CN-122006710-A - Deep desulfurization catalyst and preparation and application thereof

Abstract

The invention belongs to the technical field of deep desulfurization, and discloses a deep desulfurization catalyst and preparation and application thereof. The deep desulfurization catalyst of the invention takes ZnO-CeO 2 composite oxide as a carrier, the loaded Pt is active metal, and the molar ratio of Zn to Ce is 99:1-50:50. The catalyst provided by the invention has very high deep desulfurization capability on sulfides such as 4, 6-dimethyl dibenzothiophene and the like under mild reaction conditions, has the remarkable advantages of high desulfurization rate, large sulfur capacity, good stability, simple preparation and the like, and is suitable for pretreatment of raw materials in the catalytic process sensitive to sulfur, such as preparation of heavy oil and fine chemicals, and clean fuel production.

Inventors

• LI CHUANG
• Cong Haiyue
• LIANG CHANGHAI

Assignees

• 大连理工大学

Dates

Publication Date

20260512

Application Date

20260204

Claims (8)

1. 1. A deep desulfurization catalyst is characterized by being a Pt-supported catalyst and comprising metal Pt and an oxide carrier, wherein the oxide carrier is a ZnO-CeO 2 composite oxide, the molar ratio of Zn to Ce is 99:1-50:50, and the Pt loading is 0.1% -1%.
2. 2. The deep desulfurization catalyst according to claim 1, wherein the ZnO-CeO 2 composite oxide has a mesoporous structure, the specific surface area is not less than 40m 3 /g, the ZnO particle size is 5-30nm, and the CeO 2 particle size is 1.5-10nm.
3. 3. The preparation method of the deep desulfurization catalyst is characterized by comprising the following steps of: (1) Zinc nitrate and cerium nitrate are dissolved in water, and the molar ratio of Zn to Ce is regulated to be 99:1-50:50 on the premise that the total metal ion concentration is kept to be 1 mol/L; (2) Adding a precipitant into the solution obtained in the step (1), aging overnight, and then washing, suction filtering, drying and roasting to obtain a solid ZnO-CeO 2 composite oxide; (3) And (3) immersing the ZnO-CeO 2 composite oxide obtained in the step (2) in a methanol solution mixed with hexa-hydrated chloroplatinic acid for 7-8 hours, and performing rotary evaporation, drying and roasting after the immersion is finished to obtain the catalyst for deep desulfurization.
4. 4. A process according to claim 3, wherein, In the step (2), the precipitant is at least one of an ammonium carbonate aqueous solution and an ammonium bicarbonate aqueous solution, the temperature of the aging overnight is kept at 65-75 ℃, and the pH value of the reaction system is 7.0.
5. 5. A process according to claim 3, wherein, In the step (2), the roasting temperature is 300-500 ℃ and the roasting time is 2-3h.
6. 6. Use of a deep desulfurization catalyst in the removal of sulfur compounds.
7. 7. The method according to claim 6, wherein the sulfur-containing compound is dibenzothiophene and/or 4, 6-dimethyldibenzothiophene, and the concentration of the sulfur-containing compound in the solution of the sulfur-containing compound is not less than 100ppm.
8. 8. The method according to claim 6, wherein the reaction is carried out at a temperature of 300-400 ℃, a hydrogen pressure of 0.1-1MPa and a liquid flow rate of 0.03-0.30mL/min.

Description

Deep desulfurization catalyst and preparation and application thereof Technical Field The invention belongs to the technical field of deep desulfurization, and relates to a deep desulfurization catalyst and preparation and application thereof. Background With the increasing strictness of global environmental protection regulations and the severe requirements of high-end chemical synthesis on raw material purity, the deep desulfurization technology has become a core link of petroleum refining and fine chemical engineering. Heavy oils, residuum, and secondary processed oils (e.g., catalytically cracked gasoline, diesel oil) contain a large amount of condensed ring sulfur compounds that are difficult to remove. Conventional hydrodesulfurization techniques require severe conditions of high temperature, high pressure and high hydrogen consumption in the treatment of such compounds, and are expensive in equipment investment and operation cost. In particular to 4, 6-dimethyl dibenzothiophene with large steric hindrance, the activity of the traditional catalyst is lower. Heavy metals, nitrides and colloids in heavy oil tend to poison and deactivate hydrogenation catalysts. In addition, many fine chemical synthesis processes (e.g., pharmaceutical intermediates, fragrances, high molecular monomer synthesis) rely on noble metal (e.g., pd, ru) catalysts or acidic/basic catalysts that are extremely sulfur sensitive. Even if the raw material contains sulfide in ppm level, irreversible poisoning and deactivation of the catalyst can be caused, and the product selectivity and the process economy are seriously affected, so that the raw material needs to be subjected to pretreatment of deep desulfurization. Chinese patent publication No. CN119926448B discloses a hydrodesulfurization catalyst and a preparation method and application thereof, wherein the prepared hydrodesulfurization catalyst has the characteristics of good macromolecular diffusion performance, good carbon deposit resistance and the like, but the preparation method is more complex, the catalytic hydrodesulfurization reaction pressure is 7.5Mpa, and H 2 S can be generated. Chinese patent publication No. CN104877077A describes a process for preparing hydrogenated C9 resin, in which the first stage adopts 20wt% Ni/ZnO catalyst as hydrogenation adsorption desulfurization catalyst, the reaction pressure is 18MPa, and the requirements for reaction equipment are high, and the Ni loading is high, the sulfur capacity is low and the hydrogen consumption is large. The Chinese patent, publication No. CN114345329A, describes the application of a normal pressure ultra-deep desulfurization catalyst, which has the advantages of simple preparation, low load capacity, large sulfur capacity and the like, the concentration of sulfur compounds in a liquid solution containing sulfur compounds is 1000ppm-3000ppm, the removal of 4, 6-dimethyl dibenzothiophene is less, and the catalyst has room for improvement in the fields of deep desulfurization, high-end chemical synthesis and the like. In summary, the existing hydrodesulfurization technology needs severe reaction conditions and generates harmful gases such as H 2 S, while the existing hydrodesulfurization technology has poor desulfurization effect on 4, 6-dimethyldibenzothiophene, cannot achieve the purpose of deep desulfurization, and has low sulfur capacity. Therefore, how to achieve deep desulfurization under mild conditions is a problem that is currently in urgent need. Disclosure of Invention In order to solve the problems in the background technology, the invention provides a deep desulfurization catalyst and preparation and application thereof. According to the invention, through the introduction of CeO 2 in the carrier, the interaction between the Pt active center and the carrier is effectively regulated, and CeO 2 is used as a hydrogen overflow channel to promote active hydrogen transfer, and meanwhile, oxygen vacancies are formed to enhance the adsorption of sulfur-containing compounds. The invention realizes that the sulfur removal rate of the 4, 6-dimethyl dibenzothiophene which is most difficult to remove in sulfur-containing compounds can be 95-100% under mild conditions, thereby achieving the purpose of deep desulfurization. The technical scheme of the invention is as follows: A deep desulfurization catalyst is a Pt-supported catalyst and comprises metal Pt and an oxide carrier, wherein the oxide carrier is ZnO-CeO 2 composite oxide, the molar ratio of Zn to Ce is 99:1-50:50, preferably 90:10-70:30, and the loading amount of Pt is 0.1-1%, preferably 0.5%. The ZnO-CeO 2 composite oxide is of a mesoporous structure, the specific surface area is more than or equal to 40m 3/g, the ZnO particle size is between 5 and 30nm, and the CeO 2 particle size is between 1.5 and 10nm. Based on the weight of the deep desulfurization catalyst, the mass percentage of Pt is 0.1-1%, preferably 0.5%, and the mass percentage of ZnO-CeO 2 c