CN-122006746-A - Carbon four fraction selective hydroisomerization catalyst, preparation method and application thereof

CN122006746ACN 122006746 ACN122006746 ACN 122006746ACN-122006746-A

Abstract

The invention provides a carbon four-fraction selective hydroisomerization catalyst which comprises a carrier and an active component loaded on the carrier, wherein the carrier is a metal composite oxide modified by organic cation quaternary ammonium salt and silane reagents, the metal composite oxide contains metal elements I, the metal elements I comprise aluminum and titanium, the active component contains metal elements II, the metal elements II comprise main active component Cu and optional auxiliary active components, and the auxiliary active components comprise Ni, ru and alkali metals. The selective hydrogenation catalyst provided by the invention has the advantages that the carrier is modified, the dispersion of the active components on the surface of the carrier can be obviously improved, and the active components are controlled to exist in the form of nanoclusters on the surface of the carrier, so that the low-temperature activity of the catalyst prepared from the carrier precursor is obviously improved. The invention also provides a preparation method and application of the carbon four-fraction selective hydroisomerization catalyst, and a method for removing butadiene and preparing 1-butene by carbon four-fraction selective hydrogenation.

Inventors

DU ZHOU
LIU YANHUI
YANG GUANG
ZHANG FUCHUN
REN YUMEI

Assignees

中国石油化工股份有限公司
中石化(北京)化工研究院有限公司

Dates

Publication Date: 20260512
Application Date: 20241111

Claims (10)

1. A carbon four-fraction selective hydroisomerization catalyst is characterized by comprising a carrier and an active component loaded on the carrier, The carrier is a metal composite oxide modified by organic cation quaternary ammonium salt and silane reagent, wherein the metal composite oxide contains metal elements I, and the metal elements I comprise aluminum and titanium; The active component contains a metal element II, wherein the metal element II comprises a main active component Cu and an optional auxiliary active component, and the auxiliary active component comprises Ni, ru and alkali metal.
2. The catalyst according to claim 1, wherein the organic cationic quaternary ammonium salt comprises a hydrocarbyl quaternary ammonium salt, preferably of the formula R 4 N + X - , wherein X - is selected from the group consisting of halogen ions, acid ions, preferably the halogen ions comprise F - 、Cl - 、Br - and I - , the acid ions comprise nitrate ions and carboxylate ions, each R in the formula R 4 N + X - is the same or different and is each independently selected from the group consisting of alkyl, cycloalkyl, aryl, aralkyl and alkaryl, at least one R, preferably 1 to 2R is selected from the group consisting of C6 and higher alkyl, preferably from the group consisting of C6 to 20 alkyl, the remaining R is preferably selected from the group consisting of C1 to C4 alkyl, C7 to C11 aralkyl; preferably, the organic cationic quaternary ammonium salt comprises at least one of dioctadecyl dimethyl quaternary ammonium salt, cetyl trimethyl quaternary ammonium salt and C12-18 alkyl dimethyl benzyl quaternary ammonium salt; more preferably, the organic cationic quaternary ammonium salt is selected from at least one of dioctadecyl dimethyl ammonium chloride, cetyl trimethyl ammonium bromide, dodecyl dimethyl benzyl ammonium chloride, tetradecyl dimethyl benzyl ammonium chloride, hexadecyl dimethyl benzyl ammonium chloride and octadecyl dimethyl benzyl ammonium chloride, and/or The general formula of the silane reagent is SiR 1 x (OR 2 ) y , wherein x and y are respectively and independently selected from integers of 1-3, x+y=4, R 1 is selected from hydrogen, C1-C6 alkyl and C2-C6 alkenyl, and R 2 is selected from C1-C6 alkyl; Preferably, the silane-based reagent comprises at least one of triethoxysilane, trimethoxysilane, methyltriethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and/or The organic cation quaternary ammonium salt is used in an amount of 1% -50%, preferably 30% -50%, more preferably 35% -50% of the mass of the metal composite oxide, and/or The silane reagent is used in an amount of 0.5-30%, preferably 0.5-15%, more preferably 0.5-10% by mass of the metal composite oxide, and/or The alkali metal is at least one selected from lithium, sodium, potassium and rubidium.
3. The catalyst according to claim 1 or 2, wherein the metal composite oxide is Al 2 O 3 -TiO 2 composite oxide, preferably the Al 2 O 3 -TiO 2 composite oxide contains Ti in an amount of 5-30 wt%, preferably 8-25 wt%, calculated as TiO 2 , and Al in an amount of 70-95 wt%, preferably 75-92 wt%, calculated as Al 2 O 3 , based on the Al 2 O 3 -TiO 2 composite oxide, and/or The carrier is SiO 2 -TiO 2 -Al 2 O 3 composite oxide, preferably, based on the carrier, the carrier contains 5-25 wt% of Ti in terms of TiO 2 , 65-90 wt% of Al in terms of Al 2 O 3 , preferably 80-90 wt% of Al, and 0.5-15 wt% of Si in terms of SiO 2 , and/or Based on 100 parts by mass of the catalyst, the content of the active component Cu in the catalyst is 5-25 parts by mass of CuO, the content of the active component Ru is 0-1 part by mass of the oxide, preferably 0.1-0.5 part by mass of the oxide, the content of the active component Ni is 0-5 parts by mass of the oxide, preferably 0.1-5 parts by mass of the oxide, the content of the alkali metal is 0-1 part by mass of the oxide, preferably 0.1-0.5 part by mass of the oxide, and the content of the carrier is 70-95 parts by mass of the oxide, and/or The active component is distributed on the carrier in the form of nanoclusters, wherein the nanoclusters have a particle size of 5nm or less, and/or The specific surface of the carrier is 30-150 m 2 /g, preferably 50-90 m 2 /g, and/or The pore volume of the carrier is 0.2-0.8 mL/g, preferably 0.3-0.5 m 2 /g, and/or In the catalyst, the main active component and the auxiliary active component are each independently present in the form of their simple substance or oxide.
4. The catalyst according to any one of claims 1 to 3, wherein the preparation of the carrier comprises the steps of subjecting the metal composite oxide to a first treatment with an organic cationic quaternary ammonium salt solution, and subjecting the resulting metal composite oxide to a second treatment with a silane-based reagent to obtain the carrier; preferably, the first treatment comprises first dipping and first drying which are sequentially carried out, and/or the second treatment comprises dripping a solution of a silane reagent onto the metal composite oxide subjected to the first treatment, and then stirring, second drying and first roasting, wherein the stirring time is 1 min-60 min; preferably, the concentration of the organic cation quaternary ammonium salt solution is 0.1-10wt%, preferably 0.2-10wt%, and more preferably 1-5wt%; preferably, the solvent of the solution of the organic cationic quaternary ammonium salt comprises at least one of water, methanol, ethanol, benzene, toluene, isopropanol, acetone, sulfuric acid, hydrochloric acid, nitric acid, sodium hydroxide and potassium hydroxide; Preferably, the solution of the silane reagent is an aqueous solution of the silane reagent, and the concentration of the aqueous solution is 0.1-10wt%, preferably 1-10wt%.
5. The catalyst according to any of claims 1 to 4, wherein the first impregnation conditions comprise an impregnation temperature of 10 ℃ to 50 ℃ for 1h to 12h, preferably 1h to 8h, and/or The conditions of the first drying and the second drying independently comprise a drying temperature of 60-150 ℃, preferably 60-110 ℃ and a drying time of 4-12 h, and/or The first roasting condition comprises a roasting temperature of 300-1100 ℃, preferably 500-900 ℃ and a roasting time of 4-12 hours.
6. A process for preparing a catalyst for selective hydroisomerization of carbon four fractions according to any one of claims 1 to 5, comprising the steps of subjecting the support to a second impregnation with a copper salt solution, optionally a nickel salt solution, optionally a ruthenium salt solution and optionally an alkali metal salt solution, and subjecting the impregnated support to a third drying and a second calcination to obtain the catalyst.
7. The method according to claim 6, wherein the copper salt comprises at least one of a sulfate, nitrate, soluble carboxylate, hypophosphite and halide of copper, preferably at least one of copper sulfate, copper nitrate, copper chloride and copper acetate, and/or The nickel salt comprises at least one of nitrate, soluble carboxylate and halide of nickel, preferably at least one of nitrate, hydrochloride, oxalate and acetate of nickel, and/or The ruthenium salt comprises at least one of nitrate, soluble carboxylate and halide of ruthenium, preferably at least one of nitrate, hydrochloride, oxalate and acetate of ruthenium, and/or The alkali metal salt is at least one selected from lithium salt, sodium salt, potassium salt and rubidium salt, and/or The solvent in the copper salt solution, the nickel salt solution, the ruthenium salt solution and the alkali metal salt solution is at least one of water, methanol, ethanol, benzene, toluene and chloroethane respectively and/or The concentration of the copper salt solution is 0.1-0.6 mol/L, and/or The concentration of the nickel salt solution is 0.1-0.3 mol/L, and/or The concentration of the ruthenium salt solution is 0.01-0.1 mOl/L, and/or The concentration of the alkali metal salt solution is 0.1-0.3 mol/L.
8. The method according to claim 6 or 7, wherein the second impregnation conditions comprise a temperature of 20-70 ℃, preferably 20-40 ℃, for a time of 1-12 hours, preferably 1-4 hours, and/or The third drying condition comprises a temperature of 60-150 ℃, preferably 100-150 ℃ for 1-8 hours, preferably 4-8 hours, and/or The second roasting condition comprises the temperature of 300-600 ℃, preferably 400-500 ℃ and the time of 4-12 hours.
9. The carbon four-cut selective hydroisomerization catalyst according to any one of claims 1 to 5 or the application of the carbon four-cut selective hydroisomerization catalyst prepared by the preparation method according to claim 6 to 8 in removing butadiene and preparing 1-butene by selective hydrogenation of carbon four-cut, preferably, the selective hydrogenation condition comprises a reaction temperature of 20 ℃ to 40 ℃, a molar ratio of hydrogen to alkyne of 1 to 2.5:1, a pressure of 0.5mpa to 0.8mpa and a circulation ratio of 10 to 30:1, and/or the catalyst is packed in an upper layer and a lower layer in a composite manner, and the weight ratio of the upper layer catalyst to the lower layer catalyst is 1 to 3:1.
10. A method for removing butadiene and preparing 1-butene by selective hydrogenation of a carbon four-cut fraction, which takes the selective hydrogenation catalyst of the carbon four-cut fraction prepared by the preparation method of any one of claims 1-5 or the selective hydrogenation catalyst of any one of claims 6-8 as a catalyst, preferably, the selective hydrogenation condition comprises the reaction temperature of 20-40 ℃, the molar ratio of hydrogen to alkyne of 1-2.5:1, the pressure of 0.5 MPa-0.8 MPa and the circulation ratio of 10-30:1, and/or the catalyst is divided into an upper layer and a lower layer which are combined and packed, and the weight ratio of the upper layer catalyst to the lower layer catalyst is 1-3:1.

Description

Carbon four fraction selective hydroisomerization catalyst, preparation method and application thereof Technical Field The invention relates to the technical field of selective hydrogenation of carbon four fractions, in particular to a selective hydrogenation isomerization catalyst of carbon four fractions, a preparation method and application thereof. Background The carbon four fraction refers to a mixture of various alkanes, alkenes, dienes and alkynes containing four carbon atoms, and is mainly derived from refinery gas generated in the petroleum refining process and byproducts in the ethylene preparation process by cracking petroleum hydrocarbons, wherein the cracked carbon four fraction contains saturated hydrocarbons and unsaturated hydrocarbons such as n-butane, isobutane, 1-butene, trans-2-butene, cis-2-butene, isobutene, 1, 2-butadiene, 1, 3-butadiene, methylacetylene, ethylacetylene, vinylacetylene and the like, and is mainly used for producing 1, 3-butadiene, isobutene and 1-butene industrially. The 1-butene is an important chemical raw material, is mainly used for copolymerizing monomers of Linear Low Density Polyethylene (LLDPE) and producing poly 1-butene plastics, can be used as a main raw material for producing chemical products such as sec-butanol, methyl ethyl ketone and the like with high added value, and can be used for producing carbon octa-and carbon dodeca-alpha olefins by oligomerization of 1-butene, wherein the olefins are excellent raw materials for preparing surfactants, and have wide application in the fields of petrochemical industry, fine chemical industry, medicines, pesticides and the like. In the method for producing butene by cracking carbon four, one is to directly carry out selective hydrogenation on the cracked carbon four, hydrogenate 1, 2-butadiene, 1, 3-butadiene, methyl acetylene, ethyl acetylene and vinyl acetylene in the cracked carbon four to generate 1-butene, trans-2-butene, cis-2-butene and other mono-olefins, and simultaneously avoid further hydrogenation of the mono-olefins to generate alkane. The other method is to separate 1, 3-butadiene from the cracking of the C4, the residual byproduct mainly containing C4 alkane and C4 monoolefin is called C four raffinate, the C four raffinate contains about 1.0wt% of 1, 3-butadiene, and the butadiene is removed by hydrogenation through a selective hydrogenation method. The existing catalysts for preparing butene by four-carbon selective hydrogenation, which are applied to industrial production, comprise Pd/Al 2O3 catalysts and Pd-Ag/Al 2O3 bimetallic catalysts, and non-noble metal catalysts are rarely applied. Noble metal catalysts generally employ a large amount of palladium catalyst supported on a carrier (typically alumina) with the addition of other promoter components such as gold, silver, chromium, copper, iron, rhodium, lithium, potassium, and also lead or zinc. Noble metal catalysts have good low-temperature activity and mild reaction conditions, but have the defects of easy loss of active components of the catalyst, high price, difficult regeneration and poor hydrogenation selectivity. The non-noble metal catalyst needs to react at a higher temperature, and hydrogenation conditions are more severe, but the preparation is simple, the repeated regeneration is convenient, and the cost is relatively low, so that the catalyst still has a certain research and development value. In the hydrogenation reaction process, semi-hydrogenated free radicals adsorbed on the catalyst react with adjacent diene to generate a viscous polymer (commonly called green oil), which mainly comprises compounds with more than C6, and the polymer covers the surface of the catalyst to block micropores on the surface of the catalyst, so that the activity of the catalyst is reduced, and the service life of the catalyst is influenced. In particular, in the case of conjugated dienes (e.g., 1, 3-butadiene), polymerization is more easily performed, so that the catalyst is deactivated in a short period of time, and thus the catalyst must be frequently regenerated to be reused. In the application research in the field of selective hydrogenation of carbon tetrayne, it is recognized that for a high concentration of butadiene content raw material, a nickel-based selective hydrogenation catalyst is safer and more efficient, but the activity of the nickel-based selective hydrogenation catalyst is a certain difference from that of a noble metal palladium-based catalyst, so that the application of the nickel-based selective hydrogenation catalyst is limited. Therefore, for non-noble metal catalysts for selective hydrogenation of alkynes, further improvement of the activity and selectivity of the catalyst is also required, and countermeasures and researches are conducted for green oil problems during the use of the catalyst, and the service life of the catalyst is prolonged. For alkyne selective hydrogenation, the non-noble metal hydrogenation catalyst can