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CN-121972223-A - Large-pore ZSM-5 molecular sieve supported heteropolyacid desulfurization catalyst, preparation and application

CN121972223ACN 121972223 ACN121972223 ACN 121972223ACN-121972223-A

Abstract

The invention discloses a large pore ZSM-5 molecular sieve supported heteropolyacid desulfurization catalyst, and preparation and application thereof, and belongs to the technical field of light fuel desulfurization. The invention firstly takes sodium metavanadate dihydrate, sodium dihydrogen phosphate hydrate and sodium molybdate dihydrate as raw materials, the raw materials are added into an aqueous solution, the pH is regulated to about 4, the mixture is cooled after refluxing for 8 hours, the mixture is extracted by diethyl ether to obtain vanadium-substituted Dawson heteropolyacid, the material ratio is regulated to obtain different amounts of vanadium-substituted heteropolyacid, and then the supported catalyst POM-CNTs@MOF-199-ZSM-5 is prepared by a one-pot method, and the obtained catalyst is applied to oxidative desulfurization of a light fuel oil simulation system. Oxygen in the air is used as an oxidant, and the thiophene removal rate can reach 98.90% after 2.5h at 70 ℃.

Inventors

  • GAO YAN
  • JIN ZHANBIN
  • WEI TINGTING

Assignees

  • 忻州师范学院

Dates

Publication Date
20260505
Application Date
20260312

Claims (9)

  1. 1. A preparation method of a large pore ZSM-5 molecular sieve supported heteropolyacid desulfurization catalyst is characterized in that a heteropolyacid compound is wrapped in a hybrid material CNTs@MOF-199 and then is further supported on a large pore ZSM-5 carrier to prepare the catalyst POM-CNTs@MOF-199-ZSM-5.
  2. 2. The method for preparing the large pore ZSM-5 molecular sieve supported heteropolyacid desulfurization catalyst according to claim 2, wherein the heteropolyacid compound is synthesized into the Dawson type heteropolyacid with different vanadium substitution numbers by a solvent-extraction method.
  3. 3. The method for preparing a large pore ZSM-5 molecular sieve supported heteropolyacid desulfurization catalyst according to claim 2, wherein the heteropolyacid compound is any one of H 7 [P 2 Mo 17 V 1 O 62 ],H 8 [P 2 Mo 16 V 2 O 62 ],H 9 [P 2 Mo 15 V 3 O 62 ],H 10 [P 2 Mo 14 V 4 O 62 ] or H 11 [P 2 Mo 13 V 5 O 62 .
  4. 4. The preparation method of the large pore ZSM-5 molecular sieve supported heteropolyacid catalyst according to claim 2 is characterized in that the heteropolyacid compound is prepared by taking sodium metavanadate dihydrate, sodium dihydrogen phosphate hydrate and sodium molybdate dihydrate as raw materials, adding the raw materials into an aqueous solution, adjusting the pH to 4, refluxing for 8 hours, cooling, and extracting with diethyl ether to obtain the vanadium-substituted Dawson heteropolyacid.
  5. 5. The preparation method of the large pore ZSM-5 molecular sieve supported heteropolyacid desulfurization catalyst according to claim 2 is characterized by comprising the following steps: H 6+n [P 2 Mo 18-n V n O 62 ]·mH 2 O, wherein n=1 to 5; N mmol of NaVO 3 ·2H 2 O and NaH 2 PO 4 ·H 2 O are weighed and dissolved in distilled water to obtain a yellow mixed solution, and the mixed solution is marked as a solution A; Weighing 18-n mmol of Na 2 MoO 4 ·2H 2 O, dissolving in distilled water, and marking the solution as a solution B; pouring the solution a into a three-neck flask equipped with a reflux condensing device, and dropwise adding concentrated H 2 SO 4 under continuous stirring until the solution ph=4; then adding the solution B into the mixed solution with the pH value of 4 for a small amount for a plurality of times, changing the solution from yellow to brick red gradually, adjusting the pH value of the mixed solution to be 3.4 through concentrated H 2 SO 4 again, refluxing for 8: 8H at the temperature of 120 ℃ in an oil bath, standing and cooling to room temperature after the reaction is finished; And then transferring the solution to a separating funnel, adding an equal volume of diethyl ether, sufficiently oscillating and standing, dividing the solution into three layers, taking the lower layer of brick red heteropolyacid etherate, and drying the lower layer of brick red etherate to obtain a brick red powder compound, wherein n=1-5, and the mark is Mo 18-n V n .
  6. 6. The desulfurization catalyst of macroporous ZSM-5 molecular sieve supported heteropolyacid prepared by the preparation method according to any one of claims 1-5.
  7. 7. The desulfurization catalyst of the macroporous ZSM-5 molecular sieve supported heteropolyacid of claim 6, wherein the desulfurization catalyst has a multi-stage pore structure of macropores of mesoporous-ZSM-5 carriers with micropores-CNTs lumen and gaps of MOF-limited POM.
  8. 8. The application of the large pore ZSM-5 molecular sieve supported heteropolyacid desulfurization catalyst prepared by the preparation method according to any one of claims 1-5 in the oxidative desulfurization of a light fuel system.
  9. 9. The use of the desulfurization catalyst in the oxidation desulfurization of a light fuel system according to claim 8, wherein the removal rate of thiophene reaches 98.90% after 2.5h at 70 ℃ by taking oxygen in air as an oxidant.

Description

Large-pore ZSM-5 molecular sieve supported heteropolyacid desulfurization catalyst, preparation and application Technical Field The invention belongs to the technical field of light fuel desulfurization, and particularly relates to a preparation method of a novel macroporous ZSM-5 supported heteropolyacid catalyst and application of the catalyst in oxidative desulfurization. Background In recent years, with the increasing prominence of environmental pollution problems, environmental regulations are being issued in various regions of the world. With the increasing strictness of environmental regulations, developed countries and regions represented by the european union and the united states have more stringent requirements for emission of transportation vehicles. In order to meet the increasingly stringent regulatory policies, related policies are continually issued by various countries, and strict fuel oil quality standards, in particular strict requirements on the sulfide content of fuel oil, are established. Therefore, in order to improve the environment and meet the requirements, the production of low-sulfur fuel oil and even ultra-clean sulfur-free fuel oil becomes the most important task at present. The sulfur content requirement of the European Union in 1993 was <2000 ppm, the sulfur content was reduced to 350 ppm over a short 6-year 1997, less than 50 ppm was required in 2005, and 10 ppm was required to date in 2009. Meanwhile, china also aims at environmental protection, and continuously struggles to control the concentration of sulfur-containing compounds in fuel oil. However, the quality of the diesel oil in China still has a certain gap compared with that of developed countries. The sulfur concentration of diesel oil specification is required to be less than 2000 ppm from 2000 in China until national V standard is implemented in 2013, and the sulfur content is required to be less than 10 ppm. From the history of oil quality upgrading in China, the new century is entered, and the oil quality upgrading in China takes about 10 years to pass through roads which are 20-30 years old in European and American countries. Compared with the European union period, china is still in a relatively backward stage, so that the reduction of the sulfur content in the fuel oil and the improvement of the quality of the fuel oil are still a main task of China nowadays. Currently, widely studied desulfurization technologies mainly include hydrodesulfurization and non-hydrodesulfurization. Hydrodesulfurization is a conventional, well-established desulfurization process. Under the conditions of high temperature, high pressure and hydrogen, sulfur-containing compounds in the fuel oil are converted into H 2 S, and then hydrogen sulfide is decomposed into elemental sulfur and hydrogen, so that the purpose of desulfurizing the fuel oil is achieved. Hydrodesulfurization can effectively remove some simple sulfides in fuel oil, but with the increasing strictness of sulfur content requirements, the sulfur content requirements cannot be fully met. Thus, non-hydrodesulfurization has attracted considerable attention. The oxidation desulfurization technology in the non-hydrodesulfurization has the advantages of mild reaction conditions, low equipment investment and the like, thereby bringing great attention and research to researchers at home and abroad. The technology does not consume hydrogen, has higher desulfurization efficiency on dibenzothiophene compounds which are difficult to remove by hydrodesulfurization, and can realize ultra-deep desulfurization of fuel oil. And the sulfone or sulfoxide substances obtained after oxidative desulfurization can be used as industrial raw materials, so that the resource is optimally configured. The oxidative desulfurization technology is thus referred to as innovative refinery technology and green refinery technology for the 2l century. The heteropolyacid (Heteropolyacid, HPA) is a super solid acid catalyst, which has the characteristics of unique acidity, multifunction, false liquid phase behavior and the like, can be controllably designed by adjusting different elements, has no pollution to the environment, and is a green environment-friendly catalyst. The supported catalyst in which the heteropolyacid is supported can be widely used in various fields. Disclosure of Invention Aiming at the problems of complex desulfurization process and low desulfurization efficiency at present, the invention provides an application of a supported catalyst POM-CNTs@MOF-199-ZSM-5 in catalyzing deep desulfurization under molecular oxygen, wherein heteropolyacid is wrapped in carbon nano tube modified MOF-199 and then is further supported. In order to solve the technical problems, the invention adopts the following technical scheme: A method for preparing a large pore ZSM-5 molecular sieve supported heteropolyacid desulfurization catalyst comprises the steps of wrapping a heteropolyacid compound on a hybridiz