阅读说明：本技术 脱硫脱硝固体颗粒及其制备方法和用途 (Desulfurization and denitrification solid particle and preparation method and application thereof ) 是由 王春霞 张焜 魏闯 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种脱硫脱硝固体颗粒及其制备方法和用途。该脱硫脱硝固体颗粒由包括如下组分的原料制成：石灰粉49～54重量份,铁粉5～12重量份,氧化锰6～11重量份,氧化铈5～8重量份,氧化钴4～7重量份,尿素5～15重量份,膨润土2～8重量份,水泥3～10重量份和水10～25重量份。本发明的脱硫脱硝固体颗粒兼具有较高的穿透硫容和穿透硝容,且强度较高。(The invention discloses a desulfurization and denitrification solid particle and a preparation method and application thereof. The desulfurization and denitrification solid particle is prepared from the following raw materials: 49-54 parts of lime powder, 5-12 parts of iron powder, 6-11 parts of manganese oxide, 5-8 parts of cerium oxide, 4-7 parts of cobalt oxide, 5-15 parts of urea, 2-8 parts of bentonite, 3-10 parts of cement and 10-25 parts of water. The desulfurization and denitrification solid particles have high penetrating sulfur capacity and penetrating nitrate capacity and high strength.)

1. The desulfurization and denitrification solid particle is characterized by being prepared from the following raw materials:

2. the desulfurization and denitrification solid particle according to claim 1, wherein the desulfurization and denitrification solid particle is a spherical solid particle or a columnar solid particle; the diameter of the spherical solid particles is 2-10 mm; the diameter of the columnar solid particles is 2-10 mm, and the length of the columnar solid particles is 8-15 mm.

3. The desulfurization and denitrification solid particle according to claim 1 or 2, wherein the desulfurization and denitrification solid particle is made from a raw material comprising:

4. the desulfurization and denitrification solid particle according to claim 1, wherein the weight ratio of manganese oxide, cerium oxide and cobalt oxide is (3-5): 3: 3.

5. The desulfurization and denitrification solid particle according to claim 1, wherein the weight ratio of manganese oxide, cerium oxide and cobalt oxide is (4-5): 3: 3.

6. The desulfurization and denitrification solid particles according to claim 1, wherein the desulfurization and denitrification solid particles have a sulfur penetration capacity of 55mg/g or more, a nitrate penetration capacity of 21mg/g or more, and a strength of 220N/cm or more.

7. The desulfurization and denitrification solid particle according to any one of claims 1 to 6, wherein the desulfurization and denitrification solid particle is packed in a fixed bed for dry flue gas desulfurization and denitrification.

8. The method for preparing desulfurization and denitrification solid particles according to any one of claims 1 to 5, comprising the steps of:

mixing lime powder, iron powder, manganese oxide, cerium oxide, cobalt oxide, urea, bentonite and cement for 10-30 min, then mixing with water for 20-50 min, granulating, and drying at 190-270 ℃ to obtain the desulfurization and denitrification solid particles.

9. The preparation method according to claim 8, wherein the drying temperature is 210-260 ℃.

10. Use of the desulfurization and denitrification solid particles according to any one of claims 1 to 6 in dry flue gas desulfurization and denitrification.

Technical Field

The invention relates to a desulfurization and denitrification solid particle and a preparation method and application thereof, in particular to a desulfurization and denitrification solid particle for dry desulfurization and denitrification of flue gas and a preparation method and application thereof.

Background

The flue gas discharged from the fields of modern industrial production such as chemical industry, metallurgy, electric power and the like contains a large amount of SO₂And NO. If the sulfur oxides or nitrogen oxides cannot be effectively treated in time, the acidification of soil and water systems is increased, and the ecological balance is destroyed.

CN107485990A discloses a desulfurization and denitrification agent and a production method thereof. The desulfurization and denitrification agent comprises: MgO, CaO, SiO₂、V₂O₅、Fe₂O₃、CeO₂、CoO、Co₂O₃、Al₂O₃、MnO₂And KMnO₄And uniformly mixing the raw materials to obtain the desulfurization and denitrification agent. The desulfurization and denitrification agent takes magnesium oxide as a main active ingredient and is prepared by simple mixing, the strength of the obtained desulfurization and denitrification agent is low, the loss in the desulfurization and denitrification process is large, and the desulfurization and denitrification agent is not easy to recover.

CN110385025A discloses a preparation method of a calcium-based flue gas desulfurization and denitrification agent. The method comprises the following steps: (1) mixing calcium hydroxide, calcium carbonate, ferric oxide and potassium permanganate, adding an alumina sol binder and a small amount of water, and uniformly mixing; (2) and (3) feeding the mixture into a strip extruding machine, extruding strips, drying and forming after the strips are extruded, and obtaining the calcium-based flue gas desulfurization and denitrification agent. The calcium-based flue gas desulfurization and denitrification agent takes calcium hydroxide as a main raw material, and the desulfurization and denitrification agent has low sulfur capacity and low nitrate capacity.

CN110327774A discloses a dry-method low-temperature desulfurization and denitrification integrated catalytic desulfurization and denitrification agent and a preparation method thereof. The catalytic desulfurization and denitrification agent comprises, by mass, 50-90 parts of calcium hydroxide, 5-25 parts of an absorption aid, 5-35 parts of an oxidation aid, 0.1-0.5 part of a binder, 0.1-0.5 part of a lubricant and 2-7 parts of a reinforcing agent. The absorption aid is NaOH, KOH, Ba (OH)₂、Cu(OH)₂、Fe(OH)₃、Mn(OH)₂One or more of them. The oxidation auxiliary agent is divided into an oxidation auxiliary agent I and an oxidation auxiliary agent II, wherein the oxidation auxiliary agent I is CuO or Fe₂O₃、MnO₂、CeO₂、ZrO₂One or more of the above; the second oxidation assistant is one or more of sodium hypochlorite, calcium hypochlorite, hypochlorous acid, sodium dichloroisocyanurate, ethylenediamine and sodium dihydrogen phosphate. The binder is one or more of gypsum, cement, sesbania powder, polyoxyethylene and polyacrylamide. The catalytic desulfurization and denitrification agent takes calcium hydroxide as a main raw material, the manufacturing cost is high, and the sulfur capacity and the nitrate capacity of the catalyst are low.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a desulfurization and denitrification solid particle, which has both high sulfur penetration capacity and high nitrate penetration capacity, and has high strength. The invention also aims to provide a preparation method of the desulfurization and denitrification solid particles, and the desulfurization and denitrification solid particles obtained by the method have high penetrating sulfur capacity and penetrating nitrate capacity and high strength. Still another object of the present invention is to provide a use of the desulfurization and denitrification solid particles. The technical purpose is achieved through the following technical scheme.

The desulfurization and denitrification solid particle is prepared from the following raw materials:

the desulfurization and denitrification solid particles according to the invention are preferably spherical solid particles or columnar solid particles; the diameter of the spherical solid particles is 2-10 mm; the diameter of the columnar solid particles is 2-10 mm, and the length of the columnar solid particles is 8-15 mm.

According to the desulfurization and denitrification solid particles, preferably, the desulfurization and denitrification solid particles are made of raw materials comprising the following components:

according to the desulfurization and denitrification solid particles, the weight ratio of manganese oxide, cerium oxide and cobalt oxide is preferably (3-5): 3: 3.

According to the desulfurization and denitrification solid particles, the weight ratio of manganese oxide, cerium oxide and cobalt oxide is preferably (4-5): 3: 3.

According to the desulfurization and denitrification solid particles, preferably, the penetration sulfur capacity is greater than or equal to 55mg/g, the penetration nitrate capacity is greater than or equal to 21mg/g, and the strength is greater than or equal to 220N/cm.

According to the desulfurization and denitrification solid particles, the desulfurization and denitrification solid particles are preferably filled in a fixed bed for dry flue gas desulfurization and denitrification.

The invention also provides a preparation method of the desulfurization and denitrification solid particles, which comprises the following steps:

mixing lime powder, iron powder, manganese oxide, cerium oxide, cobalt oxide, urea, bentonite and cement for 10-30 min, then mixing with water for 20-50 min, granulating, and drying at 190-270 ℃ to obtain the desulfurization and denitrification solid particles.

According to the preparation method provided by the invention, the drying temperature is preferably 210-260 ℃.

The invention also provides application of the desulfurization and denitrification solid particles in dry flue gas desulfurization and denitrification.

The desulfurization and denitrification solid particles contain manganese oxide, cerium oxide and cobalt oxide, the oxides are mutually matched to effectively promote the oxidation of nitrogen oxides, and the desulfurization and denitrification solid particles can improve the pollutant removal capability by combining the good absorption effect of lime powder and iron oxide. The bentonite, the cement and the urea have the functions of bonding and pore-forming, and the bentonite, the cement and the urea are used together, so that the desulfurization and denitrification solid particles have proper and uniform pores and can ensure the strength of the desulfurization and denitrification solid particles, and the desulfurization and denitrification solid particles have higher penetrating sulfur capacity, penetrating nitrate capacity and strength.

Detailed Description

The present invention is described in more detail below, but the present invention is not limited thereto.

< desulfurization and denitration solid particles >

The desulfurization and denitrification solid particle is prepared from the following raw materials: lime powder, iron powder, manganese oxide, cerium oxide, cobalt oxide, urea, bentonite, cement and water. According to one embodiment of the invention, the desulfurization and denitrification solid particles are made of raw materials consisting of lime powder, iron powder, manganese oxide, cerium oxide, cobalt oxide, urea, bentonite, cement and water. The raw materials are matched with each other, so that the penetrating sulfur capacity and the penetrating nitrate capacity of the desulfurization and denitrification solid particles can be improved, and the desulfurization and denitrification solid particles have higher strength, so that the service cycle of the desulfurization and denitrification solid particles is prolonged, and the loss of the desulfurization and denitrification solid particles is reduced.

The using amount of the lime powder is 49-54 parts by weight; preferably 49 to 52 parts by weight; more preferably 50 parts by weight. Therefore, the desulfurization and denitrification solid particles can have high penetrating sulfur capacity and penetrating nitrate capacity, and the high strength of the desulfurization and denitrification solid particles is ensured.

The using amount of the iron powder is 5-12 parts by weight; preferably 7 to 10 parts by weight; more preferably 8 parts by weight. Therefore, the desulfurization and denitrification solid particles can have high penetrating sulfur capacity and penetrating nitrate capacity, and the high strength of the desulfurization and denitrification solid particles is ensured.

The using amount of the manganese oxide is 6-11 parts by weight; preferably 8 to 11 parts by weight; more preferably 10 parts by weight. Therefore, the desulfurization and denitrification solid particles can have high penetrating sulfur capacity and penetrating nitrate capacity, and the high strength of the desulfurization and denitrification solid particles is ensured.

The using amount of the cerium oxide is 5-8 parts by weight; preferably 5 to 7 parts by weight; more preferably 6 parts by weight. Therefore, the desulfurization and denitrification solid particles can have high penetrating sulfur capacity and penetrating nitrate capacity, and the high strength of the desulfurization and denitrification solid particles is ensured.

The using amount of the cobalt oxide is 4-7 parts by weight; preferably 5 to 7 parts by weight; more preferably 6 parts by weight. Therefore, the desulfurization and denitrification solid particles can have high penetrating sulfur capacity and penetrating nitrate capacity, and the high strength of the desulfurization and denitrification solid particles is ensured.

The weight ratio of the manganese oxide to the cerium oxide to the cobalt oxide is (3-5) to 3: 3. Preferably, the weight ratio of the manganese oxide to the cerium oxide to the cobalt oxide is (4-5): 3: 3. More preferably, the weight ratio of manganese oxide, cerium oxide and cobalt oxide is 5:3: 3. The oxide proportion can improve the catalytic efficiency of nitrogen oxides, and improve the penetrating sulfur capacity and the penetrating nitrate capacity of the desulfurization and denitrification solid particles; and the strength of the desulfurization and denitrification solid particles can be improved.

The using amount of the urea is 5-15 parts by weight; preferably 8 to 12 parts by weight; more preferably 10 parts by weight. The urea has a certain pore-forming effect, so that the desulfurization and denitrification solid particles can form proper and uniform pores, the absorption of sulfur dioxide and nitric oxide is facilitated, and the penetration sulfur capacity and the penetration nitrate capacity of the desulfurization and denitrification solid particles are improved.

The using amount of the bentonite is 2-8 parts by weight; preferably 3 to 6 parts by weight; more preferably 4 parts by weight. Therefore, the desulfurization and denitrification solid particles have proper pores, and the strength of the desulfurization and denitrification solid particles can be ensured.

The using amount of the cement is 3-10 parts by weight; preferably 5 to 8 parts by weight; more preferably 6 parts by weight. Therefore, the desulfurization and denitrification solid particles have proper pores, and the strength of the desulfurization and denitrification solid particles can be ensured.

The using amount of the water is 10-25 parts by weight; preferably 10 to 20 parts by weight; more preferably 15 to 20 parts by weight.

The desulfurization and denitrification solid particles can be spherical or columnar. The diameter of the spherical solid particles may be 2 to 10 mm. The diameter of the columnar solid particles can be 2-10 mm, and the length can be 8-15 mm.

The applicable temperature of the desulfurization and denitrification solid particles is 100-200 ℃; preferably 120-170 ℃; more preferably 130 to 150 ℃.

The desulfurization and denitrification solid particles are tested by GB/T30202.3-2013, and the strength is more than or equal to 220N/cm; preferably 240-290N/cm; more preferably 260 to 280N/cm. SO in simulated flue gas by penetrating sulfur capacity and nitre capacity₂The content of (A) is 2800mg/Nm³NO content of 1000mg/Nm³Testing the conditions that the water content is 10 vol%, the oxygen content is 14 vol%, the simulated flue gas temperature is 140 ℃ and the contact time of the desulfurization and denitrification solid particles and the simulated flue gas is 7s, and waiting for SO of the flue gas to be discharged₂The content is 35mg/Nm³Or NO content of 50mg/Nm³The experiment was stopped. The penetration sulfur capacity of the desulfurization and denitrification solid particles is more than or equal to 55 mg/g; preferably 60-70 mg/g; more preferably 62 to 65 mg/g. The penetration nitrate capacity of the desulfurization and denitrification solid particles is more than or equal to 21 mg/g; preferably 30-40 mg/g; more preferably 32 to 35 mg/g.

< method for producing desulfurization and denitrification solid particles >

The preparation method comprises the following steps: mixing lime powder, iron powder, manganese oxide, cerium oxide, cobalt oxide, urea, bentonite and cement, then mixing with water, granulating and drying to obtain the desulfurization and denitrification solid particles. The amounts of the respective raw materials are as described above and will not be described herein.

The mixing process of lime powder, iron powder, manganese oxide, cerium oxide, cobalt oxide, urea, bentonite and cement can be carried out in a kneader. Mixing for 10-30 min; preferably 10-20 min; more preferably 15 to 20 min.

The mixing of the other raw materials with water can be carried out in a kneader. The water may be added in several portions. For example, 2 to 5 times; preferably, the moisture is added in three portions. The mixing time can be 20-50 min; preferably 25-40 min; more preferably 30 to 40 min. This is advantageous for improving the strength of the desulfurization and denitrification solid particles.

The granulation may be carried out in a granulator.

The drying temperature can be 190-270 ℃; preferably 210-260 ℃; more preferably 200 to 250 ℃. Therefore, the penetration sulfur capacity, penetration nitrate capacity and strength of the desulfurization and denitrification solid particles can be improved.

The drying time can be 1-5 h; preferably 2-5 h; more preferably 2 to 4 hours.

< use of desulfurization and denitrification solid particles >

The desulfurization and denitrification solid particles have higher penetrating sulfur capacity and penetrating nitrate capacity and higher strength, so the desulfurization and denitrification solid particles can be applied to dry flue gas desulfurization and denitrification. The invention provides application of the desulfurization and denitrification solid particles in dry flue gas desulfurization and denitrification. Preferably, the desulfurization and denitrification solid particles are used for desulfurization and denitrification of the dry fixed bed flue gas.

The test method is described below:

the strength is tested by GB/T30202.3-2013 coal granular activated carbon test method for desulfurization and denitrification, and the specific test method is as follows:

(1) sample preparation: randomly extracting 20 samples with smooth surfaces, regularity and length-diameter ratio not less than 1;

(2) preparing an instrument: adjusting the zero point of the compressive strength instrument;

(3) and (3) sample testing: placing each sample in a V-shaped groove of a lower clamp along the axial direction of a cylinder, starting a compressive strength tester, and recording the pressure value at the moment of crushing the sample, wherein the pressure value is measured by 50daN when the pressure value is greater than 50 daN;

(4) and (3) calculating the intensity: the average value of 20 measurements is the required intensity.

Breakthrough sulfur capacity and breakthrough nitrate capacity:

the test conditions were as follows: simulating SO in flue gas₂The content of (A) is 2800mg/Nm³NO content of 1000mg/Nm³The water content was 10 vol%, and the oxygen content was 14 vol%; the simulated flue gas temperature is 140 ℃, and the contact time of the desulfurization and denitrification solid particles and the simulated flue gas is 7 s. SO of flue gas to be discharged₂The content is 35mg/Nm³Or NO content of 50mg/Nm³And stopping the experiment, and calculating the penetration sulfur capacity and the penetration nitrate capacity of the desulfurization and denitrification solid particles.

Examples 1 to 6 and comparative examples 1 to 8

Mixing lime powder, 8 parts by weight of iron powder, manganese oxide, cerium oxide, cobalt oxide, 10 parts by weight of urea, 4 parts by weight of bentonite and 6 parts by weight of cement in a kneading machine for 15 min. 15 parts by weight of deionized water were added in three equal portions and mixed for 30 min. Granulating in a granulator, drying in an oven for 3h, and cooling to obtain the desulfurization and denitrification solid particles. The desulfurization and denitrification solid particles are cylindrical, the diameter is 5-10 mm, and the length is 8-15 mm. The specific conditions are shown in Table 1, and the properties of the desulfurization and denitrification solid particles are shown in Table 2.

TABLE 1

TABLE 2

Examples 1 to 3 and comparative examples 1 to 2 differ in the amount of manganese oxide used. As can be seen from table 2, the breakthrough sulfur capacity and the breakthrough nitrate capacity of the desulfurization and denitrification solid particles show a tendency of increasing first and then decreasing with the increase of the amount of the manganese oxide. Within the dosage range of the invention, the desulfurization and denitrification solid particles have higher penetrating sulfur capacity and penetrating nitrate capacity. The strength of the desulfurization and denitrification solid particles can be kept in a higher range within the dosage range of the manganese oxide, and the dosage of the manganese oxide higher than the dosage range of the manganese oxide can greatly reduce the strength of the denitrification agent; although the strength of the desulfurization and denitrification solid particles is increased to a certain extent, the penetration sulfur capacity and the penetration nitrate capacity of the desulfurization and denitrification solid particles are obviously reduced. Therefore, the manganese oxide in the amount of the invention can give consideration to the penetration sulfur capacity, the penetration nitrate capacity and the strength of the desulfurization and denitrification solid particles, thereby prolonging the service life of the desulfurization and denitrification solid particles and reducing the loss of the desulfurization and denitrification solid particles, which is not a conventional choice.

It is understood from example 1 and comparative examples 3 to 4 that the sulfur penetration capacity, the nitrate penetration capacity and the strength of the desulfurization and denitrification solid particles tend to increase and decrease with the amount of cerium oxide, and the amount of cerium oxide within the range of the present invention can increase the sulfur penetration capacity, the nitrate penetration capacity and the strength of the desulfurization and denitrification solid particles. Therefore, this is not a conventional option.

Example 1 and comparative examples 5 to 6 differ only in the amount of cobalt oxide used. As can be seen from table 2, too high or too low amount of cobalt oxide greatly reduces the sulfur penetration capacity, the nitrate penetration capacity and the strength of the desulfurization and denitrification solid particles. The dosage of the cobalt oxide in the range of the invention can obviously improve the penetration sulfur capacity, penetration nitrate capacity and strength of the desulfurization and denitrification solid particles.

Examples 1, 4 to 6 and comparative examples 7 to 8 differ only in the drying temperature. As can be seen from Table 2, the drying temperature is too low or too high, which reduces the sulfur penetration capacity, the nitrate penetration capacity and the strength, and within the drying temperature range of the present invention, the desulfurization and denitrification solid particles have higher sulfur penetration capacity, nitrate penetration capacity and strength. This is probably because the temperature is too low to evaporate the water sufficiently, the interaction between the raw materials is insufficient, the pore structure in the solid particles for desulfurization and denitrification is formed incompletely and unevenly, and the bonding strength between the raw materials is not high, which results in the reduction of the penetrating sulfur capacity, the penetrating nitrate capacity and the strength of the solid particles for desulfurization and denitrification; the regularity and the integrity of the pore structure in the desulfurization and denitrification solid particles can be damaged due to overhigh temperature, so that the penetration sulfur capacity, the penetration nitrate capacity and the strength of the desulfurization and denitrification solid particles are reduced.

The present invention is not limited to the above-described embodiments, and any variations, modifications, and substitutions which may occur to those skilled in the art may be made without departing from the spirit of the invention.