A method for preparing a low-carbon alcohol adsorbent

Abstract

The present invention relates to a preparation method of a low-carbon alcohol adsorbent, and belongs to the technical field of adsorbents. The preparation method is as follows: (1) preparing an alkaline solution, wherein the mass ratio of each component in the solution is inorganic base: acid salt: water = 1: 0.1-10: 10-300; (2) taking a high-silicon ZSM-5 molecular sieve and mixing it with the alkaline solution prepared in step (1) according to a solid-liquid ratio of 1: 1-15, stirring at 25-95°C for 0.5-5h; then filtering and washing to obtain product 1; (3) adding product 1 to a sulfide solution, stirring the reaction at 25-115°C for 0.5-5h, washing and filtering to obtain product 2; (4) adding a binder, an acidic liquid and water to product 2, extruding to obtain product 3; (5) roasting product 3 at 500-1000°C for 0.5-5h to obtain a low-carbon alcohol adsorbent. The present invention increases the pore volume and pore diameter, thereby improving the adsorption capacity of low-carbon alcohols; after sulfidation, not only the inherent hydrophobicity is enhanced but also the lipophilicity of the molecular sieve is improved; and the problem of poor adsorption of ZSM-5 type molecular sieve is solved.

Description

Technical Field

[0001] The invention relates to a preparation method of a low-carbon alcohol adsorbent, belonging to the technical field of adsorbents. Background Art

[0002] Molecular sieves are widely used in current industrial production. They can effectively adsorb and remove contaminated ethanol molecules during material purification, ensuring the purity of industrial materials and facilitating production operations. However, existing molecular sieve structures for ethanol adsorption are often fabricated directly from single silicon and aluminum source materials, which not only affects the uniformity of material mixing but also results in poor adsorption performance. Summary of the Invention

[0003] According to the background problem, the problem to be solved by the present invention is:

[0004] The existing ZSM-5 molecular sieve has a low adsorption capacity for low-carbon alcohols.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A preparation method of a low-carbon alcohol adsorbent, the preparation method comprising:

[0007] A method for preparing a low-carbon alcohol adsorbent comprises the following steps:

[0008] (1) preparing an alkaline solution, wherein the mass ratio of each component in the solution is inorganic base: acid salt: water = 1:0.1-10:10-300;

[0009] (2) taking high-silicon ZSM-5 molecular sieve and the alkaline solution prepared in step 1 at a solid-liquid mass ratio of 1:1 to 15, stirring at 25 to 95°C for 0.5 to 5h; then filtering and washing with water to obtain product 1;

[0010] (3) Add product 1 to the sulfide solution, stir and react at 25-115°C for 0.5-5h, wash with water, and filter to obtain product 2;

[0011] (4) adding a binder, an acidic liquid, and water to the product 2, and extruding the product to obtain the product 3;

[0012] (5) The product 3 is calcined at 500-1000°C for 0.5-5h to obtain a low-carbon alcohol adsorbent.

[0013] Preferably, the inorganic base in step 1 is one or both of sodium hydroxide solution and potassium hydroxide solution; and the acid salt is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate.

[0014] Preferably, the mass ratio of the inorganic base to the acid salt in the alkaline solution is 1:1-10.

[0015] Preferably, in step 2, the stirring temperature is 55-85° C., and the stirring time is 1-2 h.

[0016] Preferably, the solute in the sulfiding solution in step 3 is one or more of sulfosalicylic acid, sodium sulfosalicylate, toluenesulfonic acid and o-toluenesulfonic acid, and the mass concentration of the sulfiding solution is 0.1-10%.

[0017] Preferably, in step 3, the solid-liquid mass ratio of the product 1 to the sulfide liquid is 1:1 to 100.

[0018] Preferably, the stirring temperature in step 3 is 75° C. to 100° C., and the stirring time is 1 to 2 hours.

[0019] Preferably, it is characterized in that, in step 4, the mass ratio of product 2: binder: acidic liquid: water is 1:0.1-0.5:0.01-0.5:0.5-10.

[0020] Preferably, in step 4, the binder is one or both of sesbania powder and cellulose; and the acidic liquid is one or more of acidic silica sol, oxalic acid and phosphoric acid.

[0021] The method of the present invention includes first treating a high-silicon ZSM-5 molecular sieve with an alkaline solution system, then sulfiding the treated sample, and then filtering, washing, forming, and calcining to obtain a low-carbon alcohol adsorbent. This method uses an alkaline solution system during treatment, and can obtain molecular sieves with different silicon-aluminum ratios, different mesopore sizes, specific surface areas, and pore volumes by adjusting the ratio of inorganic base to acid salt, thereby obtaining adsorption conditions with high specific surface area and rich mesopores without destroying the molecular sieve skeleton structure; the subsequent sulfidation treatment can reduce the oxygen content on the molecular sieve surface and the molecular sieve skeleton polarity, thereby improving the molecular sieve's lipophilicity; under high-temperature calcination, the sulfur element can be more stably combined with the molecular sieve, and -OH can be reduced, thereby enhancing the adsorption capacity of low-carbon alcohols on the molecular sieve surface.

[0022] The beneficial effects of the present invention are:

[0023] The low-carbon alcohol adsorbent prepared after treatment according to the method of the present invention has the following characteristics: the ZSM-5 molecular sieve treated with an alkaline solution has mesoporous properties, increased pore volume and pore diameter, thereby improving the adsorption capacity of low-carbon alcohols, and after sulfurization, not only the inherent hydrophobicity is enhanced but also the lipophilicity of the molecular sieve is improved, and then calcined under high temperature conditions can make the combination of sulfur element and molecular sieve more stable, and can also reduce -OH, thereby enhancing the adsorption capacity of low-carbon alcohols on the surface of the molecular sieve, and specifically improving the adsorption capacity of low-carbon alcohols in VOC gases in applications. The adsorption capacity of low-carbon alcohols by ZSM-5 molecular sieve is 10% to 15%, while the ethanol adsorption capacity of the low-carbon alcohol adsorbent prepared by the present invention exceeds 19.8%, and in some experiments it can exceed 23%, with performance improved by nearly 50%, solving the problem of poor adsorption of ZSM-5 molecular sieve.

[0024] The low-carbon alcohol adsorbent prepared by this technology not only has a high low-carbon alcohol adsorption capacity, but also has cheap and easily available raw materials for preparation, and has good economic efficiency. DETAILED DESCRIPTION

[0025] Example 1

[0026] 58g of sodium hydroxide solution, 1000g of deionized water, and 70.0g of sodium carbonate were added to a 2000mL beaker, heated to 60°C in a water bath, and then 150.0g of ZSM-5 molecular sieve with a silicon-aluminum ratio of 300 without a template was added. The mixture was treated in a water bath for 2h, rapidly cooled to room temperature, filtered, and washed until neutral to obtain product 1. 400g of water was added to a 1000mL beaker, 5g of sulfosalicylic acid was added and stirred, the mixture was heated to 100°C in a water bath, and then 50g of product 1 was added. The temperature was maintained for 1.0h, the temperature was rapidly cooled, filtered, washed until neutral, dried in an oven at 120°C for 12h, and then crushed to obtain product 2. To 20 g of product 2, add 2 g of sesbania powder, 0.2 g of acidic silica sol, and 10 g of water, stir evenly, and extrude using a 1.6 mm circular orifice plate to obtain product 3. Place it in an oven and dry it at 120 ° C for 8 h. Then, calcine it at 600 ° C for 1 h in a muffle furnace. The obtained sample is a low-carbon alcohol adsorbent.

[0027] According to the molecular sieve static water adsorption determination method (GBT_6287-2021), the water absorption rate of the low-carbon alcohol adsorbent was measured to be 8.1%, and according to the molecular sieve static ethanol adsorption determination method, the ethanol adsorption rate of the ethanol adsorbent was measured to be 23.5%; the ethanol adsorption capacity of the ZSM-5 molecular sieve is between 10% and 15%, while the ethanol adsorption capacity of the low-carbon alcohol adsorbent prepared by the present invention exceeds 23%.

[0028] Example 2

[0029] 100g of sodium hydroxide, 1000g of deionized water, 2g of potassium carbonate, and 8g of sodium carbonate were added to a 2000mL beaker, heated to 25°C in a water bath, and then 200.0g of ZSM-5 molecular sieve with a silicon-aluminum ratio of 300 without a template was added. The mixture was treated in a water bath for 5h, rapidly cooled to room temperature, filtered, and washed until neutral to obtain product 1. 500g of water was added to a 1000mL beaker, 3g of sodium sulfosalicylate was added and stirred, the mixture was heated to 25°C in a water bath, and then 50g of product 1 was added. The temperature was maintained for 5h, the temperature was rapidly cooled, filtered, washed until neutral, dried in an oven at 120°C for 12h, and then crushed to obtain product 2. 20 g of product 2 was added with 2 g of sesbania powder, 30 g of acidic silica sol, and 200 g of water. After stirring evenly, the mixture was extruded using a 1.6 mm circular orifice plate to obtain product 3. Product 3 was placed in an oven, dried at 120 ° C for 8 h, and calcined at 500 ° C for 5 h in a muffle furnace. The obtained sample was a low-carbon alcohol adsorbent.

[0030] According to the molecular sieve static water adsorption determination method (GBT_6287-2021), the water absorption rate of the low-carbon alcohol adsorbent was measured to be 7.2%, and according to the molecular sieve static ethanol adsorption determination method, the ethanol adsorption rate of the ethanol adsorbent was measured to be 19.8%.

[0031] Example 3

[0032] 3g of sodium hydroxide, 900g of deionized water, and 30.0g of sodium carbonate were added to a 2000mL beaker, heated to 95°C in a water bath, and then 150.0g of ZSM-5 molecular sieve with a silicon-aluminum ratio of 300 without a template was added. The mixture was treated in a water bath for 0.5h, rapidly cooled to room temperature, filtered, and washed until neutral to obtain product 1. 450g of water was added to a 1000mL beaker, and 15g of sulfosalicylic acid, 5g of sodium sulfosalicylate, 15g of toluenesulfonic acid, and 15g of o-toluenesulfonic acid were added and stirred. The mixture was heated to 115°C in a water bath, and then 100g of product 1 was added. The temperature was maintained for 0.5h, the temperature was rapidly cooled, filtered, washed until neutral, and dried in an oven at 120°C for 12h before being crushed. 10 g of sesbania powder, 5 g of oxalic acid and 5 g of phosphoric acid, and 100 g of water were added to 20 g of product 2, stirred evenly, and extruded using a 1.6 mm circular orifice plate to obtain product 3. Product 3 was placed in an oven, dried at 120°C for 8 h, and calcined in a muffle furnace at 1000°C for 0.5 h. The obtained sample was a low-carbon alcohol adsorbent.

[0033] According to the molecular sieve static water adsorption determination method (GBT_6287-2021), the water absorption rate of the low-carbon alcohol adsorbent was measured to be 7.5%, and according to the molecular sieve static ethanol adsorption determination method, the ethanol adsorption rate of the ethanol adsorbent was measured to be 22.5%.

[0034] Example 4

[0035] 15g of sodium hydroxide, 15g of potassium hydroxide, 990g of deionized water, and 30.0g of sodium bicarbonate were added to a 2000mL beaker, heated to 90°C in a water bath, and then 70.0g of ZSM-5 molecular sieve with a silicon-aluminum ratio of 300 without a template was added. The mixture was treated in a water bath for 1 hour, rapidly cooled to room temperature, filtered, and washed until neutral to obtain product 1. 499.5g of water was added to a 1000mL beaker, 0.5g of sulfosalicylic acid was added and stirred, the mixture was heated to 90°C in a water bath, and then 50g of product 1 was added. The temperature was maintained for 1 hour, the temperature was rapidly cooled, filtered, washed until neutral, and dried in an oven at 120°C for 12 hours before being crushed. 5 g of cellulose and 5 g of sesbania powder, 10 g of acidic silica sol, and 100 g of water were added to 20 g of product 2, stirred evenly, and extruded using a 1.6 mm circular orifice plate to obtain product 3. Product 3 was placed in an oven, dried at 120°C for 8 h, and calcined in a muffle furnace at 1000°C for 0.5 h. The obtained sample was a low-carbon alcohol adsorbent.

[0036] According to the molecular sieve static water adsorption determination method (GBT_6287-2021), the water absorption rate of the low-carbon alcohol adsorbent was measured to be 6.2%, and according to the molecular sieve static ethanol adsorption determination method, the ethanol adsorption rate of the ethanol adsorbent was measured to be 25.6%.

[0037] Example 5

[0038] 10g of potassium hydroxide, 480g of deionized water, and 10.0g of potassium bicarbonate were added to a 2000mL beaker, heated to 90°C in a water bath, and then 500.0g of ZSM-5 molecular sieve with a silicon-aluminum ratio of 300 without a template was added. The mixture was treated in a water bath for 1 hour, rapidly cooled to room temperature, filtered, and washed until neutral to obtain product 1. 490g of water was added to a 1000mL beaker, and 10g of sulfosalicylic acid was added with stirring. The mixture was heated to 90°C in a water bath, and then 5g of product 1 was added. The temperature was maintained for 1 hour, and the temperature was rapidly cooled, filtered, washed until neutral, and dried in an oven at 120°C for 12 hours before being crushed. 2g of sesbania powder, 5g of acidic silica sol, 3g of phosphoric acid and 100g of water were added to 20g of product 2, stirred evenly and extruded using a 1.6mm circular orifice plate to obtain product 3. Product 3 was placed in an oven, dried at 120°C for 8h, and calcined at 800°C in a muffle furnace for 0.5h. The obtained sample was a low-carbon alcohol adsorbent.

[0039] According to the molecular sieve static water adsorption determination method (GBT_6287-2021), the water absorption rate of the low-carbon alcohol adsorbent was measured to be 8.1%, and according to the molecular sieve static ethanol adsorption determination method, the ethanol adsorption rate of the ethanol adsorbent was measured to be 23.5%.

[0040] The ethanol adsorption capacity of the low-carbon alcohol adsorbent prepared by the present invention exceeds 19.8%, and in most experiments it can exceed 23%, which is nearly 50% higher than the performance of commercially available products, solving the problem of poor adsorption of ZSM-5 molecular sieves.

Claims

1. A method for preparing a low-carbon alcohol adsorbent, characterized in that: The following steps are involved: (1) Prepare an alkaline solution, wherein the mass ratio of each component in the solution is inorganic base: acid salt: water = 1: 0.1~10: 10~300; (2) Mixing the high-silicon ZSM-5 molecular sieve with the alkaline solution prepared in step 1 at a solid-liquid mass ratio of 1:1-15, stirring at 25-95°C for 0.5-5h; filtering and washing with water to obtain product 1; (3) Add product 1 to the sulfide solution, stir and react at 25-115°C for 0.5-5h, wash with water, and filter to obtain product 2; (4) adding a binder, an acidic liquid and water to the product 2, and extruding the product 2 to obtain the product 3; (5) Calcinate the product 3 at 500-1000°C for 0.5-5h to obtain a low-carbon alcohol adsorbent; The acid salt is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate; In the step 3, the solute in the sulfiding liquid is one or more of sulfosalicylic acid, sodium sulfosalicylate, toluenesulfonic acid and o-toluenesulfonic acid, and the mass concentration of the sulfiding liquid is 0.1-10%; The acidic liquid is one or more of acidic silica sol, oxalic acid and phosphoric acid.

2. The method for preparing a low-carbon alcohol adsorbent according to claim 1, characterized in that: The inorganic base in step 1 is one or both of sodium hydroxide solution and potassium hydroxide solution.

3. The method for preparing a low-carbon alcohol adsorbent according to claim 1, characterized in that: The mass ratio of the inorganic base to the acid salt in the alkaline solution is 1:1-10.

4. The method for preparing a low-carbon alcohol adsorbent according to claim 1, characterized in that: In step 2, the stirring temperature is 55-85° C. and the stirring time is 1-2 h.

5. The method for preparing a low-carbon alcohol adsorbent according to claim 1, characterized in that: In the step 3, the solid-liquid mass ratio of the product 1 to the sulfide liquid is 1:1-100.

6. The method for preparing a low-carbon alcohol adsorbent according to claim 1, characterized in that: In step 3, the stirring temperature is 75° C. to 100° C., and the stirring time is 1 to 2 h.

7. The method for preparing a low-carbon alcohol adsorbent according to claim 1, characterized in that: In the step 4, the mass ratio of product 2: binder: acidic liquid: water is 1: 0.1~0.5: 0.01~0.5: 0.5~10.

8. The method for preparing a low-carbon alcohol adsorbent according to claim 1, characterized in that: In step 4, the binder is one or both of sesbania powder and cellulose.