Preparation and granulation method of deacidification agent for removing acidic gas in flue gas

Abstract

The invention relates to a preparation and granulation method of a deacidification agent for removing acid gas in flue gas, and the preparation method of the deacidification agent comprises the following steps: preparing raw materials which comprise solid powder and water in a weight ratio of (10-15): 1; the solid powder comprises fly ash, calcium hydroxide and an additive, and the weight ratio of the fly ash to the calcium hydroxide to the additive is 1: 1: 0.5-3: 1: 1; carrying out hydration reaction on the raw materials to obtain slurry; and carrying out suction filtration on the slurry, and drying to obtain the deacidification agent. The fly ash is used as a raw material, so that waste resource recycling is realized; the coal ash, calcium hydroxide and the additive are used as raw materials to prepare the deacidification agent in a hydration reaction mode, multi-component acid gas can be absorbed at the same time, and the prepared deacidification agent is long in effective absorption time and large in adsorption capacity by limiting the proportion of all the components in the raw materials.

Description

Technical Field

[0001] The invention relates to the technical field of deacidification process in nuclear industry, and in particular to a preparation and granulation method of a deacidification agent for removing acidic gas in flue gas. Background Art

[0002] At present, traditional alkaline deacidification materials such as lime have the following main problems: small reaction area, large consumption, short effective reaction time, insufficient reaction, single application form, etc. In addition, the hot-selling high-efficiency deacidification materials (such as SDG adsorbents) in the market are scarce, and there are problems such as procurement difficulties, limited sources, and high economic efficiency. The above problems need to be solved urgently. Summary of the invention

[0003] The invention discloses a preparation and granulation method of a deacidifying agent for removing acidic gas from flue gas, aiming to solve the technical problems existing in the prior art.

[0004] The present invention adopts the following technical solutions:

[0005] The present invention provides a method for preparing a deacidifying agent for removing acidic gases in flue gas, which comprises the following steps:

[0006] Prepare raw materials, the raw materials include solid powder and water, the weight ratio of the solid powder to water is 10-15:1; the solid powder includes fly ash, calcium hydroxide and additives, the weight ratio of the fly ash, calcium hydroxide and additives is 1:1:0.5-3:1:1.

[0007] The raw material is subjected to a hydration reaction to obtain a slurry;

[0008] The slurry is filtered and dried to obtain a deacidifying agent.

[0009] In the method for preparing a deacidifying agent for removing acidic gases from flue gas of the present invention, the hydration reaction time is 6-12 hours, the reaction temperature is 60-90° C., and the stirring speed is 200-300 r / min.

[0010] In the method for preparing a deacidifying agent for removing acidic gases from flue gas of the present invention, the additive is a salt that is alkaline upon hydrolysis.

[0011] In the method for preparing a deacidifying agent for removing acidic gas from flue gas of the present invention, the fly ash is Class F fly ash with a particle size of 100-200 meshes.

[0012] In the method for preparing a deacidifying agent for removing acidic gases from flue gas of the present invention, the temperature of the drying process is less than or equal to 100°C.

[0013] In a second aspect, the present invention further provides a granulation method for granulating the deacidifying agent prepared by the above preparation method, the method comprising the following steps:

[0014] The deacidifying agent is crushed, and then the crushed deacidifying agent and a binder are added into a container, wherein the amount of the binder added is 30-50% of the weight of the deacidifying agent;

[0015] kneading the contents in the container, and then extruding through an extruder to obtain a strip-shaped material;

[0016] Shearing the strip material to obtain granular material;

[0017] The granular material is dried to a constant weight to obtain a granular product.

[0018] In the granulation method of the present invention, the binder is water or sodium silicate.

[0019] In the granulation method of the present invention, the binder is water, and the added amount is 30-50% of the weight of the deacidifying agent.

[0020] In the granulation method of the present invention, the diameter or length of the granular material is 3-5 mm.

[0021] In the granulation method of the present invention, the extruder is a single-screw screw extruder.

[0022] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0023] The present invention mainly provides a method for preparing a deacidifying agent for removing acidic gases from flue gas. The method uses fly ash as a raw material to realize the recycling of waste resources. The deacidifying agent is prepared by hydration reaction using fly ash, calcium hydroxide and additives as raw materials, and can absorb multi-component acid gases at the same time. By limiting the ratio of each component in the raw material, the effective absorption time of the prepared deacidifying agent is long and the adsorption capacity is large. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described in conjunction with the specific embodiments of the present invention. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0025] Unless expressly indicated to the contrary, the numerical parameters in this specification and the appended claims may be approximate values ​​and can be changed according to the desired properties obtained by the content of the present invention. Specifically, all numbers used in the specification and claims to express the content of the composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. In general, the meaning of the expression is to include a change of ±10% in some embodiments, a change of ±5% in some embodiments, a change of ±1% in some embodiments, and a change of ±0.5% in some embodiments by a specific number.

[0026] Furthermore, the word "comprising" does not exclude the presence of materials or steps not listed in the claims. Ordinal numbers such as "first", "second", "third" and Arabic numerals, letters, etc. used in the specification and claims to modify corresponding elements or steps do not themselves mean the order of the manufacturing method. The use of these ordinals is only used to make the steps clearly distinguishable.

[0027] In addition, unless the steps are specifically described or must occur in sequence, the order of the above steps is not limited to the above list, and can be changed or rearranged according to the required design. And the above embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0028] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In order to solve the problems existing in the prior art, the embodiments of the present application provide a method for preparing and granulating a deacidifying agent for removing acidic gases from flue gas.

[0030] A method for preparing a deacidifying agent for removing acidic gases from flue gas comprises the following steps:

[0031] Prepare raw materials, which include solid powder and water, and the weight ratio of the solid powder to water is 10:-15:1; the solid powder includes fly ash, calcium hydroxide and additives, and the weight ratio of the fly ash, calcium hydroxide and additives is 1:1:0.5-3:1:1.

[0032] The raw materials are subjected to a hydration reaction to obtain a slurry. Specifically, the container for the hydration reaction can be a three-necked flask, a beaker, etc., or a homemade reaction container according to special needs.

[0033] The slurry is filtered and dried to obtain a deacidifying agent.

[0034] The invention discloses a method for preparing a deacidifying agent for removing acidic gas from flue gas. The method uses fly ash as a raw material, thereby realizing the recycling of waste resources. The deacidifying agent is prepared by a hydration reaction using fly ash, calcium hydroxide and additives as raw materials, and can absorb multi-component acid gases at the same time. Moreover, by limiting the ratio of each component in the raw material, the effective absorption time of the prepared deacidifying agent is long and the adsorption capacity is large.

[0035] In some preferred embodiments, the hydration reaction time is 6-12 h, the reaction temperature is 60-90° C., and the stirring speed is 200-300 r / min.

[0036] In some preferred embodiments, the additive is a salt that is alkaline upon hydrolysis, specifically, one or more of sulfate, carbonate, phosphate and silicate.

[0037] In some preferred embodiments, the fly ash is Class F fly ash with a particle size of 100-200 meshes.

[0038] In some preferred embodiments, the temperature of the drying process is less than or equal to 100°C.

[0039] A granulation method, used for granulating the deacidifying agent prepared by the above-mentioned preparation method, comprises the following steps:

[0040] The deacidifying agent is crushed, and then the crushed deacidifying agent and a binder are added into a container, wherein the amount of the binder added is 30-50% of the weight of the deacidifying agent;

[0041] Kneading the contents in the container, and then extruding through an extruder to obtain a strip-shaped material;

[0042] Shearing the strip material to obtain granular material;

[0043] The granular material is dried to constant weight to obtain a granular product.

[0044] The granulation method of the present invention can adjust the shape and size of the high-activity granular deacidifying agent according to actual working conditions, so that the material is suitable for more severe and cruel acid gas environment.

[0045] In some preferred embodiments, the binder is water or sodium silicate.

[0046] In some preferred embodiments, the binder is water, and the amount added is 30-50% by weight of the deacidifying agent.

[0047] In some preferred embodiments, the diameter or length of the particulate material is 3-5 mm.

[0048] In some preferred embodiments, the extruder is a single screw auger extruder.

[0049] Example 1

[0050] In this embodiment, the added amounts of fly ash, calcium hydroxide and additives in the solid powder are 72g, 24g and 24g respectively, wherein the fly ash is Class F fly ash with a particle size of 200 mesh; the additive is CaSO4; the mass ratio of the solid powder to water is 10:1, that is, the added amount is 1200g;

[0051] The container selected for the hydration reaction is a three-necked flask. The raw materials are added into the three-necked flask, and then the three-necked flask is placed in a heat-collecting constant-temperature magnetic stirrer and the stirring and heating functions are started to carry out the hydration reaction; the reaction time is 8 hours. After the reaction is completed, the slurry in the three-necked flask is filtered and then dried to constant weight to obtain a deacidifying agent.

[0052] Weigh 120 g of the prepared deacidifying agent and crush it into 200 mesh, add 60 g of water, knead it manually, and then extrude it through a single-screw extruder. Shear the extruded strip material into granular materials with a diameter or length of 3 mm. Place the granular materials in a drying oven and dry them at 100°C to constant weight to obtain active granules of the deacidifying agent.

[0053] Performance test shows that the specific surface area of ​​the active particles of the deacidifier is 30.54m2 / g, while the specific surface area of ​​fly ash is 1.64m2 / g;

[0054] A simulation experiment was conducted on the deacidification performance of the prepared deacidification agent active particles in the presence of multiple components of acid gas, wherein the contents of each acid gas were HCl-3000ppm, SO2-1000ppm, and NO-500ppm; the measurement showed that the deacidification agent active particles could absorb multiple components of acid gas simultaneously, and the effective absorption time for HCl, SO2, and NO components was 30h, 15h, and 8h, respectively, and the adsorption capacity was 179.46mg / g, 29.91mg / g, and 7.98mg / g, respectively; the granulation rate during granulation was 86%.

[0055] Example 2

[0056] In this embodiment, the added amounts of fly ash, calcium hydroxide and additives in the solid powder are 24g, 24g and 24g respectively; the rest are the same as in Embodiment 1.

[0057] Performance test shows that the specific surface area of ​​the active particles of the deacidifier is 31.78m2 / g, while the specific surface area of ​​the fly ash is 1.64m2 / g. A simulation experiment is carried out on the deacidification performance of the prepared active particles of the deacidifier in the presence of multi-component acid gases, wherein the contents of each acid gas are HCl-3000ppm, SO2-1000ppm, and NO-500ppm. It is measured that the active particles of the deacidifier can absorb multi-component acid gases simultaneously, and the effective absorption time for HCl, SO2, and NO components is 29.5h, 17h, and 11h, respectively, and the adsorption capacity is 168.64mg / g, 35.22mg / g, and 11.5mg / g, respectively. The granulation rate during granulation is 88%.

[0058] Example 3

[0059] In this embodiment, the added amounts of fly ash, calcium hydroxide and additives in the solid powder are 24g, 24g and 12g respectively; the rest is the same as in Embodiment 1.

[0060] Performance test shows that the specific surface area of ​​the active particles of the deacidifier is 33.10m2 / g, while the specific surface area of ​​the fly ash is 1.64m2 / g. A simulation experiment is carried out on the deacidification performance of the prepared active particles of the deacidifier in the presence of multi-component acid gases, wherein the contents of each acid gas are HCl-3000ppm, SO2-1000ppm, and NO-500ppm. It is measured that the active particles of the deacidifier can absorb multi-component acid gases simultaneously, and the effective absorption time for HCl, SO2, and NO components is 28h, 17h, and 10h, respectively, and the adsorption capacity is 170.53mg / g, 35.62mg / g, and 9.45mg / g, respectively. The granulation rate during granulation is 92%.

[0061] The embodiments of the present invention are described above, but the present invention is not limited to the above-mentioned specific implementation modes. The above-mentioned specific implementation modes are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A method for preparing a deacidifying agent for removing acidic gases from flue gas, characterized in that: The steps include: Prepare raw materials, the raw materials include solid powder and water, the weight ratio of the solid powder to water is 10-15:1; the solid powder includes fly ash, calcium hydroxide and additives, the weight ratio of the fly ash, calcium hydroxide and additives is 1:1:0.5-3:1:1; The raw material is subjected to a hydration reaction to obtain a slurry; The slurry is filtered and dried to obtain a deacidifying agent.

2. The method for preparing a deacidifying agent for removing acidic gases from flue gas according to claim 1, characterized in that: The hydration reaction time is 6-12 hours, the reaction temperature is 60-90° C., and the stirring speed is 200-300 r / min.

3. The method for preparing a deacidifying agent for removing acidic gas from flue gas according to claim 1, characterized in that: The additive is a salt that becomes alkaline upon hydrolysis.

4. The method for preparing a deacidifying agent for removing acidic gas from flue gas according to claim 1, characterized in that: The fly ash is Class F fly ash with a particle size of 100-200 meshes.

5. The method for preparing a deacidifying agent for removing acidic gas from flue gas according to claim 1, characterized in that: The temperature of the drying process is less than or equal to 100°C.

6. A granulation method for granulating a deacidifying agent prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: The deacidifying agent is crushed, and then the crushed deacidifying agent and a binder are added into a container, wherein the amount of the binder added is 30-50% of the weight of the deacidifying agent; kneading the contents in the container, and then extruding through an extruder to obtain a strip-shaped material; Shearing the strip material to obtain granular material; The granular material is dried to a constant weight to obtain a granular product.

7. The granulation method according to claim 6, characterized in that The binder is water or sodium silicate.

8. The granulation method according to claim 6, characterized in that The binder is water, and the added amount is 30-50% of the weight of the deacidifying agent.

9. The granulation method according to claim 6, characterized in that The diameter or length of the granular material is 3-5 mm.

10. The granulation method according to claim 6, characterized in that The extruder is a single-screw extruder.