Aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid and preparation method thereof

Abstract

The invention discloses an aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion auxiliary agent and a preparation method thereof, and the preparation method comprises the following steps: preparing an aza-tetrafluorene ring by using xylene, 2, 7-diaminofluorene, sodium bicarbonate and dibromoethane, preparing aza-tetrafluorene cyclotetracarboxylic acid by using the aza-tetrafluorene ring, dimethyl sulfoxide, sodium methoxide, allyl chloride drops and other raw materials, and preparing the aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion auxiliary agent by using the aza-tetrafluorene cyclotetracarboxylic acid. And preparing the aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion auxiliary agent by using aza-tetrafluorene cyclotetracarboxylic acid, ferrocene, rare earth chloride and an organic solvent. The aza-tetrafluorene cyclotetracarboxylic acid rare earth gas combustion aid prepared by the method is sprayed into a boiler combustion area in an atomization manner to promote combustion, so that the gas combustion efficiency is increased by 10-16%, and meanwhile, the aza-tetrafluorene cyclotetracarboxylic acid rare earth gas combustion aid has the advantages of low equipment investment, convenience in operation and the like.

Description

Technical Field

[0001] The invention relates to an aza-tetrafluorene-cyclotetracarboxylic acid rare earth fuel gas combustion aid and a preparation method thereof, belonging to the field of fuel gas catalysts. Background Art

[0002] A gas boiler is a boiler equipment that uses gas as energy, usually composed of a burner, a furnace, a heat exchanger, a control system, etc. It has the advantages of high efficiency, environmental protection, safety, and reliability, and is widely used in industrial, commercial, and civil fields. The principle of a gas boiler is to use the high-temperature flue gas generated by gas combustion to transfer heat to water or other media through a heat exchanger to heat it to the required temperature. This type of boiler equipment includes gas-fired water boilers, gas-fired hot water boilers, gas-fired steam boilers, etc., among which gas-fired hot water boilers are also called gas-fired heating boilers or gas-fired bathing boilers. The combustion efficiency of a gas boiler is usually between 90% and 99%. After adopting full premixing and FGR flue gas recirculation technology, the thermal efficiency can reach about 100% to 108%. However, the use of full premixing, FGR flue gas recirculation and other combustion technologies on old boilers requires a high equipment modification cost. The reasons for the low combustion efficiency of gas boilers may include poor fuel quality, burner adjustment, ash accumulation or scaling inside the boiler, insufficient or uneven air supply system, poor gas quality, unreasonable boiler design, improper operation management and system maintenance, etc. The purity, calorific value and other quality factors of gas have an important impact on the combustion effect and thermal efficiency of gas boilers. If the gas quality is poor, it will lead to incomplete combustion. The impurities in the gas used by gas boilers mainly include tar, dust, moisture, etc. The accumulation of tar will not only affect the normal combustion of gas, but also cause incomplete combustion and carbon deposits, which will affect the thermal efficiency of the boiler. The raw gas produced in the pyrolysis and gasification process of biomass boilers contains tar vapor impurities. The catalytic combustion of tar through a catalyst can improve the combustion effect and thermal efficiency and reduce carbon deposits.

[0003] At present, the research on improving the combustion efficiency of gas by assisting with catalytic additives has received extensive attention. There are now reports on multiple combustion-supporting patent technologies. For example, the patent with publication number CN102690696B discloses a method for preparing a nano rare earth combustion-supporting agent for dimethyl ether gas, and uses a hydrothermal method to prepare cerium chloride-modified neodymium lanthanum oxide nanoparticles as a combustion-supporting agent for dimethyl ether gas. Although the combustion-supporting agent prepared by this method can improve the combustion efficiency of gas, the prepared combustion-supporting agent is only for dimethyl ether gas and cannot be used for natural gas. The patent with publication number CN106147907B discloses a liquefied natural gas combustion-supporting agent, and tung oil, ethanol, n-butanol, cyclopentanol, ethylene glycol monobutyl ether, methyl ethyl ketone, borane tetrahydrofuran, etc. are prepared into a liquefied natural gas combustion-supporting agent. Although the combustion-supporting agent can improve the calorific value of gas, the composition of the combustion-supporting agent is complex and the preparation cost is high. Patent CN103160348B discloses a rare earth catalytic enhancer for light alkane fuel gas and its preparation method. The enhancer formula is composed of the following raw materials by weight: 3-6 parts of cerium iodide, 0.3-0.6 parts of ferrocene, 30-50 parts of ethanol, 10-20 parts of acetone, and 15-25 parts of petroleum ether; the enhancer is prepared by the steps of preparing additives, mixing and filtering raw materials. Cerium iodide belongs to oxidizing solid category 2, which decomposes at high temperature and releases highly toxic nitrogen oxide gas. Ethanol and acetone are easily precursor chemicals, and their production and transportation are strictly controlled. Summary of the invention

[0004] In view of the above-mentioned problems, the purpose of the present invention is to provide an azotetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid and a preparation method thereof, so as to solve the problems of the prior art that the combustion aid composition is complex, raw materials that are easily toxic are used, and the catalytic efficiency is still low for fuel gases such as natural gas.

[0005] In view of the above purpose, the present invention first provides an aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid, which has the following structure:

[0006]

[0007] In formula (I), R is a rare earth ion, including any one of lanthanum (La), cerium (Cs), and europium (Eu).

[0008] The present invention also provides a method for preparing an aza-tetrafluorene-cyclotetracarboxylic acid rare earth fuel gas combustion aid, comprising the following steps:

[0009] (1) Under nitrogen protection, 2,7-diaminofluorene and sodium bicarbonate are added to xylene, cooled to 4-10° C., dibromoethane is added dropwise, and then stirred at 30-90° C. for 2-8 hours. After the reaction is completed, the reaction mixture is poured into 10-15 times the volume of ice water and stirred for 5-10 minutes, filtered, and the precipitate is washed with water 3 times to obtain aza-tetrafluorene ring;

[0010] (2) Under nitrogen protection, aza-tetrafluorene ring is added to dimethyl sulfoxide, and then sodium methoxide is added. After the reaction, allyl chloride is added dropwise to the reaction mixture, and the reaction is continued to be stirred. After the reaction is completed, distilled water is added to the reaction mixture, filtered, and the precipitate is transferred to dichloromethane, and sodium periodate, potassium perchromate and water are added. After the reaction is completed, the reaction product is washed twice with a saturated sodium chloride aqueous solution, and the organic layer is dried with anhydrous Na2SO4 for 0.5 to 1.5 hours, filtered, and the solvent is removed on a vacuum rotary evaporator to obtain aza-tetrafluorene ring tetracarboxylic acid;

[0011] (3) Adding the aza-tetrafluorene cyclotetracarboxylic acid prepared in step (2) to an organic solvent to prepare an aza-tetrafluorene cyclotetracarboxylic acid solution, then adding an aqueous solution of a rare earth chloride, mixing and shaking for 5 to 30 minutes, standing and stratifying, collecting the organic phase, drying it with anhydrous calcium chloride for 0.5 to 1.5 hours, and then adding ferrocene to obtain an aza-tetrafluorene cyclotetracarboxylic acid rare earth gas combustion aid.

[0012] In one embodiment of the present invention, in step (1), the mass volume ratio of the 2,7-diaminofluorene to xylene is (0.5-5) g:(30-100) mL, the mass volume ratio of the sodium bicarbonate to xylene is (0.1-0.4) g:(15-50) mL, and the volume ratio of the dibromoethane to xylene is (2-25):(30-100).

[0013] In one embodiment of the present invention, in step (1), the yield of the azatetrafluorene ring is 82-97.2%.

[0014] In one embodiment of the present invention, in step (2), the mass volume ratio of the azatetrafluorene ring to dimethyl sulfoxide is (1.5-3) g: (30-100) mL, and the mass volume ratio of the sodium methoxide to dimethyl sulfoxide is (1-3) g: (15-50) mL.

[0015] In one embodiment of the present invention, in step (2), after sodium methoxide is added, the reaction is stirred at 25 to 40° C. for 30 to 120 minutes.

[0016] In one embodiment of the present invention, in step (2), the volume ratio of the added amount of allyl chloride to dimethyl sulfoxide is (0.02-0.15):(30-100), and after adding allyl chloride, the reaction is continued for 3-6 hours.

[0017] In one embodiment of the present invention, in step (2), the volume ratio of the amount of dichloromethane added to dimethyl sulfoxide is 1:1, the mass volume ratio of the potassium periodate to dichloromethane is (1-3) g: (30-100) mL, the mass volume ratio of the potassium perchromate to dichloromethane is (0.5-4) g: (30-100) mL, the volume ratio of the amount of water added to dichloromethane is (1-2): (30-100), and after adding sodium periodate, sodium perchromate and water, the reaction is carried out at 25-35° C. for 16-18 hours.

[0018] In one embodiment of the present invention, in step (2), the yield of the aza-tetrafluorene cyclotetracarboxylic acid is 75-85%.

[0019] In one embodiment of the present invention, in step (3), the organic solvent comprises at least one of dibutyl ether, ethyl acetate, ethylene glycol dibutyl ether, and propyl acetate, preferably dibutyl ether.

[0020] In one embodiment of the present invention, in step (3), the mass concentration of the aza-tetrafluorene cyclotetracarboxylic acid solution is 45-55%.

[0021] In one embodiment of the present invention, in step (3), the rare earth chloride includes any one of lanthanum chloride, cerium chloride, and europium chloride, the mass concentration of the rare earth chloride in the aqueous solution of the rare earth chloride is 15-25%, and the volume ratio of the rare earth chloride aqueous solution to the organic solvent is 1:1.

[0022] In one embodiment of the present invention, in step (3), after ferrocene is added, the mass concentration of ferrocene is 5-10%.

[0023] The invention also discloses an application of the aza-tetrafluorene-cyclotetracarboxylic acid rare earth fuel gas combustion aid in catalytic combustion.

[0024] In one embodiment of the present invention, the application includes spraying the above-mentioned aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid through a sprayer to form atomization in the combustion area of ​​the boiler.

[0025] In one embodiment of the present invention, the injection amount is 0.1-0.5 liter of aza-tetrafluorene-cyclotetracarboxylic acid rare earth fuel gas combustion aid per cubic meter of fuel gas.

[0026] Beneficial effects of the present invention:

[0027] (1) The present invention prepares azatetrafluorene ring and azatetrafluorene cyclotetracarboxylic acid first, and then uses azatetrafluorene cyclotetracarboxylic acid, ferrocene, rare earth chlorides and organic solvents such as dibutyl ether to prepare azatetrafluorene cyclotetracarboxylic acid rare earth gas combustion aid. In the preparation process of the combustion aid, rare earth chlorides such as lanthanum chloride (La), cerium chloride (Cs), europium chloride (Eu) and organic solvents such as dibutyl ether are used. These raw materials are not easily precursor chemicals and do not have the characteristics of being flammable and explosive. Since there is no nitro group in the rare earth chloride, it will not produce highly toxic nitrogen oxide gas after high-temperature decomposition.

[0028] (2) The present invention prepares the aza-tetrafluorene cyclotetracarboxylic acid rare earth combustion aid by reacting aza-tetrafluorene cyclotetracarboxylic acid, ferrocene, rare earth chloride and organic solvents such as dibutyl ether. The final prepared material has a single component, and the raw materials used in the preparation process are all conventional raw materials, so the preparation cost is not high.

[0029] (3) The preparation method of the present invention is simple. The prepared aza-tetrafluorene cyclotetracarboxylic acid itself has a certain combustion-supporting effect. On the other hand, the catalytic effect of the rare earth element can accelerate the decomposition of tar impurities in the fuel gas, increase the combustion speed of the fuel gas, reduce carbon deposition, and improve the combustion effect and thermal efficiency of the boiler.

[0030] (4) The aza-tetrafluorene-cyclotetracarboxylic acid rare earth combustion aid prepared by the method of the present invention can be used as a combustion aid for natural gas. When promoting the combustion of natural gas, the combustion efficiency of the gas can be increased by 10-16%.

[0031] (5) The rare earth gas combustion catalyst of azotetrafluorene cyclotetracarboxylic acid can be sprayed into the combustion area of ​​the boiler in an atomized manner to promote combustion, with low equipment investment and easy operation. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The xylene used in the embodiments of the present invention and the comparative examples is derived from Shandong Qilin Chemical Co., Ltd., 2,7-diaminofluorene is derived from Hubei Baidu Chemical Co., Ltd., sodium bicarbonate is purchased from Shandong Haihua Supply Chain Co., Ltd., dibromoethane is provided by Jiangsu Bosite Chemical Technology Co., Ltd., dimethyl sulfoxide is derived from Changzhou Qidi Chemical Co., Ltd., sodium methoxide is derived from Shandong Yuanjin New Materials Co., Ltd., allyl chloride is derived from Shandong Polychemistry, dichloromethane is derived from Changzhou Qidi Chemical Co., Ltd., sodium periodate is purchased from New Kinetic Energy Chemical Co., Ltd., potassium perchromate is purchased from Wuhan Jiyesheng Chemical Co., Ltd., dibutyl ether is provided by Shandong Jinyueyuan New Materials Co., Ltd., and cerium chloride, lanthanum oxide, europium oxide and anhydrous calcium chloride are provided by Ganzhou Liantuo New Materials Co., Ltd.

[0034] Example 1

[0035] A method for preparing an aza-tetrafluorene-cyclotetracarboxylic acid rare earth fuel gas combustion aid comprises the following steps:

[0036] (1) Under nitrogen protection, 5 g of 2,7-diaminofluorene and 0.8 g of sodium bicarbonate were added to 100 mL of xylene. After cooling to 10° C., 25 mL of dibromoethane was added dropwise within half an hour. The mixture was stirred at 90° C. for 8 h. After the reaction was completed, the reaction mixture was poured into 15 times the volume of ice water and stirred for 10 minutes. The mixture was filtered and the precipitate was washed with water for 3 times to obtain aza-tetrafluorene ring with a yield of 97.2%.

[0037] (2) Under nitrogen protection, add 3 g of aza-tetrafluorene ring to 100 mL of dimethyl sulfoxide, then add 6 g of sodium methoxide, and then stir at 40 ° C for 120 min. Then, add 0.15 mL of allyl chloride dropwise to the reaction mixture, and continue to stir and react for 6 h. After the reaction is completed, add 20 times the volume of distilled water to the reaction mixture, filter, transfer the precipitate to 100 mL of dichloromethane, add 3 g of sodium periodate, 4 g of potassium perchromate and 2 mL of water. Stir the reaction at 35 ° C for 18 h. After the reaction is completed, wash the reaction mixture twice with 100 mL of saturated sodium chloride (Shandong Ocean Star Chemical Technology Co., Ltd.) aqueous solution, dry the organic layer with 4 g of anhydrous Na2SO4 (Weifang Dakang Chemical Co., Ltd.) for 1.5 h, filter and remove the solvent on a vacuum rotary evaporator to obtain aza-tetrafluorene ring tetracarboxylic acid with a yield of 85%;

[0038] (3) Aza-tetrafluorene cyclotetracarboxylic acid was added to 100 mL of dibutyl ether to prepare a dibutyl ether solution of aza-tetrafluorene cyclotetracarboxylic acid with a mass concentration of 50% (w / v), and then 100 mL of a 20% (w / v) aqueous solution of cerium chloride was added. The mixture was mixed and shaken for 30 minutes, and the mixture was allowed to stand for stratification. The organic phase was collected and dried with 10 g of anhydrous calcium chloride for 1.5 hours. Then, ferrocene was added to make the mass concentration of ferrocene 10%, thereby obtaining an aza-tetrafluorene cyclotetracarboxylic acid rare earth gas combustion catalyst.

[0039] Application of aza-tetrafluorene-cyclotetracarboxylic acid rare earth gas combustion aid in catalytic combustion.

[0040] The application site is a vertical fully automatic oil (gas) steam boiler owned by Changzhou Zhongna Chemical Co., Ltd., model: LHS0.3-0.4 (0.7) -Y (Q), rated evaporation capacity: 0.3t / h, rated steam pressure: 0.7Mpa, heating area: 7.32m 2 .

[0041] The aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid obtained in this example was sprayed through a sprayer (produced by Shandong Qingzhou Haili Machinery, Model FZ-6) and then atomized in the combustion area of ​​the boiler. The spraying amount was 0.5 L of aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid per cubic meter of fuel gas.

[0042] Calculated based on the average daily gas consumption, the gas combustion efficiency increased by 10% after the injection of the rare earth gas combustion additive aza-tetrafluorene cyclotetracarboxylate.

[0043] Example 2

[0044] A method for preparing an aza-tetrafluorene-cyclotetracarboxylic acid rare earth fuel gas combustion aid comprises the following steps:

[0045] (1) Under nitrogen protection, add 0.5 g of 2,7-diaminofluorene and 0.2 g of sodium bicarbonate to 30 mL of xylene, cool to 4°C, and drop 5 mL of dibromoethane within half an hour. Then stir and react at 30°C for 8 hours. After the reaction is completed, pour the reaction mixture into 10 times the volume of ice water and stir for 50 minutes, filter, and wash the precipitate with water 3 times to obtain aza-tetrafluorene ring with a yield of 82%;

[0046] (2) Under nitrogen protection, 1.5 g of aza-tetrafluorene ring was added to 30 mL of dimethyl sulfoxide, and then 2 g of sodium methoxide was added, and then stirred at 25°C for 30 minutes. Then, 0.02 mL of allyl chloride was added dropwise to the reaction mixture, and the reaction was continued to stir for 3 h. After the reaction was completed, 10 volumes of distilled water were added to the reaction mixture, filtered, and the precipitate was transferred to 30 mL of dichloromethane, and 1 g of sodium periodate, 0.5 g of potassium perchromate and 1 mL of water were added. The reaction was stirred at 25°C for 16 h. After the reaction was completed, the reaction mixture was washed twice with 50 mL of saturated sodium chloride aqueous solution, and the organic layer was dried with 2 g of anhydrous Na2SO4 for 0.5 h, filtered and the solvent was removed on a vacuum rotary evaporator to obtain aza-tetrafluorene ring tetracarboxylic acid with a yield of 75%.

[0047] (3) Aza-tetrafluorene cyclotetracarboxylic acid was added to 30 mL of dibutyl ether to prepare a dibutyl ether solution of aza-tetrafluorene cyclotetracarboxylic acid with a mass concentration of 45% (w / v), and then 30 mL of a 15% (w / v) aqueous solution of lanthanum chloride was added. The mixture was mixed and shaken for 5 minutes, and the mixture was allowed to stand for stratification. The organic phase was collected and dried with 3 g of anhydrous calcium chloride for 0.5 hour, and ferrocene was added to make the mass concentration of ferrocene 5%, thereby obtaining aza-tetrafluorene cyclotetracarboxylic acid rare earth gas combustion aid.

[0048] Application of aza-tetrafluorene-cyclotetracarboxylic acid rare earth gas combustion aid in catalytic combustion.

[0049] The application site is a YYL(W) oil (gas) organic carrier boiler produced by Suzhou Zhongyong Environmental Protection Technology Co., Ltd., model: YYL(W)-3500Y(Q), rated calorific value: 300kCal, rated steam pressure: 0.8Mpa, maximum operating temperature: 320℃.

[0050] The aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid obtained in this example was sprayed through a sprayer (produced by Shandong Qingzhou Haili Machinery, Model FZ-6) and then atomized in the combustion area of ​​the boiler. The spraying amount was 0.4 L of aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid per cubic meter of fuel gas.

[0051] Calculated based on the average daily gas consumption, the gas combustion efficiency increased by 16% after the injection of the rare earth gas combustion additive aza-tetrafluorene cyclotetracarboxylate.

[0052] Example 3

[0053] A method for preparing an aza-tetrafluorene-cyclotetracarboxylic acid rare earth fuel gas combustion aid comprises the following steps:

[0054] (1) Under nitrogen protection, add 3 g of 2,7-diaminofluorene and 0.5 g of sodium bicarbonate to 80 mL of xylene, cool to 8°C, and add 15 mL of dibromoethane dropwise within half an hour. Then stir and react at 60°C for 6 hours. After the reaction is completed, pour the reaction mixture into 12 times the volume of ice water and stir for 8 minutes, filter, and wash the precipitate with water 3 times to obtain aza-tetrafluorene ring with a yield of 86%;

[0055] (2) Under nitrogen protection, add 2 g of aza-tetrafluorene ring to 70 mL of dimethyl sulfoxide, then add 4 g of sodium methoxide, and then stir at 35°C for 90 minutes. Then, add 0.1 mL of allyl chloride dropwise to the reaction mixture, and continue stirring the reaction for 5 hours. After the reaction is completed, add 12 times the volume of distilled water to the reaction mixture, filter, transfer the precipitate to 80 mL of dichloromethane, add 2 g of sodium periodate, 3 g of potassium perchromate and 1 ml of water. Stir the reaction at 30°C for 18 hours. After the reaction is completed, wash the reaction mixture twice with 80 mL of saturated sodium chloride aqueous solution, dry the organic layer with 3 g of anhydrous Na2SO4 for 1 hour, filter and remove the solvent on a vacuum rotary evaporator to obtain aza-tetrafluorene ring tetracarboxylic acid with a yield of 80%;

[0056] (3) Aza-tetrafluorene cyclotetracarboxylic acid was added to 80 mL of dibutyl ether to prepare a dibutyl ether solution of aza-tetrafluorene cyclotetracarboxylic acid with a mass concentration of 55% (w / v), and then 60 mL of a 25% (w / v) aqueous solution of europium chloride was added. The mixture was mixed and shaken for 20 minutes, and the mixture was allowed to stand for stratification. The organic phase was collected and dried with 8 g of anhydrous calcium chloride for 1 hour, and then 8% (w / v) ferrocene was added to obtain aza-tetrafluorene cyclotetracarboxylic acid rare earth gas combustion aid.

[0057] Application of aza-tetrafluorene-cyclotetracarboxylic acid rare earth gas combustion aid in catalytic combustion.

[0058] The application site is a horizontal vacuum hot water boiler produced by Taian Weiye Electromechanical Technology Co., Ltd., model: ZKW2.1, rated calorific value: 2.1MW, rated steam pressure: 1.25Mpa.

[0059] The aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid obtained in this example was sprayed through a sprayer (produced by Shandong Qingzhou Haili Machinery, Model FZ-6) and then atomized in the combustion area of ​​the boiler. The spraying amount was 0.3 L of aza-tetrafluorene cyclotetracarboxylic acid rare earth fuel gas combustion aid per cubic meter of fuel gas.

[0060] Calculated based on the average daily gas consumption, the gas combustion efficiency increased by 14% after the injection of the rare earth gas combustion additive azotetrafluorene cyclotetracarboxylate.

[0061] Comparative Example 1

[0062] A method for preparing a combustion improver based on a dibutyl ether solution of aza-tetrafluorene cyclotetracarboxylic acid comprises the following steps:

[0063] (1) Under nitrogen protection, 5 g of 2,7-diaminofluorene and 0.8 g of sodium bicarbonate were added to 100 mL of xylene. After cooling to 10° C., 25 mL of dibromoethane was added dropwise within half an hour. The mixture was stirred at 90° C. for 8 h. After the reaction was completed, the reaction mixture was poured into 15 times the volume of ice water and stirred for 10 minutes. The mixture was filtered and the precipitate was washed with water for 3 times to obtain aza-tetrafluorene ring with a yield of 97.2%.

[0064] (2) Under nitrogen protection, add 3 g of aza-tetrafluorene ring to 100 mL of dimethyl sulfoxide, then add 6 g of sodium methoxide, and then stir at 40°C for 120 min. Then, add 0.15 mL of allyl chloride dropwise to the reaction mixture, and continue stirring the reaction for 6 h. After the reaction is completed, add 20 times the volume of distilled water to the reaction mixture, filter, transfer the precipitate to 100 mL of dichloromethane, add 3 g of sodium periodate, 4 g of potassium perchromate and 2 mL of water. Stir the reaction at 35°C for 18 h. After the reaction is completed, wash the reaction mixture twice with 100 mL of saturated sodium chloride aqueous solution, dry the organic layer with 4 g of anhydrous Na2SO4 for 1.5 h, filter and remove the solvent on a vacuum rotary evaporator to obtain aza-tetrafluorene ring tetracarboxylic acid with a yield of 85%;

[0065] (3) Azatetrafluorene cyclotetracarboxylic acid was added to 100 mL of dibutyl ether to prepare a dibutyl ether solution of azatetrafluorene cyclotetracarboxylic acid with a mass concentration of 50% (w / v).

[0066] The application site is a vertical fully automatic oil (gas) steam boiler owned by Changzhou Zhongna Chemical Co., Ltd., model: LHS0.3-0.4 (0.7) -Y (Q), rated evaporation capacity: 0.3t / h, rated steam pressure: 0.7Mpa, heating area: 7.32m 2 .

[0067] The aza-tetrafluorene cyclotetracarboxylic acid dibutyl ether solution obtained in this example was sprayed by a sprayer (produced by Shandong Qingzhou Haili Machinery, FZ-6 model) and then atomized in the combustion area of ​​the boiler, with the spraying amount being 0.7L of aza-tetrafluorene cyclotetracarboxylic acid dibutyl ether solution per cubic meter of gas. Calculated based on the average daily gas consumption, the gas combustion efficiency increased by 1.5% after spraying the aza-tetrafluorene cyclotetracarboxylic acid rare earth gas combustion aid.

[0068] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A rare earth gas combustion aid of aza-tetrafluorene cyclotetracarboxylic acid, characterized in that: The auxiliary agent has the structure of the following formula (I): In formula (I), R is a rare earth ion, including any one of lanthanum (La), cerium (Cs), and europium (Eu).

2. A method for preparing the aza-tetrafluorene cyclotetracarboxylic acid rare earth gas combustion aid according to claim 1, characterized in that: The steps include: (1) Under nitrogen protection, 2,7-diaminofluorene and sodium bicarbonate are added to xylene, cooled to 4-10° C., dibromoethane is added dropwise, and then stirred at 30-90° C. for 2-8 hours. After the reaction is completed, the reaction mixture is poured into 10-15 times the volume of ice water and stirred for 5-10 minutes, filtered, and the precipitate is washed with water 3 times to obtain aza-tetrafluorene ring; (2) Under nitrogen protection, aza-tetrafluorene ring is added to dimethyl sulfoxide, and then sodium methoxide is added. After stirring the reaction at 25-40° C. for 30-120 min, allyl chloride is added dropwise to the reaction mixture, and the reaction is continued with stirring. After the reaction is completed, distilled water is added to the reaction mixture, filtered, and the precipitate is transferred to dichloromethane, and sodium periodate, potassium perchromate and water are added. After the reaction is completed, the reaction product is washed twice with a saturated sodium chloride aqueous solution, and the organic layer is dried with anhydrous Na2SO4 for 0.5-1.5 h, filtered, and the solvent is removed on a vacuum rotary evaporator to obtain aza-tetrafluorene ring tetracarboxylic acid; (3) Adding the aza-tetrafluorene cyclotetracarboxylic acid prepared in step (2) to an organic solvent to prepare an aza-tetrafluorene cyclotetracarboxylic acid solution, then adding an aqueous solution of a rare earth chloride, mixing and shaking for 5 to 30 minutes, standing and stratifying, collecting the organic phase, drying it with anhydrous calcium chloride for 0.5 to 1.5 hours, and then adding ferrocene to obtain an aza-tetrafluorene cyclotetracarboxylic acid rare earth gas combustion aid.

3. The preparation method according to claim 2, characterized in that: In step (1), the mass volume ratio of the 2,7-diaminofluorene to xylene is (0.5-5) g:(30-100) mL, the mass volume ratio of the sodium bicarbonate to xylene is (0.1-0.4) g:(15-50) mL, the volume ratio of the dibromoethane to xylene is (2-25):(30-100), and the yield of the aza-tetrafluorene ring is 82-97.2%.

4. The preparation method according to claim 2, characterized in that: In step (2), the mass volume ratio of the aza-tetrafluorene ring to dimethyl sulfoxide is (1.5-3) g:(30-100) mL, the mass volume ratio of the sodium methoxide to dimethyl sulfoxide is (1-3) g:(15-50) mL, and the volume ratio of the added amount of the allyl chloride to dimethyl sulfoxide is (0.02-0.15):(30-100). After adding the allyl chloride, the reaction is continued for 3-6 hours.

5. The preparation method according to claim 2, characterized in that: In step (2), the volume ratio of the added amount of dichloromethane to dimethyl sulfoxide is 1:1, the mass volume ratio of the potassium periodate to dichloromethane is (1-3) g:(30-100) mL, the mass volume ratio of the potassium perchromate to dichloromethane is (0.5-4) g:(30-100) mL, the volume ratio of the added amount of water to dichloromethane is (1-2):(30-100), after adding sodium periodate, sodium perchromate and water, reacting at 25-35° C. for 16-18 hours, the yield of the aza-tetrafluorene cyclotetracarboxylic acid is 75-85%.

6. The preparation method according to claim 2, characterized in that: In step (3), the organic solvent includes at least one of dibutyl ether, ethyl acetate, ethylene glycol dibutyl ether, and propyl acetate, and the mass concentration of the aza-tetrafluorene cyclotetracarboxylic acid solution is 45-55%.

7. The preparation method according to claim 2, characterized in that: In step (3), the rare earth chloride includes any one of lanthanum chloride, cerium chloride and europium chloride, the mass concentration of the rare earth chloride in the aqueous solution of the rare earth chloride is 15-25%, and the volume ratio of the rare earth chloride aqueous solution to the organic solvent is 1:

1.

8. The preparation method according to claim 2, characterized in that: In step (3), after ferrocene is added, the mass concentration of ferrocene is 5-10%.

9. Use of the aza-tetrafluorene-cyclotetracarboxylic acid rare earth fuel gas combustion aid according to claim 1 in catalytic combustion.

10. The use according to claim 9, characterized in that: The application comprises spraying the aza-tetrafluorene cyclotetracarboxylate rare earth fuel gas combustion aid through a sprayer to form atomization in the combustion area of ​​the boiler, and the spraying amount is 0.1-0.5 liters of the aza-tetrafluorene cyclotetracarboxylate rare earth fuel gas combustion aid per cubic meter of fuel gas.

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