Fire coal catalyst as well as preparation method and application thereof

Abstract

The invention relates to the technical field of catalyst preparation, in particular to a coal-fired catalyst and a preparation method and application thereof.The coal-fired catalyst is at least prepared from, by weight, 180-300 parts of organic salt solution, 200-350 parts of inorganic salt solution and 50-70 parts of water, the organic salt solution at least comprises pyridinium acetate or sodium benzoate, and the inorganic salt solution at least comprises ammonium acetate or sodium benzoate; the problems that an existing oxygen supply combustion-supporting additive is poor in using effect, coal cannot be fully combusted, and the combustion efficiency cannot be remarkably improved are solved, and the application requirement of the subsequent fire coal field is better met.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst preparation, and specifically to a coal combustion catalyst, its preparation method and application. Background Art

[0002] Coal is one of the important energy mineral resources and chemical raw materials in China. It is the most commonly used energy raw material in modern industry and is widely used in industrial production such as power, steel, and chemical industries, as well as in the field of residents' life. Among them, the coal consumption in the power industry accounts for more than 60% of the national coal consumption. With the development of the economy, the annual demand for coal in the power industry shows a significant increasing trend.

[0003] Although China's coal reserves are relatively rich, since coal is a primary energy source and cannot be recycled, improving the combustion efficiency of coal, increasing the heat release of coal, and making coal combustion more complete are important issues that all coal-related industries, especially the power industry, are working hard to solve.

[0005] In recent years, several types of coal energy-saving additives have been introduced to the market in China. These coal energy-saving additives are mainly oxygen-supplying combustion-supporting additives. Oxygen-supplying combustion-supporting additives improve the combustion efficiency by using substances that can decompose and release oxygen at high temperatures (such as potassium nitrate, sodium nitrate, potassium permanganate, potassium chlorate, ammonium nitrate, etc.). For example, Chinese Patent (authorized publication number CN 113814002 B) discloses a coal combustion catalyst, its preparation method and application. Sodium chloride, potassium salts, transition metal oxides, limestone, and sodium ningmingsu are added to the system. Although such additives have a certain effect on boilers with low combustion efficiency, their coal-saving effect is not obvious enough. When they are applied to low-quality coal or low-calorie coal, their effect is minimal. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides a coal combustion catalyst, which overcomes the problems of poor use effect of existing oxygen-supplying combustion-supporting additives, inability to make coal burn fully, and inability to significantly improve the combustion efficiency, and better meets the application requirements in the subsequent coal combustion field.

[0007] The present invention provides a coal combustion catalyst, which, by weight, at least comprises the following raw materials: 180 - 300 parts of an organic salt solution, 200 - 350 parts of an inorganic salt solution, and 50 - 70 parts of water, wherein the organic salt solution at least comprises pyridine acetate or sodium benzoate.

[0008] As a preferred technical solution, the inorganic salt solution is composed of an inorganic salt composition and water, and the mass ratio of the inorganic salt composition to water is (20 - 50) : (150 - 250), preferably (29 - 45) : (210 - 240).

[0009] As a preferred technical solution, the inorganic salt composition at least includes sodium nitrate and iron nitrate.

[0010] Preferably, the inorganic salt composition further includes at least two of zinc nitrate, nickel nitrate, manganese nitrate or chromium nitrate.

[0011] Preferably, the inorganic salt composition further includes an oxidant, and the oxidant is at least one of potassium persulfate and sodium chlorite.

[0012] As a preferred technical solution, by weight, the inorganic salt composition includes: 10-28 parts of sodium nitrate, 3-5 parts of iron nitrate, 3-5 parts of zinc nitrate, 2-5 parts of nickel nitrate, 5-10 parts of manganese nitrate, and 0-10 parts of potassium persulfate.

[0013] Through a large number of experimental studies, the present invention finds that by optimizing the combination of the inorganic salt composition and the organic salt in the coal combustion catalyst, through the synergistic effect among various substances, the combustion can be accelerated, thereby increasing the heat release rate, reducing the basic heat, and further increasing the heat release. In particular, controlling the inorganic salt composition in the system to include: 10-28 parts of sodium nitrate, 3-5 parts of iron nitrate, 3-5 parts of zinc nitrate, 2-5 parts of nickel nitrate, 5-10 parts of manganese nitrate, and 0-10 parts of potassium persulfate can ensure the effect of coal combustion catalysis while avoiding unnecessary waste, effectively avoiding the generation of sulfides and nitrogen oxides during the combustion process, overcoming the problem of corrosion of equipment caused by the introduction of excessive chloride ions, and better meeting the actual application requirements.

[0014] Furthermore, by introducing pyridine acetate or sodium benzoate in combination, especially introducing sodium benzoate, when the provided coal combustion catalyst is actually applied, it can significantly improve the combustion characteristics of coal, accelerate the flame propagation speed at the initial stage of pulverized coal ignition, accelerate the breakage of various bonding bonds during the coal pyrolysis process, increase the evolution rate of coal volatile matter, reduce the ignition temperature of coal, accelerate the combustion speed of coke, shorten the combustion time, and thus improve the combustion efficiency of coal.

[0015] In addition, from the actual application results, the coal combustion catalyst system using 10-28 parts of sodium nitrate, 3-5 parts of iron nitrate, 3-5 parts of zinc nitrate, 2-5 parts of nickel nitrate, 5-10 parts of manganese nitrate, 0-10 parts of potassium persulfate + sodium benzoate can even meet some coal combustion fields with complex compositions, including coal combustion applications in the cement industry. During the process of producing clinker in a cement plant, coal is involved. When a conventional coal combustion catalyst is added and applied, the coal consumption cannot be effectively reduced. The above-mentioned coal combustion catalytic system provided by the present invention can effectively overcome the influence of complex components such as iron powder and waste in raw materials on the coal combustion catalytic effect, greatly reduce the coal consumption, and save costs.

[0016] As a preferred technical solution, the organic salt solution is composed of pyridinium acetate or sodium benzoate and water, and the mass ratio of pyridinium acetate or sodium benzoate to water is (5 - 20):(150 - 250), preferably (8 - 12):(210 - 240).

[0017] As a preferred technical solution, by weight, the organic salt solution is composed of 8 - 12 parts of sodium benzoate and 210 - 240 parts of water.

[0018] On the other hand, the present invention provides a preparation method of a coal - burning catalyst, which includes the following steps: preparing an organic salt solution and an inorganic salt solution respectively, and obtaining the coal - burning catalyst after stirring and mixing the organic salt solution, the inorganic salt solution and water.

[0019] In the third aspect of the present invention, an application of a coal - burning catalyst is provided, which is applied to the field of coal combustion. The weight ratio of the coal - burning catalyst to coal is (0.6 - 1.2):1000, preferably (0.6 - 1.0):1000.

[0020] The coal - burning catalyst provided by the present invention is applied to the coal - fired boilers in power plants or the clinker production in cement plants. The coal - fired boilers in power plants include pulverized coal boilers or circulating fluidized bed boilers in power plants.

[0021] The coal - burning catalyst provided by the present invention has no particular limitation on the type of coal and can be applied to the coal - burning process of various coals. Preferably, the coal - burning catalyst is applied to the coal - burning process of coal with a volatile content not exceeding 50wt%. When the volatile content of coal exceeds 50wt%, the coal itself has a relatively high volatile content and a relatively low ignition point, and is itself flammable. Therefore, there is no need to use the coal - burning catalyst, and the effect is not obvious when used.

[0022] The dosage of the coal - burning catalyst provided by the present invention can be determined according to the carbon content of the coal. The higher the carbon content of the coal, the higher the dosage of the coal - burning catalyst. When the dosage of the coal - burning catalyst is lower than the above range, the sufficient catalytic effect may not be achieved. When the dosage of the coal - burning catalyst is higher than the above range, the coal - burning effect will not be further improved, and unnecessary waste will be caused.

[0023] The coal - burning catalyst contacts with coal in a solid form or an aqueous solution form; preferably, the coal - burning catalyst contacts with coal in an aqueous solution form.

[0024] Through the above - mentioned technical solution, the combustion of coal can be accelerated, the heat release during coal combustion can be accelerated, thereby reducing the supply of basic heat, improving the combustion efficiency of coal, and at the same time, the waste heat power generation can be increased, and the production cost and operation cost of enterprises can be reduced.

[0025] Through the above technical solution, the coal combustion catalyst has an expansion effect on the pore structure and pore size of coal. After expansion, the coal has larger pore structures and pore sizes, which helps to better accommodate oxygen and promote its diffusion and combustion. Therefore, the melting temperature, thermal conductivity, heat capacity, etc. of the coal will also have a positive impact on the expansion effect.

[0026] In the present invention, the coal saving rate refers to the difference in fuel consumption for generating the same amount of heat by burning the same fuel under the same combustion environment, that is, the coal saving rate = (original coal consumption - coal consumption after using this coal combustion catalyst) / original coal consumption; the combustion efficiency of the coal refers to the ratio of the actual heat released after coal combustion to the heat released after its complete combustion, which is an important index for examining the degree of complete combustion of the fuel.

[0027] Beneficial effects

[0028] 1. The present invention provides a coal combustion catalyst, which overcomes the problems of poor use effect of existing oxygen supply and combustion assistance additives, inability to make coal burn fully, and inability to significantly improve the combustion efficiency, and better meets the application requirements in the subsequent coal combustion field.

[0029] 2. Through a large number of experimental studies, the present invention finds that by optimizing the combination of inorganic salts and organic salts in the coal combustion catalyst and through the synergistic effect among various substances, the combustion can be accelerated, thereby increasing the heat release rate, reducing the basic heat, and further increasing the heat release.

[0030] 3. By controlling the inorganic salt composition in the system to include: 10 - 28 parts of sodium nitrate, 3 - 5 parts of iron nitrate, 3 - 5 parts of zinc nitrate, 2 - 5 parts of nickel nitrate, 5 - 10 parts of manganese nitrate, and 0 - 10 parts of potassium persulfate, while ensuring the effect of coal combustion catalysis, unnecessary waste is avoided, sulfides and nitrogen oxides generated during combustion are effectively avoided, and the problem of equipment corrosion caused by introducing excessive chloride ions is overcome, better meeting the actual application requirements.

[0031] 4. By introducing pyridine acetate or sodium benzoate in combination, especially introducing sodium benzoate, the coal combustion catalyst provided can significantly improve the combustion characteristics of coal during actual application, accelerate the flame propagation speed at the initial stage of pulverized coal ignition, accelerate the breaking of various bonding bonds during the coal pyrolysis process, increase the release rate of coal volatile matter, reduce the ignition temperature of coal, accelerate the combustion speed of coke, shorten the combustion time, and thus improve the combustion efficiency of coal.

[0032] 5. The coal combustion catalyst provided by the present invention can reduce the ignition point of coal, improve the combustion efficiency of coal, increase the waste heat power generation of the boiler, reduce coal consumption, and reduce the emission of pollutant substances, and has extremely high market promotion value. Specific embodiments

[0033] Examples 1 - 6

[0034] Examples 1-6 of the present invention provide a coal combustion catalyst. By weight, the formulation is shown in Table 1.

[0035] Table 1

[0036]

[0037]

[0038] On the other hand, Example 1 of the present invention provides a preparation method of a coal combustion catalyst, comprising the following steps: stirring and mixing the raw materials of the organic salt solution for 13 min to obtain the organic salt solution, stirring and mixing the raw materials of the inorganic salt solution for 23 min to obtain the inorganic salt solution, and stirring and mixing the organic salt solution, the inorganic salt solution and water for 13 min to obtain the coal combustion catalyst.

[0039] On the other hand, Example 2 of the present invention provides a preparation method of a coal combustion catalyst, comprising the following steps: stirring and mixing the raw materials of the organic salt solution for 11 min to obtain the organic salt solution, stirring and mixing the raw materials of the inorganic salt solution for 21 min to obtain the inorganic salt solution, and stirring and mixing the organic salt solution, the inorganic salt solution and water for 11 min to obtain the coal combustion catalyst.

[0040] On the other hand, Example 3 of the present invention provides a preparation method of a coal combustion catalyst, comprising the following steps: stirring and mixing the raw materials of the organic salt solution for 14 min to obtain the organic salt solution, stirring and mixing the raw materials of the inorganic salt solution for 22 min to obtain the inorganic salt solution, and stirring and mixing the organic salt solution, the inorganic salt solution and water for 15 min to obtain the coal combustion catalyst.

[0041] On the other hand, Example 4 of the present invention provides a preparation method of a coal combustion catalyst, comprising the following steps: stirring and mixing the raw materials of the organic salt solution for 10 min to obtain the organic salt solution, stirring and mixing the raw materials of the inorganic salt solution for 20 min to obtain the inorganic salt solution, and stirring and mixing the organic salt solution, the inorganic salt solution and water for 10 min to obtain the coal combustion catalyst.

[0042] On the other hand, Example 5 of the present invention provides a preparation method of a coal combustion catalyst, comprising the following steps: stirring and mixing the raw materials of the organic salt solution for 13 min to obtain the organic salt solution, stirring and mixing the raw materials of the inorganic salt solution for 22 min to obtain the inorganic salt solution, and stirring and mixing the organic salt solution, the inorganic salt solution and water for 13 min to obtain the coal combustion catalyst.

[0043] Another aspect of Embodiment 6 of the present invention provides a method for preparing a coal combustion catalyst, which includes the following steps: Stir and mix the raw materials of the organic salt solution for 14 minutes to obtain the organic salt solution, stir and mix the raw materials of the inorganic salt solution for 23 minutes to obtain the inorganic salt solution, and then stir and mix the organic salt solution, the inorganic salt solution and water for 14 minutes to obtain the coal combustion catalyst.

[0044] Performance test

[0045] 1. The coal combustion catalysts provided in Embodiments 1-6 were used in the pulverized coal furnace and circulating fluidized bed boiler of a power plant according to the addition amounts in Table 2 (for coal quality analysis, see Table 3), and were added and applied for 5 days. The coal saving rate was calculated as follows: Coal saving rate = (original coal consumption - coal consumption after using the coal combustion catalyst) / original coal consumption. The test results are shown in Table 2.

[0046] Table 2

[0047]

[0048] Table 3

[0049]

[0050] 2. A raw coal nitrogen and oxygen combustion analyzer was used to simulate the combustion of coal in the actual production process. The coal saving rate was determined based on the change in calorific value before and after adding the coal combustion catalyst. Specifically, the coal combustion catalyst provided in Embodiment 1 and raw coals 1-7 were dried for 1 hour. First, the bomb calorific values of raw coals 1-7 were tested; then, the bomb calorific values of the mixtures of raw coals 1-7 + the coal combustion catalyst in Embodiment 1 were tested. The addition amount of the coal combustion catalyst in Embodiment 1 was 1 / 1000 of the mass of the raw coal. Each experiment was parallel for 30 minutes and tested three times in parallel. The test results were averaged and are shown in Table 4; the carbon content and bomb calorific values of raw coals 1-7 are shown in Table 5.

[0051] Table 4

[0052]

[0053]

[0054] Table 5

[0055] Raw coal Carbon content (wt%) Bomb calorific value (cal) Raw coal 1 68.45 5921.47 Raw coal 2 65.12 5508.00 Raw coal 3 65.04 5454.77 Raw coal 4 77.96 6708.81 Raw coal 5 77.21 6648.31 Raw coal 6 72.85 6337.31 Raw coal 7 69.47 5908.12

[0056] 3. The coal combustion catalyst provided in Embodiment 1 was used in the actual production of clinker in a cement plant in Tibet. The results are shown in Table 6.

[0057]

[0058] Test description:

[0059] 1. September 29th to October 3rd was used as the blank period.

[0060] 2. October 6th to October 8th are used as the transition period.

[0061] 3. October 9th to October 10th are used as the additive test period.

[0062] 4. The additive is added at 13:00 on October 6th and stopped at 1:30 on October 11th. During this period, a total of 2,461 tons of raw coal are produced, 2.0 tons of coal combustion catalyst are used, equivalent to an additive dosage of 8.1‰.

[0063] Benefit analysis:

[0064] 1. After removing the cost per ton of clinker, the benefit is: 5.9 / 1000 * 1090 - 97.5 / 1000 * 8.1‰ * 20980 = 4.79 yuan (Note: 5.9 is the saved physical coal consumption after adding the additive, the arrival price of raw coal is 1090 yuan / ton, the arrival price of coal combustion catalyst is 20980 yuan / ton, the additive dosage of coal combustion catalyst is 8.1‰, and the physical coal consumption is 97.5 kg / t).

[0065] 2. The hourly output of clinker before adding the additive is 205.5 t / h, and after adding the additive, it is 208.7 t / h, with an increase of 3.2 t / h in the hourly output of clinker.

[0066] 3. The annual production of clinker is 950,000 tons. After adding the additive, 4.79 yuan is saved per ton of clinker, and the annual savings are: 950,000 * 4.79 = 4,550,500 yuan

[0067] Test conclusion:

[0068] 1. Compared with the blank period during the additive period, the physical coal consumption per ton of clinker is reduced by 5.9 kg / t.

[0069] 2. Compared with the blank period during the test period, the pulverized coal burns better during the test period, the thermal intensity of the burning zone is increased, the hourly output of clinker is increased by 3.2 t / h, and the thermal process system of the kiln is further stabilized.

[0070] 3. Through this test, the use effect of the coal combustion catalyst is obvious, which is beneficial to the enterprise's energy conservation and consumption reduction.

[0071] 4. This test of the coal combustion catalyst has no impact on the quality of clinker.

Claims

1. A coal combustion catalyst, characterized in that, By weight, it at least includes the following raw materials: 180 - 300 parts of organic salt solution, 200 - 350 parts of inorganic salt solution, and 50 - 70 parts of water. Among them, the organic salt solution at least includes pyridine acetate or sodium benzoate.

2. The coal combustion catalyst according to claim 1, wherein, The inorganic salt solution is composed of an inorganic salt composition and water, and the inorganic salt composition at least includes sodium nitrate and iron nitrate.

3. The coal combustion catalyst according to claim 2, characterized in that, The inorganic salt composition further includes at least two of zinc nitrate, nickel nitrate, manganese nitrate, or chromium nitrate.

4. The coal combustion catalyst according to claim 2, wherein, The inorganic salt composition further includes an oxidant, and the oxidant is at least one of potassium persulfate and sodium chlorite.

5. The coal combustion catalyst according to claim 2, characterized in that, By weight, the inorganic salt composition includes: 10 - 28 parts of sodium nitrate, 3 - 5 parts of iron nitrate, 3 - 5 parts of zinc nitrate, 2 - 5 parts of nickel nitrate, 5 - 10 parts of manganese nitrate, and 0 - 10 parts of potassium persulfate.

6. The coal combustion catalyst according to claim 1, characterized in that, The organic salt solution is composed of pyridine acetate or sodium benzoate and water, and the mass ratio of pyridine acetate or sodium benzoate to water is (5 - 20):(150 - 250).

7. The coal combustion catalyst according to claim 1, wherein By weight, the organic salt solution is composed of 8 - 12 parts of sodium benzoate and 210 - 240 parts of water.

8. A preparation method of the coal combustion catalyst according to any one of claims 1-7, characterized in that, It includes the following steps: Prepare the organic salt solution and the inorganic salt solution separately, and obtain the coal combustion catalyst after stirring and mixing the organic salt solution, the inorganic salt solution, and water.

9. Use of the coal combustion catalyst according to any one of claims 1-7, characterized in that, Applied to the coal combustion field, the weight ratio of the coal combustion catalyst to coal is (0.6 - 1.2):1000.

10. The application of the coal combustion catalyst according to claim 9, characterized in that, The weight ratio of the coal combustion catalyst to coal is (0.8 - 1.2):1000.

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