Boiler decoking and deashing combustion improver and preparation method thereof

Abstract

The invention discloses a boiler decoking and deashing combustion improver and a preparation method thereof, and relates to the technical field of decoking and deashing combustion improvers, the boiler decoking and deashing combustion improver comprises the following components by weight: 2-6 g of nano activated carbon, 1-4 g of iron oxide powder, 20-35 g of a functional auxiliary agent, 3-8 g of a functional filler, 6-20 g of nitrate, 20-48 g of carbonate, 2-7 g of borax, 15-48 g of diatomite, and 15-50 g of chlorate. According to the invention, surface tension can be reduced through the surfactant, so that the surfactant can permeate into the interface between coke dirt and dust and the boiler wall and weaken the adhesive force between the coke dirt and dust, the alkaline absorbent can react with acidic substances in the coke dirt and dust, so that the ash slag becomes loose, is easy to pulverize and is convenient to remove, and meanwhile, the alkaline absorbent can play a catalytic role at high temperature; the fuel is combusted more sufficiently, so that the combustion efficiency is improved, and the combustion-supporting effect is achieved; and the components in the functional filler can form a layer of protective film on the heating surface of the boiler, so that the deposition of impurities and ash in the fuel on the heating surface is reduced, and the formation of coking is inhibited.

Description

Technical Field

[0001] The invention relates to the technical field of decoking and dust-clearing combustion-supporting agents, and in particular to a decoking and dust-clearing combustion-supporting agent for boilers and a preparation method thereof. Background Art

[0002] Referring to the Chinese patent boiler decoking and ash cleaning combustion aid (Announcement No.: CN101955818A), it is suitable for various boilers, kilns and other fuel furnaces using coal, oil, coal gas and natural gas as fuel, such as industrial boilers, civil boilers, marine boilers, tea stoves, steam locomotives, etc. It is made of the following raw materials in weight percentage: sodium nitrate 12.5%-30%, potassium nitrate 17.50%-25%, calcium nitrate 5.50%-11%, salt 15%-19%, borax 15%-49.50%, the product can prevent the formation of new coke, is conducive to the full combustion of fuel, makes the accumulated smoke scale completely burned, reduces sticky carbon and carbonized products, plays a certain corrosion inhibition role on the boiler, and prolongs the service life of the boiler; however, the combustion aid prepared by the above-mentioned prior art will produce harmful gases when used, thereby having an adverse effect on the environment; for this reason, the present invention proposes a boiler decoking and ash cleaning combustion aid and a preparation method thereof to solve the above-mentioned problems. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In view of the deficiencies in the prior art, the present invention provides a boiler decoking and ash cleaning combustion aid and a preparation method thereof, which solves the problems mentioned in the above background technology.

[0005] (II) Technical solution

[0006] To achieve the above objectives, the present invention is implemented by the following technical scheme: a boiler decoking and ash cleaning combustion aid, the boiler decoking and ash cleaning combustion aid comprises the following components by weight: 2-6g of nano activated carbon, 1-4g of iron oxide powder, 20-35g of functional additive, 3-8g of functional filler, 6-20g of nitrate, 20-48g of carbonate, 2-7g of borax, 15-48g of diatomaceous earth, and 15-50g of chlorate;

[0007] Wherein, the nitrate is selected from one or more of sodium nitrate, potassium nitrate, copper nitrate, and calcium ammonium nitrate; the carbonate is selected from one or more of sodium carbonate, magnesium carbonate, and calcium carbonate; the chlorate is selected from one or more of sodium chloride and sodium chlorate;

[0008] The preparation method of the functional filler is as follows: pour 50-65 mL of deionized water into 0.5-2 g of sodium carboxymethyl cellulose, mix well, and then add 1.5-3 g of a surfactant and 4-5 g of an alkaline absorbent.

[0009] Preferably, the surfactant is a mixture of sodium α-olefin sulfonate and fatty alcohol polyoxyethylene ether, and the mass ratio thereof is 1:(0.7-1).

[0010] Preferably, the alkaline absorbent is a mixture of sodium carbonate and sodium silicate, and the mass ratio thereof is (1.5-2):1.

[0011] A method for preparing a boiler decoking and ash cleaning combustion-supporting agent comprises the following preparation steps:

[0012] Step 1: Stir and mix the functional filler and the functional additive at a speed of 300-500 r / min for 40-60 min;

[0013] Step 2: Add nano activated carbon, iron oxide powder, nitrate, carbonate, borax, diatomaceous earth and chlorate, stir at a speed of 500-800r / min for 60-90min, and then put it into a drying oven at 90-120°C for 10-12h to obtain a boiler decoking and ash cleaning combustion aid.

[0014] Preferably, the preparation method of the functional additive is:

[0015] (1) Pre-treating the zeolite, specifically: pouring 2.5-4 g of zeolite into a ball mill, crushing it, taking it out and sieving it;

[0016] (2) activating the sieved zeolite, pouring it into 10-15 mL of deionized water, and ultrasonically treating it until it is completely dissolved to prepare solution A;

[0017] (3) Pour 50-60 mL of acetic acid solution into 2-3.6 g of chitosan and allow to react for 10-12 h to obtain solution B;

[0018] (4) Slowly add solution A to solution B, and after sufficient reaction for 4-6 hours, add 100-115 mL of 2 mol / L sodium hydroxide solution;

[0019] (5) washing the reaction product with deionized water until its pH is neutral;

[0020] (6) Add 40-52 mL of 7.5%-8.5% glutaraldehyde solution, heat to 60-70° C., and react for 2.5-3.5 hours;

[0021] (7) After the reaction is completed, freeze-dry for 20-24 hours to obtain the functional additive.

[0022] Preferably, in said (1), the crushing treatment is carried out at a rotation speed of 250-280 r / min for 10-15 min, and then the crushed product is taken out and passed through a 60-100 mesh sieve.

[0023] Preferably, in (2), the specific method for activating the zeolite is: placing the sieved zeolite in a high-temperature furnace, heating it to 800-1000°C and calcining it for 55-70 minutes, and then naturally cooling it to room temperature in the furnace.

[0024] Preferably, in (3), the concentration of chitosan is 4% g / mL; and the molar fraction of the acetic acid solution is 5%.

[0025] (III) Beneficial effects

[0026] The present invention provides a boiler decoking and ash cleaning combustion-supporting agent and a preparation method thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) In the present invention, the surface tension can be reduced by the surfactant, so that it can penetrate into the interface between the coke scale and dust and the boiler wall, weakening the adhesion between the two. The alkaline absorbent can react with the acidic substances in the coke scale and dust, making the ash slag loose and easy to pulverize, which is convenient for removal. At the same time, the alkaline absorbent will play a catalytic role at high temperature, making the fuel burn more fully and preventing the formation of new coke; and the components in the functional filler can form a protective film on the heating surface of the boiler, reducing the deposition of impurities and ash in the fuel on the heating surface, thereby inhibiting the formation of coke; through the addition of the functional filler, it not only has the function of removing coke and cleaning ash, but also can play a role in combustion, and at the same time can also reduce the pollution caused by incomplete combustion, which is more environmentally friendly.

[0028] (2) In the present invention, the zeolite itself has adsorption and ion exchange properties, and can adsorb and remove part of the coke scale and dust in the boiler. After combining with chitosan, the formed complex has better surface activity and adsorption performance, which helps to further remove the coke scale and dust; by activating the zeolite and then combining it with chitosan and its derivatives, the combustion can be more complete and the decoking effect can be improved; the various components in the functional additive cooperate with each other, give play to their respective advantages, produce synergistic effects, so that the comprehensive performance of the combustion aid in decoking, cleaning, combustion and other aspects is improved, and it is more environmentally friendly.

[0029] (3) In the present invention, iron oxide powder acts as a catalyst for the combustion reaction, which reduces the activation energy of the combustion reaction, makes the fuel easier to ignite and burn completely, and reduces coking; borax can reduce the melting point of ash, so that the ash forms liquid slag with good fluidity at a lower temperature, which is easy to flow down from the boiler wall, further reducing ash accumulation and coking. It works together with carbonate to effectively improve the decoking and cleaning effect; at the same time, diatomaceous earth has good adsorption properties and high temperature resistance, and can adsorb dust and tiny coke particles in the boiler, causing them to aggregate into larger particles, which are easy to be carried out by flue gas or deposited under the action of gravity, thereby reducing the adhesion of dust and coke particles to the heating surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a comparison chart of the carbon content test in the ash provided by the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0032] Example 1

[0033] A method for preparing a boiler decoking and ash cleaning combustion-supporting agent comprises the following preparation steps:

[0034] Step 1: 3 g of functional filler and 20 g of functional additive were stirred and mixed at a speed of 300 r / min for 40 min;

[0035] The preparation method of the functional filler is as follows: pour 50 mL of deionized water into 0.5 g of sodium carboxymethyl cellulose, mix well, add 1.7 g of a mixture of sodium α-olefin sulfonate and fatty alcohol polyoxyethylene ether in a mass ratio of 1:0.7, and 5 g of a mixture of sodium carbonate and sodium silicate in a mass ratio of 1.5:1;

[0036] The preparation method of the functional additive is as follows: pre-treating the zeolite, specifically: pouring 2.5g of the zeolite into a ball mill, crushing it at a speed of 250r / min for 10min, and then taking it out and passing it through a 60-mesh sieve; activating the sieved zeolite, specifically: placing the sieved zeolite in a high-temperature furnace, heating it to 800℃ and roasting it for 55min, and then naturally cooling it to room temperature in the furnace; then pouring it into 10mL of deionized water, ultrasonically treating it until it is completely dissolved, to obtain solution A; pouring 50mL of acetic acid solution with a mass fraction of 5% into 2g of chitosan with a concentration of 4%g / mL, and fully reacting it for 10h to obtain solution B; slowly dropping solution A into solution B, and after fully reacting it for 4h, dropping 100mL of sodium hydroxide solution with a concentration of 2mol / L; washing the reaction product with deionized water until its pH is neutral; adding 40mL 7.5% glutaraldehyde solution, heated to 60°C, reacted for 2.5 hours; after the reaction was completed, freeze-dried for 20 hours to obtain a functional additive;

[0037] Step 2: Add 2g of nano-activated carbon, 1g of iron oxide powder, 6g of sodium nitrate, 20g of sodium carbonate, 2g of borax, 15g of diatomaceous earth and 15g of sodium chloride, stir at a speed of 500r / min for 60min, and dry in a drying oven at 90°C for 10h to obtain a boiler decoking and ash cleaning combustion aid.

[0038] Example 2

[0039] A method for preparing a boiler decoking and ash cleaning combustion-supporting agent comprises the following preparation steps:

[0040] Step 1: 6 g of functional filler and 25 g of functional additive were stirred and mixed at a speed of 400 r / min for 50 min;

[0041] The preparation method of the functional filler is as follows: pour 60 mL of deionized water into 1.5 g of sodium carboxymethyl cellulose, mix well, add 1.8 g of a mixture of sodium α-olefin sulfonate and fatty alcohol polyoxyethylene ether in a mass ratio of 1:0.8, and 4.5 g of a mixture of sodium carbonate and sodium silicate in a mass ratio of 2:1;

[0042] The preparation method of the functional additive is as follows: pre-treating the zeolite, specifically: pouring 3g of the zeolite into a ball mill, crushing it at a speed of 260r / min for 12min, and then taking it out and passing it through an 80-mesh sieve; activating the sieved zeolite, specifically: placing the sieved zeolite in a high-temperature furnace, heating it to 900°C and roasting it for 60min, and then naturally cooling it to room temperature in the furnace; then pouring it into 13mL of deionized water, ultrasonically treating it until it is completely dissolved, to obtain solution A; pouring 55mL of acetic acid solution with a mass fraction of 5% into 2.8g of chitosan with a concentration of 4% g / mL, and fully reacting it for 11h to obtain solution B; slowly dropping solution A into solution B, and after fully reacting it for 5h, dropping 110mL of sodium hydroxide solution with a concentration of 2mol / L; washing the reaction product with deionized water until its pH is neutral; adding 46mL 8% glutaraldehyde solution, heated to 65°C, reacted for 3 hours; after the reaction was completed, freeze-dried for 22 hours to obtain a functional additive;

[0043] Step 2: Add 4g of nano-activated carbon, 2.5g of iron oxide powder, 15g of potassium nitrate, 30g of magnesium carbonate, 4g of borax, 30g of diatomaceous earth and 30g of sodium chlorate, stir at a speed of 600r / min for 80min, and then put it in a drying oven at 100°C for 11h to obtain a boiler decoking and ash cleaning combustion aid.

[0044] Example 3

[0045] A method for preparing a boiler decoking and ash cleaning combustion-supporting agent comprises the following preparation steps:

[0046] Step 1: 8 g of functional filler and 35 g of functional additive were stirred and mixed at a speed of 500 r / min for 60 min;

[0047] The functional filler is prepared by pouring 65 mL of deionized water into 2 g of sodium carboxymethyl cellulose, mixing well, and then adding 3 g of a mixture of sodium a-olefin sulfonate and fatty alcohol polyoxyethylene ether in a mass ratio of 1:1, and 4.8 g of a mixture of sodium carbonate and sodium silicate in a mass ratio of 2:1;

[0048] The preparation method of the functional additive is as follows: pre-treating the zeolite, specifically: pouring 4g of zeolite into a ball mill, crushing it at a speed of 280r / min for 15min, and then taking it out and passing it through a 100-mesh sieve; activating the sieved zeolite, specifically: placing the sieved zeolite in a high-temperature furnace, heating it to 1000℃ and roasting it for 70min, and then naturally cooling it to room temperature in the furnace; then pouring it into 15mL of deionized water, ultrasonically treating it until it is completely dissolved, to obtain solution A; pouring 60mL of acetic acid solution with a mass fraction of 5% into 3.6g of chitosan with a concentration of 4%g / mL, fully reacting it for 12h, to obtain solution B; slowly dropping solution A into solution B, fully reacting it for 6h, and then dropping 115mL of acetic acid solution with a concentration of 2mo l / L sodium hydroxide solution; wash the reaction product with deionized water until its pH is neutral; add 52mL 8.5% glutaraldehyde solution, heat to 70°C, and react for 3.5h; after the reaction is completed, freeze-dry for 24h to obtain a functional additive;

[0049] Step 2: Add 6g of nano-activated carbon, 4g of iron oxide powder, 20g of copper nitrate, 48g of calcium carbonate, 7g of borax, 48g of diatomaceous earth and 50g of sodium chlorate, stir at a speed of 800r / min for 90min, and then put it in a drying oven at 120°C and dry it for 12h to obtain a boiler decoking and ash cleaning combustion aid.

[0050] Comparative Example 1

[0051] Compared with Example 1, the difference is that no functional additive is added; the rest remains unchanged.

[0052] Comparative Example 2

[0053] Compared with Example 1, the difference is that no functional filler is added; the rest remains unchanged.

[0054] Comparative Example 3

[0055] Compared with Example 1, the difference is that no nano activated carbon is added; the rest remains unchanged.

[0056] Coal and boiler decoking and cleaning combustion aid were taken in a mass ratio of 10000:1, ignited until they were completely burned, and the carbon content in the ash was measured. Figure 1 As shown; the complete combustion time was tested, and the results are shown in Table 1; during the test, the coking situation of each group of boilers was recorded separately, and the results are shown in Table 1.

[0057] Table 1

[0058] Burning time / min Coking Example 1 158 No coking Example 2 156 No coking Example 3 155 No coking Comparative Example 1 137 Large area coking Comparative Example 2 139 Large area coking Comparative Example 3 145 A small amount of fine coking

[0059] like Figure 1 As shown, compared with comparative examples 1-3, the carbon content of Examples 1-3 after complete combustion is significantly reduced, indicating that the decoking and ash cleaning combustion aid in the present application effectively decomposes or gasifies the coke produced during the coal combustion process, reduces the accumulation of coke, and reduces the amount of coke generated.

[0060] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0061] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0062] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A boiler decoking and ash cleaning combustion aid, characterized in that: The boiler decoking and ash cleaning combustion-supporting agent comprises the following components by weight: 2-6g of nano-activated carbon, 1-4g of iron oxide powder, 20-35g of functional additive, 3-8g of functional filler, 6-20g of nitrate, 20-48g of carbonate, 2-7g of borax, 15-48g of diatomaceous earth, and 15-50g of chlorate; Wherein, the nitrate is selected from one or more of sodium nitrate, potassium nitrate, copper nitrate, and calcium ammonium nitrate; the carbonate is selected from one or more of sodium carbonate, magnesium carbonate, and calcium carbonate; the chlorate is selected from one or more of sodium chloride and sodium chlorate; The preparation method of the functional filler is as follows: pour 50-65 mL of deionized water into 0.5-2 g of sodium carboxymethyl cellulose, mix well, and then add 1.5-3 g of a surfactant and 4-5 g of an alkaline absorbent.

2. A boiler decoking and ash cleaning combustion-supporting agent according to claim 1, characterized in that: The surfactant is a mixture of sodium α-olefin sulfonate and fatty alcohol polyoxyethylene ether, and the mass ratio thereof is 1:(0.7-1).

3. A boiler decoking and ash cleaning combustion-supporting agent according to claim 1, characterized in that: The alkaline absorbent is a mixture of sodium carbonate and sodium silicate, and the mass ratio thereof is (1.5-2):

1.

4. A method for preparing a boiler decoking and ash cleaning combustion-supporting agent according to claim 1, characterized in that: The method comprises the following preparation steps: Step 1: Stir and mix the functional filler and the functional additive at a speed of 300-500 r / min for 40-60 min; Step 2: Add nano activated carbon, iron oxide powder, nitrate, carbonate, borax, diatomaceous earth and chlorate, stir at a speed of 500-800r / min for 60-90min, and then put it into a drying oven at 90-120°C for 10-12h to obtain a boiler decoking and ash cleaning combustion aid.

5. The method for preparing a boiler decoking and ash cleaning combustion-supporting agent according to claim 4, characterized in that: The preparation method of the functional additive is: (1) Pre-treating the zeolite, specifically: pouring 2.5-4 g of zeolite into a ball mill, crushing it, taking it out and sieving it; (2) activating the sieved zeolite, pouring it into 10-15 mL of deionized water, and ultrasonically treating it until it is completely dissolved to prepare solution A; (3) Pour 50-60 mL of acetic acid solution into 2-3.6 g of chitosan and allow to react for 10-12 h to obtain solution B; (4) Slowly add solution A to solution B, and after sufficient reaction for 4-6 hours, add 100-115 mL of 2 mol / L sodium hydroxide solution; (5) washing the reaction product with deionized water until its pH is neutral; (6) Add 40-52 mL of 7.5%-8.5% glutaraldehyde solution, raise the temperature to 60-70° C., and react for 2.5-3.5 hours; (7) After the reaction is completed, freeze-dry for 20-24 hours to obtain the functional additive.

6. The method for preparing a boiler decoking and ash cleaning combustion-supporting agent according to claim 5, characterized in that: In the above (1), the crushing process is carried out at a rotation speed of 250-280 r / min for 10-15 min, and then the crushed product is taken out and passed through a 60-100 mesh sieve.

7. The method for preparing a boiler decoking and ash cleaning combustion-supporting agent according to claim 5, characterized in that: In the above (2), the specific method for activating the zeolite is: placing the sieved zeolite in a high-temperature furnace, heating it to 800-1000°C and calcining it for 55-70 minutes, and then naturally cooling it to room temperature in the furnace.

8. The method for preparing a boiler decoking and ash cleaning combustion-supporting agent according to claim 5, characterized in that: In (3), the concentration of chitosan is 4% g / mL; the amount fraction of the acetic acid solution is 5%.

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