Fire coal dispersing agent and application thereof in preparation of environment-friendly liquid fire coal additive

Abstract

The invention discloses a fire coal dispersing agent and application thereof in preparation of an environment-friendly liquid fire coal additive, a preparation method of the fire coal dispersing agent comprises the following steps: S1, mixing polyvinyl alcohol, oxetane-3-methanol, a strong alkali catalyst and a first solvent, and heating for reaction to obtain a comb-shaped polymer; s2, mixing the comb-shaped polymer, sodium bis (lauryl alcohol polyether-7) citrate, a strong acid catalyst, a polymerization inhibitor and a second solvent, and performing heating reaction to obtain a fire coal dispersing agent; the fire coal dispersing agent is used for preparing an environment-friendly liquid fire coal additive, and the obtained environment-friendly liquid fire coal additive can remarkably reduce the pollutant emission concentration of fire coal and improve the pollutant emission reduction rate of the fire coal.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of environmental protection type liquid coal combustion additives, and particularly relates to a coal combustion dispersant and application thereof in preparation of an environmental protection type liquid coal combustion additive. BACKGROUND

[0002] China is a country rich in coal, poor in oil and short of gas, and at present, many modern industries such as cement production, power generation, steel smelting and the like all use coal as fuel, but coal combustion will produce a large amount of SOx, NOx and other pollution gases and smoke dust and the like, which pollute the environment, and in order to improve the serious pollution problem of coal combustion flue gas to the air, China has put forward higher requirements for the flue gas emission concentration of key pollution sources such as coal-fired power plants. Therefore, how to improve the combustion performance of coal and reduce the pollution gases and smoke dust produced by coal combustion has important significance.

[0003] The environmental protection type additive refers to an additive for reducing the emission concentration of pollutants such as oxidized sulfur and oxidized nitrogen in the coal combustion process. By using the environmental protection type liquid coal combustion additive, the environmental protection performance of coal can be significantly improved. At present, the environmental protection type liquid coal combustion additive generally uses the following substances as components: 1) alkali metal, alkaline earth metal and transition metal oxides such as magnesium oxide and calcium oxide; 2) alkali metal, alkaline earth metal and transition metal bases or salts such as nitrate, carbonate, chlorate, chloride and some organic acid salts; 3) oxidizing agents such as permanganate and potassium nitrate; 4) surfactants and the like. The dispersing performance of the surfactant used in the existing environmental protection type liquid coal combustion additive is poor, and thus the environmental protection type liquid coal combustion additive is difficult to reduce the pollutant emission concentration of coal combustion and improve the pollutant emission reduction rate of coal combustion. SUMMARY

[0004] In view of the deficiencies in the prior art, a coal combustion dispersant is provided, which contains an anion group in the molecular structure, the anion group has electrostatic action with metal cations in catalysts, sulfur-fixing agents, rare earth compounds and the like of the environmental protection type liquid coal combustion additive, and the molecular structure of the coal combustion dispersant contains a hydroxyl group, hydrogen bond action exists between the dispersants and between the dispersants and other substances, the interaction force between the dispersants and between the dispersants and other substances is improved, the dispersing action of the coal combustion dispersant is significantly improved, and thus the environmental protection type liquid coal combustion additive can significantly reduce the pollutant emission concentration of coal combustion and improve the pollutant emission reduction rate of coal combustion.

[0005] The present application aims to provide a preparation method of a coal combustion dispersant, which comprises the following steps:

[0006] S1. mixing polyvinyl alcohol, oxetane-3-methanol, a strong base catalyst and a first solvent, and reacting under heating to obtain a comb-shaped polymer;

[0007] S2. The comb-shaped polymer, sodium di(laureth-7) citrate, strong acid catalyst, polymerization inhibitor and second solvent are mixed, and the reaction is carried out at an elevated temperature to obtain the coal combustion dispersant.

[0008] The comb-shaped polymer obtained by the reaction of the hydroxyl group of the polyvinyl alcohol and the epoxy group of the oxetane-3-methanol, and the etherification reaction of the terminal hydroxyl group of the comb-shaped polymer and the hydroxyl group of the sodium di(laureth-7) citrate, contains an ether bond and a hydroxyl group in the side chain of the molecular structure, and the coal combustion dispersant obtained by the reaction of the hydroxyl group of the comb-shaped polymer and the anion group of the sodium di(laureth-7) citrate contains a hydroxyl group, an ether bond and an anion group in the molecular structure.

[0009] In some embodiments of the present application, in S1, the mass ratio of the polyvinyl alcohol to the oxetane-3-methanol is 8:2-5.

[0010] In some embodiments of the present application, in S1, the number average molecular weight of the polyvinyl alcohol is 500-1800 g / mol.

[0011] In some embodiments of the present application, in S1, the amount of the basic catalyst is 2000-4000 ppm of the total reaction raw materials.

[0012] In some embodiments of the present application, in S1, the strong base catalyst includes one of potassium hydroxide, sodium hydroxide, potassium tert-butoxide, sodium tert-butoxide, sodium methoxide, sodium ethoxide and sodium isopropoxide.

[0013] In some embodiments of the present application, in S1, the first solvent is at least one selected from dichloromethane, chloroform, tetrahydrofuran, toluene, 1,1-dichloroethane and 1,2-dichloroethane.

[0014] In some embodiments of the present application, in S1, the temperature of the reaction at an elevated temperature is 90-130°C, and the time is 10-20 hours.

[0015] In some embodiments of the present application, in S2, the mass ratio of the comb-shaped polymer to the sodium di(laureth-7) citrate is 5-10:1.

[0016] In some embodiments of the present application, in S2, the mass ratio of the comb-shaped polymer, the strong acid catalyst and the polymerization inhibitor is 1:0.1-0.2:0.05-0.08.

[0017] In some embodiments of the present application, in S2, the strong acid catalyst is at least one selected from sulfuric acid, phosphoric acid, p-toluenesulfonic acid and methylsulfonic acid.

[0018] In some embodiments of the present application, in S2, the polymerization inhibitor is at least one selected from hydroquinone, methylhydroquinone, tert-butylhydroquinone and 2,6-di-tert-butylhydroquinone.

[0019] In some embodiments of the present application, in S2, the second solvent is selected from at least one of dichloromethane, chloroform, tetrahydrofuran, toluene, 1,1-dichloroethane, 1,2-dichloroethane, xylene.

[0020] In some embodiments of the present application, in S2, the temperature is raised to 100-130℃, and the reaction is carried out for 3-6 hours.

[0021] Another object of the present application is to provide a coal dispersant prepared by the method.

[0022] Another object of the present application is to provide an environmentally friendly liquid coal additive comprising an effective amount of the coal dispersant.

[0023] In some embodiments of the present application, the coal dispersant is used in an amount of 5-8% by weight of the environmentally friendly liquid coal additive.

[0024] In some embodiments of the present application, the environmentally friendly liquid coal additive further comprises the following raw materials in the following amounts: iron oxide 4-10%, cerium nitrate 1-2.5%, calcium oxide 0.1-0.5%, ammonium bicarbonate 0.2-0.5%, potassium carbonate 2.5-4.5%, kaolin 0.5-2.5%, magnesium chloride 0.5-2%, and the balance of water.

[0025] Another object of the present application is to provide a method for preparing the environmentally friendly liquid coal additive, comprising the following steps:

[0026] (1) adding the balance of water into a reaction kettle, stirring, and adding iron oxide 4-10% and cerium nitrate 0.5-2% into the reaction kettle, stirring until completely dissolved to obtain a mixture A;

[0027] (2) adding calcium oxide 0.1-0.5%, ammonium bicarbonate 0.2-0.5%, potassium carbonate 2.5-4.5%, kaolin 0.5-2.5%, and magnesium chloride 0.5-2% into the mixture A, continuing to stir, and controlling the reaction temperature to 30-60℃ to obtain a mixture B;

[0028] (3) adding the coal dispersant 1.5-2.5% into the mixture B, and stirring at high speed for 30-60 minutes to obtain the environmentally friendly liquid coal additive.

[0029] Another object of the present application is to provide a modified coal comprising the environmentally friendly liquid coal additive and coal.

[0030] Compared with the prior art, the present application has the following advantages:

[0031] The coal combustion dispersant of the present application contains an anion group in the molecular structure, the anion group has electrostatic interaction with metal cations in the catalyst, the sulfur-fixing agent, the rare earth compound and other substances of the environmental protection type liquid coal additive, and the coal combustion dispersant contains a hydroxyl group in the molecular structure, the hydrogen bond interaction exists between the dispersants and between the dispersants and other substances, the interaction force between the dispersants and between the dispersants and other substances is improved, the dispersion effect of the coal combustion dispersant is significantly improved, and then the environmental protection type liquid coal additive significantly reduces the pollutant emission concentration of the coal combustion and improves the pollutant emission reduction rate of the coal combustion. DETAILED DESCRIPTION

[0032] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0033] The raw materials used in the present application are all conventional commercial products.

[0034] Embodiment 1

[0035] The present embodiment provides a coal combustion dispersant, and the specific preparation steps are as follows:

[0036] S1. The number average molecular weight of polyvinyl alcohol (8 g), potassium hydroxide (0.02 g) and toluene (50 g) is 500-1800 g / mol, which is added to a reflux reactor, mixed, stirred, heated to 130℃, and then oxetane-3-methanol (2 g) is added, stirred, and reacted for 10 hours to obtain a comb-shaped polymer;

[0037] S2. The comb-shaped polymer (10 g), sodium dilaureth-7 citrate (1 g) dissolved in water, p-toluenesulfonic acid (1 g), hydroquinone (0.8 g) and toluene (30 g) are mixed, stirred, heated to 130℃ and reacted for 6 hours. After the reaction is completed, the reaction crude product is slowly added to ethanol to precipitate the polymer, and the coal combustion dispersant is obtained. The number average molecular weight of the coal combustion dispersant is 4500-8000 g / mol detected by GPC.

[0038] Embodiment 2

[0039] The present embodiment provides a coal combustion dispersant, and the specific preparation steps are as follows:

[0040] S1. Polyvinyl alcohol (8g), potassium hydroxide (0.05g), and toluene (50g) with a number average molecular weight of 500~1800g / mol were added to a reflux reactor, mixed, stirred, heated to 130℃, and oxetane-3-methanol (5g) was added. The mixture was stirred and reacted for 20 hours to obtain a comb-shaped polymer.

[0041] S2. Mix the comb-shaped polymer (10g), sodium bis(lauryl ether-7) citrate (2g), p-toluenesulfonic acid (2g), hydroquinone (0.5g), and toluene (30g) dissolved in water, stir, and heat to 130℃ for 3 hours. After the reaction is completed, slowly add the crude product to ethanol to precipitate the polymer, thus obtaining the coal combustion dispersant. According to GPC testing, the number average molecular weight of the coal combustion dispersant is 3500~6000g / mol.

[0042] Example 3

[0043] This embodiment provides an environmentally friendly liquid coal combustion additive, and the specific preparation steps are as follows:

[0044] (1) Add the remaining water to the reactor by weight percentage, stir, add 4% iron oxide and 2% cerium nitrate to the reactor, stir until completely dissolved, and obtain mixture A;

[0045] (2) Add 0.1% calcium oxide, 0.5% ammonium bicarbonate, 2.5% potassium carbonate, 2.5% kaolin and 0.5% magnesium chloride to mixture A, continue stirring, and control the reaction temperature to 30~60℃ to obtain mixture B;

[0046] (3) Add 8% of the coal dispersant prepared in Example 1 to mixture B, and stir at high speed for 30-60 minutes to obtain an environmentally friendly liquid coal additive.

[0047] Example 4

[0048] This embodiment provides an environmentally friendly liquid coal combustion additive, and the specific preparation steps are as follows:

[0049] (1) Add the remaining water to the reactor by weight percentage, stir, add 10% iron oxide and 0.5% cerium nitrate to the reactor, stir until completely dissolved, and obtain mixture A;

[0050] (2) Add 0.5% calcium oxide, 0.2% ammonium bicarbonate, 4.5% potassium carbonate, 0.5% kaolin and 2% magnesium chloride to mixture A, continue stirring, and control the reaction temperature to 30~60℃ to obtain mixture B;

[0051] (3) Add 5% of the coal dispersant prepared in Example 2 to mixture B, and stir at high speed for 30-60 minutes to obtain an environmentally friendly liquid coal additive.

[0052] Comparative Example 1

[0053] The present comparative example provides an environmentally friendly liquid coal additive, which is different from Example 4 only in that a polyvinyl alcohol dispersant is used. The specific preparation steps are as follows:

[0054] (1) Add the remaining water to the reaction kettle in terms of weight percentage, stir, and add iron oxide 10% and cerium nitrate 0.5% to the reaction kettle, stir until completely dissolved, to obtain mixture A;

[0055] (2) Add calcium oxide 0.5%, ammonium bicarbonate 0.2%, potassium carbonate 4.5%, kaolin 0.5%, and magnesium chloride 2% to mixture A, continue to stir, and control the reaction temperature to 30-60°C, to obtain mixture B;

[0056] (3) Add polyvinyl alcohol with a number average molecular weight of 500-1800 g / mol 5% to mixture B, high-speed stirring for 30-60 minutes, to obtain an environmentally friendly liquid coal additive.

[0057] Comparative Example 2

[0058] The present comparative example provides an environmentally friendly liquid coal additive, which is different from Example 4 only in that an octadecanol polyoxyethylene ether dispersant is used. The specific preparation steps are as follows:

[0059] (1) Add the remaining water to the reaction kettle in terms of weight percentage, stir, and add iron oxide 10% and cerium nitrate 0.5% to the reaction kettle, stir until completely dissolved, to obtain mixture A;

[0060] (2) Add calcium oxide 0.5%, ammonium bicarbonate 0.2%, potassium carbonate 4.5%, kaolin 0.5%, and magnesium chloride 2% to mixture A, continue to stir, and control the reaction temperature to 30-60°C, to obtain mixture B;

[0061] (3) Add octadecanol polyoxyethylene ether dispersant with a number average molecular weight of 4000-5000 g / mol 5% to mixture B, high-speed stirring for 30-60 minutes, to obtain an environmentally friendly liquid coal additive.

[0062] Comparative Example 3

[0063] The present comparative example provides an environmentally friendly liquid coal additive, which is different from Example 4 only in that a polycarboxylate dispersant is used. The specific preparation steps are as follows:

[0064] (1) Add the remaining water to the reaction kettle in terms of weight percentage, stir, and add iron oxide 10% and cerium nitrate 0.5% to the reaction kettle, stir until completely dissolved, to obtain mixture A;

[0065] (2) adding calcium oxide 0.5%, ammonium bicarbonate 0.2%, potassium carbonate 4.5%, kaolin 0.5% and magnesium chloride 2% into the mixture A, continuing to stir, and controlling the reaction temperature to 30-60°C, to obtain mixture B;

[0066] (3) adding polycarboxylate dispersant with number average molecular weight of 3000-6000 g / mol 5% into the mixture B, high-speed stirring for 30-60 minutes, to obtain the environment-friendly liquid coal combustion additive.

[0067] Combustion experiment:

[0068] In use, 10 kg of the environment-friendly liquid coal combustion additive prepared in the examples 3-4 and the comparative examples 1-3 is respectively added into water to be diluted into 2 tons, the diluted environment-friendly liquid coal combustion additive is respectively sprayed on 20 tons of coal with heat output of 6000 Kcal / kg by using a spraying device for combustion, and the comparison results of the combustion of the coal added with the additive and the coal without the additive are shown in Table 1.

[0069] Table 1. Comparison of combustion performance.

[0070]

[0071] As shown in Table 1, the dispersion performance of the coal combustion dispersant of the present application is high, and the environment-friendly liquid coal combustion additive can significantly improve the combustion performance of the coal.

[0072] It should be finally pointed out that the above examples are only used to illustrate the technical solutions of the present application but not to limit the same, and although the present application has been described in detail by referring to the above examples, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced by the same after reading the present application, but these modifications or changes are still within the scope of the present application.

Claims

1. A method for preparing a coal combustion dispersant, characterized in that, Includes the following steps: S1. Polyvinyl alcohol, oxetane-3-methanol, a strong base catalyst and a first solvent are mixed and reacted at a higher temperature to obtain a comb-shaped polymer; S2. The comb-shaped polymer, sodium di(lauryl ether-7) citrate, strong acid catalyst, polymerization inhibitor, and second solvent are mixed and reacted at elevated temperature to obtain a coal combustion dispersant.

2. The method for preparing the coal dispersant as described in claim 1, characterized in that, In S1, the mass ratio of polyvinyl alcohol to oxetane-3-methanol is 8:2~5; And / or, the amount of the alkaline catalyst is 2000~4000 ppm of the total reactants; And / or, the strong base catalyst comprises one of potassium hydroxide, sodium hydroxide, potassium tert-butoxide, sodium tert-butoxide, sodium methoxide, sodium ethoxide, and sodium isopropoxide; And / or, the first solvent is selected from at least one of dichloromethane, chloroform, tetrahydrofuran, toluene, 1,1-dichloroethane, 1,2-dichloroethane, and xylene; And / or, the temperature of the heating reaction is 90~130℃, and the time is 10~20 hours.

3. The method for preparing the coal dispersant as described in claim 1, characterized in that, In S2, the mass ratio of the comb-shaped polymer to sodium di(lauryl ether-7) citrate is 5~10:1; And / or, the mass ratio of the comb-shaped polymer, the strong acid catalyst, and the polymerization inhibitor is 1:0.1~0.2:0.05~0.

08.

4. The method for preparing the coal dispersant as described in claim 1, characterized in that, In S2, the strong acid catalyst is selected from at least one of sulfuric acid, phosphoric acid, p-toluenesulfonic acid, and methanesulfonic acid; And / or, the polymerization inhibitor is selected from at least one of hydroquinone, methyl hydroquinone, tert-butyl hydroquinone, and 2,6-di-tert-butyl hydroquinone; And / or, the second solvent is selected from at least one of dichloromethane, chloroform, tetrahydrofuran, toluene, 1,1-dichloroethane, 1,2-dichloroethane, and xylene; And / or, the heating reaction is carried out by heating to 100~130℃ and reacting for 3~6 hours.

5. A coal combustion dispersant, characterized in that, The coal dispersant is prepared by the method for preparing the coal dispersant according to any one of claims 1 to 4.

6. An environmentally friendly liquid coal additive, characterized in that, Includes an effective amount of the coal dispersant as described in claim 5.

7. The environmentally friendly liquid coal additive as described in claim 6, characterized in that, The amount of the coal dispersant used, by weight percentage, is 5-8% of that used in environmentally friendly liquid coal additives.

8. The environmentally friendly liquid coal additive as described in claim 7, characterized in that, The environmentally friendly liquid coal additive also includes the following raw materials in the following mass fractions: 4-10% iron oxide, 1-2.5% cerium nitrate, 0.1-0.5% calcium oxide, 0.2-0.5% ammonium bicarbonate, 2.5-4.5% potassium carbonate, 0.5-2.5% kaolin, 0.5-2% magnesium chloride, and the balance being water.

9. A method for preparing an environmentally friendly liquid coal additive, characterized in that, Includes the following steps: (1) Add the remaining water to the reaction vessel and stir. Add 4-10% iron oxide and 0.5-2% cerium nitrate to the reaction vessel and stir until completely dissolved to obtain mixture A; (2) Add 0.1-0.5% calcium oxide, 0.2-0.5% ammonium bicarbonate, 2.5-4.5% potassium carbonate, 0.5-2.5% kaolin and 0.5-2% magnesium chloride to mixture A, continue stirring, and control the reaction temperature to 30-60℃ to obtain mixture B; (3) Add 1.5-2.5% of the coal dispersant as described in claim 5 to mixture B, and stir at high speed for 30-60 minutes to obtain an environmentally friendly liquid coal additive.

10. A modified coal comprising the environmentally friendly liquid coal additive and coal as described in any one of claims 6 to 8.

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