CN110893312A

CN110893312A - Novel high-efficiency desulfurizer and preparation method thereof

Info

Publication number: CN110893312A
Application number: CN201911273657.4A
Authority: CN
Inventors: 黄镕; 闫毅; 刘晓宇; 黄宇琪
Original assignee: Shandong Geng Chen Environmental Protection New Material Co Ltd
Current assignee: Shandong Geng Chen Environmental Protection New Material Co Ltd
Priority date: 2019-12-12
Filing date: 2019-12-12
Publication date: 2020-03-20

Abstract

The invention relates to a novel high-efficiency desulfurizer and a preparation method thereof, wherein the novel high-efficiency desulfurizer mainly comprises oxides and/or hydroxides of Mg, Ca or Na, activated carbon, red mud, a binder and a pore-forming agent, and is prepared from the raw materials through a special process. The desulfurizer of the invention overcomes the defects of the existing desulfurization process, has the advantages of high desulfurization efficiency, high desulfurization precision, low power consumption, low investment and the like, can effectively reduce the desulfurization cost and reduce the economic pressure for enterprise desulfurization, and can deeply desulfurize SO₂Removing to less than or equal to 1mg/m³The desulfurization efficiency is obviously improved; the inventionThe desulfurizer can be used for secondary fine desulfurization of power plant flue gas and can also be used for tail gas SO in industries such as fine chemical engineering, pharmacy, metal smelting and the like₂The treatment has great market value.

Description

Novel high-efficiency desulfurizer and preparation method thereof

Technical Field

The invention belongs to the technical field of solid waste treatment and flue gas purification, and particularly relates to a novel efficient desulfurizer and a preparation method thereof.

Background

The common desulfurization process at present is a wet or semi-dry desulfurization process mainly based on a calcium-based desulfurizing agent. Dry desulfurization, also known as dry flue gas desulfurization, refers to the use of powdery or granular absorbents, adsorbents, or catalysts to remove sulfide-containing gases from flue gases. The method has the advantages of simple process, no sewage and waste acid treatment problems, low energy consumption, particularly higher temperature of the purified flue gas, contribution to exhaust diffusion of a chimney, no generation of white smoke and the like, but has the defects of lower desulfurization efficiency, low sulfur capacity, low mechanical strength, high cost, huge equipment, large investment, large occupied area, high operation technical requirement and the like, and the defects directly cause the increase of enterprise desulfurization cost and cause larger economic burden of enterprises.

At present, the country contains SO₂The desulfurization mode of the waste gas mainly adopts a semi-dry method and a wet method which mainly adopt calcium-based desulfurizer. SO before flue gas desulfurization₂Content 2000-4000mg/m³For example, the removal rate of wet desulfurization is calculated as 95%, and SO in the flue gas after desulfurization₂The content is 100-200mg/m³And about, the standard of GB13271-2014 'emission standard of boiler atmospheric pollutants' is just met. With the improvement of environmental protection requirements, part of districts release new atmospheric pollutant emission standards (DB 12/810 in Tianjin City and 2018 thermal power plant atmospheric pollutant emission standards), wherein the emission limit value of sulfur dioxide is 10mg/m³Therefore, the existing desulfurization mode is difficult to meet the requirement of environmental protection.

Disclosure of Invention

Based on the problems, the invention provides a novel high-efficiency desulfurizer and a preparation method thereof. The desulfurizer of the invention has the advantages of high sulfur capacity, high mechanical strength, high desulfurization efficiency, low power consumption, low investment and the like; the novel high-efficiency desulfurizer can perform deep desulfurization and can remove SO₂Removing to less than or equal to 1mg/m³The method can effectively reduce the desulfurization cost and reduce the economic pressure for enterprise desulfurization.

The technical scheme of the invention is as follows:

a novel high-efficiency desulfurizer comprises the following raw material components: 10-50 parts of alkaline compound, 5-30 parts of activated carbon, 10-50 parts of red mud, 20-50 parts of binder and 1-5 parts of pore-forming agent.

Further preferably, the novel efficient desulfurizer comprises the following raw material components: 20-40 parts of alkaline compound, 10-25 parts of activated carbon, 20-40 parts of red mud, 30-40 parts of binder and 2-4 parts of pore-forming agent.

Further preferably, the novel efficient desulfurizer comprises the following raw material components: 35 parts of alkaline compound, 17.5 parts of activated carbon, 30 parts of red mud, 35 parts of binder and 3 parts of pore-forming agent.

The alkaline compound is an oxide and/or hydroxide of Mg, Ca or Na.

Further, the alkaline compound is calcium oxide and/or calcium hydroxide.

The alkaline compound is a mixture of calcium oxide and calcium hydroxide in a mass ratio of (1-3) to (1-3).

The binder is water glass.

The pore-forming agent is wood dust;

the preparation method of the wood chips comprises the following steps: firstly, carrying out acid pickling on the wood chips to obtain acid-pickled wood chips; and washing and drying the pickled sawdust to obtain the sawdust.

Further, the acid used for acid washing is any one of hydrochloric acid or sulfuric acid, the acid washing frequency is 1-2 times, and the time for each acid washing is 10-30 min; the washing times are 2-4 times, and the washing time is 30-40min each time; the drying temperature is 60-70 ℃, and the drying time is 60-90 min.

The preparation method of the novel high-efficiency desulfurizing agent comprises the following steps:

(1) respectively crushing the raw materials except the binder to obtain raw material particles;

(2) uniformly mixing the raw material particles to obtain a mixed raw material;

(3) adding water and a binder into the mixed raw material, and then mixing and grinding to obtain a muddy raw material;

(4) forming and drying the muddy raw material to obtain an intermediate;

(5) and shaping and screening the intermediate by a pair of rollers to obtain the desulfurizer.

Further, in the step (1), the particle size of each raw material particle is 100-200 meshes.

Further, in the step (3), the mass of the added water is 30-40% of that of the mixed raw materials, and the mixing and grinding time is 50-70 min.

Further, in the step (4), the drying temperature is 50-150 ℃, and the drying time is 1-3 h.

Further, the particle size of the screened desulfurizer is 0.5-2 mm.

In order to facilitate understanding of the present invention, the raw materials and functions of the present invention will be further described below.

Oxides and/or hydroxides of Mg, Ca or Na, all being alkaline substances which readily react with SO₂、SO₃、H₂SO₄The reaction occurs and is the main substance in the formula.

Activated carbon, having catalytic oxidation effect and being capable of converting SO₂Conversion to SO₃，SO₃Is absorbed by water and becomes H₂SO₄. Is the main material in the formula.

The red mud is Bayer process red mud, the main components of the red mud are oxides or hydroxides of iron, aluminum and sodium, the pH value of the red mud is about 9-11, the substances can react with sulfuric acid to generate stable sulfate, and the problem of pollution caused by the open stacking of the red mud can be solved.

The adhesive is water glass (sodium silicate), and has the desulfurization function while serving as the adhesive.

The pore-forming agent is wood dust, the specification is larger than 100 meshes, the pore-forming agent has the function of framework support, the structure of a product formed after the wood dust is added is relatively loose, and the utilization rate of a desulfurizer is greatly improved.

Sulfur capacity: absorption of SO₂The amount of (B) is the percentage of the desulfurizer usage amount, and the unit is%.

For ease of understanding, the following description is appropriate for the four desulfurization modes involved in the present invention:

and (3) dry desulfurization: also called the in-furnace calcium spraying techniqueGrinding limestone to about 150 meshes, spraying compressed air into an optimal temperature area in a furnace to ensure that the limestone in the desulfurizer is in good contact with flue gas, the limestone is heated and decomposed into calcium oxide and carbon dioxide, the calcium oxide reacts with sulfur dioxide in the flue gas to generate calcium sulfite and calcium sulfate, and the calcium sulfite and the calcium sulfate are finally oxidized into the calcium sulfate by the desulfurizer; comprises irradiating SO with electron beam or adsorbing with activated carbon₂The conversion to generate ammonium sulfate or sulfuric acid is generally called dry desulfurization technology, and the desulfurization efficiency can only reach about 80 percent.

Semi-dry desulfurization: the desulfurizing agent is in a wet state and simultaneously enters a desulfurizing tower along with flue gas, the desulfurizing agent reacts with sulfur dioxide in the flue gas, and the heat of the flue gas is utilized to carry out desulfurization to remove water in the desulfurizing agent, so that a dry powder product is finally generated; in order to improve the desulfurization efficiency, lime powder is generally subjected to digestion pulping as a desulfurizing agent, and SO is generated by the method₂The removal rate can reach more than 80 percent.

And (3) wet desulphurization: the flue gas enters a wet absorption tower of a desulfurization device and is in countercurrent contact with alkaline limestone slurry fog drops sprayed from top to bottom, wherein the acidic oxide SO is₂Other pollutants such as HCl and HF are absorbed, so that the flue gas is fully purified; absorption of SO₂The slurry is reacted to generate CaSO₃CaSO produced by forced oxidation and crystallization₄·2H₂Dehydrating the O to obtain a desulfurization byproduct (gypsum), and finally realizing the comprehensive treatment of the sulfur-containing flue gas; the desulfurization rate of the method is generally more than 95 percent and reaches 98 percent at most.

The desulfurization method comprises the following steps: the flue gas or waste gas enters a desulfurizing device (a moving bed or a fixed bed) to contact with a desulfurizing agent in a reactor, and SO in the flue gas or waste gas is catalyzed by active carbon in the desulfurizing agent₂Firstly with O in the flue gas₂The sulfur trioxide is converted into sulfur trioxide by catalytic oxidation, the sulfur trioxide is converted into sulfuric acid after meeting water in the flue gas, the sulfuric acid is reacted with alkaline substances in a desulfurizer to generate relatively stable sulfate, and finally, the deep desulfurization of the sulfur-containing flue gas or waste gas is realized, and the desulfurization rate is more than 99%.

The invention has the beneficial effects that:

(1) the novel efficient desulfurizer is prepared by the following raw materials, wherein the raw materials mainly comprise oxides and/or hydroxides of Mg, Ca or Na, activated carbon, red mud, a binder and a pore-forming agent, and the novel efficient desulfurizer is prepared by the raw materials through a special process. The desulfurizer provided by the invention overcomes the defects of the existing desulfurization process, has the advantages of high sulfur capacity, high mechanical strength, high desulfurization efficiency, high desulfurization precision, low power consumption, low investment and the like, and further can effectively reduce the desulfurization cost and achieve the emission reduction target of sulfur dioxide.

(2) The desulfurization method of the desulfurizer of the invention is essentially different from the desulfurization mode of the existing desulfurizer: the existing semi-dry and wet desulphurization methods are that calcium hydroxide or calcium carbonate directly reacts with sulfur dioxide to generate calcium sulfite, and the calcium sulfite is oxidized by air to generate relatively stable calcium sulfate; the desulfurization mode of the desulfurizer is a novel desulfurization process, and specifically comprises the following steps: when the waste gas containing sulfur dioxide passes through the desulfurizer, the sulfur dioxide is firstly mixed with O in the flue gas under the catalytic action of active carbon in the desulfurizer₂The sulfur trioxide is converted into sulfur trioxide through catalytic oxidation, the sulfur trioxide is converted into sulfuric acid after meeting water in the flue gas, and the sulfuric acid reacts with alkaline substances in the desulfurizer to generate relatively stable sulfate, so that high-efficiency desulfurization is realized. The desulfurizing agent has extremely high sulfur dioxide removal rate and desulfurization precision, the sulfur dioxide removal rate is more than 99.9 percent, and the desulfurization precision can reach less than or equal to 1mg/m³(the amount of sulfur dioxide contained in per cubic meter of waste gas is less than or equal to 1mg), which is an index which cannot be achieved by the existing desulfurization process and is also the core of the application.

(3) When the desulfurizer is used, the waste gas is fully contacted with the desulfurizer in the desulfurization tower, so that high-efficiency desulfurization can be realized, and compared with a wet desulfurization method, the desulfurizer can effectively reduce the formation of aerosol (reduce the generation of haze) and realize deep desulfurization, so that the desulfurization efficiency is obviously improved; the desulfurizer of the invention can be used for secondary fine desulfurization of power plant flue gas, and can also be used for tail gas SO in industries of fine chemistry, pharmacy, metal smelting and the like₂The treatment has great market value.

(4) The novel high-efficiency desulfurizer is solid particles, the desulfurizer is used in a fixed bed or a moving bed, the operation technology requirement is reduced, equipment and occupied area are reduced, and the same or similar method is not available in the market at present.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.

In the following examples 1 part by weight represents 1 g.

Example 1

This example provides a method for producing wood chips: firstly, pickling the wood chips with hydrochloric acid for 1 time for 30min to obtain pickled wood chips; and washing the sawdust subjected to acid washing for 2 times, wherein the washing time is 40min each time, and drying for 90min at 60 ℃ to obtain the sawdust.

The embodiment provides a novel efficient desulfurizer, which comprises the following raw material components:

10 parts of magnesium oxide, 5 parts of activated carbon, 10 parts of red mud, 20 parts of water glass and 1 part of sawdust.

(1) respectively crushing other raw materials except water glass into particles with the particle size of 100 meshes to obtain raw material particles;

(2) uniformly mixing the raw material particles to obtain a mixed raw material;

(3) adding water accounting for 30% of the mass of the mixed raw materials and the water glass into the mixed raw materials, and then mixing and grinding for 50min to obtain a pasty raw material;

(4) forming the pasty raw material, and drying at 50 ℃ for 3h to obtain the intermediate;

(5) and shaping and screening the intermediate by a pair of rollers to obtain the desulfurizer with the particle size of 0.5 mm.

Example 2

This example provides a method for producing wood chips: firstly, carrying out sulfuric acid washing on the wood chips for 2 times, wherein the acid washing time is 10min each time, so as to obtain acid-washed wood chips; and washing the sawdust subjected to acid washing for 4 times, wherein the washing time is 30min each time, and drying for 60min at 70 ℃ to obtain the sawdust.

50 parts of magnesium hydroxide, 30 parts of activated carbon, 50 parts of red mud, 50 parts of water glass and 5 parts of sawdust.

(1) respectively crushing other raw materials except water glass into particles with the particle size of 200 meshes to obtain raw material particles;

(2) uniformly mixing the raw material particles to obtain a mixed raw material;

(3) adding water accounting for 40% of the mass of the mixed raw materials and the water glass into the mixed raw materials, and then mixing and grinding for 70min to obtain a pasty raw material;

(4) forming the pasty raw material, and drying at 150 ℃ for 1h to obtain the intermediate;

(5) and shaping and screening the intermediate by a pair of rollers to obtain the desulfurizer with the particle size of 2 mm.

Example 3

This example provides a method for producing wood chips: firstly, pickling the wood chips with hydrochloric acid for 2 times, wherein the pickling time is 20min each time, so as to obtain pickled wood chips; and washing the pickled sawdust for 3 times, wherein the washing time is 35min each time, and drying for 75min at 65 ℃ to obtain the sawdust.

20 parts of sodium oxide, 10 parts of activated carbon, 20 parts of red mud, 30 parts of water glass and 2 parts of sawdust.

(2) uniformly mixing the raw material particles to obtain a mixed raw material;

Example 4

This example provides a method for producing wood chips: firstly, carrying out sulfuric acid washing on the wood chips for 1 time, wherein the acid washing time is 30min each time, so as to obtain acid-washed wood chips; and washing the sawdust subjected to acid washing for 4 times, wherein the washing time is 40min each time, and drying for 90min at 70 ℃ to obtain the sawdust.

40 parts of calcium hydroxide, 25 parts of activated carbon, 40 parts of red mud, 40 parts of water glass and 4 parts of sawdust.

(2) uniformly mixing the raw material particles to obtain a mixed raw material;

Example 5

This example provides a method for producing wood chips: firstly, pickling the wood chips with hydrochloric acid for 2 times, wherein the pickling time is 20min each time, so as to obtain pickled wood chips; and washing the pickled sawdust for 3 times, wherein the washing time is 35min each time, and drying the sawdust for 80min at 65 ℃ to obtain the sawdust.

17.5 parts of calcium oxide, 17.5 parts of calcium hydroxide, 17.5 parts of activated carbon, 30 parts of red mud, 35 parts of water glass and 3 parts of wood chips.

(1) respectively crushing other raw materials except water glass into particles with the particle size of 150 meshes to obtain raw material particles;

(2) uniformly mixing the raw material particles to obtain a mixed raw material;

(3) adding water accounting for 35% of the mass of the mixed raw materials and the water glass into the mixed raw materials, and then mixing and grinding for 60min to obtain a pasty raw material;

(4) forming the pasty raw material, and drying at 100 ℃ for 2h to obtain the intermediate;

(5) and shaping and screening the intermediate by a pair of rollers to obtain the desulfurizer with the particle size of 1.25 mm.

Comparative example 1

The comparative example differs from example 5 only in the composition of the raw material, and the raw material of the comparative example does not contain calcium oxide, calcium hydroxide and wood chips, and the other operations are the same as example 5.

Comparative example 2

The comparative example is different from example 5 only in the composition of the raw material, and the raw material of the comparative example does not contain calcium oxide and calcium hydroxide, and the other operations are the same as example 5.

Examples of the experiments

Desulfurization Effect measurement of desulfurizing agent obtained in example 5 and comparative examples 1 to 2

1. The desulfurization operations were carried out using the desulfurization agents obtained in example 5 and comparative examples 1-2, and the sample information and desulfurization process data records of the respective groups of desulfurization agents are shown in tables 1-3.

TABLE 1 desulfurization procedure record of desulfurizing agent obtained in comparative example 1

TABLE 2 desulfurization procedure record of desulfurizing agent obtained in comparative example 2

TABLE 3 desulfurization procedure record of desulfurizing agent obtained in example 5

2. The desulfurization effect of the desulfurizing agents obtained in example 5 and comparative examples 1-2 was compared as shown in Table 4

TABLE 4 comparison of the sulfur capacities of the desulfurizing agents obtained in example 5 and comparative examples 1 and 2

Group of	Example 5	Comparative example 1	Comparative example 2
				Sulfur content (%)	40.2	9.2	11.8

As can be seen from Table 4, the sulfur capacity of the desulfurizer obtained in example 5 is 40.2%, which is much higher than the sulfur capacities of the desulfurizers obtained in comparative examples 1 and 2, and thus it is shown that the sulfur capacity of the desulfurizer can be significantly increased and SO in the exhaust gas can be effectively removed by adding calcium oxide and calcium hydroxide to the desulfurizer of the present invention₂And has great market value.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A novel high-efficiency desulfurizer is characterized by comprising the following raw materials: 10-50 parts of alkaline compound, 5-30 parts of activated carbon, 10-50 parts of red mud, 20-50 parts of binder and 1-5 parts of pore-forming agent.

2. The novel efficient desulfurizing agent according to claim 1, wherein the raw material components comprise: 35 parts of alkaline compound, 17.5 parts of activated carbon, 30 parts of red mud, 35 parts of binder and 3 parts of pore-forming agent.

3. The new and highly efficient desulfurizing agent according to any one of claims 1-2, characterized in that said basic compound is an oxide and/or hydroxide of Mg, Ca or Na.

4. The new and highly efficient desulfurizing agent according to claim 3, wherein said basic compound is calcium oxide and/or calcium hydroxide.

5. The novel efficient desulfurizing agent according to claim 4, wherein said alkaline compound is a mixture of calcium oxide and calcium hydroxide in a mass ratio of (1-3) to (1-3).

6. The new and efficient desulfurizing agent according to any one of claims 1-2, wherein said binder is water glass.

7. The novel efficient desulfurizing agent according to any one of claims 1-2, wherein said pore-forming agent is wood chips;

8. The novel high-efficiency desulfurizing agent according to claim 7, wherein the acid used for acid washing is any one of hydrochloric acid or sulfuric acid, the number of acid washing is 1-2, and the time of each acid washing is 10-30 min; the washing times are 2-4 times, and the washing time is 30-40min each time; the drying temperature is 60-70 ℃, and the drying time is 60-90 min.

9. A method for preparing the novel high-efficiency desulfurizing agent according to any one of claims 1 to 8, comprising the steps of:

(2) uniformly mixing the raw material particles to obtain a mixed raw material;

(4) forming and drying the muddy raw material to obtain an intermediate;

10. The method for preparing a novel and efficient desulfurizing agent according to claim 9, wherein in step (1), the particle size of each raw material particle is 100-200 mesh;

in the step (3), the mass of the added water accounts for 30-40% of the mixed raw materials, and the mixing and grinding time is 50-70 min;

in the step (4), the drying temperature is 50-150 ℃, and the drying time is 1-3 h;

in the step (5), the particle size of the sieved desulfurizer is 0.5-2 mm.