CN-121988354-A - Pre-hydrogenation catalyst for carbon tetraalkylation raw materials and preparation method thereof

CN121988354ACN 121988354 ACN121988354 ACN 121988354ACN-121988354-A

Abstract

According to the research, the inventor discovers that by introducing F with the strongest electronegativity into a carrier, pd is in an electron-deficient state Pd δ+ under the strong electron-withdrawing effect of F, bonding strength between Pd and S is weakened, sulfur resistance of the carbon tetraalkylating raw material prehydrogenation catalyst can be remarkably improved, further, coking carbon four raw materials containing impurity sulfur are treated, meanwhile, an organic cage with a regular structure is arranged on the inner surface of the F-modified carrier, pd and Au are limited by the size of the organic cage and are loaded in the organic cage to form an alloy, so that the size of an active center of the PdAU alloy is uniform, the Pd and the Au can be well dispersed on the surface of the carrier, the active site is fully exposed, the utilization rate of the active atom is improved, and the hydrogenation activity of the catalyst is further improved. Meanwhile, the catalyst has a certain 1-butene isomerization capacity.

Inventors

MA PING
LI RUOYU
XIANG YONGSHENG
MA HAOWEN
XIE YUAN
ZHAN XUECHENG
SUN LIMIN
HU XIAOLI
CHEN MINGLIN
GUO DAJIANG

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (10)

1. A carbon tetraalkylating feedstock pre-hydrogenation catalyst comprising a F-modified support comprising alumina and an active component comprising Pd and Au; the F modified carrier is internally provided with an organic cage, wherein the size of the cavity of the organic cage is 4-6nm, and Pd and Au are loaded in the cavity of the organic cage; The mass of the carrier is 100%, the F content is 0.3% -3%, the Pd content is 0.30% -0.50%, and the Au content is 0.01% -0.05%.
2. The pre-hydrogenation catalyst for a carbon tetraalkylating raw material according to claim 1, wherein the specific surface area of the pre-hydrogenation catalyst for a carbon tetraalkylating raw material is 60-150 m 2 /g, and the pore volume is 0.30-0.50 cm 3 /g.
3. The pre-hydrogenation catalyst for a carbon tetraalkylating raw material according to claim 1 or 2, wherein said organic cage is prepared by an aldol condensation reaction of an aromatic diamine compound and tris (4-formylphenyl) amine, and preferably said aromatic diamine compound is selected from 4, 4' -diaminoterphenyl.
4. A process for preparing a pre-hydrogenation catalyst for a carbon tetraalkylating feedstock according to any one of claims 1 to 3, comprising the steps of: 1) Completely polymerizing hydrophilic polymerizable monomers in the pore canal of the F modified carrier, preventing the generated polymer from decomposing, and controlling the polymer to occupy more than 80% of the pore volume of the F modified carrier to obtain a semi-finished catalyst B; 2) Dripping a solution of an aromatic diamine compound into the mixture to carry out aldehyde-amine condensation reaction to form an organic cage-shaped object, and washing and drying after the reaction is finished to obtain a semi-finished catalyst C; 3) Dropwise adding a solution of an organic palladium compound into the mixture of the semi-finished catalyst C and alcohol under the stirring state, adding a reducing agent, uniformly mixing, washing, drying and roasting for one time after the organic palladium compound is completely loaded, so as to obtain a semi-finished catalyst D; 4) Immersing the semi-finished catalyst D into a gold salt solution, washing, drying, and roasting at the temperature of less than or equal to 450 ℃ for the second time to completely decompose the polymer after the gold salt is completely loaded, so as to obtain a carbon tetraalkylation raw material pre-hydrogenation catalyst; Wherein the molar ratio of the tri (4-formylphenyl) amine to the aromatic diamine compound is 1:1.0-2.0; The temperature of the primary calcination is equal to or higher than the decomposition temperature of the organic palladium compound and lower than the decomposition temperature of the polymer.
5. The method of preparing the F-modified solid support according to claim 4, wherein the method of preparing the F-modified solid support comprises the steps of: Immersing the carrier in a fluorine inorganic salt solution, drying and roasting after the fluorine inorganic salt is completely loaded, wherein the fluorine inorganic salt is preferably at least one selected from ammonium fluoride, sodium fluoride and potassium fluoride, and the roasting temperature is 300-400 ℃ and the time is 4-6 hours.
6. The method according to claim 4 or 5, wherein the mass ratio of palladium in the organic palladium compound to the tris (4-formylphenyl) amine is (0.90 to 6.0): 1.
7. The process according to claim 4, wherein in step 1) the hydrophilic polymerizable monomer has a volume of 80% to 100%, preferably 80% to 95%, of the pore volume of the F-modified support.
8. The preparation method according to claim 4, wherein in the step 2), the mass ratio of the tri (4-formylphenyl) amine to the catalyst is 2000-6000:1.
9. The method according to claim 4, wherein the primary firing is carried out at a temperature of 250 to 450 ℃ for a time of 2 to 6 hours; the temperature of the secondary roasting is 200-450 ℃ and the time is 2-6 hours.
10. The method of claim 4, wherein the hydrophilic polymerizable monomer is selected from the group consisting of organic compounds containing carbonyl, carboxyl, or carbon-carbon double bonds, preferably wherein the hydrophilic polymerizable monomer is selected from the group consisting of formaldehyde or lactic acid; The catalyst is halogenated acetic acid, preferably fluoro acetic acid or chloroacetic acid, more preferably trifluoroacetic acid or dichloroacetic acid; The organic palladium compound is selected from palladium acetate or palladium acetylacetonate; The gold salt in the gold salt solution is selected from chloroauric acid.

Description

Pre-hydrogenation catalyst for carbon tetraalkylation raw materials and preparation method thereof Technical Field The invention relates to the technical field of catalysts, in particular to a carbon tetraalkylation raw material pre-hydrogenation catalyst and a preparation method thereof. Background The catalytic cracking device of the oil refinery and the steam cracking device of the ethylene plant are two main sources of carbon four fractions, and are related to the process of cracking hydrocarbon macromolecules into small molecules under the non-hydrogen condition, so that the unsaturated hydrocarbon content in the components is high, and most of the unsaturated hydrocarbon is used as civil liquefied gas to be burnt out due to the fact that comprehensive utilization is not in place. The butene and the isobutane can be subjected to an alkyl reaction under the action of an acid catalyst to generate the alkylation gasoline, and the alkylation gasoline has the characteristics of high octane number, low sulfur, low nitrogen and low olefin, so the alkylation gasoline has good antiknock performance and environmental protection performance, is the most ideal gasoline blending component, and is an important means for realizing the quality upgrading of domestic gasoline. With the increasing strictness of domestic environmental regulations, the continuous growth of the demand for high octane gasoline is continuously pushing the explosive development of the carbon tetraalkylated gasoline industry. The raw materials used in the alkylation device of the hydrofluoric acid method (or sulfuric acid method) in the oil refinery are usually mixed carbon four fractions generated by a catalytic cracking device, wherein the mixed carbon four fractions generally contain thousands of ppm of butadiene, and the butadiene is easy to undergo a superposition reaction under the action of an acid catalyst to generate viscous heavy oil, so that the dry point of an alkylated oil product is increased, the octane number is reduced, and the acid consumption is increased. Butadiene in the alkylation raw material is converted into butene through selective hydrogenation reaction, and 1-butene in the raw material is isomerized into 2-butene, so that the yield and quality of the alkylate oil can be improved, the acid consumption can be reduced, and the environmental protection pressure of enterprises can be reduced. The selective hydrogenation catalysts used industrially are generally composed of an inert carrier and palladium supported thereon as an active component. The palladium catalyst has good hydrogenation activity and high selectivity, and the current domestic alkylation devices adopt the palladium catalyst to carry out selective hydrogenation on the carbon four raw materials to remove butadiene impurities. However, with the increasing weight and inferior quality of the processed crude oil, the coking carbon tetrad volume of the byproduct of the refinery is gradually increased, and the blending of the coking carbon tetrad with high-quality carbon tetrad as the raw material of the alkylation device has higher economic benefit. However, coked carbon four generally contains sulfide impurities which are difficult to remove, and sulfide can form covalent bonds with d-orbit electrons of active metal Pd to be adsorbed on the surface of the Pd, so that the catalyst is deactivated. Therefore, improving the activity, selectivity and impurity resistance of Pd-based alkylation feedstock pre-hydrogenation catalysts is a difficult research point in the field. Aiming at the difficulties, the Chinese patent document CN114160196A discloses a preparation method of a Pd cluster catalyst, wherein the method limits the agglomeration of Pd clusters by synthesizing an organic cage, adopts the cavity size of the organic molecular cage to regulate and control the particle size of the Pd clusters, and indirectly regulates and controls the catalytic activity. The method has good hydrogenation activity, selectivity and stability in alkynol hydrogenation reaction. But the catalyst is not suitable for butadiene hydrogenation. The Chinese patent document CN102240547A discloses a method for preparing a carbon four-selective hydrogenation catalyst by reducing a main metal active component precursor and a metal auxiliary active component precursor which are loaded on a carrier through ionizing radiation, wherein the main metal active component is in a Pd simple substance state, the average diameter of main metal active component particles and metal auxiliary active component particles is smaller than 10nm, and the catalyst has the advantages of high activity and selectivity, no need of hydrogen reduction in advance, direct use and the like. However, the preparation of the catalyst has strict requirements on equipment and has certain problems in industrial production. The Chinese patent document CN110054542A discloses a method for removing butadiene by adding a C4 compone