A catalytic improver for raw coal combustion

Abstract

The present invention belongs to the field of coal energy technology, and in particular to a catalytic improver for raw coal combustion, which is composed of a mixture of metal oxides, iron-containing compounds, metal carboxylates, alumina, rare earths and water, and is characterized in that: the metal oxides include Al 2 O 3 , Fe 2 O 3 , Fe 3 O 4 and MnO 2 ; Iron compounds include FeCl 3 and FeCl 2 ; Metal carboxylates include Mg(CH 3 COO 2 and Na 2 C 2 O 4 ; Alumina is Al 2 O 3 ·3H 2 O; rare earth is La(NO 3 ) 3 The present invention can effectively improve the combustion characteristics of coal, greatly improve the reactivity and combustibility of coal, thereby improving the combustion efficiency of raw coal, reducing energy consumption, and effectively reducing SO in exhaust gas. 2 , CO, and NOx contents, thereby achieving the effect of energy conservation and emission reduction. During boiler operation, the boiler thermal efficiency is increased by 3.11%-3.98%, and the coal saving rate reaches 4-12%, which has good economic benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of coal energy, and in particular relates to a catalytic improver for raw coal combustion. Background Art

[0002] Raw coal contains high ash and gangue content and many harmful impurities. The utilization rate of raw coal directly used for boiler combustion is low and it will cause great harm to the environment. Therefore, how to improve the combustion efficiency of raw coal and then improve the thermal efficiency of equipment to achieve the goal of energy conservation and emission reduction, among which raw coal catalyst is a hot issue currently being studied and improved.

[0003] Raw coal catalyst has excellent combustion promotion effect, and also has good desulfurization and denitrification effect. In recent years, the raw coal catalyst has been continuously improved and studied, and certain results have been achieved. For example, a coal combustion catalyst disclosed in patent announcement number CN107460018B is composed of a mixture of rare earth compounds, transition metal salts, alkali metal salts, alkaline earth metal salts, oxygen group element compounds and water, which can effectively reduce energy consumption. In large thermal power units, coal can be saved by 5-10g per kilowatt-hour, and the oxygen content of boiler operation can be reduced by 20%; the coal saving rate in small and medium-sized kilns is 5-30%; the combustion temperature can be increased by 150-250℃, which has obvious economic benefits.

[0004] Another example is a coal combustion catalyst disclosed in patent announcement number CN103103006B and a preparation and use method thereof. The catalyst is composed of the following raw materials by weight: 326-472 parts of water, 202-292 parts of ferrous chloride, 125-181 parts of potassium chloride, 77-111 parts of calcium chloride, 48-69 parts of urotropine, 19-27 parts of tourmaline powder, 18-26 parts of fumed silica, 15-21 parts of octylphenol polyoxyethylene ether, 15-21 parts of sodium dodecylbenzene sulfonate, and 11-16 parts of sodium methylene dinaphthalene sulfonate. When used, the catalyst is diluted with water activated by tourmaline and then evenly sprinkled on the coal. The catalyst raw material of the present invention is cheap, has no safety hazards, has good stability, and is easy to use. Through the activation treatment of tourmaline, the catalyst efficacy is further improved, the coal saving and sulfur fixation effects are significant, and the occurrence of boiler coking accidents can be prevented.

[0005] Another example is a coal combustion catalyst disclosed in patent publication number CN104371791A, which is made of the following raw materials in weight percentage: 13-22% diethanol monoisoalcohol amine, 25-35% triethanolamine, 10-15% non-ionic surfactant, 13-20% papermaking black liquor, 15-20% sugar factory waste liquid, 1-6% alkali metal salt, and 0.2-0.8% rare earth element compound. The invention optimizes the performance of the coal catalyst and reduces its cost. The coal combustion catalyst of the present invention can reduce the ignition point and burnout temperature of coal, accelerate the combustion rate of coal, and at the same time, the coal can be fully burned, which not only reduces coal consumption and cost, but also reduces the emission of harmful gases such as SO2 and NOx, providing favorable conditions for changing the burning of high-quality coal to inferior coal.

[0006] The "desulfurization, combustion-aiding and decoking cleaning agent for coal combustion" developed by Shaanxi Province's "Yililai" Company has achieved good environmental value and economic benefits, and has been adopted by many large coal-consuming enterprises in Shanxi, Shaanxi and Inner Mongolia. According to materials, this technology can reduce sulfur dioxide emissions by 40%-55%, reduce nitrogen oxides by 20%-30%, and save 3%-8% of coal in general, significantly reduce the blackness of exhaust smoke, and remove ash and coke by more than 90%.

[0007] The raw coal catalyst in the prior art has the following deficiencies:

[0008] 1. The formula and use method of the raw coal catalyst are relatively complicated. For example, the coal combustion catalyst and its preparation and use method disclosed in patent announcement number CN103103006B, in which the catalyst needs to be diluted with water activated by tourmaline and then evenly sprinkled on the coal. The process is complicated and technically difficult, the production cost of the catalyst is high, and there is a problem that it cannot be mass-produced and applied;

[0009] 2. Existing catalysts have poor stability. For example, a coal combustion catalyst disclosed in patent publication number CN104371791A contains a large amount of triethanolamine. Triethanolamine belongs to the third category of dangerous goods and is flammable. It is dangerous to cause combustion when exposed to high heat, open flame or contact with oxidants. The cost of storage and transportation is greatly increased, and there are risks of combustion and explosion.

[0010] 3. Raw coal is produced without screening and processing in coal mines, including natural coke and inferior coal, with high ash and gangue content. The types, contents, particle sizes and other factors of impurities in the raw coal will affect the catalytic effect of the catalyst. Raw coal has not been crushed and processed, and its larger particle size will reduce the contact area with the catalyst, thereby reducing the catalytic effect. In addition, the raw coal contains more impurities such as sulfur and phosphorus, which will inactivate the active ingredients in the catalyst, thereby affecting the catalytic effect of the catalyst. Existing coal catalysts have not effectively solved the above problems. For example, a coal combustion catalyst disclosed in patent announcement number CN107460018B has no significant coal saving and emission reduction effects in actual application in raw coal catalysis, and has low economic benefits. Summary of the invention

[0011] The purpose of the present invention is to provide a catalytic improver for raw coal combustion that can reduce energy consumption, has good energy-saving and emission-reduction effects, and has good economic benefits, in response to the problems of high cost and technical difficulty of catalyst production, poor catalyst stability, and low economic benefits raised in the above-mentioned background technology.

[0012] To achieve the above object, the present invention adopts the following technical scheme: a catalytic improver for raw coal combustion, which is composed of a mixture of metal oxides, iron-containing compounds, metal carboxylates, alumina, rare earths and water, and is characterized in that:

[0013] Metal oxides include Al2O3, Fe2O3, Fe3O4 and MnO2;

[0014] Iron-containing compounds include FeCl3 and FeCl2;

[0015] Metal carboxylates include Mg(CH3COO)2 and Na2C2O4;

[0016] Alumina is Al2O3·3H2O;

[0017] Rare earth is La(NO3)3.

[0018] Furthermore, the catalyst improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0019] Metal oxide Al2O3 is 3-5

[0020] Metal oxide Fe2O3 is 3.5-5

[0021] Metal oxide Fe3O4 is 2-6

[0022] Metal oxide MnO2 is 0.5-3

[0023] Iron compound FeCl3 is 2.25-4.75

[0024] Iron compounds FeCl2 is 8-19

[0025] Metal carboxylate Mg(CH3COO)2 is 1.5-6

[0026] Metal carboxylates Na2C2O4 are 2-3.5

[0027] Alumina Al2O3·3H2O is 0.25-1.3

[0028] Rare earth La(NO3)3 is 0.3-1

[0029] The rest is water.

[0030] The beneficial effects of the present invention are:

[0031] 1. The present invention can effectively improve the combustion characteristics of coal, greatly improve the reactivity and combustibility of coal, thereby improving the combustion efficiency of raw coal, reducing energy consumption, and effectively reducing the content of SO2, CO, and NOx in exhaust gas, thereby achieving the effect of energy saving and emission reduction. During boiler operation, the thermal efficiency of the boiler is increased by 3.11%-3.98%, and the coal saving rate reaches 4-12%, which has good economic benefits.

[0032] 2. In the present invention, Fe2O3 can be used as a carrier to adsorb harmful substances in raw coal, reduce the toxicity and pollution of raw coal, and provide active vacancies to promote the oxidation reaction of CO and SO2 in raw coal, reduce the combustion point of raw coal, and at the same time, dissociate harmful substances in raw coal to prevent them from participating in the combustion reaction, thereby achieving the purpose of lowering the combustion point of raw coal. MnO2 can improve the combustion performance of coal powder, thereby increasing the combustion rate of coal powder, and the combustion rate of raw coal is increased by 3%-8%.

[0033] 3. In the present invention, FeCl3 and FeCI2 can increase the volatile matter during coal combustion and reduce the ignition temperature of coal coke, thereby increasing the combustion rate during low-temperature combustion and making the ignition and combustion of raw coal easier.

[0034] 4. In the present invention, Mg(CH3COO)2 and Na2C2O4 promote mass transfer and reaction between coal and oxygen by modifying the surface of coal, thereby reducing combustion temperature and improving combustion efficiency. They can also convert harmful gases such as SO2, CO, and NOx in exhaust gas into harmless substances, effectively reducing the content of SO2, CO, and NOx in exhaust gas, and reducing the emission of pollutants such as nitrogen oxides and sulfur oxides.

[0035] 5. In the present invention, alumina and rare earth are used as carriers of catalyst improvers, which have high thermal stability and chemical stability, thereby improving the performance stability of the catalyst improvers.

[0036] 6. In the present invention, the catalyst improver has low raw material cost. Metal oxides, iron-containing compounds and metal carboxylates are added to water in proportion, fully mixed in a reactor, and then alumina and rare earth are added. The mixture is heated to 50°C and stirred for 1 hour. The preparation method is simple. Compared with the existing technology and products, the catalyst improver of the present invention has low raw material cost and is more conducive to large-scale production and application.

[0037] 7. In the present invention, the catalyst improver has a wide range of applications, not only suitable for boilers and coal furnaces, but also suitable for use in thermal power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a bar chart of the mass percentages of the components in Example 1 of a catalytic improver for raw coal combustion provided by the present invention;

[0039] Figure 2 It is a bar chart of the mass percentages of the components in Example 2 of a catalytic improver for raw coal combustion provided by the present invention;

[0040] Figure 3 It is a bar chart of the mass percentages of the components in Example 3 of a catalytic improver for raw coal combustion provided by the present invention;

[0041] Figure 4 It is a bar chart of the mass percentages of the components in Example 4 of a catalytic improver for raw coal combustion provided by the present invention;

[0042] Figure 5 It is a bar chart of the mass percentages of the components in Example 5 of a catalytic improver for raw coal combustion provided by the present invention;

[0043] Figure 6 It is a bar chart of the mass percentages of the components in Example 6 of a catalytic improver for raw coal combustion provided by the present invention;

[0044] Figure 7 It is a bar chart of the mass percentages of the components in Example 7 of a catalytic improver for raw coal combustion provided by the present invention;

[0045] Figure 8 It is a bar chart of the mass percentages of the components in Example 8 of a catalytic improver for raw coal combustion provided by the present invention;

[0046] Fig. 9 It is a bar chart of the mass percentages of the components in Example 9 of a catalytic improver for raw coal combustion provided by the present invention. DETAILED DESCRIPTION

[0047] The following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0048] Example 1

[0049] Reference Figure 1 , a catalytic improver for raw coal combustion, the catalytic improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0050] Metal oxide Al2O3 is 3.5

[0051] Metal oxide Fe2O3 is 5

[0052] Metal oxide Fe3O4 is 3.5

[0053] Metal oxide MnO2 is 2.25

[0054] The iron compound FeCl3 is 3

[0055] The iron compound FeCl2 is 13

[0056] Metal carboxylate Mg(CH3COO)2 is 3

[0057] Metal carboxylates Na2C2O4 is 2.75

[0058] Alumina Al2O3·3H2O is 1.25

[0059] Rare earth La(NO3)3 is 0.5

[0060] The rest is water.

[0061] Example 2

[0062] Reference Figure 2 , a catalytic improver for raw coal combustion, the catalytic improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0063] Metal oxide Al2O3 is 3.5

[0064] Metal oxide Fe2O3 is 5

[0065] Metal oxide Fe3O4 is 3.5

[0066] Metal oxide MnO2 is 2.25

[0067] The iron compound FeCl3 is 3

[0068] The iron compound FeCl2 is 15

[0069] Metal carboxylate Mg(CH3COO)2 is 3

[0070] Metal carboxylates Na2C2O4 is 2.75

[0071] Alumina Al2O3·3H2O is 1.25

[0072] Rare earth La(NO3)3 is 1

[0073] The rest is water.

[0074] Example 3

[0075] Reference Figure 3 , a catalytic improver for raw coal combustion, the catalytic improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0076] Metal oxide Al2O3 is 3.5

[0077] Metal oxide Fe2O3 is 5

[0078] Metal oxide Fe3O4 is 3.5

[0079] Metal oxide MnO2 is 2.25

[0080] The iron compound FeCl3 is 3

[0081] The iron compound FeCl2 is 16

[0082] Metal carboxylate Mg(CH3COO)2 is 3

[0083] Metal carboxylates Na2C2O4 is 2.75

[0084] Alumina Al2O3·3H2O is 1.25

[0085] Rare earth La(NO3)3 is 0.5

[0086] The rest is water.

[0087] Example 4

[0088] Reference Figure 4 , a catalytic improver for raw coal combustion, the catalytic improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0089] Metal oxide Al2O3 is 3.5

[0090] Metal oxide Fe2O3 is 5

[0091] Metal oxide Fe3O4 is 3.5

[0092] Metal oxide MnO2 is 2.25

[0093] The iron compound FeCl3 is 3

[0094] The iron compound FeCl2 is 16

[0095] Metal carboxylate Mg(CH3COO)2 is 3

[0096] Metal carboxylates Na2C2O4 are 3

[0097] Alumina Al2O3·3H2O is 1.2

[0098] Rare earth La(NO3)3 is 0.5

[0099] The rest is water.

[0100] Example 5

[0101] Reference Figure 5 , a catalytic improver for raw coal combustion, the catalytic improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0102] Metal oxide Al2O3 is 3.5

[0103] Metal oxide Fe2O3 is 5

[0104] Metal oxide Fe3O4 is 3.5

[0105] Metal oxide MnO2 is 2.25

[0106] The iron compound FeCl3 is 3

[0107] The iron compound FeCl2 is 18

[0108] Metal carboxylate Mg(CH3COO)2 is 3

[0109] Metal carboxylates Na2C2O4 are 3

[0110] Alumina Al2O3·3H2O is 1.2

[0111] Rare earth La(NO3)3 is 1

[0112] The rest is water.

[0113] Example 6

[0114] Reference Figure 6 , a catalytic improver for raw coal combustion, the catalytic improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0115] Metal oxide Al2O3 is 3.5

[0116] Metal oxide Fe2O3 is 5

[0117] Metal oxide Fe3O4 is 3.5

[0118] Metal oxide MnO2 is 3

[0119] The iron compound FeCl3 is 3

[0120] The iron compound FeCl2 is 17

[0121] Metal carboxylate Mg(CH3COO)2 is 3

[0122] Metal carboxylates Na2C2O4 are 3

[0123] Alumina Al2O3·3H2O is 1.2

[0124] Rare earth La(NO3)3 is 1

[0125] The rest is water.

[0126] Example 7

[0127] Reference Figure 7 , a catalytic improver for raw coal combustion, the catalytic improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0128] Metal oxide Al2O3 is 3.5

[0129] Metal oxide Fe2O3 is 5

[0130] Metal oxide Fe3O4 is 3.5

[0131] Metal oxide MnO2 is 3

[0132] The iron compound FeCl3 is 3

[0133] The iron compound FeCl2 is 16

[0134] Metal carboxylate Mg(CH3COO)2 is 3

[0135] Metal carboxylates Na2C2O4 are 3

[0136] Alumina Al2O3·3H2O is 1

[0137] Rare earth La(NO3)3 is 1

[0138] The rest is water.

[0139] Example 8

[0140] Reference Figure 8 , a catalytic improver for raw coal combustion, the catalytic improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0141] Metal oxide Al2O3 is 3.5

[0142] Metal oxide Fe2O3 is 3.5

[0143] Metal oxide Fe3O4 is 3.5

[0144] Metal oxide MnO2 is 3

[0145] The iron compound FeCl3 is 3

[0146] The iron compound FeCl2 is 18

[0147] Metal carboxylate Mg(CH3COO)2 is 3

[0148] Metal carboxylates Na2C2O4 are 3

[0149] Alumina Al2O3·3H2O is 1

[0150] Rare earth La(NO3)3 is 1

[0151] The rest is water.

[0152] Example 9

[0153] Reference Fig. 9 , a catalytic improver for raw coal combustion, the catalytic improver uses water as a dispersion medium, and each component is mixed in water according to the following mass percentages of raw materials:

[0154] Metal oxide Al2O3 is 3.5

[0155] Metal oxide Fe2O3 is 3.5

[0156] Metal oxide Fe3O4 is 3.5

[0157] Metal oxide MnO2 is 3

[0158] The iron compound FeCl3 is 4.5

[0159] The iron compound FeCl2 is 18

[0160] Metal carboxylate Mg(CH3COO)2 is 3

[0161] Metal carboxylates Na2C2O4 are 3

[0162] Alumina Al2O3·3H2O is 1

[0163] Rare earth La(NO3)3 is 0.3

[0164] The rest is water.

[0165] Experiments have proved that the present invention can effectively improve the combustion characteristics of coal, greatly improve the reactivity and combustibility of coal, thereby improving the combustion efficiency of raw coal, reducing energy consumption, and effectively reducing the content of SO2, CO, and NOx in exhaust gas, thereby achieving the effect of energy saving and emission reduction. During boiler operation, the thermal efficiency of the boiler is increased by 3.11%-3.98%, and the coal saving rate reaches 4-12%, which has good economic benefits.

[0166] Fe2O3 can be used as a carrier to adsorb harmful substances in raw coal, reduce the toxicity and pollution of raw coal, and provide active vacancies to promote the oxidation reaction of CO and SO2 in raw coal, reduce the combustion point of raw coal, and at the same time dissociate harmful substances in raw coal to prevent them from participating in the combustion reaction, thereby achieving the purpose of lowering the combustion point of raw coal. MnO2 can improve the combustion performance of coal powder, thereby increasing the combustion rate of coal powder, and the combustion rate of raw coal is increased by 3%-8%.

[0167] FeCl3 and FeCI2 can increase the volatile matter in the coal combustion process and reduce the ignition temperature of coal coke, increase the combustion rate in the low-temperature combustion process, and make the ignition and combustion of raw coal easier.

[0168] Mg(CH3COO)2 and Na2C2O4 promote mass transfer and reaction between coal and oxygen by modifying the coal surface, thereby reducing combustion temperature and improving combustion efficiency. They can also convert harmful gases such as SO2, CO, and NOx in exhaust gas into harmless substances, effectively reducing the content of SO2, CO, and NOx in exhaust gas, and reducing the emission of pollutants such as nitrogen oxides and sulfur oxides.

[0169] Alumina and rare earth as carriers of catalyst improvers have high thermal stability and chemical stability, which improve the performance stability of catalyst improvers.

[0170] In order to more accurately examine the coal-saving and SO2 emission reduction effects of the catalytic improver on the test boiler, the experiment was carried out under a stable production cycle. The operating load of the boiler should be relatively stable during the test. During the test, the boiler load, the quality of the coal fed into the boiler, and the particle size of the raw coal should be as consistent as possible.

[0171] From the experimental results, adding catalytic improver to the boiler has certain economic benefits. The experimental results are shown in the following table:

[0172]

[0173]

[0174] The catalyst improver has low raw material cost for preparation. Metal oxide, iron-containing compound and metal carboxylate are added into water in proportion, fully and evenly mixed in a reaction kettle, and then alumina and rare earth are added. The mixture is heated to 50° C. and mixed and stirred for 1 hour. The preparation method is simple. Compared with the existing technology and products, the catalyst improver of the present invention has low raw material cost and is more conducive to large-scale production and application. It is not only suitable for boilers and coal furnaces, but also suitable for use in thermal power plants, and has better economic benefits and wider applicability.

[0175] Further, the experimental results were verified by using the catalyst improver of the present invention in a thermal power plant. A comparative experiment was conducted before and after adding the raw coal combustion catalyst improver in three 260t / h boilers of the thermal power plant for 35 days. The experimental results are shown in the following table:

[0176] Comparison of experimental results of adding catalytic improver to raw coal combustion in three 260t / h boilers

[0177]

[0178] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A catalytic improver for raw coal combustion, which is a mixture of metal oxides, iron-containing compounds, metal carboxylates, alumina, rare earths and water, characterized in that: Metal oxides include Al2O3, Fe2O3, Fe3O4 and MnO2; Iron-containing compounds include FeCl3 and FeCl2; Metal carboxylates include Mg(CH3COO)2 and Na2C2O4; Alumina is Al2O3·3H2O; Rare earth is La(NO3)3; The catalyst improver uses water as the dispersion medium, and each component is mixed in water according to the following mass percentage of raw materials: Metal oxide Al2O3 is 3-5 Metal oxide Fe2O3 is 3.5-5 Metal oxide Fe3O4 is 2-6 Metal oxide MnO2 is 0.5-3 Iron compound FeCl3 is 2.25-4.75 Iron compounds FeCl2 is 8-19 Metal carboxylate Mg(CH3COO)2 is 1.5-6 Metal carboxylates Na2C2O4 are 2-3.5 Alumina Al2O3·3H2O is 0.25-1.3 Rare earth La(NO3)3 is 0.3-1 The rest is water; The preparation method is as follows: Metal oxides, iron-containing compounds and metal carboxylates are added to water in proportion, and after being fully mixed in a reaction kettle, alumina and rare earth are added, and the mixture is heated to 50° C. and then mixed and stirred for 1 hour.

Images