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CN-121988292-A - Carbon material with through type multistage pore canal and hydrophobic surface for removing organic sulfur in natural gas and preparation method thereof

CN121988292ACN 121988292 ACN121988292 ACN 121988292ACN-121988292-A

Abstract

The invention discloses a carbon material with a through type multistage pore canal and a hydrophobic surface for removing organic sulfur in natural gas and a preparation method thereof, and belongs to the technical field of removal of organic sulfur in natural gas. The preparation method comprises the steps of firstly adding a triblock copolymer into sodium alginate to prepare a hydrogel precursor, firstly adding diammonium hydrogen phosphate into the hydrogel precursor, then introducing SiO 2 nanospheres as a hard template, forming nitrogen-phosphorus co-doped microspheres through spray drying, adopting a dipping-reduction method to dip a Fe (NO 3 ) 3 solution and a Cu (NO 3 ) 2 solution) into the microspheres, then pre-carbonizing to obtain a pre-carbonized sample, carbonizing the pre-carbonized sample at a high temperature in an NH 3 atmosphere, and constructing a hydrophobic silane layer on the surface of the obtained carbon material in a hexamethyldisilazane atmosphere.

Inventors

  • LIU TING
  • Hao Kaiyu
  • SUN HUIPING
  • LI JIE
  • LIU SICHENG
  • XU FEI
  • YAN FENGSHUN
  • ZHANG HUAWEI

Assignees

  • 青岛理工大学

Dates

Publication Date
20260508
Application Date
20260202

Claims (10)

  1. 1. The preparation method of the carbon material with the through type multistage pore canal and the hydrophobic surface for removing the organic sulfur in the natural gas is characterized by comprising the following steps of: a. Sequentially adding a polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and a KOH solution into the sodium alginate solution, and preparing a hydrogel precursor through microwave hydrothermal reaction; b. Adding diammonium hydrogen phosphate into the hydrogel precursor, then introducing SiO 2 nanospheres as a hard template, and forming nitrogen-phosphorus co-doped microspheres by spray drying; c. Adopting an impregnation-reduction method to impregnate Fe (NO 3 ) 3 solution and Cu (NO 3 ) 2 solution into nitrogen-phosphorus co-doped microspheres), reducing at 250-350 ℃ in an atmosphere of N 2 to form highly dispersed Fe-Cu bimetallic nano particles, and then pre-carbonizing at 250-350 ℃ in N 2 to obtain a pre-carbonized sample; d. Placing a pre-carbonized sample in a tube furnace, carbonizing again at 750-850 ℃ in NH 3 atmosphere, and then etching to remove a hard template by using NaOH solution to form a carbon material with a through three-dimensional porous foam-like structure of micropores, mesopores and macropores; e. And d, placing the carbon material obtained in the step d into a tube furnace, and constructing a hydrophobic silane layer on the surface of the carbon material at the temperature of 250 ℃ in a hexamethyldisilazane atmosphere to obtain the carbon material.
  2. 2. The preparation method of the carbon material with the through-type multistage pore canal and the hydrophobic surface for removing organic sulfur in natural gas is characterized in that in the step a, the mass ratio of sodium alginate to polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer in sodium alginate solution is 1:0.25-1.5, and sodium alginate solution is obtained by dissolving 2g of sodium alginate in 100mL of deionized water under stirring.
  3. 3. The preparation method of the carbon material with the through type multistage pore canal and the hydrophobic surface for removing organic sulfur in natural gas, which is disclosed in claim 2, is characterized in that the mass ratio of sodium alginate to polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer in sodium alginate solution is 1:0.5, and in step a, the microwave hydrothermal reaction is carried out in a microwave reactor at the temperature of 140-160 ℃ for 1.5-2.5 h.
  4. 4. The method for preparing the carbon material with the through-type multistage pore canal and the hydrophobic surface for removing the organic sulfur in the natural gas according to claim 1, wherein in the step b, the mass ratio of the diammonium phosphate to the sodium alginate in the sodium alginate solution is 1:1, and the mass ratio of the SiO 2 nanospheres to the diammonium phosphate is 0.75:1.
  5. 5. The method for preparing carbon material with through-type multistage pore canal and hydrophobic surface for removing organic sulfur in natural gas according to claim 1, wherein in the step b, the inlet temperature is 170-190 ℃ during spray drying.
  6. 6. The method for preparing the carbon material with the through-type multistage pore canal and the hydrophobic surface for removing the organic sulfur in the natural gas according to claim 1, wherein in the step C, fe (NO 3 ) 3 solution and Cu (NO 3 ) 2 solution in a molar ratio of 1:0.25-1.5, total load mass of Fe-Cu bimetallic is 10%, doping mass of nitrogen is 5%, doping mass of phosphorus is 3%) is pre-carbonized at the temperature of 300 ℃.
  7. 7. The method for preparing the carbon material with the through-type multistage pore canal and the hydrophobic surface for removing the organic sulfur in the natural gas, which is disclosed in claim 1, is characterized in that in the step d, naOH solution is etched for 24 hours at the temperature of 75-85 ℃ to remove a hard template, and carbonized again at 800 ℃ in NH 3 atmosphere.
  8. 8. A carbon material with through-type multistage pore channels and hydrophobic surfaces for removing organic sulfur in natural gas, which is characterized in that the carbon material is prepared by the preparation method according to any one of claims 1-7.
  9. 9. The method for removing organic sulfur from natural gas by using carbon material with through type multistage pore canal and hydrophobic surface as claimed in claim 8, wherein the organic sulfur in natural gas is carbonyl sulfide and methyl mercaptan.
  10. 10. The method for removing organic sulfur from natural gas by using a carbon material with a through type multistage pore canal and a hydrophobic surface according to claim 9, wherein the application environment is space velocity 30000H -1 , the temperature is 30 ℃, and the simulated gas comprises 30% by volume of CH 4 , 20% by volume of CO, 40% by volume of H 2 、400ppm COS、200ppm CH 3 SH and balanced nitrogen.

Description

Carbon material with through type multistage pore canal and hydrophobic surface for removing organic sulfur in natural gas and preparation method thereof Technical Field The invention relates to the technical field of removal of organic sulfur in natural gas, in particular to a carbon material with a through type multistage pore canal and a hydrophobic surface for removing the organic sulfur in the natural gas and a preparation method thereof. Background Natural gas is used as clean energy and often contains organic sulfides such as carbonyl sulfide (COS) and methyl mercaptan (CH 3 SH) during its exploitation and utilization. These sulfides not only corrode the pipes, cause catalyst poisoning, but also generate sulfur dioxide after combustion, causing serious environmental pollution. The traditional desulfurization technology such as an amine absorption method, an adsorption method and a catalytic hydrolysis method has the problems of insufficient desulfurization precision, easy inactivation of a catalyst, generation of a solid waste catalyst, secondary pollution and the like when facing the deep desulfurization requirement although the application is wide. Especially for organic sulfur with complex components, the efficiency and economy of the traditional method are difficult to meet the increasingly strict environmental protection standard, so that the development of high-efficiency and green deep desulfurization new materials and technologies is particularly urgent. Among the numerous adsorbent materials, carbon materials are of great interest due to their high specific surface area, tunable pore structure, rich surface chemistry, good hydrophobicity, and regenerability. However, the adsorption capacity and selectivity of conventional activated carbon to organic sulfur tend to be insufficient, and the removal efficiency thereof is strongly dependent on the physicochemical structure thereof. Therefore, the core research direction is to optimize the adsorption performance of the carbon material on organic sulfur molecules by accurately designing and controllably preparing the carbon material. The method mainly comprises two aspects, namely, constructing a proper pore channel structure, creating a hierarchical pore structure taking micropores as a main part and mesopores as an auxiliary part by selecting a specific precursor and combining a physical or chemical activation method, ensuring that organic sulfur molecules can be rapidly diffused and are greatly contained, and regulating and controlling the surface chemical property, and enhancing the affinity and specific adsorption capacity of the organic sulfur molecules on polar organic sulfur molecules by introducing heteroatom functional groups such as nitrogen, oxygen and the like or supported metal oxides. At present, the research front of carbon material preparation for desulfurization focuses on selecting biomass, coal and the like as precursors, adopting chemical activators such as KOH, naOH and the like to perform high-temperature activation so as to create high specific surface area and developed pores, and further performing surface modification by an ammoniation, acid treatment or impregnation method. Although these methods show great potential, challenges remain in practical applications, such as how to achieve precise regulation of pore structure to avoid excessive activation, how to ensure uniform distribution and stability of surface functional groups or active sites, and how to balance the relationship between high adsorption capacity and mechanical strength, regeneration performance of materials. Therefore, the development of the carbon material preparation method with low cost, green process and controllable structural performance is still a key of technical breakthrough in the field. Disclosure of Invention The invention aims to provide a preparation method of a carbon material with a through type multistage pore canal and a hydrophobic surface for removing organic sulfur in natural gas, and the carbon material prepared by the method has a through multistage pore canal structure, highly dispersed active metal sites and excellent hydrophobicity and chemical stability. In order to achieve the above purpose, the present invention adopts the following technical scheme: a preparation method of a carbon material with a through type multistage pore canal and a hydrophobic surface for removing organic sulfur in natural gas comprises the following steps: a. Sequentially adding a polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer and a KOH solution into the sodium alginate solution, and preparing a hydrogel precursor through microwave hydrothermal reaction; b. Adding diammonium hydrogen phosphate into the hydrogel precursor, then introducing SiO 2 nanospheres as a hard template, and forming nitrogen-phosphorus co-doped microspheres by spray drying; c. Adopting an impregnation-reduction method to impregnate Fe (NO 3)3 soluti