CN114181032A

CN114181032A - Method for removing phenylacetylene by selective hydrogenation of carbon eight fraction

Info

Publication number: CN114181032A
Application number: CN202010970129.0A
Authority: CN
Inventors: 谭都平; 沈立军; 刘龙; 何英华; 朱丽娜; 孙维; 隋军; 王海泉; 关东义; 张琳琳; 周磊; 辛虹
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2020-09-15
Filing date: 2020-09-15
Publication date: 2022-03-15
Anticipated expiration: 2040-09-15
Also published as: CN114181032B

Abstract

The invention relates to a method for removing phenylacetylene by selective hydrogenation of carbon eight fraction, which comprises the carbon eight fraction and H₂And (2) mixing, then feeding into an adiabatic reactor, wherein a selective hydrogenation catalyst is loaded in the adiabatic reactor, and the volume ratio of hydrogen to the inlet feed of the reactor is 1-100: 1, the temperature of a reaction inlet is 20-70 ℃, the reaction pressure is 0.1-1.0 MPa, and the liquid volume space velocity is 0.1-6 h^‑1Cooling the reaction product, and separating in a gas-liquid separating tank; the carrier of the selective hydrogenation catalyst is alumina or mainly alumina, and has a bimodal pore distribution structure, wherein the pore diameter of a small pore is 10-25 nm, the pore diameter of a large pore is 50-250 nm, the catalyst at least contains Pd, Li, Ni and Cu, and the mass of the catalyst is 100%,the content of Pd is 0.15-0.5 wt%, and the mass ratio of Li to Pd is 1-10: 1, the Ni content is 0.5-5 wt%, and the mass ratio of Cu to Ni is 0.1-1: 1. The method of the present invention has high phenylacetylene hydrogenation conversion rate, no loss and no increase of styrene, obviously reduced catalyst coking amount and prolonged catalyst life.

Description

Method for removing phenylacetylene by selective hydrogenation of carbon eight fraction

Technical Field

The invention relates to a method for removing phenylacetylene by selective hydrogenation of a carbon eight fraction, in particular to a method for removing phenylacetylene by selective hydrogenation of a cracked gasoline carbon eight fraction with high coking resistance.

Background

Styrene (ST) is an important monomer for producing polystyrene, ABS resin and styrene-butadiene rubber, the technology for producing styrene by ethylbenzene dehydrogenation is difficult to meet the requirement of the market on styrene, and the ethylbenzene dehydrogenation method has the defect of high production cost. The extraction of styrene from the eight carbon by-product fraction from cracking ethylene production is becoming an attractive new way to increase styrene yield.

The pyrolysis gasoline is a byproduct of ethylene industry, the yield is about 60-70% of the ethylene production capacity, the carbon eight fraction in the pyrolysis gasoline is used for extracting and recovering styrene, a 1000kt/a ethylene device can obtain 24-42kt/a of styrene, and simultaneously mixed xylene can be recovered, so that the pyrolysis carbon eight fraction is upgraded from the fuel value to the chemical value, the production cost is about 1/2 of styrene production by traditional ethylbenzene dehydrogenation, and the pyrolysis gasoline has strong market competitiveness; meanwhile, due to the separation of the carbon eight fraction, the load of a subsequent hydrogenation device of the pyrolysis gasoline is reduced, the hydrogen consumption is reduced, and the poisoning of the pyrolysis gasoline hydrogenation catalyst caused by the polymerization of styrene is avoided.

The scheme for recovering styrene from pyrolysis gasoline adopts an extractive distillation method at present, but the carbon eight fraction contains 4000-15000 mu g^-1The chemical structures of ST and PA are similar, and the interaction between ST and PA and an extractive distillation solvent is also similar, so that the ST and PA can not be effectively separated by the existing extractive distillation process conditions. The presence of these phenylacetylenes not only increases the catalyst consumption in SM anionic polymerization, but also has an effect on chain length and polymerization rate, and also on color, odor, and overall properties of the polymer product. Therefore, before extracting styrene from the ethylene cracking carbon eight, the phenylacetylene must be selectively hydrogenated, and the carbon eight fraction contains 30-50% of styrene, so that the hydrogenation loss of styrene should be reduced as much as possible when the phenylacetylene is hydrogenated. The lower the phenylacetylene content in the hydrogenation product is, the smaller the loss rate of the styrene is, the important index for examining the catalyst is, and the benefit of the process for recovering the styrene from the cracked gasoline carbon eight fraction is also determined. Therefore, the development of a method for removing phenylacetylene by selective hydrogenation of carbon eight fractions with high phenylacetylene hydrogenation rate and low styrene loss rate becomes the key of the technology.

CN1852877A discloses a process for the selective hydrogenation of phenylacetylene in the presence of styrene monomer, the catalyst being a reduced copper compound contained on a theta alumina support, in a hydrogenation reactor at a pressure of at least 60 ℃ and 30psig, to hydrogenate phenylacetylene to styrene. The phenylacetylene hydrogenation rate is only about 70 percent, large pressure drop occurs in two weeks of operation, the catalyst cannot be continuously operated, the service life of the catalyst is short, the strength is small, the catalyst is easy to break, the loss rate of the styrene reaches about 3 percent, and the catalyst is not suitable for industrial application.

CN1087892A discloses a method and apparatus for catalytic purification of styrene monomer by hydrogenation, wherein hydrogen is diluted by nitrogen (molar ratio about 2:1 to 1:4), hydrogen is mixed with a catalyst selectivity improver (such as carbon monoxide), and phenylacetylene impurities are hydrogenated to styrene in a catalytic bed by using a reactor with multiple catalytic beds or by using a reactor with multiple catalytic beds respectively. The catalyst of the patent is only applicable to the phenylacetylene in a low concentration (about 300 ppm), and the content of the phenylacetylene in the carbon eight fraction of the cracked gasoline is usually more than 5000 ppm.

CN101475438B discloses a method for selectively hydrogenating phenylacetylene in the presence of styrene, wherein the catalyst is a carbon-containing oxide catalyst, and the carbon content of the catalyst is 0.02-8%. The catalyst needs to be subjected to carbon deposition treatment in advance, and the preparation process is complex; the carbon deposition treatment process affects the pore structure of the catalyst and affects the operation life of the catalyst.

CN1298376A discloses a method for hydrogenating phenylacetylene in a styrene-containing medium by using a supported nickel catalyst with a nickel content of 10-25 wt% and a bubbling bed reactor, but the patent only introduces a method for selectively hydrogenating phenylacetylene from the aspect of process control, but the catalyst hydrogenation performance is not ideal under high-severity process conditions, and the loss of styrene in the process is not described in detail.

Patent CN103785858A discloses a preparation method of amorphous nano-palladium-rhodium alloy and its catalytic application, which adopts an intermittent operation mode to control the generation of styrene by the selective reduction of phenylacetylene, but the selectivity of styrene is not high and the selectivity of styrene for a long time is not considered.

In the hydrogenation process of removing phenylacetylene by selective hydrogenation of the carbon eight fraction, the polymerization of unsaturated hydrocarbon is easy to occur, and an oligomer with wider molecular weight, commonly called as 'colloid', is generated. The colloid is adsorbed on the surface of the catalyst and further forms coke to block the pore channels of the catalyst, so that reactants cannot diffuse to the surface of the active center of the catalyst, thereby causing the activity of the catalyst to be reduced, and influencing the stability and the service life of the catalyst. How to reduce the coking of the catalyst becomes an important index for evaluating the excellence of the catalyst.

Patent CN1736589 reports a Pd/gamma-Al prepared by adopting a complete adsorption impregnation method₂O₃The hydrogenation catalyst is selected, and the catalyst has larger colloid generation amount in the use process. Patent CN200810114744.0 discloses an unsaturated hydrocarbon selective hydrogenation catalyst and a preparation method thereof. The catalyst uses alumina as a carrier, uses palladium as an active component, and improves the impurity resistance and the coking resistance of the catalyst by adding rare earth, alkaline earth metal and fluorine, but the selectivity of the catalyst is not ideal.

The catalyst adopts the catalyst with single distribution of pore diameter, and is influenced by internal diffusion in the fixed bed reaction process, and the selectivity of the catalyst is poor. The carrier with bimodal pore distribution can reduce the influence of internal diffusion and improve the selectivity of the catalyst while ensuring the high activity of the catalyst.

Patent ZL971187339 discloses a hydrogenation catalyst, the carrier is a honeycomb type carrier, and is a large-aperture carrier, and the selectivity of the catalyst is effectively improved. CN1129606 discloses a hydrocarbon conversion catalyst, the supported catalyst of which comprises alumina, nickel oxide, iron oxide, etc., and the catalyst comprises two pores, one of which is used for improving the catalytic reaction surface, and the other is favorable for diffusion. The patent CN101433842 provides a hydrogenation catalyst, which is characterized in that the catalyst has bimodal pore distribution, the radius of the small pore part can be 2-50 nm at most, and the radius of the large pore part can be 50-250 nm at most, and the catalyst has good hydrogenation activity and good selectivity due to the bimodal pore distribution.

Coking of the catalyst is an important factor affecting the service life of the catalyst. The activity, selectivity and service life of the catalyst form the overall performance of the catalyst, and the methods listed above provide better ways for improving the activity and selectivity of the catalyst, but do not solve the problem that the catalyst is easy to coke, or solve the problem that the catalyst is easy to generate colloid and coke, but do not solve the problem of selectivity. Although the carrier with a macroporous structure can improve the selectivity, larger molecules generated by polymerization and chain growth reaction are easy to accumulate in the macropores of the carrier, so that the catalyst is coked and inactivated, and the service life of the catalyst is influenced.

Disclosure of Invention

The invention aims to provide a method for removing phenylacetylene by selective hydrogenation of carbon eight fractions, in particular to a method for removing phenylacetylene by selective hydrogenation of carbon eight fractions of pyrolysis gasoline with high coking resistance, which provides qualified raw materials for a subsequent styrene extraction device.

The invention relates to a method for removing phenylacetylene by selective hydrogenation of a carbon eight fraction, which comprises the steps of the carbon eight fraction and H₂And (2) mixing, then feeding into an adiabatic reactor, wherein a selective hydrogenation catalyst is loaded in the adiabatic reactor, and the volume ratio of hydrogen to the inlet feed of the reactor is 1-100: 1, the temperature of a reaction inlet is 20-70 ℃, the reaction pressure is 0.1-1.0 MPa, and the liquid volume space velocity is 0.1-6 h^-1And cooling the reaction product, and separating in a gas-liquid separating tank. The reactor is filled with catalyst containing Pd, Li, Ni and Cu components, the catalyst has bimodal pore size distribution, Ni, Cu and a small amount of Pd in the catalyst are prepared by a microemulsion method, and the particle size of the microemulsion is larger than the pore size of the small pore and smaller than the pore size of the large pore.

The carrier of the selective hydrogenation catalyst is alumina or mainly alumina, and has a bimodal pore distribution structure, wherein the pore diameter of a small pore is 10-25 nm, the pore diameter of a large pore is 50-250 nm, the catalyst at least contains Pd, Li, Ni and Cu, the mass of the catalyst is 100%, the content of Pd is 0.15-0.5 wt%, and the mass ratio of Li to Pd is 1-10: 1, the Ni content is 0.5-5 wt%, and the mass ratio of Cu to Ni is 0.1-1: 1, wherein Ni and Cu are loaded in a micro-emulsion mode and distributed in macropores of a carrier; li is loaded by a solution method, and Pd is loaded by a solution method and a microemulsion method.

In the method disclosed by the invention, the adiabatic reactor is a trickle bed adiabatic reactor or a bubbling bed adiabatic reactor. The present invention recommends the use of a bubbling bed adiabatic reactor, preferably a single-stage bubbling bed reactor. For a single-stage adiabatic bubbling bed reactor, the volume ratio of hydrogen to the reactor inlet feed is preferably 10-50: 1. the multistage adiabatic bubbling bed reactor is characterized by comprising two or more stages of adiabatic bubbling bed reactors, and when the multistage adiabatic bubbling bed reactor is adopted, the molar ratio of the hydrogen amount at each stage of inlet to phenylacetylene in the material to be hydrogenated at the stage of inlet is preferably 10-30.

According to the method disclosed by the invention, different reaction conditions can be selected in the adiabatic reactor according to different contents of raw material components, and because the reaction is a liquid phase reaction, the requirement on the accuracy of the hydrogenation of phenylacetylene is higher, and the loss rate of styrene is strictly controlled, the selection of reaction temperature and pressure is very important, the polymerization of olefin and alkyne is accelerated when the temperature is too high, the side reaction is accelerated when the pressure is too high, and the loss rate of styrene is increased; the temperature of the reaction inlet is generally 20 to 70 ℃, preferably 20 to 50 ℃; the reaction pressure is generally 0.1 to 1MPa, preferably 0.1 to 0.7 MPa; the liquid airspeed is 0.1-6 h^-1Preferably 1 to 4 hours^-1。

The idea of the hydrogenation method is as follows: active components of nickel/copper and a small amount of palladium are loaded in the big holes, and active components of palladium are loaded in the small holes. The phenylacetylene is subjected to selective hydrogenation reaction mainly in the small holes to generate the styrene. And the by-product with larger molecular size generated in the reaction, mainly the carbon sixteen fraction, is easier to enter the macropores and generates saturated hydrogenation reaction under the action of the nickel active component in the macropores. Since these molecules are saturated by hydrogenation, their molecular chains do not grow any longer and are therefore easily carried out of the reactor by the feed. The copper has the function of forming an alloy with the nickel and reducing the reduction temperature of the nickel; the reduction temperature of nickel can be further greatly reduced by loading a small amount of palladium on the surface of nickel-copper, so that the active component palladium is not aggregated in the high-temperature reduction process. The initial activity and selectivity of the catalyst are not affected by the reduction process.

Researches show that as the coking resistance of the catalyst in the method is obviously enhanced, when the phenylacetylene content in the inlet raw material reaches 1.3 wt% and the styrene content reaches 45%, the hydrogenation activity and selectivity of the catalyst still keep higher levels, and the hydrogenation product adopting the method can still meet the requirements of the subsequent extraction process.

In view of the above situation, the present invention provides a method for removing phenylacetylene by selective hydrogenation of carbon eight fractions.

The method of the invention adopts a catalyst containing Pd, Li, Ni and Cu in the hydrogenation reaction. The catalyst carrier adopted by the method is alumina with a bimodal pore size distribution structure, the pore size of a small pore of the carrier is 10-25 nm, and the pore size of a large pore is 50-250 nm.

The catalyst adopted by the invention has active components Pd and Li loaded by an aqueous solution method, Ni, Cu and a small amount of Pd loaded by a W/O microemulsion dipping method, wherein the mass fraction of the Pd loaded by the microemulsion method is 1/100-1/200 of Ni and Cu, and the loading is carried out after the Ni and Cu are loaded.

The grain diameter of the microemulsion is larger than the maximum aperture of the small hole and smaller than the maximum aperture of the big hole. Due to steric resistance, these components can only enter the large pores, so that active centers with different hydrogenation are formed in the large and small pores of the catalyst. The macropores contain active centers consisting of Ni/Cu and Pd, and the active centers have good hydrogenation saturation effect on colloid molecules, so that the colloid molecules entering the macropores are not polymerized any more, and can be gradually moved out of the reactor and are not easy to coke.

The inventors have found that if Ni and Cu are impregnated simultaneously, both will form an alloy, and the reduction temperature of Ni will be reduced to a large extent, up to 350 ℃ at the lowest, due to the presence of Cu, but this temperature is still high for Pd catalysts. Research also finds that after a small amount of Pd is loaded on the Ni/Cu catalyst, the reduction temperature is greatly reduced to 150 ℃, which is completely acceptable for the Pd catalyst, because the reduction temperature of the general Pd catalyst is 100-120 ℃, and the catalyst can run for a longer time at 120 ℃ in some cases, which indicates that the aggregation of active components cannot be caused at 120-150 ℃.

The preparation process of the catalyst adopted by the invention is as follows:

the invention also provides a preparation method of the used catalyst, which comprises the following steps:

(1) dissolving precursor salts of Ni and Cu in water, adding metered oil phase, surfactant and cosurfactant, and fully stirring to form the microemulsion. The conditions provided in the present invention are: the weight ratio of the surfactant to the cosurfactant is 1-1.2, the weight ratio of the water phase to the oil phase is 1-2, and the weight ratio of the surfactant to the oil phase is 0.4-0.7, and the microemulsion with the particle size of 25-250 nm can be formed by adopting the method. Adding the carrier into the prepared microemulsion, dipping for 0.5-4 hours, filtering out residual liquid, drying for 1-6 hours at the temperature of 60-150 ℃, and roasting for 1-6 hours at the temperature of 300-700 ℃ to obtain a semi-finished catalyst A.

(2) Preparing active component impregnation liquid from Pd precursor salt, adjusting the pH value to 1.5-2.5, adding the semi-finished catalyst A into the Pd active component impregnation liquid, performing impregnation adsorption for 0.5-4 h, drying at 60-150 ℃ for 1-6 h, and roasting at 300-700 ℃ for 1-6 h to obtain a semi-finished catalyst B.

(3) The Li loading is carried out by a saturated dipping method, namely, the prepared Li salt solution is 80-110% of the saturated water absorption of the carrier. And (3) soaking the semi-finished product catalyst B in the prepared solution, drying at 60-150 ℃ for 1-6 hours, and roasting at 300-700 ℃ for 1-6 hours. Obtaining a semi-finished product catalyst C.

(4) Dissolving Pd precursor salt in water, adding metered oil phase, surfactant and cosurfactant, and fully stirring to form microemulsion. The conditions provided in the present invention are: the weight ratio of the surfactant to the cosurfactant is 1-1.2, the weight ratio of the water phase to the oil phase is 1-2, and the weight ratio of the surfactant to the oil phase is 0.4-0.7, and the microemulsion with the particle size of 25-250 nm can be formed by adopting the method. And adding the semi-finished product catalyst C into the prepared microemulsion, soaking for 0.5-4 hours, filtering out residual liquid, drying for 1-6 hours at the temperature of 60-150 ℃, and roasting for 1-6 hours at the temperature of 300-700 ℃ to obtain the required catalyst.

In the above preparation steps, step (1) and step (2) may be interchanged, step (3) following step (2), and step (4) following step (1).

For one sample, the conditions of step (1) and step (4) may be the same, or different, preferably the same, so as to ensure more uniform loading of Pd on the surface of the Ni/Cu alloy.

The carrier in the step (1) is alumina or mainly alumina and Al₂O₃The crystal form is preferably a theta and/or alpha mixed crystal form. The alumina content in the catalyst carrier is preferably above 80%, and the carrier may also contain other metal oxides such as magnesia, titania, etc.

The carrier in the step (1) can be spherical, dentate spherical, cylindrical, clover-shaped and the like.

The precursor salts of Ni, Cu, Li and Pd in the above steps are soluble salts, and can be nitrates, chlorides or other soluble salts thereof.

In the catalyst, the molar ratio of Li to Pd is 1-10: 1, the molar ratio of Cu to Ni is 0.1-1: 1, and the content of Pd loaded by a microemulsion method is 1/100-1/200 of the sum of mass fractions of Ni and Cu.

The surfactant in the steps (1) and (4) is an ionic surfactant or a nonionic surfactant, preferably a nonionic surfactant, and more preferably polyethylene glycol octyl phenyl ether (Triton X-100) or cetyltrimethylammonium bromide (CTAB).

The oil phase in the above steps (1) and (4) is C₆～C₈Saturated alkanes or cycloalkanes, preferably cyclohexane, n-hexane.

The cosurfactant in the steps (1) and (4) is C₄～C₆Alcohols, preferably n-butanol, n-pentanol.

The reduction temperature of the catalyst of the invention is preferably 150 to 200 ℃.

The catalyst of the invention has the following characteristics: at the beginning of the hydrogenation reaction, the hydrogenation activity of palladium is high and the palladium is mainly distributed in the small holes, so that the selective hydrogenation reaction of phenylacetylene mainly occurs in the small holes. With the prolonging of the operation time of the catalyst, a part of by-products with larger molecular weight are generated on the surface of the catalyst, and due to the larger molecular size, the substances enter the macropores more frequently and the retention time is longer, the hydrogenation reaction of double bonds can be generated under the action of the nickel catalyst, so that aromatic hydrocarbon without isolated double bonds is generated, and substances with larger molecular weight are not generated any more.

The inventor also finds that the method has the advantages that even if the reaction raw materials contain more phenylacetylene and styrene, the generation amount of catalyst colloid is greatly increased, the coking amount of the catalyst is not obviously increased, and the selective hydrogenation activity and selectivity are not obviously reduced.

Drawings

FIG. 1 shows the temperature programmed reduction results of samples prepared by micro-emulsion method loaded Cu/Ni and Pd-Cu/Ni.

FIG. 2 is a process flow diagram of an evaluation device for removing phenylacetylene by selective hydrogenation of a carbon eight fraction.

Wherein, the reference numbers:

1-a stock tank;

2-raw material pump;

3-a reactor;

4-a condenser;

5-gas-liquid separator;

6, a product tank;

7-wet gas meter.

Detailed Description

The following examples illustrate the invention in detail: the present example is carried out on the premise of the technical scheme of the present invention, and detailed embodiments and processes are given, but the scope of the present invention is not limited to the following examples, and the experimental methods without specific conditions noted in the following examples are generally performed according to conventional conditions.

The analysis method comprises the following steps:

the catalyst of the invention is characterized by the following methods in the preparation process: a dynamic light scattering particle size analyzer, wherein the particle size distribution of the microemulsion of the Ni-Cu alloy is analyzed on an M286572 dynamic light scattering analyzer; the carrier N was carried out by using Tristar 3000 type physical adsorption apparatus manufactured by Micrometrics, USA₂Physical adsorption test, namely calculating the specific surface area, the pore size distribution and the pore volume of the sample by respectively using a BET formula and a BJH equation; the mercury intrusion detector model 9510 of Michkovic USA is adopted to measure the loadThe specific surface area and pore structure of the volume; the contents of Pd, Li, Ni and Cu in the catalyst were determined on an A240FS atomic absorption spectrometer.

The adopted Cetyl Trimethyl Ammonium Bromide (CTAB), polyethylene glycol octyl phenyl ether (Triton X-100) and Sodium Dodecyl Sulfate (SDS) are all expressed by the abbreviation.

The invention is further illustrated by the following examples, which are not to be construed as limiting the invention thereto.

Example 1

Catalyst carrier:

a commercially available spherical alumina carrier with bimodal pore distribution and a diameter of 4mm was used. After roasting for 4 hours at 950 ℃, the bimodal pore size distribution ranges from 10 nm to 15nm and from 50nm to 150nm, the water absorption rate is 63 percent, and the specific surface area is 155m²(ii) in terms of/g. 100g of the carrier was weighed.

Preparing a catalyst:

(1) weighing nickel nitrate and copper chloride, dissolving in 43mL of deionized water, adding 43g of cyclohexane, adding Triton X-10030 g and 30g of n-butanol, fully stirring to form a microemulsion, soaking 100g of the weighed carrier calcined at high temperature into the prepared microemulsion, shaking for 30min, filtering out residual liquid, and washing with a deionized water washing agent. Drying at 80 deg.C for 6 hr, and calcining at 400 deg.C for 6 hr. Referred to as semi-finished catalyst a.

(2) Preparing palladium chloride into an active component impregnation liquid, adjusting the pH value to 2.0, then impregnating the semi-finished catalyst A into the prepared Pd salt solution, drying for 6 hours at 80 ℃ after 30min of impregnation, and roasting for 4 hours at 500 ℃. Obtaining a semi-finished product catalyst B.

(3) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst B prepared in the step (2) in the prepared lithium nitrate solution containing lithium, shaking, drying at 130 ℃ for 3 hours after the solution is completely absorbed, and roasting at 500 ℃ for 6 hours to obtain a semi-finished catalyst C.

(4) Weighing palladium chloride, dissolving in 43mL of deionized water, adding 43g of cyclohexane, adding Triton X-10030 g and adding 30g of n-butanol, fully stirring to form a microemulsion, placing the semi-finished catalyst C prepared in the step (3) in the prepared microemulsion, shaking for 30min, filtering out residual liquid, and using a deionized water washing agent. Drying at 80 deg.C for 6 hr, and calcining at 400 deg.C for 6 hr. The desired catalyst is obtained.

The particle size of the microemulsion prepared was 56nm as determined by dynamic light scattering.

And (3) reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device and is mixed with N₂:H₂1:1 at 200 ℃ for 8 h.

Example 2

Carrier:

a commercially available spherical alumina carrier with bimodal pore distribution and a diameter of 3mm is used. After roasting for 4 hours at 970 ℃, the bimodal pore size distribution ranges from 10 nm to 20nm and from 55 nm to 150nm, the water absorption rate is 63 percent, and the specific surface area is 140m²(ii) in terms of/g. 100g of the carrier was weighed.

Preparing a catalyst:

(1) weighing nickel nitrate and copper chloride, dissolving in 56mL deionized water, adding 47g of n-hexane, adding CTAB33g and 28g of n-amyl alcohol, fully stirring to form microemulsion, soaking 100g of the weighed carrier calcined at high temperature into the prepared microemulsion, shaking for 90min, filtering out residual liquid, drying at 100 ℃ for 5 hours, and calcining at 500 ℃ for 4 hours. Referred to as semi-finished catalyst D.

(2) Preparing palladium chloride into an active component impregnation liquid, adjusting the pH value to 1.8, then impregnating the semi-finished catalyst D into the prepared Pd salt solution, drying for 5 hours at 100 ℃ after impregnating for 60 minutes, and roasting for 6 hours at 400 ℃. Obtaining a semi-finished product catalyst E.

(3) Weighing lithium carbonate to prepare a solution, soaking the semi-finished catalyst E prepared in the step (2) in the prepared lithium carbonate solution containing lithium, shaking, drying at 140 ℃ for 2 hours after the solution is completely absorbed, and roasting at 500 ℃ for 4 hours to obtain a semi-finished catalyst F.

(4) Weighing palladium chloride, dissolving in 56mL of deionized water, adding 47g of n-hexane, adding CTAB33g and 28g of n-amyl alcohol, fully stirring to form a microemulsion, dipping the semi-finished catalyst F prepared in the step (3) into the prepared microemulsion, shaking for 90min, filtering out residual liquid, drying at 100 ℃ for 5 hours, and roasting at 500 ℃ for 4 hours. The desired catalyst is obtained.

The particle size of the microemulsion prepared was 65nm as determined by dynamic light scattering.

And (3) reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device and is mixed with N₂:H₂1:1, at 150 ℃, reduction treatment for 8 h.

Example 3

Carrier:

a commercially available spherical alumina carrier with bimodal pore distribution and a diameter of 4mm was used. After roasting for 4 hours at 980 ℃, the bimodal pore size distribution ranges from 10 nm to 20nm and from 55 nm to 190nm, the water absorption rate is 62%, and the specific surface area is 130m²(ii) in terms of/g. 100g of the carrier was weighed.

Preparing a catalyst:

(1) weighing nickel nitrate and copper chloride, dissolving in 59mL deionized water, adding cyclohexane 45g, adding SDS 27g, adding n-butanol 25g, stirring thoroughly to form microemulsion, soaking the weighed 100g of the carrier calcined at high temperature into the prepared microemulsion, shaking for 240min, filtering to remove residual liquid, drying at 120 deg.C for 3 hr, and calcining at 600 deg.C for 2 hr. Referred to as semi-finished catalyst G.

(2) Weighing palladium nitrate, dissolving the palladium nitrate in deionized water, adjusting the pH value to 2, dipping the semi-finished catalyst G into the prepared Pd salt solution, drying the catalyst G for 4 hours at 120 ℃ after dipping for 90min, and roasting the catalyst G for 4 hours at 500 ℃. Obtaining a semi-finished product catalyst H.

(3) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst H prepared in the step (2) in the prepared lithium nitrate solution containing lithium, shaking, drying at 150 ℃ for 2 hours after the solution is completely absorbed, and roasting at 500 ℃ for 6 hours to obtain a semi-finished catalyst J.

(4) Weighing palladium nitrate, dissolving in 59mL of deionized water, adding 45g of cyclohexane, 27g of SDS and 25g of n-butanol, fully stirring to form a microemulsion, dipping the semi-finished catalyst J prepared in the step (3) into the prepared microemulsion, shaking for 240min, filtering out residual liquid, drying at 120 ℃ for 3 hours, and roasting at 600 ℃ for 2 hours. The desired catalyst is obtained.

The particle size of the microemulsion prepared was 70nm as determined by dynamic light scattering.

And (3) reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device and is reduced by pure hydrogen for 8 hours at the temperature of 150 ℃.

Example 4

Carrier:

a commercial bimodal pore distribution spherical alumina-titania carrier is adopted, the mass fraction of the titania is 20%, and the diameter is 3 mm. After roasting for 4 hours at 1020 ℃, the bimodal pore size distribution ranges from 30nm to 40nm and from 60 nm to 230nm, the water absorption rate is 61 percent, and the specific surface area is 100m²(ii) in terms of/g. 100g of the carrier was weighed.

Preparing a catalyst:

(1) weighing nickel chloride and copper nitrate, dissolving in 73mL deionized water, adding 43g of n-hexane, 17g of SDS and 15g of n-amyl alcohol, fully stirring to form microemulsion, dipping 100g of the carrier calcined at high temperature into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying at 80 ℃ for 4 hours, and calcining at 600 ℃ for 2 hours. Referred to as semi-finished catalyst K.

(2) Weighing palladium chloride, dissolving in 73mL deionized water, adding 43g of n-hexane, 17g of SDS and 15g of n-amyl alcohol, fully stirring to form a microemulsion, dipping the semi-finished catalyst K into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying at 80 ℃ for 4 hours, and roasting at 600 ℃ for 2 hours. Referred to as semi-finished catalyst M.

(3) Weighing palladium chloride, dissolving in deionized water, adjusting pH to 2.0, soaking the semi-finished catalyst M in the prepared Pd salt solution for 120min, drying at 130 ℃ for 3 hours, and roasting at 600 ℃ for 2 hours. Obtaining the semi-finished catalyst N.

(4) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst N prepared in the step (2) in the prepared lithium nitrate solution containing lithium, shaking, drying at 100 ℃ for 4 hours after the solution is completely absorbed, and roasting at 600 ℃ for 2 hours to obtain the required catalyst.

The particle size of the microemulsion prepared was 78nm as determined by dynamic light scattering.

And (3) reduction of the catalyst:

use ofPlacing the mixture in a fixed bed reaction device in a molar ratio of N₂:H₂1:1 at 200 ℃ for 8 h.

Example 5

Carrier:

a commercially available spherical alumina-magnesia carrier with bimodal pore distribution is adopted, the mass fraction of magnesia is 3%, and the diameter is 3 mm. After roasting for 4 hours at 1000 ℃, the bimodal pore size distribution ranges from 15nm to 20nm and from 60 nm to 200nm, the water absorption rate is 60 percent, and the specific surface area is 100m²(ii) in terms of/g. 100g of the carrier was weighed.

Preparing a catalyst:

(1) weighing palladium chloride, dissolving in deionized water, adjusting the pH value to 2.5, then soaking the carrier in the prepared Pd salt solution, drying for 3 hours at 130 ℃ after soaking for 120min, and roasting for 2 hours at 600 ℃ to obtain a semi-finished catalyst O.

(2) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst O prepared in the step (2) in the prepared lithium nitrate solution containing lithium, shaking, drying at 100 ℃ for 4 hours after the solution is completely absorbed, and roasting at 300 ℃ for 8 hours to obtain a semi-finished catalyst P.

(3) Weighing nickel chloride and copper nitrate, dissolving in 68mL deionized water, adding 40g of n-hexane, adding 40g of Triton X-10020g and 18g of n-hexanol, fully stirring to form a microemulsion, dipping the semi-finished product catalyst P prepared in the step (2) into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying at 70 ℃ for 6 hours, and roasting at 600 ℃ for 2 hours to obtain the semi-finished product catalyst Q.

(4) Weighing palladium chloride, dissolving in 68mL deionized water, adding 40g of n-hexane, adding Triton X-10020g and 18g of n-hexanol, fully stirring to form a microemulsion, dipping the prepared semi-finished catalyst Q into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying at 70 ℃ for 6 hours, and roasting at 600 ℃ for 2 hours. The desired catalyst is obtained.

The particle size of the microemulsion prepared was 80nm as determined by dynamic light scattering.

And (3) reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device and is used in a molar ratioIs N₂:H₂Reducing the mixed gas at 180 ℃ for 8h under the condition of 1: 1.

Example 6

Carrier:

a commercially available spherical alumina-magnesia carrier with bimodal pore distribution is adopted, the mass fraction of magnesia is 3%, and the diameter is 3 mm. After roasting for 4 hours at 1000 ℃, the bimodal pore size distribution ranges from 15nm to 20nm and from 60 nm to 200nm, the water absorption rate is 60 percent, and the specific surface area is 110m²(ii) in terms of/g. 100g of the carrier was weighed.

Preparing a catalyst:

(1) weighing nickel chloride and copper nitrate, dissolving in 69mL deionized water, adding 46g of n-hexane, adding SDS23g and 20g of n-hexanol, fully stirring to form a microemulsion, dipping 100g of the weighed carrier calcined at high temperature into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying at 70 ℃ for 6 hours, and calcining at 600 ℃ for 2 hours. Referred to as semi-finished catalyst R.

(2) Weighing palladium chloride, dissolving in deionized water, adjusting the pH value to 1.8, soaking the semi-finished catalyst R in the prepared Pd salt solution for 120min, drying at 130 ℃ for 3 hours, and roasting at 600 ℃ for 2 hours. Obtaining the semi-finished product catalyst S.

(3) Weighing lithium carbonate to prepare a solution, soaking the semi-finished catalyst S prepared in the step (2) in the prepared lithium carbonate solution containing lithium, shaking, drying at 100 ℃ for 4 hours after the solution is completely absorbed, and roasting at 600 ℃ for 2 hours to obtain a semi-finished catalyst U.

(4) Weighing palladium chloride, dissolving in 69mL deionized water, adding 46g of n-hexane, adding SDS23g and 20g of n-hexanol, fully stirring to form a microemulsion, dipping the semi-finished catalyst U prepared in the step (3) into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying at 70 ℃ for 6 hours, and roasting at 600 ℃ for 2 hours. The desired catalyst is obtained.

The particle size of the microemulsion prepared was 76nm as determined by dynamic light scattering.

And (3) reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device and is mixed with N₂:H₂1:1 mixed gasAnd reducing for 8h at the temperature of 200 ℃.

Example 7

Carrier:

a commercially available spherical alumina carrier with bimodal pore distribution and a diameter of 3mm is used. After roasting for 4 hours at 1040 ℃, the bimodal pore size distribution ranges from 20nm to 25nm and 70nm to 250nm, the water absorption rate is 63 percent, and the specific surface area is 85m²(ii) in terms of/g. 100g of the carrier was weighed.

Preparing a catalyst:

(1) weighing nickel chloride and copper nitrate, dissolving in 72mL of deionized water, adding 38g of n-hexane, 19g of CTAB and 16g of n-amyl alcohol, fully stirring to form microemulsion, soaking 100g of the carrier calcined at high temperature into the prepared microemulsion, shaking for 90min, filtering out residual liquid, drying at 80 ℃ for 5 hours, and calcining at 500 ℃ for 4 hours to obtain the semi-finished catalyst V.

(2) Weighing palladium chloride, dissolving in deionized water, adjusting the pH value to 1.8, then dipping the semi-finished catalyst V into the prepared Pd salt solution, drying for 5 hours at 100 ℃ after dipping for 60 minutes, and roasting for 6 hours at 400 ℃ to obtain the semi-finished catalyst W.

(3) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst W prepared in the step (2) in the prepared lithium nitrate solution containing lithium, shaking, drying at 140 ℃ for 2 hours after the solution is completely absorbed, and roasting at 500 ℃ for 4 hours to obtain a semi-finished catalyst X.

(4) Weighing palladium chloride, dissolving in 72mL of deionized water, adding 38g of n-hexane, adding CTAB19g and 16g of n-amyl alcohol, fully stirring to form a microemulsion, dipping the semi-finished catalyst X prepared in the step (3) into the prepared microemulsion, shaking for 90min, filtering out residual liquid, drying at 80 ℃ for 5 hours, and roasting at 500 ℃ for 4 hours to obtain the required catalyst.

The particle size of the microemulsion prepared was 92nm as determined by dynamic light scattering.

And (3) reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device and is mixed with N₂:H₂Reducing the mixed gas at 150 ℃ for 8h under the condition of 1: 1.

TABLE 1 example catalyst component content

Comparative example 1

The same support as in example 1 was used, and the catalyst preparation conditions were the same as in example 1 except that comparative example 1 did not support Cu.

Preparing a catalyst:

(1) weighing nickel nitrate, dissolving in 43mL of deionized water, adding 43g of cyclohexane, adding Triton X-10030 g and adding 30g of n-butanol, fully stirring to form a microemulsion, soaking 100g of the weighed carrier calcined at high temperature into the prepared microemulsion, shaking for 30min, filtering out residual liquid, and using a deionized water washing agent. Drying at 80 deg.C for 6 hr, and calcining at 400 deg.C for 6 hr. Referred to as semi-finished catalyst a 1.

(2) Preparing palladium chloride into an active component impregnation liquid, adjusting the pH value to 2.0, then impregnating the semi-finished catalyst A1 into the prepared Pd salt solution, drying for 6 hours at 80 ℃ after 30min of impregnation, and roasting for 4 hours at 500 ℃. To obtain a semi-finished catalyst B1.

(3) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst B1 prepared in the step (2) in the prepared lithium nitrate solution containing lithium, shaking, drying at 130 ℃ for 3 hours after the solution is completely absorbed, and roasting at 500 ℃ for 6 hours to obtain the semi-finished catalyst C1.

(4) Weighing palladium chloride, dissolving in 43mL of deionized water, adding 43g of cyclohexane, adding Triton X-10030 g of n-butanol and stirring fully to form a microemulsion, placing the semi-finished catalyst C1 prepared in the step (3) in the prepared microemulsion, shaking for 30min, filtering out residual liquid, and using a deionized water washing agent. Drying at 80 deg.C for 6 hr, and calcining at 400 deg.C for 6 hr. The desired catalyst is obtained.

And (3) reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device and is mixed with N₂:H₂1:1 blendAnd (4) reducing the gas at 200 ℃ for 8 h.

Comparative example 2

The catalyst preparation process was the same as in comparative example 1 except that the catalyst reduction temperature in comparative example 2 was 350 ℃.

Comparative example 3

The same support as in example 2 was used and the catalyst preparation conditions were the same as in example 2 except that Cu was supported by the solution method in comparative example 3.

Preparing a catalyst:

(1) weighing nickel chloride, dissolving in 56mL deionized water, adding 47g of n-hexane, adding CTAB33g and 28g of n-amyl alcohol, fully stirring to form microemulsion, soaking 100g of the weighed carrier calcined at high temperature into the prepared microemulsion, shaking for 90min, filtering out residual liquid, drying at 100 ℃ for 5 hours, and calcining at 500 ℃ for 4 hours. Referred to as semi-finished catalyst D1.

(2) Weighing palladium chloride, dissolving in deionized water, adjusting pH to 1.8, soaking the semi-finished catalyst D1 in the prepared Pd salt solution for 60min, drying at 100 ℃ for 5 hours, and roasting at 400 ℃ for 6 hours. To obtain a semi-finished catalyst E1.

(3) Weighing lithium carbonate and copper chloride to prepare a solution, soaking the semi-finished catalyst E1 prepared in the step (2) in the prepared solution, shaking, drying at 140 ℃ for 2 hours after the solution is completely absorbed, and roasting at 500 ℃ for 4 hours to obtain the semi-finished catalyst F1.

(4) Weighing palladium chloride, dissolving in 56mL deionized water, adding 47g of n-hexane, adding CTAB33g and 28g of n-pentanol, fully stirring to form a microemulsion, dipping the semi-finished catalyst F1 prepared in the step (3) into the prepared microemulsion, shaking for 90min, filtering out residual liquid, drying at 100 ℃ for 5 hours, and roasting at 500 ℃ for 4 hours. The desired catalyst is obtained.

And (3) reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device and is mixed with N₂:H₂Reducing the mixed gas at 350 deg.C for 8 ═ 1:1h。

Comparative example 4

The catalyst preparation conditions were the same as in comparative example 3 except that in comparative example 4 the catalyst reduction temperature was 250 ℃.

Comparative example 5

The same support as in example 3 was used, and the catalyst preparation conditions were the same as in example 3, except that the step of loading Pd by the microemulsion method was eliminated.

Preparing a catalyst:

(1) weighing nickel nitrate and copper chloride, dissolving in 59mL deionized water, adding cyclohexane 45g, adding SDS 27g, adding n-butanol 25g, stirring thoroughly to form microemulsion, soaking the weighed 100g of the carrier calcined at high temperature into the prepared microemulsion, shaking for 240min, filtering to remove residual liquid, drying at 120 deg.C for 3 hr, and calcining at 600 deg.C for 2 hr. Referred to as semi-finished catalyst G1.

(2) Weighing palladium nitrate, dissolving in deionized water, adjusting the pH value to 2, soaking the semi-finished catalyst G1 in the prepared Pd salt solution for 90min, drying at 120 ℃ for 4 hours, and roasting at 500 ℃ for 4 hours. A semi-finished catalyst H1 was obtained.

(3) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst H1 prepared in the step (2) in the prepared lithium nitrate solution containing lithium, shaking, drying at 150 ℃ for 2 hours after the solution is completely absorbed, and roasting at 400 ℃ for 6 hours to obtain the required catalyst.

And (3) reduction of the catalyst:

Comparative example 6

The catalyst preparation conditions were the same as in comparative example 5 except that the catalyst reduction temperature was 350 ℃.

Comparative example 7

The support and the preparation conditions were the same as in example 4, except that no Ni was present in the comparative example.

(1) Weighing copper nitrate, dissolving in 73mL deionized water, adding 43g of n-hexane, 17g of SDS and 15g of n-amyl alcohol, fully stirring to form a microemulsion, dipping 100g of the carrier calcined at high temperature into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying at 80 ℃ for 4 hours, and calcining at 600 ℃ for 2 hours. Referred to as semi-finished catalyst K1.

(2) Weighing palladium chloride, dissolving in 73mL deionized water, adding 43g of n-hexane, 17g of SDS and 15g of n-amyl alcohol, fully stirring to form a microemulsion, dipping the semi-finished catalyst K1 into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying for 4 hours at 80 ℃, and roasting for 2 hours at 600 ℃. Referred to as semi-finished catalyst M1.

(3) Weighing palladium chloride, dissolving in deionized water, adjusting pH to 2.0, soaking the semi-finished catalyst M1 in the prepared Pd salt solution for 120min, drying at 130 ℃ for 3 hours, and roasting at 600 ℃ for 2 hours. A semi-finished catalyst N1 was obtained.

(4) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst N1 prepared in the step (3) in the prepared lithium nitrate solution containing lithium, shaking, drying at 100 ℃ for 4 hours after the solution is completely absorbed, and roasting at 600 ℃ for 2 hours to obtain the required catalyst.

And (3) reduction of the catalyst:

Comparative example 8

The catalyst preparation conditions were the same as in example 5, except that the preparation steps (3) and (4) were reversed in order.

Preparing a catalyst:

(1) weighing palladium chloride, dissolving in deionized water, adjusting the pH value to 2.5, then soaking the carrier in the prepared Pd salt solution for 120min, drying at 130 ℃ for 3 hours, and roasting at 600 ℃ for 2 hours to obtain a semi-finished catalyst O1.

(2) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst O1 prepared in the step (1) in the prepared lithium nitrate solution containing lithium, shaking, drying at 100 ℃ for 4 hours after the solution is completely absorbed, and roasting at 300 ℃ for 8 hours to obtain the semi-finished catalyst P1.

(3) Weighing palladium chloride, dissolving in 68mL deionized water, adding 40g of n-hexane, adding Triton X-10020g and 18g of n-hexanol, fully stirring to form a microemulsion, dipping the prepared semi-finished catalyst P1 into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying at 70 ℃ for 6 hours, and roasting at 600 ℃ for 2 hours to obtain the semi-finished catalyst Q1.

(4) Weighing nickel chloride and copper nitrate, dissolving in 68mL deionized water, adding 40g of n-hexane, adding 40g of Triton X-10020g and 18g of n-hexanol, fully stirring to form a microemulsion, dipping the semi-finished catalyst Q1 prepared in the step (3) into the prepared microemulsion, shaking for 180min, filtering out residual liquid, drying at 70 ℃ for 6 hours, and roasting at 600 ℃ for 2 hours. The desired catalyst is obtained.

And (3) reduction of the catalyst:

Comparative example 9

The catalyst preparation conditions were the same as in example 6, except that the catalyst reduction temperature was 500 ℃.

And (3) reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device and is mixed with N₂:H₂Reducing the mixed gas at 500 ℃ for 8h under the condition of 1: 1.

Comparative example 10

The difference compared with example 7 is that steps (2) and (3) are reversed during the loading of the catalyst.

Preparing a catalyst:

(1) weighing nickel chloride and copper nitrate, dissolving in 72mL of deionized water, adding 38g of n-hexane, 19g of CTAB and 16g of n-amyl alcohol, fully stirring to form microemulsion, soaking 100g of the weighed carrier calcined at high temperature into the prepared microemulsion, shaking for 90min, filtering out residual liquid, drying at 80 ℃ for 5 hours, and calcining at 500 ℃ for 4 hours, thus obtaining the semi-finished catalyst V1.

(2) Weighing lithium nitrate to prepare a solution, soaking the semi-finished catalyst V1 prepared in the step (1) in the prepared lithium nitrate solution containing lithium, shaking, drying at 140 ℃ for 2 hours after the solution is completely absorbed, and roasting at 500 ℃ for 4 hours to obtain the semi-finished catalyst W1.

(3) Weighing palladium chloride, dissolving in deionized water, adjusting the pH value to 1.8, soaking the semi-finished catalyst W1 in the prepared Pd salt solution for 60min, drying at 100 ℃ for 5 hours, and roasting at 400 ℃ for 6 hours to obtain the semi-finished catalyst X1.

(4) Weighing palladium chloride, dissolving in 72mL of deionized water, adding 38g of n-hexane, adding CTAB19g and 16g of n-pentanol, fully stirring to form a microemulsion, dipping the semi-finished catalyst X1 prepared in the step (3) into the prepared microemulsion, shaking for 90min, filtering out residual liquid, drying at 80 ℃ for 5 hours, and roasting at 500 ℃ for 4 hours to obtain the catalyst.

Dynamic light Scattering measurement the particle size of the microemulsion prepared in step (1) was 92 nm.

And (3) reduction of the catalyst:

Performance of catalyst applied to reaction for removing phenylacetylene by selective hydrogenation of carbon eight fractions

The cracked gasoline carbon eight fraction used in the test is from a cracked gasoline unit of landlocked petrochemical company, and the properties thereof are shown in tables 2 and 3.

TABLE 2 cracked gasoline carbon octadistillate Properties

TABLE 3 high phenylacetylene cracked gasoline carbon eight cuts

The performance of the prepared catalyst was evaluated by using a fixed bed reactor, and the loading of the catalyst was 100 mL.

The catalyst evaluation results are shown in Table 4.

Catalysts

1, 2, 3, 4, 5, 6, 7 were derived from the catalysts prepared in examples 1, 2, 3, 4, 5, 6, 7, respectively, and comparative examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 were derived from the catalysts prepared in comparative examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, respectively.

TABLE 4 catalyst evaluation results

Note: the conversion rate of phenylacetylene (the content of phenylacetylene in the raw material-the content of phenylacetylene in the hydrogenated product)/the content of phenylacetylene in the raw material; styrene loss is the styrene content in the feed-hydrogenated product.

As can be seen from the comparison of the catalyst evaluation results in table 4:

it can be seen from the data analysis of the examples and comparative examples that the conversion rate of phenylacetylene in the hydrogenation product reaches up to 99.99% by selective hydrogenation of the carbon eight fraction with the hydrogenation method of the present invention, and the styrene is not lost but increased. After long cycle operation, it can be seen that the coke yield of the examples is significantly lower than the comparative examples. Therefore, the hydrogenation method has the advantages of higher phenylacetylene hydrogenation conversion rate, no loss and increase of styrene, obvious reduction of the catalyst coking amount and prolongation of the catalyst service life.

The present invention is capable of other embodiments, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. Carbon eight-fraction separationThe selective hydrogenation method for removing phenylacetylene is characterized by that it uses carbon octant fraction and H₂And (2) mixing, then feeding into an adiabatic reactor, wherein a selective hydrogenation catalyst is loaded in the adiabatic reactor, and the volume ratio of hydrogen to the inlet feed of the reactor is 1-100: 1, the temperature of a reaction inlet is 20-70 ℃, the reaction pressure is 0.1-1.0 MPa, and the liquid volume space velocity is 0.1-6 h^-1Cooling the reaction product, and separating in a gas-liquid separating tank; the carrier of the selective hydrogenation catalyst is alumina or mainly alumina, and has a bimodal pore distribution structure, wherein the pore diameter of a small pore is 10-25 nm, the pore diameter of a large pore is 50-250 nm, the catalyst at least contains Pd, Li, Ni and Cu, the mass of the catalyst is 100%, the content of Pd is 0.15-0.5 wt%, and the mass ratio of Li to Pd is 1-10: 1, the Ni content is 0.5-5 wt%, and the mass ratio of Cu to Ni is 0.1-1: 1.

2. The method for removing phenylacetylene through selective hydrogenation of carbon eight fraction according to claim 1, wherein in the preparation process of the catalyst, Ni and Cu are loaded in a microemulsion mode and distributed in macropores of a carrier; li is loaded by a solution method, and Pd is loaded by a solution method and a microemulsion method; the sequence of the solution method loading of Pd and the Ni/Cu loading is not limited, the step of loading Pd by the microemulsion is after the step of loading Ni/Cu by the microemulsion, and the step of loading Li by the solution method is after the step of loading Pd by the solution method.

3. The method for removing phenylacetylene through selective hydrogenation of carbon eight fractions according to claim 1, wherein the volume ratio of hydrogen to the reactor inlet feed is 10-50; the temperature of a reaction inlet is 20-50 ℃, the reaction pressure is 0.1-0.7 MPa, and the liquid volume space velocity is 1-4 h^-1。

4. The method for removing phenylacetylene through selective hydrogenation of carbon eight fraction according to claim 1, wherein the pore diameter of the small pore of the carrier is 10-25 nm, the pore diameter of the large pore is 50-250 nm, and the particle diameter of the microemulsion is controlled to be larger than the pore diameter of the small pore of the carrier and smaller than the pore diameter of the large pore of the carrier.

5. The method for removing phenylacetylene through selective hydrogenation of carbon eight fraction according to claim 1, wherein the microemulsion mode loading process comprises: dissolving precursor salt in water, adding oil phase, surfactant and cosurfactant, and stirring to form microemulsion, wherein the oil phase is alkane or cycloalkane, the surfactant is ionic surfactant and/or nonionic surfactant, and the cosurfactant is organic alcohol.

6. The method for removing phenylacetylene by selective hydrogenation of carbon eight fraction according to claim 1, characterized in that the oil phase is C6-C8 saturated alkane or cycloalkane, preferably cyclohexane, n-hexane; the surfactant is an ionic surfactant and/or a nonionic surfactant, preferably the nonionic surfactant, and more preferably polyethylene glycol octyl phenyl ether or cetyl trimethyl ammonium bromide; the cosurfactant is C4-C6 alcohol, preferably n-butanol and/or n-pentanol.

7. The method for removing phenylacetylene through selective hydrogenation of carbon eight fractions according to claim 4 or 5, wherein the microemulsion comprises 1 to 2 weight ratios of an aqueous phase and an oil phase, 0.4 to 0.7 weight ratio of a surfactant and an oil phase, and 1 to 1.2 weight ratios of a surfactant and a co-surfactant.

8. The method for removing phenylacetylene by selective hydrogenation of carbon eight fractions according to claim 1 or 2, wherein a catalyst preparation process is used, and the method comprises the following steps:

(1) dissolving precursor salts of Ni and Cu in water, adding an oil phase, a surfactant and a cosurfactant, fully stirring to form a microemulsion, and controlling the particle size of the microemulsion to be larger than the maximum pore diameter of a small pore and smaller than the maximum pore diameter of a large pore; adding the carrier into the prepared microemulsion, dipping for 0.5-4 hours, and filtering out residual liquid; drying at 60-150 ℃ for 1-6 hours, and roasting at 300-700 ℃ for 1-6 hours to obtain a semi-finished catalyst A;

(2) dissolving a precursor salt of Pd in water, adjusting the pH value to 1.5-2.5, adding the semi-finished catalyst A into a Pd salt solution, soaking and adsorbing for 0.5-4 h, drying at 60-150 ℃ for 1-6 h, and roasting at 300-700 ℃ for 1-6 h to obtain a semi-finished catalyst B;

(3) the Li loading is carried out by a saturated dipping method, the semi-finished product catalyst B is dried for 1-6 hours at the temperature of 60-150 ℃ after being loaded with Li, and is roasted for 1-6 hours at the temperature of 300-700 ℃ to obtain a semi-finished product catalyst C;

(4) dissolving Pd precursor salt in water, adding an oil phase, a surfactant and a cosurfactant, fully stirring to form a microemulsion, and controlling the particle size of the microemulsion to be larger than the pore diameter of a small pore of a carrier and smaller than the pore diameter of a large pore of the carrier; adding the semi-finished catalyst C into the prepared microemulsion, dipping for 0.5-4 hours, and filtering out residual liquid; drying at 60-150 ℃ for 1-6 hours, and roasting at 300-700 ℃ for 1-6 hours to obtain the required catalyst.

9. The method for removing phenylacetylene through selective hydrogenation of carbon eight fractions according to claim 1, wherein the selective hydrogenation catalyst is loaded in the adiabatic reactor, the content of Pd is 0.2-0.35 wt% based on 100% by mass of the catalyst, and the mass ratio of Li to Pd is 1-5: 1, the Ni content is 0.5-3.5%.

10. The method for removing phenylacetylene through selective hydrogenation of carbon eight fractions according to claim 1, wherein a fresh catalyst is subjected to reduction at a reduction temperature of 150 to 200 ℃ before being put into hydrogenation reaction.