Preparation method of absorbent and method for absorbing caramel pigment production tail gas
By preparing the silicon-nano-nanoma as an absorption agent, the problem of low sulfur dioxide and ammonia absorption efficiency in the production of caramel pigment production is solved, and the more efficient absorption effect is achieved, and the pollutant content in the tail gas is reduced.
Patent Information
- Application Number
- CN202411709992.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-01-21
AI Technical Summary
The prior art has low absorption efficiency of sulfur dioxide and ammonia in the tail gas for caramel pigment production, and cannot effectively reduce the sulfur dioxide content for a long time, resulting in excessive emissions.
Silica-water nanofluid is prepared as an absorbent. The nanofluid is formed through ultrasonic treatment and dispersed under stirring conditions, which significantly improves the absorption rate of sulfur dioxide and reduces the decomposition and escape of ammonia.
The absorption rate of sulfur dioxide is significantly increased, the absorption of ammonia is increased, the content of sulfur dioxide and ammonia gas in the tail gas production of caramel pigments is reduced, and the emissions are avoided.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of tail gas adsorption, and particularly relates to a method for preparing an absorbent and a method for absorbing tail gas produced by caramel pigment production. Background Art
[0002] During the production of caramel color, the reaction is violent, and a large amount of sulfur dioxide and some ammonia will be released instantly. The Class IV tail gas of caramel color contains not only sulfur dioxide but also ammonia. At present, the water absorption method is used to treat the tail gas of this Class IV caramel color production. However, the water absorption method is not efficient in absorbing sulfur dioxide and ammonia in the tail gas, and it cannot effectively reduce the sulfur dioxide content in the tail gas for a long time, resulting in excessive emissions. Because ammonia absorption is an exothermic process, the heat generated cannot be taken out, and the ammonia decomposes and escapes, resulting in a decrease in the ammonia absorption efficiency. Summary of the invention
[0003] The technical problem to be solved by the present invention is to provide a method for preparing an absorbent and a method for absorbing tail gas from the production of caramel pigment, prepare a silicon dioxide-water nanofluid as an absorbent, significantly improve the absorption rate of sulfur dioxide, reduce ammonia decomposition and escape, increase the absorption amount of ammonia, and reduce the content of sulfur dioxide and ammonia in the tail gas from the production of Class IV caramel pigment.
[0004] The present invention is achieved by providing a method for preparing an absorbent, comprising the following steps: Step 1: add 6-180 g of nano-silicon dioxide into 3 L of water to form a silica aqueous solution, and use an ultrasonic water bath to ultrasonically treat the silica aqueous solution for 30-500 minutes to obtain a silica-water nanofluid; Step 2: Add the silica-water nanofluid into 57 L of water, stir at 500 r / min, and disperse for 30 minutes to obtain the desired absorbent.
[0005] The present invention is implemented in this way, and also provides a method for absorbing tail gas from the production of caramel pigment, which uses the absorbent prepared by the absorbent preparation method as described above to absorb the tail gas from the production of caramel pigment.
[0006] Furthermore, the method for absorbing the tail gas produced by caramel colorant comprises the following steps: pre-filling the bubbling reactor with an absorbent through the liquid inlet port of the bubbling reactor, then passing the type IV caramel colorant production tail gas into the bubbling reactor through the air inlet port of the bubbling reactor, and after the tail gas and the absorbent are fully mixed, discharging the bubbling reactor from the air outlet port of the bubbling reactor.
[0007] Compared with the prior art, the method for preparing the absorbent and the method for absorbing tail gas from caramel pigment production of the present invention have the following characteristics: 1. Improve absorption efficiency: The present invention prepares silica-water nanofluid by adding nano-silicon dioxide to water. Compared with water, the absorbent prepared by the present invention has better sulfur dioxide absorption kinetics, high sulfur dioxide absorption rate, low system energy consumption, significantly improves the sulfur dioxide absorption rate of water, and reduces the sulfur dioxide content in the tail gas. In addition, the silica-water nanofluid has better heat transfer performance, which can dissipate the heat released by ammonia absorption more quickly and reduce the decomposition and escape of ammonia.
[0008] 2. Reduce production costs: The preparation method of the present invention improves the absorption rate and absorption capacity of sulfur dioxide and ammonia, can reduce water consumption, and reduce production costs.
[0009] 3. Environmentally friendly: The silicon dioxide material used in the present invention is a green and environmentally friendly material and will not cause secondary pollution to the environment. DETAILED DESCRIPTION
[0010] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0011] A preferred embodiment of the method for preparing the absorbent of the present invention comprises the following steps: Step 1: Add 6-180 g of nano-silicon dioxide into 3 L of water to form a silica aqueous solution, and use an ultrasonic water bath to ultrasonically treat the silica aqueous solution for 30-500 minutes to obtain a silica-water nanofluid.
[0012] Step 2: Add the silica-water nanofluid into 57 L of water, stir at 500 r / min, and disperse for 30 minutes to obtain the desired absorbent.
[0013] In step 1, the particle size of the silicon dioxide is 10-100 nm. In the silicon dioxide-water nanofluid, the mass ratio of silicon dioxide to water is 0.002-0.06:1.
[0014] The invention also discloses a method for absorbing tail gas produced by caramel pigment production, which uses the absorbent prepared by the absorbent preparation method as described above to absorb the tail gas produced by caramel pigment production.
[0015] Specifically, the method for absorbing the tail gas produced by caramel colorant comprises the following steps: pre-filling the bubbling reactor with an absorbent through the liquid inlet port of the bubbling reactor, then passing the Class IV caramel colorant production tail gas into the bubbling reactor through the air inlet port of the bubbling reactor, and after the tail gas and the absorbent are fully mixed, discharging the bubbling reactor from the air outlet port of the bubbling reactor.
[0016] The stirring speed of the bubbling reactor is 150-250 r / min. The temperature of the absorbent is 45° C., and the tail gas is absorbed for 2 hours.
[0017] The preparation method of the absorbent of the present invention and the effect of the method for absorbing tail gas from the production of caramel pigment are further illustrated below by means of specific examples and comparative examples.
[0018] Example 1
[0019] The first embodiment of the method for preparing the absorbent of the present invention comprises the following steps: Step 11: Add 90 g of nano-silicon dioxide into 3 L of water to form a silicon dioxide aqueous solution.
[0020] Step 12: Use a 200W ultrasonic water bath to ultrasonically treat the silica aqueous solution for 180 minutes to obtain a silica-water nanofluid.
[0021] Step 13: Add the silica-water nanofluid into 57 L of water, start stirring at 500 r / min, and stir and disperse for 30 minutes to obtain the desired absorbent.
[0022] Example 2
[0023] The second embodiment of the method for preparing the absorbent of the present invention comprises the following steps: Step 21: Add 6 g of nano-silicon dioxide into 3 L of water to form a silicon dioxide aqueous solution.
[0024] Step 22: Use a 120W ultrasonic water bath to ultrasonically treat the silica aqueous solution for 360 minutes to obtain a silica-water nanofluid.
[0025] Step 23: Add the silica-water nanofluid into 57 L of water, start stirring at 500 r / min, and stir and disperse for 30 minutes to obtain the desired absorbent.
[0026] Example 3
[0027] The third embodiment of the method for preparing the absorbent of the present invention comprises the following steps: Step 31: Add 120 g of nano-silicon dioxide into 3 L of water to form a silicon dioxide aqueous solution.
[0028] Step 32: Use a 400W ultrasonic water bath to ultrasonically treat the silica aqueous solution for 30 minutes to obtain a silica-water nanofluid.
[0029] Step 33: Add the silica-water nanofluid into 57 L of water, start stirring at 500 r / min, and stir and disperse for 30 minutes to obtain the desired absorbent.
[0030] Example 4
[0031] The fourth embodiment of the method for preparing the absorbent of the present invention comprises the following steps: Step 41: Add 180 g of nano-silicon dioxide into 3 L of water to form a silicon dioxide aqueous solution.
[0032] Step 42: Use a 20W ultrasonic water bath to ultrasonically treat the silica aqueous solution for 500 minutes to obtain a silica-water nanofluid.
[0033] Step 43: Add the silica-water nanofluid into 57 L of water, start stirring at 500 r / min, and stir and disperse for 30 minutes to obtain the desired absorbent.
[0034] Example 5
[0035] The first embodiment of the method for absorbing the tail gas of caramel pigment production of the present invention comprises the following steps: pre-filling the bubbling reactor with the absorbent prepared in Example 1, the absorbent temperature is 45°C, and then passing the Class IV caramel pigment production tail gas into the bubbling reactor through the air inlet port of the bubbling reactor, the tail gas flow rate is 20m³ / h, and the tail gas and the absorbent are fully mixed and discharged from the bubbling reactor from the air outlet port of the bubbling reactor. The stirring speed of the bubbling reactor is 200r / min. The tail gas is absorbed for 2 hours.
[0036] Comparative Example 1 This comparative example adopts a common water absorption method, which differs from Example 5 in that the bubbling reactor is filled with water instead of the absorbent prepared in Example 5. The other steps and conditions are the same as those in Example 5.
[0037] Before absorption, the sulfur dioxide concentration in the Class IV caramel color tail gas was 2%, and the ammonia concentration was 0.1%. After absorption by Example 5, the average absorption of sulfur dioxide was 12.05 mol / h, and the average absorption of ammonia was 0.86 mol / h. After absorption by Comparative Example 1, the average absorption of sulfur dioxide was 9.46 mol / h, and the average absorption of ammonia was 0.78 mol / h. Therefore, compared with Comparative Example 1, the enhancement factor of the average absorption of sulfur dioxide in Example 5 is 1.27, and the enhancement factor of the average absorption of ammonia is 1.10.
[0038] Example 6
[0039] The second embodiment of the method for absorbing the tail gas of caramel pigment production of the present invention comprises the following steps: pre-filling the bubbling reactor with the absorbent prepared in Example 2, the absorbent temperature is 45°C, and then passing the Class IV caramel pigment production tail gas into the bubbling reactor through the air inlet port of the bubbling reactor, the tail gas flow rate is 16m³ / h, and the tail gas and the absorbent are fully mixed and discharged from the bubbling reactor from the air outlet port of the bubbling reactor. The stirring speed of the bubbling reactor is 150r / min. The tail gas is absorbed for 2 hours.
[0040] Comparative Example 2 This comparative example adopts a common water absorption method, which differs from Example 6 in that the bubbling reactor is filled with water instead of the absorbent prepared in Example 6. The other steps and conditions are the same as those in Example 6.
[0041] Before absorption, the sulfur dioxide concentration in the Class IV caramel color tail gas was 2%, and the ammonia concentration was 0.1%. After absorption by Example 6, the average absorption of sulfur dioxide was 8.64 mol / h, and the average absorption of ammonia was 0.68 mol / h. After absorption by Comparative Example 2, the average absorption of sulfur dioxide was 7.07 mol / h, and the average absorption of ammonia was 0.61 mol / h. Therefore, compared with Comparative Example 2, the enhancement factor of the average absorption of sulfur dioxide in Example 6 is 1.22, and the enhancement factor of the average absorption of ammonia is 1.12.
[0042] Example 7
[0043] The third embodiment of the method for absorbing the tail gas of caramel pigment production of the present invention comprises the following steps: pre-filling the bubbling reactor with the absorbent prepared in Example 3, the absorbent temperature is 45°C, and then passing the Class IV caramel pigment production tail gas into the bubbling reactor through the air inlet port of the bubbling reactor, the tail gas flow rate is 20m³ / h, and the tail gas and the absorbent are fully mixed and discharged from the bubbling reactor from the air outlet port of the bubbling reactor. The stirring speed of the bubbling reactor is 250r / min. The tail gas is absorbed for 2 hours.
[0044] Comparative Example 3 This comparative example adopts a common water absorption method, which differs from Example 7 in that the bubbling reactor is filled with water instead of the absorbent prepared in Example 7. The other steps and conditions are the same as those in Example 7.
[0045] Before absorption, the sulfur dioxide concentration in the Class IV caramel color tail gas was 2%, and the ammonia concentration was 0.1%. After absorption by Example 7, the average absorption of sulfur dioxide was 13.30 mol / h, and the average absorption of ammonia was 0.87 mol / h. After absorption by Comparative Example 3, the average absorption of sulfur dioxide was 10.09 mol / h, and the average absorption of ammonia was 0.79 mol / h. Therefore, compared with Comparative Example 3, the enhancement factor of the average absorption of sulfur dioxide in Example 7 is 1.32, and the enhancement factor of the average absorption of ammonia is 1.09.
[0046] Example 8
[0047] The fourth embodiment of the method for absorbing the tail gas of caramel pigment production of the present invention comprises the following steps: pre-filling the bubbling reactor with the absorbent prepared in Example 4, the temperature of the absorbent being 45°C, and then passing the Class IV caramel pigment production tail gas into the bubbling reactor through the air inlet port of the bubbling reactor, the tail gas flow rate being 18m³ / h, and the tail gas and the absorbent being fully mixed and discharged from the bubbling reactor from the air outlet port of the bubbling reactor. The stirring speed of the bubbling reactor is 250r / min. The tail gas is absorbed for 2 hours.
[0048] Comparative Example 4 This comparative example adopts a common water absorption method, which differs from Example 8 in that the bubbling reactor is filled with water instead of the absorbent prepared in Example 8. The other steps and conditions are the same as those in Example 8.
[0049] Before absorption, the sulfur dioxide concentration in the Class IV caramel color tail gas was 2%, and the ammonia concentration was 0.1%. After absorption by Example 8, the average absorption of sulfur dioxide was 9.56 mol / h, and the average absorption of ammonia was 0.77 mol / h. After absorption by Comparative Example 4, the average absorption of sulfur dioxide was 8.92 mol / h, and the average absorption of ammonia was 0.71 mol / h. Therefore, compared with Comparative Example 4, the enhancement factor of the average absorption of sulfur dioxide in Example 8 is 1.07, and the enhancement factor of the average absorption of ammonia is 1.09. Compare the average absorption of sulfur dioxide and the average absorption of ammonia in Examples 5 to 8 with those in Comparative Examples 1 to 4 to obtain the data table of Table 1.
[0050] Table 1 Data table of average sulfur dioxide absorption and average ammonia absorption of Examples 5 to 8 and Comparative Examples 1 to 4
[0051] As can be seen from Table 1, the method for absorbing tail gas from caramel pigment production of the present invention uses the silicon dioxide-water nanofluid of the present invention as an absorbent, and the average absorption of sulfur dioxide and the average absorption of ammonia obtained are higher than those of the commonly used water absorption method, thereby reducing the content of sulfur dioxide and ammonia in the tail gas from the production of Class IV caramel pigment and achieving the expected effect.
[0052] 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 and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for preparing an absorbent, characterized in that: The steps include: Step 1: add 6-180 g of nano-silicon dioxide into 3 L of water to form a silica aqueous solution, and use an ultrasonic water bath to ultrasonically treat the silica aqueous solution for 30-500 minutes to obtain a silica-water nanofluid; Step 2: Add the silica-water nanofluid into 57 L of water, stir at 500 r / min, and disperse for 30 minutes to obtain the desired absorbent.
2. The method for preparing the absorbent according to claim 1, characterized in that: In step 1, the particle size of the silicon dioxide is 10-100 nm.
3. The method for preparing the absorbent according to claim 1, characterized in that: In step 1, in the silica-water nanofluid, the mass ratio of silica to water is 0.002-0.06:
1.
4. A method for absorbing tail gas from caramel pigment production, characterized in that: The absorbent prepared by the absorbent preparation method as described in any one of claims 1 to 3 is used to absorb the tail gas of caramel pigment production.
5. The method for absorbing and producing caramel colorant tail gas as claimed in claim 4, characterized in that: The method comprises the following steps: pre-filling the bubbling reactor with an absorbent through the liquid inlet port of the bubbling reactor, then introducing the tail gas produced by type IV caramel colorant into the bubbling reactor through the air inlet port of the bubbling reactor, and discharging the tail gas from the bubbling reactor from the air outlet port of the bubbling reactor after the tail gas is fully mixed with the absorbent.
6. The method for absorbing and producing caramel colorant tail gas as claimed in claim 5, characterized in that: The stirring speed of the bubbling reactor is 150-250 r / min.
7. The method for absorbing and producing caramel colorant tail gas as claimed in claim 5, characterized in that: The temperature of the absorbent is 45° C., and the tail gas is absorbed for 2 hours.