol / L chloroplatinic acid, 0.01 mol / L palladium chloride, 0.03 mol / L cobalt chloride, 0.05 mol / L nickel chloride, 0.04 mol / L bismuth acetate, 0.06 mol / L zinc chloride, 0.08 mol / L titanium tetrachloride, 0.03 mol / L zirconium chloride, and 0.02 mol / L sodium tungstate to obtain the impregnated magnesium saponite;

[0056] Step 4: calcining the impregnated magnesium soapstone at 600° C. for 5 hours to obtain a denitrification, combustion-supporting, and acid mist removal additive.

[0057] The preparation method of the modified magnesium soapstone is as follows:

[0058] S1. Dissolve sodium hydroxide and sodium bicarbonate in water to prepare lye; the mass ratio of sodium hydroxide, sodium bicarbonate, and water is 1:1.5:15;

[0059] S2. Dissolve magnesium chloride and aluminum chloride in water to prepare a magnesium-aluminum aqueous solution, wherein the mass ratio of magnesium chloride to aluminum chloride to water is 1:20:400;

[0060] S3, dissolving the polyethylene glycol ether in water to prepare an aqueous solution containing the polyethylene glycol ether, wherein the mass ratio of the polyethylene glycol ether to water is 1:5;

[0061] S4. Under a constant temperature of 85° C. and stirring conditions, 100 g of sodium aluminosilicate was first added to 600 g of alkali solution to obtain a silicon-containing liquid, and then 200 g of a magnesium-aluminum aqueous solution and 200 g of a polyethylene glycol ether aqueous solution were dropwise added to the silicon-containing liquid. After the dropwise addition, stirring was continued for 3 hours to obtain a reaction solution;

[0062] S5. The reaction solution was added to a crystallization kettle and sealed. The mixture was crystallized at a constant temperature of 160° C. for 15 hours. After the crystallization was completed, the mixture was cooled to room temperature, and then centrifuged, washed with water, vacuum-dried at 40° C. for 10 hours, crushed, and passed through a 100-mesh sieve to obtain modified magnesium soapstone.

[0063] Example 2

[0064] The preparation method of a denitrification combustion-supporting and acid mist removal auxiliary agent is basically the same as that of Example 1, the only difference being that the preparation method of the modified magnesium saponite is different.

[0065] The preparation method of the modified magnesium soapstone is as follows:

[0066] S1. Dissolve sodium hydroxide and sodium bicarbonate in water to prepare lye; the mass ratio of sodium hydroxide, sodium bicarbonate, and water is 1:1.5:15;

[0067] S2. Dissolve magnesium chloride and aluminum chloride in water to prepare a magnesium-aluminum aqueous solution, wherein the mass ratio of magnesium chloride to aluminum chloride to water is 1:20:400;

[0068] S3, dissolving polypropylene glycol in water to prepare a polypropylene glycol aqueous solution, wherein the mass ratio of polypropylene glycol to water is 1:5;

[0069] S4. Under a constant temperature of 85° C. and stirring conditions, first add 100 g of sodium aluminosilicate to 600 g of alkali solution to obtain a silicon-containing liquid, then dropwise add 200 g of magnesium aluminum aqueous solution and 200 g of polypropylene glycol aqueous solution to the silicon-containing liquid, and continue stirring for 3 hours after the dropwise addition to obtain a reaction solution;

[0070] S5. The reaction solution was added to a crystallization kettle and sealed. The mixture was crystallized at a constant temperature of 160° C. for 15 hours. After the crystallization was completed, the mixture was cooled to room temperature, and then centrifuged, washed with water, vacuum-dried at 40° C. for 10 hours, crushed, and passed through a 100-mesh sieve to obtain modified magnesium soapstone.

[0071] Example 3

[0072] The preparation method of a denitrification combustion-supporting and acid mist removal auxiliary agent is basically the same as that of Example 1, the only difference being that the preparation method of the modified magnesium saponite is different.

[0073] The preparation method of the modified magnesium soapstone is as follows:

[0074] S1. Dissolve sodium hydroxide and sodium bicarbonate in water to prepare lye; the mass ratio of sodium hydroxide, sodium bicarbonate, and water is 1:1.5:15;

[0075] S2. Dissolve magnesium chloride and aluminum chloride in water to prepare a magnesium-aluminum aqueous solution, wherein the mass ratio of magnesium chloride to aluminum chloride to water is 1:20:400;

[0076] S3, dissolving polyethylene glycol in water to prepare an aqueous solution containing polyethylene glycol, wherein the mass ratio of polyethylene glycol to water is 1:5;

[0077] S4. Under a constant temperature of 85° C. and stirring conditions, 100 g of sodium aluminosilicate was first added to 600 g of alkali solution to obtain a silicon-containing liquid, and then 200 g of magnesium aluminum aqueous solution and 200 g of polyethylene glycol aqueous solution were dropwise added to the silicon-containing liquid. After the dropwise addition, stirring was continued for 3 hours to obtain a reaction solution;

[0078] S5. The reaction solution was added to a crystallization kettle and sealed. The mixture was crystallized at a constant temperature of 160° C. for 15 hours. After the crystallization was completed, the mixture was cooled to room temperature, and then centrifuged, washed with water, vacuum-dried at 40° C. for 10 hours, crushed, and passed through a 100-mesh sieve to obtain modified magnesium soapstone.

[0079] Example 4

[0080] The preparation method of a denitrification combustion-supporting and acid mist removal auxiliary agent is basically the same as that of Example 1, the only difference being that the preparation method of the modified magnesium saponite is different.

[0081] The preparation method of the modified magnesium soapstone is as follows:

[0082] S1. Dissolve sodium hydroxide and sodium bicarbonate in water to prepare lye; the mass ratio of sodium hydroxide, sodium bicarbonate, and water is 1:1.5:15;

[0083] S2. Dissolve magnesium chloride and aluminum chloride in water to prepare a magnesium-aluminum aqueous solution, wherein the mass ratio of magnesium chloride to aluminum chloride to water is 1:20:400;

[0084] S3, dissolving the polyethylene glycol ether in water to prepare an aqueous solution containing the polyethylene glycol ether, wherein the mass ratio of the polyethylene glycol ether to water is 1:5;

[0085] S4. Under a constant temperature of 85° C. and stirring conditions, 100 g of silica sol was first added to 600 g of alkaline solution to obtain a silicon-containing liquid, and then 200 g of magnesium aluminum aqueous solution and 200 g of polyethylene glycol ether aqueous solution were dropwise added to the silicon-containing liquid. After the dropwise addition, stirring was continued for 3 hours to obtain a reaction solution;

[0086] S5. The reaction solution was added to a crystallization kettle and sealed. The mixture was crystallized at a constant temperature of 160° C. for 15 hours. After the crystallization was completed, the mixture was cooled to room temperature, and then centrifuged, washed with water, vacuum-dried at 40° C. for 10 hours, crushed, and passed through a 100-mesh sieve to obtain modified magnesium soapstone.

[0087] Example 5

[0088] The preparation method of a denitrification combustion-supporting and acid mist removal auxiliary agent is basically the same as that of Example 1, the only difference being that the preparation method of the modified magnesium saponite is different.

[0089] The preparation method of the modified magnesium soapstone is as follows:

[0090] S1. Dissolve sodium hydroxide and sodium bicarbonate in water to prepare lye; the mass ratio of sodium hydroxide, sodium bicarbonate, and water is 1:1.5:15;

[0091] S2. Dissolve magnesium chloride and aluminum chloride in water to prepare a magnesium-aluminum aqueous solution, wherein the mass ratio of magnesium chloride to aluminum chloride to water is 1:20:400;

[0092] S3, dissolving the polyethylene glycol ether in water to prepare an aqueous solution containing the polyethylene glycol ether, wherein the mass ratio of the polyethylene glycol ether to water is 1:5;

[0093] S4. Under a constant temperature of 85° C. and stirring conditions, 100 g of sodium silicate was first added to 600 g of alkali solution to obtain a silicon-containing liquid, and then 200 g of magnesium aluminum aqueous solution and 200 g of polyethylene glycol ether aqueous solution were dropwise added to the silicon-containing liquid. After the dropwise addition, stirring was continued for 3 hours to obtain a reaction solution;

[0094] S5. The reaction solution was added to a crystallization kettle and sealed. The mixture was crystallized at a constant temperature of 160° C. for 15 hours. After the crystallization was completed, the mixture was cooled to room temperature, and then centrifuged, washed with water, vacuum-dried at 40° C. for 10 hours, crushed, and passed through a 100-mesh sieve to obtain modified magnesium soapstone.

[0095] Comparative Example 1

[0096] A method for preparing a denitrification combustion-supporting and acid mist removal additive is as follows:

[0097] Step 1: 150 g of ferric chloride, 100 g of magnesium chloride, 90 g of aluminum chloride and 2 kg of water were mixed, and 500 g of 1 mol / L sodium hydroxide aqueous solution was added to prepare a crosslinker solution;

[0098] Step 2, adding a crosslinker solution to a metal salt solution, wherein the mass ratio of the crosslinker solution to the metal salt solution is 1:10, and the metal salt solution contains 0.02 mol / L silver chloride, 0.01 mol / L chloroplatinic acid, 0.01 mol / L palladium chloride, 0.03 mol / L cobalt chloride, 0.05 mol / L nickel chloride, 0.04 mol / L bismuth acetate, 0.06 mol / L zinc chloride, 0.08 mol / L titanium tetrachloride, 0.03 mol / L zirconium chloride, and 0.02 mol / L sodium tungstate, to obtain an impregnated composite;

[0099] Step 3: calcining the impregnated composite at 600° C. for 5 hours to obtain a denitrification, combustion-supporting, and acid mist removal additive.

[0100] Test Example 1

[0101] Desulfurization rate test

[0102] Desulfurization rate is a key indicator to measure the performance of denitrification, combustion and acid mist removal additives. It directly reflects the ability of the additive to capture and convert sulfur oxides (SO X ) ability. SO X , including SO2 and SO3, are acidic substances that react with water vapor in the atmosphere to form acid rain, posing a threat to the environment and human health. Therefore, the desulfurization rate directly determines the deacidification efficiency, that is, the ability to reduce the emission of these acidic substances. A high desulfurization rate means that the additive can effectively remove more SO from the flue gas. X , thereby reducing the emission of acidic substances and alleviating acid pollution to the environment. In short, the improvement of desulfurization rate directly enhances the deacidification effect and is an important means to achieve clean industrial processes and environmental protection.

[0103] The working principle is as follows: Sulfur transfer agent is added to the catalytic cracking unit in the form of an auxiliary agent to achieve SO X The absorption-release process. Reactions occur in the regenerator as shown in (1) to (3):

[0104] S (in coke) + O2 → SO2 (90%) + SO3 (10%) (1)

[0105] 2SO2+O2→2SO3 (2)

[0106] MO+SO3→MSO4 (M represents the metal oxide in the sulfur transfer agent) (3)

[0107] The sulfur transfer agent enters the reactor together with the regenerated catalyst. Under the action of low-carbon hydrocarbons, hydrogen and stripping water vapor, the metal sulfate is reduced to release H2S, completing the "transfer" process of "sulfur" from the regenerator flue gas to the reactor dry gas. At the same time, the sulfur transfer agent is regenerated and the next cycle begins, as shown in (4) to (6) below:

[0108] MSO4+4H2(or hydrocarbons)→MS+4H2O (4)

[0109] MSO4+4H2(or hydrocarbons)→MO+H2S+3H2O (5)

[0110] MS+H2O→MO+H2S (stripping section) (6)

[0111] The released H2S is separated from the dry gas and processed by the downstream sulfur recovery unit and recovered in the form of sulfur, thereby reducing SO X pollution and turn waste into treasure.

[0112] Select the XTL-5 type riser circulating fluidized bed FCC experimental device and ensure that it is clean and intact. Ensure that all analytical instruments used are calibrated and ready, including the SO3 analyzer. Fushun atmospheric residue oil (sulfur content of 0.2%) and Golmud catalytic material (sulfur content of 0.5%) were used as reaction raw materials, and the SO2 concentrations in their blank flue gases were 110ppm and 133ppm, respectively. Add 2% of denitrification, combustion-supporting and acid mist removal additives, and operate continuously for 216 hours under the oxygen-poor two-stage regeneration conditions with an oxygen content of only 0.2% in one stage. Record the desulfurization rate and calculate the average value.

[0113] The test results are shown in Table 1.

[0114] Table 1

[0115] Experimental plan Desulfurization rate (%) Example 1 94.3 Example 2 91.5 Example 3 89.7 Example 4 90.5 Example 5 91.2 Comparative Example 1 72.3

[0116] Test Example 2

[0117] Combustion performance test

[0118] There's a direct relationship between CO removal efficiency and combustion-supporting performance. In the FCC process, combustion-supporting performance generally refers to the ability of a catalyst to promote the further oxidation of CO (carbon monoxide) to CO2 (carbon dioxide). This ability is crucial for ensuring the complete combustion of CO in flue gas, reducing pollutant emissions, and improving energy efficiency. A high CO removal efficiency generally indicates that the catalyst has good combustion-supporting performance, effectively promoting the CO oxidation reaction and accelerating the removal of CO from flue gas.

[0119] Evaluate the removal efficiency of CO in flue gas by denitrification, combustion-supporting and acid mist removal additives under simulated FCC regeneration conditions, that is, the combustion-supporting performance.

[0120] The test equipment consisted of a micro quartz reactor (Φ8 × 1 mm quartz tube) and a KM9106 flue gas analyzer (for CO analysis). The test conditions were: temperature: 680°C, gas flow rate: 100 mL / min, and reaction time: 8 hours.

[0121] Weigh 1.0g of a quartz sand mixed sample containing 3.0% denitrification, combustion-supporting, and acid mist removal additives. Place the sample into a micro quartz reactor. Heat the reactor to 680°C under a nitrogen flow. Stop the nitrogen flow and introduce a mixed gas prepared in proportion. The mixed gas contains SO2 (1000mg / m 3 ), NH3(800mg / m 3 )、CO(7%v / v)、HCN(130mg / m 3 ), O2 (0.5% v / v) and N2 (the rest of the volume). After 8 hours of reaction, the CO was detected online using the above instrument. The CO removal rate was calculated as:

[0122] X=(C1-C2) / C1×100%

[0123] Where: X is the CO removal rate of the composition (%); C1 is the CO content in the gas after the reaction (v%); C2 is the CO content in the mixed gas before the reaction (v%). The test results are shown in Table 2.

[0124] Table 2

[0125] Experimental plan CO removal rate (%) Example 1 98.4 Example 2 93.7 Example 3 92.8 Example 4 95.2 Example 5 96.5 Comparative Example 1 85.7

[0126] It can be seen from Test Examples 1 and 2 that the denitrification, combustion-supporting, and acid mist removal additive obtained in Example 1 of the present invention has a good desulfurization rate and combustion-supporting performance.

[0127] In Example 1 of the present invention, the use of polyethylene glycol ether as a modifier shows better desulfurization rate and combustion-supporting performance than the polypropylene glycol in Example 2 and the polyethylene glycol in Example 3. The reason may be related to the molecular structure and properties of polyethylene glycol ether. Polyethylene glycol ether has more ether bonds (-O-), which may enhance its interaction with the magnesium soapstone layer, thereby more effectively improving the pore structure and specific surface area of ​​the material during the preparation of the modified magnesium soapstone, and increasing the number and accessibility of active sites. This structural advantage helps to improve the sulfur transfer agent in the FCC reaction-regeneration system for SO X absorption-release efficiency, thereby improving the desulfurization rate. At the same time, polyethylene glycol ether-modified magnesium soapstone may have better thermal stability and stronger metal ion coordination ability, which helps to form more stable metal oxide active components during the roasting process, thereby improving the combustion-supporting performance. In the combustion-supporting process, these active components can more effectively catalyze the oxidation of CO, promote its conversion into CO2, and achieve efficient removal of CO in flue gas. In addition, the hydrophilicity and spatial stereostructure of polyethylene glycol ether may help to improve the dispersibility of magnesium soapstone, reduce agglomeration, and maintain the activity and selectivity of the catalyst, which may also be one of the reasons why the auxiliary agent in Example 1 has better performance. Therefore, polyethylene glycol ether, as an effective modifier, has a positive effect on the structure and performance of magnesium soapstone through its unique physical and chemical properties, thereby improving the overall performance of the denitrification combustion-supporting and acid mist removal auxiliary agent.

[0128] The use of sodium aluminosilicate as a silicon source in Example 1 demonstrated superior desulfurization efficiency and combustion-supporting performance compared to the use of silica sol in Example 4 and sodium silicate in Example 5. This is likely due to the unique chemical and physical properties of sodium aluminosilicate. Sodium aluminosilicate is a highly active silicon source, effectively forming a stable framework with elements such as magnesium and aluminum during the preparation of the modified magnesium saponite, thereby enhancing the material's thermal stability and mechanical strength.

[0129] During the crystallization step, sodium aluminosilicate may promote the formation of a more uniform microporous structure with a larger specific surface area, which helps improve the dispersion and accessibility of active sites in the catalyst promoter, thereby improving the absorption capacity of sulfur oxides and the oxidation efficiency of carbon monoxide. In addition, the addition of sodium aluminosilicate may also help improve the chemical composition and pore properties of magnesium saponite, providing more active sites for the impregnation of metal salts, thereby improving the denitrification and combustion performance of the promoter. In the actual FCC process, this structural and compositional advantage helps the catalyst promoter more effectively capture and convert SO X and CO, achieving lower pollutant emissions and higher combustion efficiency. Therefore, sodium aluminosilicate plays a key role as a silicon source in the preparation of modified magnesium soapstone, providing an important material basis for the preparation of efficient denitrification, combustion-supporting and acid mist removal additives.

Claims

1. A method for preparing a denitrification combustion-supporting and acid mist removal additive, characterized in that: Here’s how: Step 1, mixing ferric chloride, magnesium chloride, aluminum chloride and water, and adding sodium hydroxide aqueous solution to prepare a crosslinking agent solution; Step 2, mixing the modified magnesium soapstone with the crosslinking agent solution prepared in step 1, heating and heat preservation treatment, to obtain crosslinked magnesium soapstone; Step 3, immersing the cross-linked magnesium saponite in a metal salt solution to obtain the impregnated magnesium saponite; Step 4: calcine the impregnated magnesium soapstone to obtain a denitrification, combustion-supporting, and acid mist removal aid.

2. The method for preparing the denitration combustion-supporting and acid mist removal additive according to claim 1, characterized in that: The weight proportions of the substances in step 1 are: 120-180 parts of ferric chloride, 80-120 parts of magnesium chloride, 80-100 parts of aluminum chloride, 1800-2200 parts of water, and 400-600 parts of 0.5-2 mol / L sodium hydroxide aqueous solution.

3. The method for preparing the denitration combustion-supporting and acid mist removal auxiliary agent according to claim 1, characterized in that: The mass ratio of the modified magnesium soapstone to the cross-linking agent solution prepared in step 1 is 1:2-4.

4. The method for preparing the denitration combustion-supporting and acid mist removal additive according to claim 1, characterized in that: The mass ratio of the cross-linked magnesium soapstone to the metal salt solution is 1:8-12.

5. The method for preparing the denitration combustion-supporting and acid mist removal auxiliary agent according to claim 1, characterized in that: The temperature-raising and heat-insulating treatment is to maintain the temperature at 40-60° C. for 10-30 hours, and then maintain the temperature at 80-110° C. for 10-30 hours.

6. The method for preparing the denitration combustion-supporting and acid mist removal additive according to claim 1, characterized in that: The metal salt solution contains 0.01-0.03 mol / L silver chloride, 0.005-0.02 mol / L chloroplatinic acid, 0.005-0.02 mol / L palladium chloride, 0.02-0.04 mol / L cobalt chloride, 0.04-0.06 mol / L nickel chloride, 0.03-0.05 mol / L bismuth acetate, 0.05-0.07 mol / L zinc chloride, 0.07-0.09 mol / L titanium tetrachloride, 0.02-0.04 mol / L zirconium chloride, and 0.01-0.03 mol / L sodium tungstate.

7. The method for preparing the denitration combustion-supporting and acid mist removal additive according to claim 1, characterized in that: The calcination temperature is 400-800° C., and the calcination time is 3-8 hours.

8. The method for preparing the denitration combustion-supporting and acid mist removal additive according to claim 1, characterized in that: The preparation method of the modified magnesium soapstone is as follows, in parts by weight: S1. Dissolve sodium hydroxide and sodium bicarbonate in water to prepare alkaline solution; the mass ratio of sodium hydroxide, sodium bicarbonate and water is 0.5-2:1-2:12-18; S2, dissolving magnesium chloride and aluminum chloride in water to prepare a magnesium-aluminum aqueous solution, wherein the mass ratio of magnesium chloride to aluminum chloride to water is 0.5-2:15-25:300-500; S3, dissolving the polyethylene glycol ether in water to prepare an aqueous solution containing the polyethylene glycol ether, wherein the mass ratio of the polyethylene glycol ether to water is 0.5-2:4-6; S4, under a constant temperature of 80-90° C. and stirring conditions, first add 80-120 parts of sodium aluminosilicate to 500-700 parts of alkali solution to obtain a silicon-containing liquid, and then dropwise add 150-250 parts of a magnesium aluminum aqueous solution and 150-250 parts of a polyethylene glycol ether aqueous solution to the silicon-containing liquid, and continue stirring for 2-4 hours after the dropwise addition to obtain a reaction liquid; S5. Add the reaction solution into a crystallization kettle and seal it. Crystallize it at a constant temperature of 150-180° C. for 10-20 hours. After the crystallization is completed, cool it to room temperature, then centrifuge, wash it with water, vacuum dry it at 30-50° C. for 5-15 hours, crush it, and pass it through a 50-200 mesh sieve to obtain modified magnesium soapstone.

9. A denitrification combustion-supporting and acid mist removal additive, characterized in that: The method is prepared according to any one of claims 1 to 8.