CN-122006731-A - Catalyst for selective hydrogenation and isomerization of mono-olefin, preparation method and application thereof

CN122006731ACN 122006731 ACN122006731 ACN 122006731ACN-122006731-A

Abstract

The invention provides a catalyst for selective hydrogenation and isomerization of mono-olefins, 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, and the metal elements II comprise main active component molybdenum and optional auxiliary active component Ni. The catalyst provided by the invention has the advantages that the carrier is treated by the organic cationic quaternary ammonium salt and the silane reagent, so that the dispersion of the active components on the surface of the carrier can be obviously improved, and the low-temperature activity of the catalyst prepared by the carrier is obviously improved. The invention also provides a preparation method and application of the catalyst for selectively hydrogenating and isomerizing mono-olefins, and a method for removing alkyne in C4 fraction and increasing butadiene yield by selectively hydrogenating four-carbon fraction alkyne.

Inventors

DU ZHOU
LIU YANHUI
ZHANG FUCHUN
YANG GUANG
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 catalyst for selectively hydrogenating and isomerizing mono-olefin 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 main active component molybdenum and optional auxiliary active component Ni.
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 C20 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-C18 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 cationic quaternary ammonium salt is used in an amount of 1 to 50% by mass, preferably 30 to 50% by mass, more preferably 35 to 50% by mass, of the metal composite oxide, and/or, The silane reagent is used in an amount of 0.5 to 30% by mass, preferably 0.5 to 15% by mass, more preferably 0.5 to 10% by mass, of the metal composite oxide.
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 content of Ti in the carrier is 5-25 wt% calculated by TiO 2 , the content of Al in the carrier is 65-90 wt% calculated by Al 2 O 3 , preferably 80-90 wt%, the content of Si in the carrier is 0.5-15 wt% calculated by SiO 2 , and/or Based on 100 parts by mass of the catalyst, the content of the main active component Mo in the catalyst is 5-25 parts by MoO, the content of the auxiliary active component Ni is 0-5 parts by oxide, preferably 0.1-5 parts by oxide, the content of the carrier is 70-95 parts by mass, 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 then subjecting the 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 into 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 are the same or different, and each independently comprises 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 selectively hydrogenating and isomerizing a mono-olefin according to any one of the claims 1 to 5, comprising the steps of subjecting the support to a second impregnation with a molybdenum salt solution and optionally a nickel 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 molybdenum salt comprises at least one of a sulfate, nitrate, soluble carboxylate, hypophosphite and halide of molybdenum, preferably at least one of molybdenum sulfate, molybdenum nitrate, molybdenum chloride and molybdenum 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 molybdenum salt solution and the nickel salt solution are at least one of water, methanol, ethanol, benzene, toluene and chloroethane respectively and independently, and/or The concentration of the molybdenum salt solution is 0.1-0.6 mol/L, and/or The concentration of the nickel salt solution is 0.05-0.3 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. Use of the catalyst for selective hydrogenation and isomerisation of mono-olefins according to any of claims 1-5 or the catalyst for selective hydrogenation and isomerisation of mono-olefins produced by the process of claims 6-8 for selective hydrogenation to remove alkynes from C4 fractions and to increase butadiene production, preferably the conditions for selective hydrogenation comprise a reaction temperature of 40-120 ℃, a pressure of 0.5-3.0 mpa, a volume ratio of hydrogen flow to fresh feed of 10-300:1 and a feed volume space velocity of 0.1-2.0 h -1 .
10. A method for removing alkynes in a C4 fraction and increasing butadiene yield by selective hydrogenation of carbon four-cut alkynes, wherein the selective hydrogenation reaction is carried out on the carbon four-cut alkynes and hydrogen in the presence of the catalyst for selective hydrogenation and isomerization of mono-olefins or the catalyst for selective hydrogenation and isomerization of mono-olefins prepared by the preparation method according to any one of claims 1 to 5, preferably, the condition of the selective hydrogenation reaction comprises a reaction temperature of 40 ℃ to 120 ℃ and a pressure of 0.5MPa to 3.0MPa, the volume ratio of the hydrogen flow to the feed amount of fresh raw materials is 10 to 300:1, and the feed volume space velocity is 0.1 to 2.0h -1 .

Description

Catalyst for selective hydrogenation and isomerization of mono-olefin, preparation method and application thereof Technical Field The invention relates to the technical field of selective hydrogenation catalysts, in particular to a catalyst for selective hydrogenation and isomerization of mono-olefins, a preparation method and application thereof. Background With the rapid expansion of oil refining capability, the FCC generates a considerable amount of byproduct C four through a hydrocarbon steam cracking process, the precious resource is mostly treated as liquefied gas at low cost, and the butene alkylation can well utilize the raw material to produce high-quality C four-alkylated gasoline. In the process, isobutane and butene are used for generating an isoparaffin mixture under the action of sulfuric acid and hydrofluoric acid, so that the isoparaffin mixture is an ideal blending component of high-quality high-octane gasoline, and has moderate saturated vapor pressure, no olefin, no sulfur, no benzene and aromatic compounds and cleanliness. Along with the continuous improvement of environmental awareness, the reduction or stop of the use of gasoline additive MTBE is urgently required, the demand for high-octane gasoline is increased, the importance of alkylation technology is increasingly outstanding, the production is required to be enlarged, and the alkylation technology is improved. The alkylation raw material from the steam cracking process and FCC generally contains 0.2% -2.0% of butadiene, and butadiene must be removed through selective hydrogenation, so that the consumption of sulfuric acid is reduced, the generation of acid solvent is reduced, the dry point of the alkylation oil is effectively reduced, the economic loss caused by acid corrosion equipment is reduced, about 70% of 1-butene is isomerized into 2-butene, and the octane number of the alkylation oil is improved (the octane number of the 2-butene alkylation oil is higher than that of the 1-butene alkylation oil by 2-3 units). In the mixed raw material containing isobutane, n-butane, isobutene, n-butene, isobutene, cis-butene and butadiene, the butadiene is removed by hydrogenation, and at the same time, 1-butene is isomerized into 2-butene, the process generally uses noble metal catalyst, such as Pd catalyst, and the catalyst carrier has Al 2O3、SiO2, etc., and adopts liquid phase fixed bed hydrogenation reaction. The existing alkylation raw material pretreatment technical scheme adopts a supported noble metal catalyst, the noble metal is expensive, the defect of higher catalyst cost exists, and the Pd has extremely strong activity, which is an important reason for initiating unsaturated hydrocarbon oligomerization reaction, so that the butene hydrogenation loss is large, the catalyst activity is reduced due to butadiene polymerization reaction, and in addition, the noble metal catalysis has poor resistance to impurities such as sulfur and the like, so that the stability is influenced. At present, the main problem of noble metal catalysts in the field is that the isomerization rate of the catalyst is low, the hydrogenation loss of butene is high, the polymerization reaction occupies high area, and the stability of the catalyst is poor. Disclosure of Invention In order to overcome at least one of the above problems in the prior art, it is an object of the present invention to provide a catalyst for selective hydrogenation and isomerization of mono-olefins, which is a non-noble metal catalyst having high isomerization selectivity and high stability, and which can save investment costs by more than 80% and has better resistance to impurity poisoning and stability compared to noble metal selective hydrogenation alkyne-removal catalysts. The second purpose of the invention is to provide a preparation method of the catalyst for selectively hydrogenating and isomerizing mono-olefins, which has the advantages of convenient preparation and good hydrogenation activity of the obtained catalyst. It is a further object of the present invention to provide a catalyst for selectively hydrogenating and isomerizing a mono-olefin as described above or a use of the catalyst for selectively hydrogenating and isomerizing a mono-olefin as produced by the above production method. The fourth object of the invention is to provide a method for removing alkyne in C4 fraction and increasing butadiene yield by selective hydrogenation of alkyne in C4 fraction. To this end, in a first aspect, the present invention provides a catalyst for selective hydrogenation and isomerisation of mono-olefins comprising a support and an active component supported on the support, 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 comp