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CN-119158622-B - Immobilized alkali-free deodorization catalyst and preparation method thereof

CN119158622BCN 119158622 BCN119158622 BCN 119158622BCN-119158622-B

Abstract

The invention discloses an immobilized alkali-free desulfurization catalyst and a preparation method thereof. The catalyst comprises 30-75% of molecular sieve, 10-55% of xMO ' 2 O 3 and 5-25% of cobalt phthalocyanine, wherein M is IIA and IIB elements, M' is IIIA and VIII elements, and x is y=0.5-30. According to the immobilized alkali-free deodorization catalyst, a microporous or mesoporous molecular sieve with a proper pore structure is selected as a basic carrier, MO and M' 2 O 3 are used as solid alkali, and meanwhile, active component cobalt phthalocyanine is immobilized in the catalyst through in-situ synthesis. The catalyst of the invention has the characteristics of firm combination between the active component of the catalyst and the cobalt phthalocyanine and the carrier molecular sieve, and the active component is not easy to run off.

Inventors

  • MENG FANZHONG
  • WANG LUYAO
  • LI YONG
  • FAN DEQUAN

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
20230618

Claims (15)

  1. 1. The preparation method of the immobilized alkali-free deodorization catalyst comprises the following steps: (1) Preparing a mixed solution containing M 2+ and M' 3+ , adding a molecular sieve into the mixed solution, and uniformly stirring; (2) The material obtained in the step (1) and the mixed solution or weak base solution containing NaOH and Na 2 CO 3 are added into a reactor at the same time, and react for a period of time under stirring; (3) Filtering, washing, drying and roasting the material obtained in the step (2) to obtain a composite carrier; (4) Preparing a cobalt-containing salt solution, and exchanging Co 2+ onto the composite carrier obtained in the step (3) in an ion exchange mode; (5) Filtering and drying the material obtained in the step (4) to obtain Co molecular sieve solid alkali; (6) Adding solid alkali of the Co molecular sieve obtained in the step (5) into a pyridine and nitrobenzene mixed solution, heating to 50-110 ℃ under stirring, adding phthalonitrile, and reacting at 150-300 ℃; (7) Filtering, washing and drying the material obtained in the step (6) to obtain the immobilized alkali-free deodorization catalyst; Wherein M is an element of IIA or IIB, M' is an element of IIIA or VIII, and the molar ratio of silicon to aluminum of the molecular sieve is 0.5-200.
  2. 2. The method according to claim 1, wherein the stirring time in the step (1) is 10min to 180min.
  3. 3. The method of claim 1, wherein M is at least one of the divalent metals selected from Mg, ca, ba, zn and M' is at least one of the trivalent metals selected from Al, fe, co, ni.
  4. 4. The preparation method of claim 1, wherein the mixed solution containing M 2+ and M ' 3+ is a nitrate solution or a hydrochloride solution of M and M', the concentrations of the mixed solution containing M 2+ and M ' 3+ are respectively 0.1 mol/L-saturated concentration and 0.02 mol/L-saturated concentration, and the molar ratio of M 2+ to M' 3+ is 0.5-30.
  5. 5. The preparation method of the aqueous ammonia solution according to claim 1, wherein the molar ratio of NaOH to Na 2 CO 3 in the mixed solution containing M 2+ and M' 3+ is 1:3-30:1, and the weak base solution is at least one selected from dilute ammonia water and dimethyl ammonia.
  6. 6. The preparation method according to claim 1, wherein in the step (2), stirring is stopped when the pH value is 9-10, and the mixture is allowed to stand for 10-180 min.
  7. 7. The preparation method of the ceramic material according to claim 1, wherein the roasting condition in the step (3) is that the temperature is 400-900 ℃ and the roasting time is 4-10h.
  8. 8. The method of claim 1, wherein the cobalt-containing salt solution of step (4) is selected from at least one of Co (NO 3 ) 2 、Co(AC) 2 or CoCl 2 ).
  9. 9. The preparation method of the ion exchange device according to claim 1, wherein the operation condition of the ion exchange in the step (4) is that the temperature is normal temperature to 200 ℃ and the exchange time is 12 to 36 hours.
  10. 10. The method according to claim 1, wherein the concentration of pyridine in the mixed solution in the step (6) is 0.1 to 0.5mol/L.
  11. 11. The preparation method of the catalyst according to claim 1, wherein the heating temperature in the step (6) is 50-110 ℃, and the reaction temperature is adjusted to 150-220 ℃ after the phthalonitrile is added, and the reaction is continued for 0.5-3 hours.
  12. 12. The immobilized alkali-free deodorization catalyst obtained by the preparation method of any one of claims 1 to 11 is characterized by comprising, by weight, 35% -65% of molecular sieve, 35% -55% of xMO ' 2 O 3 % and 5% -25% of cobalt phthalocyanine, wherein M is an element of group IIA and group IIB, M' is an element of group IIIA and group VIII, and x: y=0.5-30.
  13. 13. The supported alkali-free deodorizing catalyst according to claim 12, wherein M is at least one of divalent metals selected from Mg, ca, ba, zn and M' is at least one of trivalent metals selected from Al, fe, co, ni.
  14. 14. The supported alkali-free deodorizing catalyst according to claim 12, wherein said molecular sieve is at least one selected from the group consisting of Y-type molecular sieve, X-type molecular sieve, MCM-41 molecular sieve, al/MCM-48 molecular sieve, SBA-15 molecular sieve.
  15. 15. The immobilized alkali-free deodorizing catalyst according to claim 12, wherein the catalyst comprises 40% -55% of molecular sieve, 20% -35% of xMO' 2 O 3 % and 10% -20% of cobalt phthalocyanine by weight.

Description

Immobilized alkali-free deodorization catalyst and preparation method thereof Technical Field The invention relates to a catalyst suitable for alkali-free deodorization of light hydrocarbon or gasoline fractions and a preparation method thereof, in particular to an immobilized catalyst applied to an alkali-free deodorization process and a preparation method thereof. Background Light hydrocarbons produced in oil fields or refineries contain significant amounts of thiol components such as CH 3SH,C2H5 SH and the like. Under the background of the increasingly strict environmental legislation and the deep utilization of light hydrocarbon, the sulfur-containing components need to be removed. The liquefied gas sweetening technology is firstly proposed by UOP company in 1958, and developed to form a mature extraction and oxidation regeneration process. The most widely used are the Mei Luoke s (Merox) sweetening technique from UOP corporation and the Fiber-Film (Fiber-Film) contactor alkali treatment technique from meliken (mercem co.) corporation in the united states. The technical principle is that strong alkali reacts with mercaptan to generate sodium mercaptide, then the sodium mercaptide is oxidized under the action of phthalocyanine catalyst to generate disulfide substances, and finally the disulfide substances are separated out. The method has the defects that the cobalt phthalocyanine catalyst is in an alkali phase, is easy to aggregate and deactivate, so that the catalyst is frequently replaced, the catalyst cost is quite high, and the process needs to continuously discharge waste alkali liquor to meet the process index requirement, thereby increasing the operation cost and exacerbating the environmental protection pressure. In order to solve the above problems, UOP corporation proposes a fixed bed mercaptan removal process, the core of which is to disperse a phthalocyanine catalyst on a porous carrier and to pack the phthalocyanine catalyst in a fixed bed, and the mercaptan-containing hydrocarbon flows through the fixed bed to undergo oxidation reaction to remove mercaptan. U.S. patent No. 2988500 discloses a supported cobalt phthalocyanine catalyst, wherein cobalt phthalocyanine is supported on activated carbon, and thiol is catalytically oxidized under the action of a soluble alkali reagent. U.S. patent USP 5286372 supports the metal complex on a solid base and uses this catalyst without the need for additional lye. Chinese patent CN1200958a discloses a catalyst with a complex supported on the surface of a solid basic oxide, where the complex is formed by sulfonate cobalt phthalocyanine or carboxylate cobalt phthalocyanine having a negative ion group and quaternary ammonium salt cobalt phthalocyanine having a positive ion group, and the oxidation reaction of the catalyst does not need to add an alkali solution, so that the activity and stability are improved to a certain extent. Chinese patent CN 104588097a discloses a method for preparing a supported phthalocyanine catalyst, which is to spray a solution of metal phthalocyanine, a dispersant, an alkaline substance and water onto a porous carrier, and to achieve the purpose of highly dispersing and supporting active components by dissolving the metal phthalocyanine. The preparation of such catalysts currently adopts a method of loading (the preparation method in the above listed patents). Although the catalyst prepared by the loading method has higher activity, the active components are very easy to fall off in the process of participating in the reaction and flow out of the reaction bed along with the process stream because the carrier and the metal phthalocyanine compound are connected together only by means of physical adsorption, so that the catalyst is deactivated. Disclosure of Invention Based on the problems existing in the prior art, the invention provides an immobilized alkali-free deodorization catalyst and a preparation method thereof. The catalyst can remove mercaptan substances in light hydrocarbon under the alkali-free condition, and the active components are combined with the carrier in a bonding mode, so that the catalyst is not easy to fall off and deactivate in the reaction process, the stability of the catalyst is greatly improved, and the operation cost is reduced. According to a first aspect of the present invention, there is provided an immobilized alkali-free deodorization catalyst. The immobilized alkali-free deodorization catalyst comprises, by weight, 35% -65% of a molecular sieve, 10% -55% of xMO. YM '2O3% -25% of cobalt phthalocyanine, wherein M is an element of IIA or IIB, M' is an element of IIIA or VIII, and x is y=0.5-30. Further, M is at least one of divalent metals selected from Mg, ca, ba, zn, and M' is at least one of trivalent metals selected from Al, fe, co, ni. Further, the conventional molecular sieve is at least one selected from the group consisting of a Y-type molecular sieve, an X-type molecular sieve, an MCM-41