阅读说明：本技术 一种用于半焦燃烧脱硫脱硝的MnNbOx添加剂及其应用 (MnNbO for semicoke combustion desulfurization and denitrificationxAdditive and application thereof ) 是由 郭瑞堂 张新福 吴桂林 蔺智东 纪祥音 周珏 李正胜 潘卫国 于 2020-12-10 设计创作，主要内容包括：本发明涉及一种用于半焦燃烧脱硫脱硝的MnNbO-x添加剂及其应用,该添加剂包括锰元素和铌元素,将其均匀混合于半焦中改性半焦。与现有技术相比,本发明能有效强化半焦燃烧,减少半焦燃烧产物中的硫氧化物和氮氧化物,而且具有工艺制备简单、生产成本低、易于工业化等特点。(The invention relates to MnNbO for semicoke combustion desulfurization and denitrification x The additive comprises manganese element and niobium element, and the manganese element and the niobium element are uniformly mixed in the semicoke to modify the semicoke. Compared with the prior art, the method can effectively strengthen semicoke combustion and reduce sulfur oxides and nitrogen oxides in semicoke combustion products, and has the characteristics of simple process preparation, low production cost, easy industrialization and the like.)

1. MnNbO for semicoke combustion desulfurization and denitrification_xThe additive is characterized by comprising a manganese element and a niobium element.

2. The MnNbO for desulfurization and denitrification of semicoke combustion according to claim 1_xThe additive is characterized in that manganese oxide and niobic acid are respectively used as sources of a manganese element and a niobium element.

3. MnNbO for desulfurization and denitrification of semicoke combustion according to claim 1 or 2_xThe application of the additive is characterized in that the additive is uniformly mixed in the semicoke to modify the semicoke, so that sulfur oxides and nitrogen oxides in semicoke combustion products are reduced.

4. The MnNbO for desulfurization and denitrification of semicoke combustion according to claim 3_xThe application of the additive is characterized in that the addition amount of a manganese source substance accounts for 3 wt% of the semicoke, and the addition amount of a niobium source substance accounts for 1-4 wt% of the semicoke.

5. The MnNbO for desulfurization and denitrification of semicoke combustion according to claim 4_xThe application of the additive is characterized in that the addition amount of a manganese source substance accounts for 3 wt% of the semicoke, and the addition amount of a niobium source substance accounts for 2 wt% of the semicoke.

6. The MnNbO for desulfurization and denitrification of semicoke combustion according to claim 3_xUse of an additive, characterized in that the semicoke combustion is carried out in a fluidized-bed reactor.

7. MnNbO for desulfurization and denitrification of semicoke combustion according to claim 3 or 6_xThe application of the additive is characterized in that the burning temperature of the semicoke is 600-900 ℃.

8. The MnNbO for desulfurization and denitrification of semicoke combustion according to claim 3_xThe application of the additive is characterized in that the semicoke mixed with the additive is burnt in a powder form, and the excess air coefficient is 1.1-1.2.

9. MnNbO for desulfurization and denitrification of semicoke combustion according to claim 3 or 8_xThe application of the additive is characterized in that the particle size of the semicoke is 80 meshes.

10. MnNbO for desulfurization and denitrification of semicoke combustion according to claim 3 or 8_xThe application of the additive is characterized in that the semi-coke is obtained after pyrolysis for 1.5 hours at 650 ℃ in an argon atmosphere.

Technical Field

The invention relates to desulfurization and denitrificationThe semicoke combustion additive, in particular to MnNbO for semicoke combustion desulfurization and denitrification_xAdditives and their use.

Background

The energy structure of China is mainly coal, and although the coal resources are rich, the low-rank coal accounts for a relatively high proportion. The low-rank coal grading utilization technology can efficiently and cleanly utilize low-rank coal, wherein the main solid product semicoke has low water content, is good smokeless fuel with high calorific value, and can be used for combustion power generation and heat supply. Like coal combustion, semicoke combustion also produces SO₂And NO_x. SO in combustion flue gas₂And NO_xThe emission not only corrodes equipment, but also seriously pollutes air when being emitted into the atmosphere. SO (SO)₂And NO_xThe existing of the device can also improve the required exhaust gas temperature, waste heat energy and increase the equipment loss. Thus, controlling SO₂And NO_xGeneration and emission of (d) is a subject of great attention and research worldwide.

Disclosure of Invention

The invention aims to provide MnNbO for desulfurization and denitrification of semicoke combustion_xAdditives and their use. Effectively strengthen the semicoke combustion, reduce the sulfur oxides and nitrogen oxides in the semicoke combustion products, and has the characteristics of simple process preparation, low production cost, easy industrialization and the like.

The purpose of the invention can be realized by the following technical scheme:

the invention provides MnNbO for desulfurization and denitrification of semicoke combustion in a first aspect_xAnd the additive comprises a manganese element and a niobium element.

Preferably, manganese oxide and niobic acid are used as sources of the manganese element and niobium element, respectively.

The invention provides MnNbO for desulfurization and denitrification of semicoke combustion_xThe additive is applied, and the additive is uniformly mixed in the semicoke to modify the semicoke, so that sulfur oxides and nitrogen oxides in semicoke combustion products are reduced.

Preferably, the addition amount of the manganese source substance accounts for 3 wt% of the semicoke, and the addition amount of the niobium source substance accounts for 1-4 wt% of the semicoke.

Further preferably, the source material of manganese element is added in an amount of 3 wt% of the semicoke, and the source material of niobium element is added in an amount of 2 wt% of the semicoke.

Preferably, the char combustion is carried out in a fluidized bed reactor.

Preferably, the burning temperature of the semicoke is 600-900 ℃.

Preferably, the additive-mixed semicoke is combusted in the form of powder, and the excess air coefficient is 1.1-1.2.

Preferably, the particle size of the semicoke is 80 meshes.

Preferably, the semicoke is obtained after pyrolysis at 650 ℃ for 1.5 hours in an argon atmosphere.

The invention utilizes the reducibility of the semicoke, the semicoke has rich gap structure and larger specific surface area, and the niobic acid (HNbO) is generated in the combustion process of the semicoke₃) Decomposed into niobium pentoxide (Nb) by heating₂O₅) And water, then carbon monoxide (CO) and Nb generated by burning the semicoke₂O₅Reaction of Nb₂O₅Is reduced into niobium dioxide (NbO)₂). Subsequently, NO is substituted by NbO₂Reduction to N₂Finally, NbO₂Is oxidized into Nb₂O₅. Similarly, MnO₂Reduced to cerium oxide (Mn) by CO₂O₃) NO by Mn₂O₃Reduction to N₂And finally Mn₂O₃Is oxidized to MnO₂And forming oxidation-reduction cycle reaction. The composite additive improves the reactivity of semicoke combustion and synergistically catalyzes CO to reduce NO into N in a homogeneous phase manner₂Thereby improving the removal efficiency of the nitrogen oxide. See figure 2 for the reaction principle.

Compared with the prior art, the invention has the following beneficial effects:

manganese oxide (MnO) utilized₂) Has strong oxidation-reduction capability, and is added with niobic acid (HNbO)₃) The oxidizing power of manganese species is reduced and the surface acidity of the additive is increased, so that the additive hasThe nitrogen selectivity is good, the catalytic activity is high, and the generation of NO can be effectively reduced by using a small amount of the catalyst; meanwhile, the generated manganese ions and niobium ions can react with sulfur dioxide and sulfur trioxide in the flue gas to generate sulfate, SO that the sulfur-fixing effect is good, and SO is enabled to be generated₂The amount of production of (2) is reduced.

Drawings

FIG. 1 is a schematic diagram of a semicoke combustion experimental apparatus according to an embodiment of the present invention.

FIG. 2 is a reaction scheme of an embodiment of the present invention.

FIG. 3 is a graph of the amount of NO released per mass of a semicoke sample at different combustion temperatures provided in examples 1-6 of the present invention.

FIG. 4 is SO per unit mass of a semicoke sample at different combustion temperatures provided in examples 1-6 of the present invention₂Release amount graph.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

The catalytic reactor used in the embodiment of the invention adopts an SLG1100-60 type tubular furnace testing device which is purchased from Shanghai Lily testing instruments Co., Ltd and has the outer diameter of 60mm and the length of 1000mm, and the gas composition is as follows: nitrogen (N)₂) 79% and oxygen (O)₂) 21%, wherein the pyrolysis gas is argon (Ar). The gas flow was controlled by a CS200 mass flow meter available from seven stars hua chuang electronics ltd, beijing. O used in the present invention₂，N₂Ar, from mixed gas of south of the Yangtze river, O₂、N₂And Ar purity is 99.99%; manganese oxide (MnO) with purity of 99.9% is used as medicine₂) Niobic acid (HNbO)₃) Both from alatin.

Referring to fig. 1, the semicoke combustion experimental device comprises a gas cylinder 1, a quartz glass tube 2 and a gas absorption bottle 3 which are sequentially connected through a gas pipeline, a tubular furnace body 4 is sleeved outside the quartz glass tube 2, a porcelain boat 5 containing a semicoke sample is placed in the quartz glass tube 2, a mass flow meter 6 and a mixing reactor 7 are arranged on the gas pipeline between the gas cylinder 1 and the quartz glass tube 2, and the device is further provided with a temperature controller 8.

When a combustion test is carried out, the prepared sample is placed in the middle of a fixed horizontal tube furnace with the diameter of 60mm and the length of 1000mm, and a flange is connected, so that the good pipeline connection is ensured.

Setting an experimental program and setting an initial temperature C₁Temperature rise rate is 10 ℃/min and temperature rise time T is 30 DEG C₁60min, reach temperature C₂The temperature is 600 ℃; keeping the temperature for 17min each time, then raising the temperature at a rate of 10 ℃/min for 5min to reach the next target temperature of 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃ and 900 ℃ respectively, and setting the temperature to-121 after the program is finished.

After the program is set, the gas flow is set and controlled by a gas mass flowmeter, and the gas flow is set to be 1L/min. Checking the air tightness of the connecting pipeline to ensure that the air tightness is good.

Two gases, O respectively, are introduced₂And N₂The contents thereof were 21% and 79%, respectively.

After the airtightness is perfect, the set program is started, and the measurement is started when the temperature rises to 600 ℃. Every 30 seconds, the measurement time was 17 min. Similarly, NO (. mu.L/L) and SO were measured at 650 deg.C, 700 deg.C, 750 deg.C, 800 deg.C, 850 deg.C and 900 deg.C, respectively, using a TESTO 350 flue gas analyzer₂(μ L/L) content.

The following are specific examples:

example 1

1g of semicoke was weighed to prepare a semicoke sample A at 21% O₂And 79% N₂Is combusted in the atmosphere of (1), a TESTO 350 flue gas analyzer is adopted to detect and record NO and SO generated at 600-900 DEG C₂And (4) content.

Example 2

The additive for burning the desulfurization and denitrification semicoke prepared according to the invention has the following specific preparation and experimental processes:

1g of semicoke and 0.03g of manganese oxide (MnO) were weighed₂) And uniformly mixing to obtain a semicoke sample B. At 21% O₂And 79% N₂Is combusted in the atmosphere of (1), a TESTO 350 flue gas analyzer is adopted to detect and record NO and SO generated at 600-900 DEG C₂And (4) content.

Example 3

Weighing 1g of semicoke and 0.01g of niobic acid (HNbO)₃) And uniformly mixing to obtain a semicoke sample C. At 21% O₂And 79% N₂Is combusted in the atmosphere of (1), a TESTO 350 flue gas analyzer is adopted to detect and record NO and SO generated at 600-900 DEG C₂And (4) content.

Example 4

Weighing 1g of semicoke and 0.03g of manganese oxide (MnO)₂) And 0.01g of niobic acid (HNbO)₃) And uniformly mixing to obtain a semicoke sample D. At 21% O₂And 79% N₂Is combusted in the atmosphere of (1), a TESTO 350 flue gas analyzer is adopted to detect and record NO and SO generated at 600-900 DEG C₂And (4) content.

Example 5

Weighing 1g of semicoke and 0.03g of manganese oxide (MnO)₂) And 0.02g of niobic acid (HNbO)₃) And uniformly mixing to prepare a semicoke sample E. At 21% O₂And 79% N₂Is combusted in the atmosphere of (1), a TESTO 350 flue gas analyzer is adopted to detect and record NO and SO generated at 600-900 DEG C₂And (4) content.

Example 6

Weighing 1g of semicoke and 0.03g of manganese oxide (MnO)₂) And 0.04g of niobic acid (HNbO)₃) And uniformly mixing to obtain a semicoke sample F. At 21% O₂And 79% N₂Is combusted in the atmosphere of (1), a TESTO 350 flue gas analyzer is adopted to detect and record NO and SO generated at 600-900 DEG C₂And (4) content.

The results of the above tests on the amount of NO produced by burning each semi-coke sample are shown in Table 1:

TABLE 1

A graph of the amount of NO released per mass of the semicoke samples at different combustion temperatures is provided in examples 1-6 with reference to FIG. 3, wherein SC represents semicoke.

The formula for calculating the amount of NO produced in the above table is as follows:

in the above formula, M_NOAmount of NO released for coal sample, mg; f is the volume rate of combustion gas, L/s; t is t₀Measuring the start time of NO for combustion, s; Δ t is the total combustion measurement time, s; c_NOThe concentration of NO in the smoke is shown in the specification, mu.L/L.

As can be seen from Table 1, when the present invention is used under the same conditions, it is found that the addition of MnO of 3 wt% alone₂，1wt％HNbO₃When the temperature is 900 ℃, the NO generation amount is respectively reduced by 55 percent and 62 percent compared with that of the NO generation amount when NO additive is added; when 3 wt% MnO was added₂And 1 wt% HNbO₃When the additive is used, the NO generation amount is reduced by 67 percent compared with that when NO additive is added; when 3 wt% MnO was added₂And 2 wt% HNbO₃When the method of (1) is used for catalytic combustion, the NO generation amount is reduced by 77 percent compared with that when NO additive is added; when adding 3 wt% MnO₂And 4 wt% HNbO₃In this case, the amount of NO produced was reduced by 73% as compared with the case where NO additive was added. Thus, the addition of 3 wt% MnO was obtained by comparison₂And 2 wt% HNbO₃The additive (3) has the best NO control effect.

Similarly, the SO burned by each semicoke sample₂The resulting quantity test results are shown in table 2:

TABLE 2

Examples 1-6 provide SO per mass of semicoke samples at different combustion temperatures₂Release profile referring to fig. 4, SC represents the semicoke.

SO in the above table₂The formula for calculating the amount of production is as follows:

in the above-mentioned formula,SO released for coal samples₂Amount of (a), mg; f is the volume rate of combustion gas, L/s; t is t₀Measuring SO for combustion₂S; Δ t is the total combustion measurement time, s;is SO in flue gas₂Concentration,. mu.L/L.

As can be seen from Table 2, when the present invention is used under the same conditions, it is found that the addition of MnO of 3 wt% alone₂，1wt％HNbO₃At 900 ℃ in SO₂The yield is respectively reduced by 37 percent and 27.5 percent compared with that of the product without any additive; when 3 wt% MnO was added₂And 1 wt% HNbO₃When, SO₂The yield is reduced by 56 percent compared with that of the product without any additive; when 3 wt% MnO was added₂And 2 wt% HNbO₃When the method of (2) is used for catalytic combustion, SO₂The yield is reduced by 58 percent compared with that of the product without any additive; when adding 3 wt% MnO₂And 4 wt% HNbO₃When, SO₂The amount produced was reduced by 54% compared to the amount produced without any additives. Thus, the addition of 3 wt% MnO was obtained by comparison₂And 2 wt% HNbO₃When additive of (3), SO₂The control effect is best.

Therefore, sulfur dioxide and nitrogen oxides in the coke powder combustion product containing the semicoke combustion desulfurization and denitrification additive in the embodiment are obviously reduced, the flue gas amount generated during combustion of the coke powder is reduced, the load of subsequent desulfurization and denitrification equipment is reduced, and the pollution to the environment is reduced.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.