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CN-118056606-B - Volatile organic compound adsorption material and preparation method thereof

CN118056606BCN 118056606 BCN118056606 BCN 118056606BCN-118056606-B

Abstract

The invention relates to a volatile organic compound adsorption material and a preparation method thereof, wherein a lithium modified 5A molecular sieve is adopted, and then a Li-V-5A adsorption material is obtained through vanadium modification, wherein the content of Li is 0.8% -4.5% and the content of V is 0.2% -1% based on the total mass of the adsorption material. The adsorption material prepared by the method of the invention takes the 5A molecular sieve as a matrix, and the Li-V-5A adsorption material obtained by modification has the advantages of good adsorption effect of low-carbon hydrocarbon, strong sulfur poisoning resistance and the like, and particularly has high adsorption and removal rate of ethane.

Inventors

  • HAO XIAOXIA
  • WANG PENG
  • ZHAO LEI
  • WANG XUEHAI

Assignees

  • 中国石油化工股份有限公司
  • 中石化（大连）石油化工研究院有限公司

Dates

Publication Date
20260505
Application Date
20221118

Claims (20)

  1. 1. A volatile organic matter adsorbing material is characterized in that a lithium modified 5A molecular sieve is adopted, then a Li-V-5A adsorbing material obtained through vanadium modification is adopted, the content of Li is 0.8% -4.5% and the content of V is 0.2% -1% based on the total mass of the adsorbing material, the preparation method of the volatile organic matter adsorbing material comprises the following steps of (1) immersing the 5A molecular sieve in a lithium salt solution at the temperature of 60-90 ℃, filtering, washing, drying and roasting after treatment, and (2) immersing the Li-5A molecular sieve in a vanadium salt solution, filtering, washing, drying and roasting to obtain the Li-V-5A adsorbing material.
  2. 2. The adsorbent material of claim 1, wherein the pores in the adsorbent material comprise more than 85% of the total pore volume, and the sum of the pore volumes of pores with pore diameters distributed between 4-6A is 60% -80%.
  3. 3. The adsorbent material according to claim 1, wherein the specific surface area of the adsorbent material is 450-520 m 2 /g and the pore volume is 0.24-0.28 cm 3 /g.
  4. 4. The adsorbent material according to claim 1, wherein the 5A molecular sieve in the step (1) has a specific surface area of 400-550 m 2 /g, a pore volume of 0.2-0.5 cm 3 /g, an average pore diameter of 1-3 nm, and an average particle diameter of 1-3 mm.
  5. 5. The adsorbent material according to claim 4, wherein the 5A molecular sieve in the step (1) has a specific surface area of 500-550 m 2 /g and a pore volume of 0.28-0.35 cm 3 /g.
  6. 6. The absorbent material of claim 1, wherein the lithium salt solution in step (1) is at least one of LiCl solution, lithium nitrate solution, and lithium sulfate solution.
  7. 7. The absorbent material of claim 6, wherein the lithium salt solution in step (1) is LiCl solution.
  8. 8. The absorbent according to claim 1, 6 or 7, wherein the concentration of the lithium salt solution in the step (1) is 0.3 to 2.0mol/L.
  9. 9. The absorbent material according to claim 8, wherein the concentration of the lithium salt solution in the step (1) is 0.5 to 1.5mol/L.
  10. 10. The adsorption material according to claim 1,6 or 7, wherein the mass-to-volume ratio of the 5A molecular sieve to the lithium salt solution in the step (1) is 1 g:5-13 mL.
  11. 11. The adsorption material according to claim 1, wherein the 5A molecular sieve in the step (1) is immersed in a lithium salt solution for 1-5 hours at a temperature of 70-80 ℃.
  12. 12. The adsorption material according to claim 1, wherein the drying condition in the step (1) is that the drying temperature is 70-120 ℃, the drying time is 2-10 hours, and the roasting condition is that the roasting temperature is 450-600 ℃ and the roasting time is 1-10 hours.
  13. 13. The adsorption material according to claim 12, wherein the drying condition in the step (1) is that the drying temperature is 80-100 ℃, the drying time is 2-5 hours, and the roasting condition is that the roasting temperature is 500-550 ℃ and the roasting time is 2-6 hours.
  14. 14. The absorbent material of claim 1, wherein the vanadium salt in step (2) is a soluble vanadium salt.
  15. 15. The adsorption material of claim 14, wherein the vanadium salt in step (2) is at least one of ammonium metavanadate, sodium vanadate, vanadyl oxalate and vanadyl sulfate.
  16. 16. The method of claim 15, wherein the vanadium salt in step (2) is ammonium metavanadate.
  17. 17. The absorbent material according to claim 1 or 14, wherein the vanadium content in the vanadium salt solution in the step (2) is 0.05-0.5 mol/L.
  18. 18. The adsorption material according to claim 17, wherein the vanadium content in the vanadium salt solution in the step (2) is 0.1-0.3 mol/L.
  19. 19. The adsorption material according to claim 1 or 14, wherein the mass-to-volume ratio of the Li-5A molecular sieve to the vanadium salt solution in the step (2) is 1 g:20-50 mL.
  20. 20. The adsorption material according to claim 1, wherein in the step (2), the Li-5A molecular sieve is immersed in a vanadium salt solution for treatment at room temperature for 1-5 hours.

Description

Volatile organic compound adsorption material and preparation method thereof Technical Field The invention belongs to the technical field of air pollution control, and particularly relates to a volatile organic compound adsorption material and a preparation method thereof. Background Volatile Organic Compounds (VOCs) are one of the main atmospheric pollutants, are one of important reactants participating in the generation of photochemical smog and haze, and the excessive amount of the VOCs brings serious harm to human health and ecological environment. Among VOCs discharged in the chemical industry, ethane and propane are VOCs molecules with smaller sizes, have weaker polarity and are often difficult to remove. The VOCs adsorption separation technology is suitable for low-concentration VOCs waste gas treatment, and the key of adsorption purification efficiency is an adsorption material. The adsorption material has high specific surface area and proper pore structure, and can retain VOCs pollutant through chemical adsorption or physical adsorption, thus realizing waste gas purification. The types of VOCs are complex, wherein the higher the molecular weight is, the stronger the polarity is, the easier the VOCs are adsorbed, and the lower hydrocarbon, especially ethane and propane, are VOCs with smaller size, the weaker the polarity is, the conventional adsorption material is difficult to realize efficient adsorption. In addition, VOCs waste gas often contains sulfur-containing substances such as hydrogen sulfide, and the like, and adsorbent poisoning failure can be caused in the adsorption process, so that the sulfur poisoning resistance of the molecular sieve is very necessary to be improved. CN201710620400.6 discloses a polydopamine-pitch-based composite porous carbon adsorption material for preferentially adsorbing ethane, and a preparation method and application thereof, wherein the method comprises the following steps of carbonizing pitch at high temperature in nitrogen atmosphere to obtain pitch-based non-porous carbon material; acidifying the asphalt-based nonporous carbon material to obtain an acidified asphalt-based nonporous carbon material, adding a dopamine hydrochloride aqueous solution (solution B) into a mixture A obtained by mixing the acidified asphalt-based nonporous carbon material with ethanol, water and ammonia water to react to obtain a polydopamine-asphalt-based composite carbon material, mixing the polydopamine-asphalt-based composite carbon material with KOH, and then placing the mixture in a nitrogen atmosphere to activate to obtain the polydopamine-asphalt-based composite porous carbon adsorption material. The porous carbon adsorption material has the characteristic of preferentially adsorbing ethane, the specific surface area can reach more than 1500m 2/g, and the adsorption capacity of ethane is between 4.3 and 4.52mmol/g under the conditions of 0.3bar and 298 k. CN202110917888.5 discloses an oxygen-containing microporous activated carbon material, a preparation method thereof and application in selective adsorption of ethane. In the oxygen-containing microporous activated carbon, the sum of pore volumes of pores with pore diameters distributed between 5 and 15A is 40% -80% of the total pore volume, and the adsorption capacity of ethane can reach more than 6mmol/g at 1bar and 25 ℃. The preparation method comprises the steps of grinding and mixing biomass charcoal with the mass ratio of 1:1-10 with KOH, vacuum drying, activating in an inert atmosphere at 300-1000 ℃, and cleaning and drying an activated product to obtain the oxygen-containing microporous activated charcoal. However, both of these patents have poor adsorption capacity under normal pressure, so that the adsorption effect is achieved under the operation of pressure, the adsorption material is carbon-based, the safety risk exists in the exothermic process of VOCs adsorption, and the deep thermal regeneration is difficult. The invention discloses a preparation method of ethane adsorption silica gel, which comprises the specific steps of preparing a silica gel-based adsorbent by modifying alkali metal ions on the surface of the silica gel, changing the adsorption capacity of the silica gel to ethane, carrying out intensified mixing on sodium silicate solution and dilute sulfuric acid solution, carrying out neutralization reaction to generate hydrogel, carrying out acid foam on the generated hydrogel by using HCl, fixing a framework, preventing the continuous neutralization reaction in the silica gel, washing the hydrogel after the acid foam by using deionized water, then adopting an equal volume impregnation method, modifying alkali metal ions on the surface of the silica gel after the water washing by using BaCl 2 solution, and finally drying to obtain the ethane adsorption silica gel. The ethane adsorption silica gel has increased micropore number, micropore specific surface area up to 480m 2/g, ethane adsorption capaci