CN114181032B

CN114181032B - Method for removing phenylacetylene through selective hydrogenation of carbon eight fractions

Info

Publication number: CN114181032B
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: 2024-09-06
Anticipated expiration: 2040-09-15
Also published as: CN114181032A

Abstract

The invention relates to a method for removing phenylacetylene by selective hydrogenation of carbon eight fractions, which comprises the steps of mixing the carbon eight fractions with H ₂, then feeding the mixture into an adiabatic reactor, loading a selective hydrogenation catalyst in the adiabatic reactor, and enabling the feeding volume ratio of hydrogen to the inlet of the reactor to be 1-100: 1, the temperature of a reaction inlet is 20-70 ℃, the reaction pressure is 0.1-1.0 MPa, the liquid volume airspeed is 0.1-6 h ^‑1, and a reaction product enters a gas-liquid separation tank for separation after being cooled; the carrier of the selective hydrogenation catalyst is alumina or mainly alumina, and has a bimodal pore distribution structure, wherein the pore diameter of small pores is 10-25 nm, the pore diameter of large pores is 50-250 nm, the catalyst at least contains Pd, li, ni, 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, ni content is 0.5-5 wt%, and mass ratio of Cu to Ni is 0.1-1:1. The method of the invention has high phenylacetylene hydrogenation conversion rate, styrene is not lost but also increased, the coking amount of the catalyst can be obviously reduced, and the service life of the catalyst can be prolonged.

Description

Method for removing phenylacetylene through selective hydrogenation of carbon eight fractions

Technical Field

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

Background

Styrene (ST) is an important monomer for producing polystyrene, ABS resin and styrene-butadiene rubber, and the technology for producing styrene by ethylbenzene dehydrogenation alone hardly meets the demand of the market for styrene, and the ethylbenzene dehydrogenation method has the disadvantage of high production cost. The extraction of styrene from the eight-carbon fraction, a byproduct of ethylene production by cracking, is becoming an attractive new way of increasing styrene production.

The pyrolysis gasoline is a byproduct of ethylene industry, the yield is about 60-70% of the ethylene productivity, the styrene is recovered by utilizing the extraction of the carbon eight fraction in the pyrolysis gasoline, a set of 1000kt/a ethylene device can obtain 24-42kt/a styrene, and meanwhile, 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 that of the styrene produced by the traditional ethylbenzene dehydrogenation, and the pyrolysis gasoline has very strong market competitiveness; meanwhile, due to the separation of the carbon eight fractions, 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 mug.g ^-1 Phenylacetylene (PA), and the chemical structure of ST is similar to that of PA, and the interaction between the two solvents is similar, so that the effective separation of ST and PA can not be realized through the existing extractive distillation process conditions. The presence of these phenylacetylene not only increases the catalyst consumption in the SM anionic polymerization, but also affects the chain length and polymerization rate, and also affects the color, odor and overall properties of the polymerization product. Therefore, before the styrene is extracted 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 hydrogenated product and the smaller the styrene loss rate are, which are important indexes for checking the catalyst and determine the benefit of the process for recovering styrene from the pyrolysis gasoline carbon eight fraction. Therefore, developing a method for removing phenylacetylene by selective hydrogenation of a carbon eight fraction with high phenylacetylene hydrogenation rate and low styrene loss rate becomes a 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, the phenylacetylene being hydrogenated to styrene in a hydrogenation reactor at a temperature of at least 60 ℃ and a pressure of 30 psig. The phenylacetylene hydrogenation rate of the technology is lower than about 70%, a large pressure drop appears in two weeks of operation, the operation cannot be continued, the catalyst has short service life and small strength, the catalyst is fragile, the loss rate of the styrene reaches about 3%, and the technology is not suitable for industrial application.

CN1087892a discloses a method and apparatus for catalytic purification of styrene monomer by hydrogenation by diluting hydrogen with nitrogen (molar ratio about 2:1 to 1:4), mixing hydrogen with selectivity improver for catalyst (e.g. carbon monoxide), using a multistage catalytic bed reactor or using a multistage reactor containing a single catalytic bed, respectively, to hydrogenate phenylacetylene impurity into styrene in the catalytic bed. The application range of the catalyst is that the phenylacetylene is in a lower concentration (about 300 ppm), and the phenylacetylene content in the pyrolysis gasoline carbon eight fraction is usually more than 5000 ppm.

CN101475438B discloses a method for selectively hydrogenating phenylacetylene in the presence of styrene, 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 can affect the pore channel structure of the catalyst and the service life of the catalyst.

CN1298376a discloses a process for hydrogenating phenylacetylene in a styrene-containing medium by means of a catalyst by using a nickel catalyst supported on a carrier having a nickel content of 10 to 25wt% and a bubbling bed reactor, but this patent describes only a process for selectively hydrogenating phenylacetylene in a process control, but the hydrogenation performance of the catalyst is not ideal under high severe 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 catalytic application thereof, which adopts intermittent operation mode to control phenylacetylene to be selectively reduced to produce styrene, 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 oligomers with wider molecular weight are generated, which are commonly called as 'colloid'. The colloid is adsorbed on the surface of the catalyst, and further forms coking to block the pore canal of the catalyst, so that reactants cannot diffuse to the surface of the active center of the catalyst, thereby reducing the activity of the catalyst and affecting the stability and service life of the catalyst. How to reduce the coking of the catalyst becomes an important index for evaluating the excellent performance of the catalyst.

Patent CN1736589 reports a Pd/gamma-Al ₂O₃ selective hydrogenation catalyst prepared by a complete adsorption impregnation method, and the catalyst has a large gum formation during use. Patent CN200810114744.0 discloses an unsaturated hydrocarbon selective hydrogenation catalyst and a preparation method thereof. The catalyst takes alumina as a carrier and palladium as an active component, and the rare earth, alkaline earth metal and fluorine are added to improve the impurity resistance and coking resistance of the catalyst, but the selectivity of the catalyst is not ideal.

The catalyst adopts a catalyst with single pore diameter distribution, and in the fixed bed reaction process, the catalyst selectivity is poor under the influence of internal diffusion. The carrier with double-peak pore distribution ensures high activity of the catalyst, and the existence of macropores can reduce the influence of internal diffusion and improve the selectivity of the catalyst.

Patent ZL971187339 discloses a hydrogenation catalyst, the carrier is a honeycomb carrier, which is a large-aperture carrier, and the selectivity of the catalyst is effectively improved. CN1129606 discloses a hydrocarbon conversion catalyst, its carrier catalyst includes alumina, nickel oxide, iron oxide, etc., and said catalyst includes two kinds of holes, one is used for raising catalytic reaction surface, and another is favorable for diffusion. The hydrogenation catalyst provided by the patent CN101433842 is characterized by having double-peak hole distribution, wherein the most probable radius of a small hole part is 2-50 nm, and the most probable radius of a large hole part is 50-250 nm.

Coking of the catalyst is an important factor affecting the catalyst life. The activity, selectivity and service life of the catalyst form the overall performance of the catalyst, and the methods listed above provide a better approach to 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. The carrier with a macroporous structure can improve the selectivity, but larger molecules generated by polymerization and chain growth reaction are easy to accumulate in macropores of the carrier, so that the catalyst is coked and deactivated, 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 a carbon eight fraction, in particular to a method for removing phenylacetylene by selective hydrogenation of a carbon eight fraction 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 carbon eight fractions, which comprises the steps of mixing the carbon eight fractions with H ₂, then entering an adiabatic reactor, loading a selective hydrogenation catalyst in the adiabatic reactor, and enabling the feeding volume ratio of hydrogen to the inlet of the reactor to be 1-100: 1, the temperature of a reaction inlet is 20-70 ℃, the reaction pressure is 0.1-1.0 MPa, the liquid volume space velocity is 0.1-6 h ^-1, and a reaction product enters a gas-liquid separation tank for separation after being cooled. The reactor is filled with a catalyst containing Pd, li, ni, cu components, the catalyst has a 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 small pores and smaller than the pore size of large pores.

The carrier of the selective hydrogenation catalyst is alumina or mainly alumina, and has a bimodal pore distribution structure, wherein the pore diameter of small pores is 10-25 nm, the pore diameter of large pores is 50-250 nm, the catalyst at least contains Pd, li, ni, 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, ni content 0.5-5 wt%, cu to Ni mass ratio 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 two methods, namely a solution method and a microemulsion method.

The method disclosed by the invention comprises the steps of 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 Duan Juere bubbling bed reactor, the ratio of hydrogen to reactor inlet feed volume is preferably from 10 to 50:1. the multi-section adiabatic bubbling bed reactor is an adiabatic bubbling bed reactor with two or more sections, and when the multi-section adiabatic bubbling bed reactor is adopted, the molar ratio of the hydrogen amount at the inlet of each section to phenylacetylene in the material to be hydrogenated at the inlet of the section 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 as the reaction is a liquid phase reaction, the requirement on the hydrogenation precision of phenylacetylene is high, and the styrene loss rate is strictly controlled, the selection of the reaction temperature and the reaction pressure is very important, the polymerization of alkene and alkyne can be accelerated when the temperature is too high, the progress of side reaction can be aggravated when the pressure is too high, and the styrene loss rate is increased; the reaction inlet temperature is generally 20-70 ℃, preferably 20-50 ℃; the reaction pressure is generally 0.1 to 1MPa, preferably 0.1 to 0.7MPa; the liquid space velocity is 0.1-6 h ^-1, preferably 1-4 h ^-1.

The idea of the hydrogenation method is as follows: the active component nickel/copper and a small amount of palladium are loaded in the macropores, and the active component palladium is loaded in the micropores. The phenylacetylene mainly undergoes selective hydrogenation reaction in small holes to generate styrene. The byproduct with larger molecular size generated in the reaction is mainly carbon sixteen fraction, and is easier to enter into the macropores, and saturation hydrogenation reaction is carried out under the action of the nickel active component in the macropores. Since these molecules are saturated by hydrogenation, their molecular chains are no longer growing and are thus easily carried out of the reactor by the feed. Copper has the function of forming an alloy with nickel, and reducing the reduction temperature of the nickel; the load of a small amount of palladium on the surface of nickel-copper can further greatly reduce the reduction temperature of nickel, 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.

The research shows that the catalyst has obviously raised coking resistance, and when phenylacetylene content in the inlet material reaches 1.3wt% and styrene content reaches 45%, the hydrogenating activity and selectivity of the catalyst are maintained at high level.

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

The method adopts a catalyst containing Pd, li, ni, cu in hydrogenation reaction. The catalyst carrier adopted by the method is alumina with a bimodal pore diameter distribution structure, the pore diameter of small pores of the carrier is 10-25 nm, and the pore diameter of large pores of the carrier is 50-250 nm.

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

The grain diameter of the microemulsion is larger than the largest pore diameter of the small hole and smaller than the largest pore diameter of the large hole. Because of the steric drag, these components can only enter the macropores, thus forming active sites with different hydrogenation effects in the macropores and micropores of the catalyst. The macroporous catalyst contains active center composed of Ni/Cu and Pd, which has good hydrogenation saturation effect on colloid molecules, so that colloid molecules entering the macropores are not polymerized, and therefore, the colloid molecules can be gradually removed from the reactor, and coking is not easy to occur.

The inventors found that if Ni and Cu were impregnated simultaneously, both would form an alloy, the reduction temperature of Ni would be reduced significantly due to the presence of Cu, up to 350 ℃ at the minimum, but this temperature is still higher for Pd catalysts. It was also found that a small amount of Pd on Ni/Cu catalyst, after supporting it, had a significant reduction in its reduction temperature, which could be reduced to 150℃which is fully acceptable for Pd catalysts, since the reduction temperature of Pd catalysts is typically 100-120℃and the catalyst can be run for a longer period of time in some cases at 120℃indicating that 120-150℃does not cause aggregation of the active components.

The preparation process of the catalyst adopted by the invention comprises the following steps:

the invention also provides a preparation method of the 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 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, soaking for 0.5-4 hours, filtering residual liquid, drying for 1-6 hours at 60-150 ℃, and roasting for 1-6 hours at 300-700 ℃ to obtain the semi-finished catalyst A.

(2) Preparing Pd precursor salt into active component impregnating solution, regulating pH to 1.5-2.5, adding the semi-finished catalyst A into the Pd active component impregnating solution, impregnating 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 the semi-finished catalyst B.

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

(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 catalyst C into the prepared microemulsion, soaking for 0.5-4 hours, filtering residual liquid, drying at 60-150 ℃ for 1-6 hours, and roasting at 300-700 ℃ for 1-6 hours to obtain the required catalyst.

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

The conditions of step (1) and step (4) may be the same or different, preferably the same, for one sample, so that a more uniform loading of Pd on the surface of the Ni/Cu alloy can be ensured.

The carrier in the step (1) is alumina or mainly alumina, and the Al ₂O₃ crystal form is preferably a theta and/or alpha mixed crystal form. The alumina content in the catalyst carrier is preferably 80% or more, and other metal oxides such as magnesium oxide, titanium oxide, etc. may be contained in the carrier.

The carrier in the step (1) can be spherical, tooth-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 nitrate salts, chloride salts or other soluble salts thereof.

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

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

The oil phase in the step (1) and the step (4) is C ₆～C₈ saturated alkane or cycloalkane, preferably cyclohexane or n-hexane.

The cosurfactant in the step (1) and the step (4) is C ₄～C₆ alcohols, preferably n-butanol and n-amyl alcohol.

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

The catalyst of the invention has the following characteristics: at the beginning of the hydrogenation reaction, the selective hydrogenation reaction of phenylacetylene mainly occurs in the pores because palladium has high hydrogenation activity and is mainly distributed in the pores. Along with the extension of the running time of the catalyst, a part of byproducts with larger molecular weight are generated on the surface of the catalyst, and the substances enter the macropores more due to larger molecular size, and the stay time is longer, so that double bond hydrogenation reaction can occur under the action of the nickel catalyst, aromatic hydrocarbon without isolated double bonds is generated, and substances with larger molecular weight are not generated.

The inventor also found that, by using the method, even if the reaction raw material contains more phenylacetylene and styrene, the colloid generation amount of the catalyst is greatly increased, the coking amount of the catalyst is not obviously increased, and the selective hydrogenation activity and the selectivity are not obviously reduced.

Drawings

FIG. 1 shows the temperature programmed reduction results of samples prepared by carrying Cu/Ni and Pd-Cu/Ni by a microemulsion method.

FIG. 2 is a process flow diagram of a carbon eight fraction selective hydrogenation phenylacetylene removal evaluation apparatus.

Wherein, the reference numerals:

1-a raw material tank;

2-a raw material pump;

3-a reactor;

4-a condenser;

5-a gas-liquid separator;

6, a product tank;

7-a wet gas meter.

Detailed Description

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

The analysis method comprises the following steps:

The catalyst of the invention adopts the following characterization method in the preparation process: a dynamic light scattering particle size analyzer, wherein the microemulsion particle size distribution of the Ni-Cu alloy is analyzed on the M286572 dynamic light scattering analyzer; performing N ₂ physical adsorption test of the carrier by using a Tristar 3000 physical adsorption instrument manufactured by Micrometrics corporation in America, and calculating the specific surface area, pore size distribution and pore volume of the sample by using a BET formula and a BJH equation respectively; the specific surface area and pore structure of the support were measured using a mercury porosimeter model 9510 from America microphone company; the Pd, li, ni and Cu contents of the catalyst were measured on an A240FS atomic absorption spectrometer.

The Cetyl Trimethyl Ammonium Bromide (CTAB), polyethylene glycol octyl phenyl ether (Triton X-100) and Sodium Dodecyl Sulfate (SDS) are used, and are hereinafter referred to as "CTAB" respectively.

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 bimodal pore distribution spherical alumina carrier was used, 4mm in diameter. 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 is 63%, and the specific surface area is 155m ²/g. 100g of the carrier was weighed.

And (3) preparing a catalyst:

(1) Nickel nitrate and copper chloride are weighed and dissolved in 43mL of deionized water, 43g of cyclohexane is added, 30g of Triton X-100 is added, 30g of n-butanol is added, the mixture is fully stirred to form microemulsion, 100g of the weighed and high-temperature roasted carrier is immersed into the prepared microemulsion, the mixture is shaken for 30min, residual liquid is filtered, and deionized water is used for washing. Drying at 80deg.C for 6 hr, and calcining at 400deg.C for 6 hr. Referred to as semi-finished catalyst a.

(2) Preparing palladium chloride into an active component impregnating solution, adjusting the pH to 2.0, impregnating the semi-finished catalyst A into the prepared Pd salt solution for 30min, drying at 80 ℃ for 6 hours, and roasting at 500 ℃ for 4 hours. Semi-finished catalyst B was obtained.

(3) Weighing lithium nitrate to prepare a solution, immersing the semi-finished catalyst B prepared in the step (2) in the prepared lithium nitrate solution, 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) And (3) weighing palladium chloride, dissolving in 43mL of deionized water, adding 43g of cyclohexane, adding 30g of Triton X-100, adding 30g of n-butanol, fully stirring to form microemulsion, placing the semi-finished catalyst C prepared in the step (3) in the prepared microemulsion, shaking for 30min, filtering out residual liquid, and washing with deionized water. Drying at 80deg.C for 6 hr, and calcining at 400deg.C for 6 hr. The desired catalyst is obtained.

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

Reduction of the catalyst:

Before use, the mixture is placed in a fixed bed reaction device, and is subjected to reduction treatment for 8 hours at the temperature of 200 ℃ by using mixed gas with the molar ratio of N ₂:H₂ =1:1.

Example 2

And (3) a carrier:

A commercially available bimodal pore distribution spherical alumina carrier was used, 3mm in diameter. After baking 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%, and the specific surface area is 140m ²/g. 100g of the carrier was weighed.

And (3) preparing a catalyst:

(1) Nickel nitrate and copper chloride are weighed and dissolved in 56mL of deionized water, 47g of normal hexane is added, 33g of CTAB is added, 28g of normal amyl alcohol is added, the mixture is fully stirred to form microemulsion, 100g of the weighed and high-temperature roasted carrier is immersed into the prepared microemulsion, the microemulsion is shaken for 90min, residual liquid is filtered out, the solution is dried at 100 ℃ for 5 hours, and the solution is roasted at 500 ℃ for 4 hours. Referred to as semi-finished catalyst D.

(2) Preparing palladium chloride into an active component impregnating solution, adjusting the pH to 1.8, impregnating the semi-finished catalyst D into the prepared Pd salt solution for 60min, drying at 100 ℃ for 5 hours, and roasting at 400 ℃ for 6 hours. Semi-finished catalyst E was obtained.

(3) Weighing lithium carbonate to prepare a solution, immersing the semi-finished catalyst E prepared in the step (2) in the prepared lithium carbonate 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 F.

(4) And (3) weighing palladium chloride, dissolving in 56mL of deionized water, adding 47g of normal hexane, adding 33g of CTAB (CTAB), adding 28g of normal amyl alcohol, stirring fully to form a microemulsion, immersing 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 5h, and roasting at 500 ℃ for 4h. The desired catalyst is obtained.

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

Reduction of the catalyst:

Before use, the mixture is placed in a fixed bed reaction device, and is subjected to reduction treatment for 8 hours at 150 ℃ by using mixed gas with a molar ratio of N ₂:H₂ =1:1.

Example 3

And (3) a carrier:

A commercially available bimodal pore distribution spherical alumina carrier was used, 4mm in diameter. 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 is 62%, and the specific surface area is 130m ²/g. 100g of the carrier was weighed.

And (3) preparing a catalyst:

(1) Nickel nitrate and copper chloride are weighed and dissolved in 59mL of deionized water, 45g of cyclohexane, 27g of SDS and 25g of n-butanol are added, the mixture is fully stirred to form microemulsion, 100g of the weighed and high-temperature roasted carrier is immersed into the prepared microemulsion, the microemulsion is shaken for 240min, residual liquid is filtered out, the solution is dried at 120 ℃ for 3 hours, and the solution is roasted at 600 ℃ for 2 hours. Referred to as semi-finished catalyst G.

(2) And (3) weighing palladium nitrate, dissolving the palladium nitrate in deionized water, adjusting the pH value to be 2, immersing the semi-finished catalyst G in the prepared Pd salt solution for 90min, drying at 120 ℃ for 4 hours, and roasting at 500 ℃ for 4 hours. Semi-finished catalyst H is obtained.

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

(4) And (3) weighing palladium nitrate, dissolving in 59mL of deionized water, adding 45g of cyclohexane, adding 27g of SDS, adding 25g of n-butanol, stirring fully to form a microemulsion, immersing 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 by dynamic light scattering measurement was 70nm.

Reduction of the catalyst:

Before use, the mixture is placed in a fixed bed reaction device, and is subjected to reduction treatment for 8 hours at the temperature of 150 ℃ by pure hydrogen.

Example 4

And (3) a carrier:

adopts a commercial bimodal pore distribution spherical alumina-titania carrier, the mass fraction of the titania is 20 percent, and the diameter is 3mm. After roasting for 4 hours at 1020 ℃, the bimodal pore diameter distribution ranges from 30nm to 40nm and from 60 nm to 230nm, the water absorption rate is 61%, and the specific surface area is 100m ²/g. 100g of the carrier was weighed.

And (3) preparing a catalyst:

(1) Nickel chloride and copper nitrate are weighed and dissolved in 73mL of deionized water, 43g of n-hexane is added, 17g of SDS is added, 15g of n-amyl alcohol is added, the mixture is fully stirred to form microemulsion, 100g of the weighed and high-temperature roasted carrier is immersed into the prepared microemulsion, the microemulsion is shaken for 180min, residual liquid is filtered out, the solution is dried at 80 ℃ for 4 hours, and the solution is roasted at 600 ℃ for 2 hours. Referred to as semi-finished catalyst K.

(2) Palladium chloride was weighed and dissolved in 73mL of deionized water, 43g of n-hexane was added, 17g of SDS was added, 15g of n-amyl alcohol was added, and the mixture was stirred well to form a microemulsion, the semi-finished catalyst K was immersed in the prepared microemulsion, shaken for 180min, the residual solution was filtered off, dried at 80 ℃ for 4 hours, and calcined at 600 ℃ for 2 hours. Referred to as semifinished catalyst M.

(3) And (3) weighing palladium chloride, dissolving in deionized water, regulating the pH value to be 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. To obtain the semi-finished catalyst N.

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

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

Reduction of the catalyst:

Example 5

And (3) a carrier:

Adopts a commercial bimodal pore distribution spherical alumina-magnesia carrier, wherein the mass fraction of magnesia is 3 percent, and the diameter is 3mm. After roasting for 4 hours at 1000 ℃, the bimodal pore size distribution ranges from 15 nm to 20nm and from 60 nm to 200nm, the water absorption is 60%, and the specific surface area is 100m ²/g. 100g of the carrier was weighed.

And (3) preparing a catalyst:

(1) And (3) weighing palladium chloride, dissolving in deionized water, regulating the pH value to be 2.5, 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 the semi-finished catalyst O.

(2) Weighing lithium nitrate to prepare a solution, immersing the semi-finished catalyst O prepared in the step (2) in the prepared lithium nitrate solution, 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 P.

(3) And (3) weighing nickel chloride and copper nitrate, dissolving in 68mL of deionized water, adding 40g of normal hexane, adding 20g of Triton X-100 g of normal hexanol, adding 18g of normal hexanol, stirring fully to form a microemulsion, immersing the semi-finished 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 catalyst Q.

(4) Palladium chloride is weighed and dissolved in 68mL of deionized water, 40g of normal hexane is added, triton X-10020g of normal hexanol is added, 18g of normal hexanol is added, the mixture is fully stirred to form microemulsion, the prepared semi-finished catalyst Q is immersed into the prepared microemulsion, the mixture is shaken for 180min, residual liquid is filtered out, the mixture is dried at 70 ℃ for 6 hours, and the mixture is baked at 600 ℃ for 2 hours. The desired catalyst is obtained.

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

Reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device, and is subjected to reduction treatment for 8 hours at the temperature of 180 ℃ by using mixed gas with the molar ratio of N ₂:H₂ =1:1.

Example 6

And (3) a carrier:

Adopts a commercial bimodal pore distribution spherical alumina-magnesia carrier, wherein the mass fraction of magnesia is 3 percent, and the diameter is 3mm. After roasting for 4 hours at 1000 ℃, the bimodal pore size distribution ranges from 15 nm to 20nm and from 60 nm to 200nm, the water absorption is 60%, and the specific surface area is 110m ²/g. 100g of the carrier was weighed.

And (3) preparing a catalyst:

(1) Nickel chloride and copper nitrate are weighed and dissolved in 69mL of deionized water, 46g of normal hexane is added, 23g of SDS is added, 20g of normal hexanol is added, the mixture is fully stirred to form microemulsion, 100g of the weighed and high-temperature roasted carrier is immersed into the prepared microemulsion, the microemulsion is shaken for 180min, residual liquid is filtered out, the solution is dried at 70 ℃ for 6 hours, and the solution is roasted at 600 ℃ for 2 hours. Referred to as semifinished catalyst R.

(2) And (3) weighing palladium chloride, dissolving in deionized water, adjusting the pH 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. To obtain a semi-finished catalyst S.

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

(4) And (3) weighing palladium chloride, dissolving in 69mL of deionized water, adding 46g of n-hexane, adding 23g of SDS, adding 20g of n-hexanol, stirring fully to form a microemulsion, immersing 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 by dynamic light scattering measurement was 76nm.

Reduction of the catalyst:

Example 7

And (3) a carrier:

A commercially available bimodal pore distribution spherical alumina carrier was used, 3mm in diameter. After being roasted for 4 hours at 1040 ℃, the bimodal pore diameter distribution ranges from 20nm to 25nm and from 70 nm to 250nm, the water absorption rate is 63%, and the specific surface area is 85m ²/g. 100g of the carrier was weighed.

And (3) preparing a catalyst:

(1) Nickel chloride and copper nitrate are weighed and dissolved in 72mL of deionized water, 38g of normal hexane is added, 19g of CTAB is added, 16g of normal amyl alcohol is added, the mixture is fully stirred to form microemulsion, 100g of the weighed and high-temperature roasted carrier is immersed into the prepared microemulsion, the microemulsion is shaken for 90min, residual liquid is filtered out, the solution is dried at 80 ℃ for 5 hours, and the solution is roasted at 500 ℃ for 4 hours, so that the semi-finished catalyst V is obtained.

(2) And (3) weighing palladium chloride, dissolving in deionized water, regulating the pH value to be 1.8, soaking the semi-finished catalyst V 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 W.

(3) Weighing lithium nitrate to prepare a solution, immersing the semi-finished catalyst W prepared in the step (2) in the prepared lithium nitrate 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 X.

(4) And (3) weighing palladium chloride, dissolving in 72mL of deionized water, adding 38g of normal hexane, adding 19g of CTAB (CTAB), adding 16g of normal amyl alcohol, stirring fully to form a microemulsion, immersing 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 desired catalyst.

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

Reduction of the catalyst:

Before use, the mixture is placed in a fixed bed reaction device, and is subjected to reduction treatment for 8 hours at the temperature of 150 ℃ by using mixed gas with the molar ratio of N ₂:H₂ =1:1.

Table 1 example catalyst component content

Comparative example 1

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

And (3) preparing a catalyst:

(1) Nickel nitrate was weighed and dissolved in 43mL of deionized water, 43g of cyclohexane was added, 30g of Triton X-100 was added, 30g of n-butanol was added, and the mixture was stirred well to form a microemulsion, 100g of the weighed and high temperature calcined support was immersed in the prepared microemulsion, and the microemulsion was shaken for 30 minutes, and the residual solution was filtered off and washed with deionized water. Drying at 80deg.C for 6 hr, and calcining at 400deg.C for 6 hr. Referred to as semi-finished catalyst A1.

(2) Palladium chloride is prepared into an active component impregnating solution, the pH value is adjusted to 2.0, then the semi-finished catalyst A1 is impregnated into the prepared Pd salt solution, and after 30 minutes of impregnation, the semi-finished catalyst A1 is dried for 6 hours at 80 ℃ and baked for 4 hours at 500 ℃. Semi-finished catalyst B1 was obtained.

(3) Weighing lithium nitrate to prepare a solution, immersing 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) And (3) weighing palladium chloride, dissolving in 43mL of deionized water, adding 43g of cyclohexane, adding 30g of Triton X-100, adding 30g of n-butanol, fully stirring to form microemulsion, placing the semi-finished catalyst C1 prepared in the step (3) in the prepared microemulsion, shaking for 30min, filtering residual liquid, and washing with deionized water. Drying at 80deg.C for 6 hr, and calcining at 400deg.C for 6 hr. The desired catalyst is obtained.

Reduction of the catalyst:

Before use, the mixture is placed in a fixed bed reaction device, and is subjected to reduction treatment for 8 hours at 200 ℃ by using mixed gas with a molar ratio of N ₂:H₂ =1:1.

Comparative example 2

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

And (3) preparing a catalyst:

(1) Nickel chloride was weighed and dissolved in 56mL of deionized water, 47g of n-hexane was added, 33g of CTAB was added, 28g of n-amyl alcohol was added, and the mixture was stirred well to form a microemulsion, 100g of the weighed and high-temperature calcined carrier was immersed in the prepared microemulsion, the mixture was shaken for 90 minutes, the residual solution was filtered off, dried at 100℃for 5 hours, and calcined at 500℃for 4 hours. Referred to as semi-finished catalyst D1.

(2) And (3) weighing palladium chloride, dissolving in deionized water, adjusting the 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. Semi-finished catalyst E1 was obtained.

(3) Weighing lithium carbonate and copper chloride to prepare a solution, immersing 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) And (3) weighing palladium chloride, dissolving in 56mL of deionized water, adding 47g of normal hexane, adding 33g of CTAB (CTAB), adding 28g of normal amyl alcohol, fully stirring to form a microemulsion, immersing 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.

Reduction of the catalyst:

before use, the mixture is placed in a fixed bed reaction device, and is subjected to reduction treatment for 8 hours at the temperature of 350 ℃ by using mixed gas with the molar ratio of N ₂:H₂ =1:1.

Comparative example 4

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

Comparative example 5

The same carrier 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 omitted.

And (3) preparing a catalyst:

(1) Nickel nitrate and copper chloride are weighed and dissolved in 59mL of deionized water, 45g of cyclohexane, 27g of SDS and 25g of n-butanol are added, the mixture is fully stirred to form microemulsion, 100g of the weighed and high-temperature roasted carrier is immersed into the prepared microemulsion, the microemulsion is shaken for 240min, residual liquid is filtered out, the solution is dried at 120 ℃ for 3 hours, and the solution is roasted at 600 ℃ for 2 hours. Referred to as semi-finished catalyst G1.

(2) And (3) weighing palladium nitrate, dissolving the palladium nitrate in deionized water, adjusting the pH value to be 2, immersing 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. Semi-finished catalyst H1 is obtained.

(3) Weighing lithium nitrate to prepare a solution, immersing 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.

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 preparation conditions were the same as in example 4, except that no Ni was used in the comparative example.

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

(2) Palladium chloride is weighed and dissolved in 73mL of deionized water, 43g of n-hexane is added, 17g of SDS is added, 15g of n-amyl alcohol is added, the mixture is fully stirred to form microemulsion, a semi-finished catalyst K1 is immersed into the prepared microemulsion, the mixture is shaken for 180min, residual liquid is filtered, the mixture is dried at 80 ℃ for 4 hours, and the mixture is baked at 600 ℃ for 2 hours. Referred to as semifinished catalyst M1.

(3) And (3) weighing palladium chloride, dissolving in deionized water, regulating the pH value to be 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. To obtain a semi-finished catalyst N1.

(4) Weighing lithium nitrate to prepare a solution, immersing the semi-finished catalyst N1 prepared in the step (3) in the prepared lithium nitrate solution, 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.

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 sequentially reversed.

And (3) preparing a catalyst:

(1) And (3) weighing palladium chloride, dissolving in deionized water, regulating the pH value to be 2.5, 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 the semi-finished catalyst O1.

(2) Weighing lithium nitrate to prepare a solution, immersing the semi-finished catalyst O1 prepared in the step (1) in the prepared lithium nitrate solution, 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) Palladium chloride is weighed and dissolved in 68mL of deionized water, 40g of normal hexane is added, triton X-10020g of normal hexanol is added, 18g of normal hexanol is added, the mixture is fully stirred to form microemulsion, the prepared semi-finished catalyst P1 is immersed into the prepared microemulsion, the mixture is shaken for 180min, residual liquid is filtered out, the mixture is dried at 70 ℃ for 6 hours, and the mixture is baked at 600 ℃ for 2 hours, so that the semi-finished catalyst Q1 is obtained.

(4) And (3) weighing nickel chloride and copper nitrate, dissolving in 68mL of deionized water, adding 40g of normal hexane, adding 20g of Triton X-100 g of normal 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.

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 ℃.

Reduction of the catalyst:

Before use, the mixture is placed in a fixed bed reaction device, and is subjected to reduction treatment for 8 hours at the temperature of 500 ℃ by using mixed gas with the molar ratio of N ₂:H₂ =1:1.

Comparative example 10

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

And (3) preparing a catalyst:

(1) Nickel chloride and copper nitrate are weighed and dissolved in 72mL of deionized water, 38g of normal hexane is added, 19g of CTAB is added, 16g of normal amyl alcohol is added, the mixture is fully stirred to form microemulsion, 100g of the weighed and high-temperature roasted carrier is immersed into the prepared microemulsion, the microemulsion is shaken for 90min, residual liquid is filtered out, the solution is dried at 80 ℃ for 5 hours, and the solution is roasted at 500 ℃ for 4 hours, so that the semi-finished catalyst V1 is obtained.

(2) Weighing lithium nitrate to prepare a solution, immersing the semi-finished catalyst V1 prepared in the step (1) in the prepared lithium nitrate 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 W1.

(3) And (3) weighing palladium chloride, dissolving in deionized water, regulating the pH value to be 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) And (3) weighing palladium chloride, dissolving in 72mL of deionized water, adding 38g of normal hexane, adding 19g of CTAB (CTAB), adding 16g of normal amyl alcohol, stirring fully to form a microemulsion, immersing 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 desired catalyst.

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

Reduction of the catalyst:

Performance of catalyst in carbon eight fraction selective hydrogenation phenylacetylene removal reaction

The eight fractions of pyrolysis gasoline used in the test were obtained from pyrolysis gasoline units of Lanzhou petrochemical company, and the properties are shown in tables 2 and 3.

Table 2 properties of the carbon eight fraction of pyrolysis gasoline

TABLE 3 high phenylacetylene pyrolysis gasoline carbon eight fraction

The prepared catalyst was subjected to performance evaluation using a fixed bed reactor, and the catalyst loading was 100mL.

The results of the catalyst evaluation are shown in Table 4. Catalysts 1, 2, 3, 4, 5, 6, 7 were derived from 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 catalysts prepared in comparative examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, respectively.

Table 4 results of catalyst evaluation

Note that: phenylacetylene conversion = (phenylacetylene content in raw material-phenylacetylene content in hydrogenated product)/phenylacetylene content in raw material; styrene loss = styrene content in feedstock-styrene content in hydrogenated product.

From the comparison of the catalyst evaluation results in Table 4, it can be seen that:

As can be seen from the data analysis of the examples and the comparative examples, the hydrogenation method of the invention is used for carrying out the selective hydrogenation of the carbon eight fraction to remove phenylacetylene, the hydrogenation conversion rate of phenylacetylene in the hydrogenation product is up to 99.99%, and the styrene is not only not lost, but also increased. After a long period of operation, the coking levels of the examples were found to be significantly lower than those of the comparative examples. Therefore, the hydrogenation method of the invention has higher phenylacetylene hydrogenation conversion rate, styrene is not lost but also increased, and simultaneously, the coking amount of the catalyst can be obviously reduced, and the service life of the catalyst is prolonged.

Of course, the present invention is capable of other various embodiments and its several details are capable of modification and variation in light of the present invention by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for removing phenylacetylene by selective hydrogenation of carbon eight fraction is characterized in that the carbon eight fraction is mixed with H ₂ and then enters an adiabatic reactor, a selective hydrogenation catalyst is loaded in the adiabatic reactor, and the feeding volume ratio of hydrogen to the inlet 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, the liquid volume airspeed is 0.1-6 h ^-1, and a reaction product enters a gas-liquid separation tank for separation after being cooled; the carrier of the selective hydrogenation catalyst is alumina or mainly alumina, and has a bimodal pore distribution structure, wherein the pore diameter of small pores is 10-25 nm, the pore diameter of large pores is 50-250 nm, the catalyst at least contains Pd, li, ni, 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, ni content is 0.5-5 wt%, and mass ratio of Cu to Ni is 0.1-1:1;

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 two methods of the solution method and a microemulsion method; controlling the particle size of the microemulsion to be larger than the pore diameter of the carrier small pore and smaller than the pore diameter of the carrier large pore; the sequence of loading Pd by a solution method and loading Ni/Cu is not limited, the step of loading Pd by the microemulsion is carried out after the step of loading Ni/Cu by the microemulsion, and the step of loading Li by the solution method is carried out after the step of loading Pd by the solution method.

2. The method for removing phenylacetylene by selective hydrogenation of carbon eight fraction according to claim 1, wherein the ratio of hydrogen to the inlet feed volume of the reactor is 10-50; the reaction inlet temperature is 20-50 ℃, the reaction pressure is 0.1-0.7 MPa, and the liquid volume airspeed is 1-4 h ^-1.

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

4. The method for removing phenylacetylene by selective hydrogenation of a carbon eight fraction according to claim 3, wherein the oil phase is C6-C8 saturated alkane or cycloalkane; the cosurfactant is C4-C6 alcohol.

5. The method for removing phenylacetylene by selective hydrogenation of a carbon eight fraction according to claim 3, wherein the oil phase is cyclohexane or n-hexane; the surfactant is polyethylene glycol octyl phenyl ether or cetyl trimethyl ammonium bromide; the cosurfactant is n-butanol and/or n-amyl alcohol.

6. The method for removing phenylacetylene by selective hydrogenation of eight carbon fractions according to claim 3 or 4, wherein the microemulsion has a weight ratio of water phase to oil phase of 1-2, a weight ratio of surfactant to oil phase of 0.4-0.7, and a weight ratio of surfactant to cosurfactant of 1-1.2.

7. The method for removing phenylacetylene by selective hydrogenation of carbon eight fraction according to claim 1, wherein the catalyst preparation process comprises the following steps:

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

(2) Dissolving Pd precursor salt in water, regulating the pH value to be 1.5-2.5, adding the semi-finished catalyst A into 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) Li is loaded by a saturated impregnation method, and the semi-finished catalyst B is dried for 1 to 6 hours at 60 to 150 ℃ and baked for 1 to 6 hours at 300 to 700 ℃ after Li is loaded, so as to obtain a semi-finished catalyst C;

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

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

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