A process for the selective hydrogenation of a c1-c3 cut

Abstract

The application provides a C1-C3 fraction selective hydrogenation method, wherein the C1-C3 fraction is from the overhead of a depropanizer of an ethylene device, and the process conditions of the hydrogenation reaction are as follows: the reactor inlet temperature is 90-130 ℃, the gas volume space velocity is 6000-20000 h ‑1 -1; the H2 content in the C1-C3 fraction is 10%-30%, the C2H4 content is 25%-40%, the C2H2 content is 0.4%-0.9%, the C3H6 content is 5%-11%, the PDMA content is 0.2%-1.2%, the CO content is 0.03%-0.2%, the butadiene content is ≦0.2%, and the balance is methane, ethane and propane. The hydrogenation method uses a catalyst with non-noble metal Fe as the main active component, and the process parameters are controlled, so that the CO fluctuation resistance of the catalyst is improved, the C1-C3 fraction selective hydrogenation efficiency is ensured, and the catalyst cost is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrogenation, and particularly relates to a C1-C3 fraction selective hydrogenation method. BACKGROUND

[0002] Ethylene obtained by steam cracking of petroleum hydrocarbon (such as ethane, naphtha, diesel, hydrogenated tail oil, etc.) contains 0.2%-2.5% of acetylene in mass fraction. When used for polymerization, acetylene in ethylene can reduce the activity of a polymerization catalyst and affect the physical properties of a polymer, and therefore must be removed. At present, the method of selective hydrogenation is generally used in industry to remove acetylene, and the catalysts used mainly include Pd, Pt, Au and other noble metal catalysts. In order to ensure that ethylene generated by hydrogenation of acetylene and the original ethylene in the raw material do not continue to be hydrogenated to generate ethane, and do not cause the loss of ethylene, it is necessary to ensure the high hydrogenation selectivity of the catalyst, so as to obtain good economic benefits.

[0003] According to the relative position of the carbon two hydrogenation reactor and the dealkylation, carbon two hydrogenation is divided into front hydrogenation and rear hydrogenation. The carbon two front hydrogenation reactor is before the de-methanization tower, and the hydrogenated material generally contains carbon one, carbon two and carbon three fractions. In addition to hydrogen and methane, the carbon one fraction also contains CO. The material composition of the front de-propane front hydrogenation is: H2 15%-30%, C2H6 4%-10%, C2H4 25%-40%, C2H2 0.4%-0.7%, C3H8 8%-11%, C3H8 1%-2%, propyne 0.1%-0.6%, propadiene 0.1%-0.6%, CO 0.04%-0.15%.

[0004] The noble metal catalyst has high activity, but is easy to generate green oil in the use process, which causes coking and deactivation of the catalyst, and affects the stability and service life of the catalyst. For example, Chinese patent document CN101664682 discloses a non-noble metal supported selective hydrogenation catalyst and a preparation method and application thereof, which comprises a carrier and a main active component and an auxiliary active component supported on the carrier, wherein the main active component is Ni, and the auxiliary active component is selected from at least one of Mo, La, Ag, Bi, Cu, Nd, Cs, Ce, Zn and Zr, the main active component and the auxiliary active component are in an amorphous state, the average particle size is <10 nm, the carrier is a porous material without oxidation, and the catalyst is prepared by a microemulsion method.

[0005] The catalysts for selective hydrogenation of acetylenes and dienes are prepared by loading noble metals such as palladium on porous inorganic material carriers (US4762956). In order to increase the selectivity of the catalyst and reduce the deactivation of the catalyst caused by the green oil produced by oligomerization during hydrogenation, the prior art uses the method of adding, for example, elements of Group IB as a cocatalyst component to the catalyst: Pd-Au (US4490481), Pd-Ag (US4404124), Pd-Cu (US3912789), or adding alkali metals or alkaline earth metals (US5488024), etc., and the carriers used are alumina, silica (US5856262), honeycomb cordierite (CN1176291), etc. US patent document US4404124 prepared a selective hydrogenation catalyst with a shell layer distribution of the active component palladium by a stepwise impregnation method, which can be applied to the selective hydrogenation of carbon di- and carbon tri- fractions to eliminate acetylene in ethylene and propyne and propadiene in propylene. US patent document US5587348 discloses a carbon di-hydrogenation catalyst with excellent performance prepared by using alumina as a carrier, adjusting the action of the cocatalyst silver and palladium, and adding alkali metals, chemically bonded fluorine. The catalyst has the characteristics of reducing the generation of green oil, improving the selectivity of ethylene, and reducing the amount of oxygen-containing compounds. US patent document US5519566 discloses a method for preparing a silver and palladium catalyst by wet reduction, by adding an organic or inorganic reducing agent to the impregnation solution to prepare a silver and palladium two-component selective hydrogenation catalyst.

[0006] The traditional carbon di-hydrogenation processes described above mostly use catalysts prepared by impregnation, and the active phase is mostly Pd, Ag bimetallic. This method has the following disadvantages: (1) The dispersion of the active component cannot be accurately controlled due to the influence of the pore structure of the carrier, and the randomness is strong. (2) The metal active component precursor is deposited on the surface of the carrier in the form of aggregates due to the influence of the surface tension of the impregnation solution and the solvation effect, and cannot form a uniform distribution. (3) Carbon di-hydrogenation has high selectivity requirements for the catalyst, and the traditional preparation method promotes the role of the Ag additive by increasing the amount of Ag, which hinders the transfer of hydrogen, increases the possibility of oligomerization, and increases the amount of green oil, affecting the service life of the catalyst. The occurrence of the above three phenomena easily leads to poor dispersion of the metal active component, low selectivity of the reaction, high green oil production, and further affects the overall performance of the catalyst.

[0007] To solve the above problems, Chinese patent document CN102205243B discloses a catalyst applied to carbon dioxide hydrogenation process. A specific polymer compound is adsorbed on the carrier to form a polymer coating layer on the surface of the carrier with a certain thickness. The compound with a functional group is reacted with the polymer to have a functional group capable of complexing with the active component. The complexation reaction of the active component on the functional group on the surface of the carrier ensures the order and high dispersion of the active component. However, the amount of the polymer compound adsorbed on the carrier is limited by the number of hydroxyl groups of the alumina. The complexation of the functionalized polymer with Pd is not strong, and sometimes the active component loading cannot meet the requirements. There is still part of the active component remaining in the impregnation solution, which increases the cost of the catalyst.

[0008] In order to improve the anti-coking performance of the catalyst and reduce the surface coking degree of the catalyst, in recent years, carbon dioxide selective hydrogenation catalysts and preparation methods using bimodal pore carriers and microemulsion method to load active components have been disclosed. For example, Chinese patent document CN104096572B discloses a selective hydrogenation catalyst, the carrier of which is mainly alumina and has a bimodal pore distribution structure, wherein the pore diameter of the small pores is within 50 nm, and the pore diameter of the large pores is 60-800 nm. The catalyst contains Pd 0.01-0.5 wt%, which is distributed in a shell layer with a thickness of 1-500 um; and contains Ni 0.2-5 wt%. The anti-coking component Ni is controlled to have a microemulsion particle size larger than the particle size of the small pores of the carrier by the microemulsion method, so that the Ni is mainly distributed in the large pores of the carrier. Chinese patent document CN104096573B discloses a preparation method of a hydrogenation catalyst. The catalyst carrier is mainly alumina and has a bimodal pore distribution structure. The catalyst contains Pd and Ni double active components. The anti-coking component Ni is in the form of microemulsion into the large pores of the carrier during the preparation of the catalyst, and the active component Pd is mainly distributed on the surface of the carrier, especially in the small pores. Chinese patent document CN104098426A discloses a carbon dioxide fraction selective hydrogenation method suitable for pre-depropanization and pre-hydrogenation process. The selective hydrogenation catalyst used in the method has a carrier of alumina or mainly alumina and has a bimodal pore distribution structure. The catalyst contains double active components Pd and Ni, and the anti-coking component Ni is mainly distributed in the large pores. Although the above-mentioned hydrogenation catalysts improve the anti-coking performance of the catalyst, the single component Ni in the large pores of the catalyst carrier is reduced at a temperature of 500°C or above. At this temperature, the reduction causes the active component Pd of the catalyst to aggregate, which greatly reduces the activity of the catalyst. In order to compensate for the loss of catalyst activity, the amount of active component needs to be increased, which leads to the decrease of the selectivity of the catalyst and the utilization rate of the active component.

[0009] Chinese patent document CN112675872A discloses a carbon fraction front deethanization front hydrogenation catalyst, the carrier is alumina or mainly alumina, and has a bimodal pore distribution structure, the specific surface area of the catalyst is 4-12 m2 / g, the pore diameter of the small pores is 55-72 nm, the pore diameter of the large pores is 300-640 nm, the catalyst contains at least Pd, Ni and Cu, wherein Pd and Ni are loaded in the form of microemulsion and solution, Cu is loaded in the form of microemulsion, the content of Pd loaded in the form of solution is 0.03-0.04% based on 100% of the mass of the catalyst, the weight ratio of Ni loaded in the form of solution to Pd loaded in the form of solution is 2.5-3.5, the content of Ni loaded in the form of microemulsion is 1.0-4.5%, and the weight ratio of Cu to Ni loaded in the form of microemulsion is 0.1-1.0; wherein, the Ni, Cu and Pd loaded in the form of microemulsion are mainly distributed in the large pores of 300-640 nm of the carrier. However, the content of the main active component Pd of the catalyst is relatively high, and the cost of the catalyst is high.

[0010] Chinese patent document CN112939718B discloses a method for removing alkynes in a front depropanization front hydrogenation process, the overhead effluent from the front depropanization column in an ethylene plant is introduced into an adiabatic bed reactor for selective hydrogenation to remove alkynes and dienes therein, the reaction conditions are: inlet temperature of 50-100℃ for the first stage, 50-100℃ for the second stage, and 50-100℃ for the third stage, pressure of 1.5-4.0 MPa, and space velocity of 10,000-20,000 h-1; the preferred hydrogenation conditions are: inlet temperature of 53-95℃ for the first stage, 55-95℃ for the second stage, and 60-95℃ for the third stage, pressure of 2.8-3.8 MPa, and space velocity of 12,000-18,000 h-1; the catalyst contains at least active components Pd, Au, Ni and Cu, wherein Pd is loaded in the form of microemulsion and solution, Ni and Cu are loaded in the form of microemulsion, and Au is loaded in the form of solution, the content of Pd loaded in the form of solution is 0.035-0.065%, preferably 0.037-0.045%, the weight ratio of Au to Pd loaded in the form of solution is 1.3-3.0, preferably 1.5-2.5, the content of Ni is 0.5-8.0%, preferably 2.0-5.8%, the weight ratio of Cu to Ni is 0.1-0.9, preferably 0.3-0.8, and the content of Pd loaded in the form of microemulsion is 1 / 150-1 / 250 of the content of Ni+Cu, the catalyst carrier is alumina or mainly alumina, and has a bimodal pore distribution structure. However, the main active components of the catalyst are Pd and Au, and the contents of Pd and Au are both relatively high, so the cost of the catalyst is high. SUMMARY

[0011] The application aims to provide a C1-C3 fraction selective hydrogenation method, which uses non-noble metal Fe as the main active component of the catalyst, improves the CO fluctuation resistance of the catalyst, ensures the C1-C3 fraction selective hydrogenation efficiency, and reduces the catalyst cost.

[0012] To achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0013] A C1-C3 fraction selective hydrogenation method, wherein the C1-C3 fraction is from the top of a depropanizer of an ethylene device, and the C1-C3 fraction and hydrogen are subjected to selective hydrogenation reaction in a fixed bed reactor containing a catalyst, and the process conditions of the selective hydrogenation reaction are as follows: the reactor inlet temperature is 90-130 ℃, the gas volume space velocity is 6000-20000 h-1, the volume content of CO in the C1-C3 fraction is 0.03%-0.2%, and the volume content of CO in the hydrogen is 0.0001%-0.01%. -1

[0014] The catalyst used in the selective hydrogenation reaction is as follows: the carrier is alumina or mainly alumina, the specific surface area is 3-15 m 2 / g, and the carrier has a bimodal pore size distribution characteristic, wherein the small pore size is 30-80 nm, and the large pore size is 300-800 nm; the active component comprises Pd, Ni and Fe, the Pd is loaded by a microemulsion method and a solution method, the Ni is loaded by the microemulsion method, and the Fe is loaded by the solution method; the Pd loaded by the solution method is loaded after the Fe loaded by the solution method, and the Pd loaded by the microemulsion method is loaded after the Ni loaded by the microemulsion method; the Pd and the Ni loaded by the microemulsion method are located in the large pores, and the Fe and the Pd loaded by the solution method are located in the small pores.

[0015] The content of the Ni is 0.5%-2.5%, the content of the Fe is 0.5%-1.5%, and the content of the Pd loaded by the solution method is 0.007%-0.015% based on 100% of the mass of the carrier; the content of the Pd loaded by the microemulsion method is 0.002-0.007 of the content of the Ni.

[0016] The catalyst is reduced at 180-230 ℃ before being put into the selective hydrogenation reaction, preferably for 4-12 h, and the reduction space velocity is 100-400 / h.

[0017] In the selective hydrogenation method, the Fe in the catalyst is the main active component of the selective hydrogenation. In the hydrogenation process, the CO in the crude hydrogen also participates in the reaction, mainly undergoing formylation reaction with hydrogen and olefins to generate compounds containing carbonyl groups. The adsorption strength of the compounds containing carbonyl groups on the alumina is higher than that of the olefins, and the compounds containing carbonyl groups stay on the catalyst for a longer time, which reduces the hydrogenation activity of the Fe.

[0018] ​And the catalyst needs to be reduced before hydrogenation reaction, including Pd, Ni component needs to be reduced from oxidation state to metal state under the action of hydrogen, the reduction temperature of Pd oxide is not higher than 150 DEG C, the reduction temperature of Ni oxide is 350-400 DEG C, which is too high for Pd, which is easy to cause the aggregation of active center, form larger size active center, and reduce the activity and selectivity of hydrogenation reaction.

[0019] Therefore, in this hydrogenation process, two key problems need to be solved: 1) the hydrogenation activity of Fe; 2) the growth of Pd particles caused by the reduction temperature of 350-400 DEG C.

[0020] The present inventors have found that the hydrogenation activity is greatly improved after loading Fe by solution method and then loading a small amount of Pd by solution method, which is speculated to be due to the small amount of Pd loaded by solution method playing a role in hydrogenation transfer rate, thereby accelerating the hydrogenation reaction. The present inventors have also found that the reduction temperature of NiO can be reduced to 180-230 DEG C by loading Ni by microemulsion method and then loading a small amount of Pd by microemulsion method.

[0021] The above hydrogenation method provided by the present application uses non-noble metal iron as the main active component and a catalyst with a carrier having a bimodal pore size distribution (large pores loaded with Ni and a small amount of Pd, and small pores loaded with Fe and a small amount of Pd). In addition to acetylene, ethylene and ethane, the hydrogenation material also contains hydrogen, methane and CO. During hydrogenation, the selective hydrogenation of acetylene mainly occurs in the small pores loaded with Fe and a small amount of Pd. The by-products generated in the hydrogenation reaction are more likely to enter the large pores of the catalyst due to their larger volume. Under the action of the Ni active center, the by-products undergo saturation hydrogenation to become alkanes, and no polymerization reaction occurs, thereby greatly reducing the coking rate.

[0022] Optionally, in the above C1-C3 fraction selective hydrogenation method provided by the present application, the H2 content is 10%-30%, the C2H4 content is 25%-40%, the C2H2 content is 0.4%-0.9%, the C3H6 content is 5%-11%, the PDMA content is 0.2%-1.2%, the CO content is 0.03%-0.2%, the butadiene content is ≤0.2%, and the balance is methane, ethane and propane, based on 100% of the total volume of the C1-C3 fraction.

[0023] Optionally, in the above C1-C3 fraction selective hydrogenation method provided by the present application, the selective hydrogenation reaction is single-stage hydrogenation, two-stage hydrogenation or three-stage hydrogenation.

[0024] Optionally, in the selective hydrogenation method for C1 to C3 fractions provided by the present invention, the process of loading Ni or Pd by microemulsion includes the following steps: dissolving the precursor salt of Ni or the precursor salt of Pd in ​​water to obtain an aqueous phase, and then adding an oil phase, a surfactant, and a co-surfactant to the aqueous phase and stirring to form a microemulsion.

[0025] Optionally, in the above-mentioned selective hydrogenation method for C1-C3 fractions provided by the present invention, microemulsion loading refers to traditional impregnation loading, where the impregnation liquid is a microemulsion; solution loading refers to traditional impregnation loading, where the impregnation liquid is a solution. The process of microemulsion loading of Ni or microemulsion loading of Pd recommended by the present invention includes the following steps: dissolving the precursor salt of Ni or the precursor salt of Pd in ​​water to obtain an aqueous phase, and then adding an oil phase, a surfactant, and a co-surfactant to the aqueous phase and stirring to form a microemulsion.

[0026] Optionally, in the selective hydrogenation method for C1-C3 fractions provided by the present invention, the particle size of the microemulsion is not lower than the maximum pore size of the micropores of the support but not higher than the maximum pore size of the macropores, for example, the particle size of the microemulsion is 300-800 nm. For a specific catalyst support with a bimodal pore size distribution, the pore size and macropore size are each a size range, while the particle size of the microemulsion being not lower than the maximum pore size of the micropores but not higher than the maximum pore size of the macropores means that the particle size of the microemulsion prepared during loading is not lower than the upper limit of the pore size range of a specific catalyst support and not higher than the upper limit of the pore size range of the macropores of the catalyst support. Preferably, the particle size of the microemulsion is greater than 300 nm (inclusive) and less than 800 nm (inclusive).

[0027] The microemulsion particles have a diameter larger than the pore size of the micropores but smaller than the maximum pore size of the macropores. Due to steric hindrance, these components can only enter the macropores, thus forming active centers with different hydrogenation effects in both the micropores and macropores of the catalyst. The macropores contain active centers composed of Ni, which have a good hydrogenation saturation effect on green oil molecules, preventing the green oil molecules entering the macropores from polymerizing and thus gradually moving out of the reactor, making it less prone to coking.

[0028] In the process of loading Ni or Pd using the microemulsion method recommended by this invention, the mass ratio of the aqueous phase to the oil phase is 2.0 to 4.5, the mass ratio of the surfactant to the oil phase is 0.10 to 0.4, and the mass ratio of the surfactant to the co-surfactant is 1.0 to 1.5.

[0029] Optionally, in the process of loading Ni or Pd using the microemulsion method recommended by the present invention, the oil phase is a C6-C8 saturated alkane or cycloalkanes, preferably cyclohexane or n-hexane.

[0030] The surfactant is an ionic surfactant and / or a non-ionic surfactant, preferably a non-ionic surfactant, more preferably polyethylene glycol octylphenyl ether or cetyltrimethylammonium bromide;

[0031] The co-surfactant is an organic alcohol; preferably C4-C6 alcohols, more preferably n-butanol and / or n-pentanol.

[0032] Optionally, the present application provides the above-mentioned selective hydrogenation method of C1-C3 fraction, the sequence of loading the active components into the carrier comprises the following steps:

[0033] microemulsion loading of Ni, solution method loading of Fe, solution method loading of Pd, microemulsion method loading of Pd; or

[0034] microemulsion loading of Ni, solution method loading of Fe, microemulsion method loading of Pd, solution method loading of Pd; or

[0035] solution method loading of Fe, microemulsion loading of Ni, solution method loading of Pd, microemulsion method loading of Pd; or

[0036] microemulsion loading of Ni, microemulsion method loading of Pd, solution method loading of Fe, solution method loading of Pd.

[0037] Specifically, the present application provides the above-mentioned selective hydrogenation method of C1-C3 fraction, the preparation of the catalyst comprises the following steps:

[0038] (1) dissolving the precursor salt of Ni in water, adding the oil phase, the surfactant and the co-surfactant, and fully stirring to form a microemulsion; the preparation conditions of the microemulsion are as follows: the mass ratio of the water phase to the oil phase is 2.0-4.5, the mass ratio of the surfactant to the oil phase is 0.10-0.4, and the mass ratio of the surfactant to the co-surfactant is 1.0-1.5; adding the calcined carrier into the prepared microemulsion for impregnation, drying after the microemulsion is completely absorbed, and calcining at 400-600°C to obtain a semi-finished catalyst A;

[0039] (2) dissolving the precursor salt of Fe in deionized water, the volume of the solution is equivalent to the water absorption amount of the carrier, adding the semi-finished catalyst A into the prepared solution, drying after the solution is completely absorbed, and calcining at 250-600°C to obtain a semi-finished catalyst B;

[0040] (3) dissolving the precursor salt of Pd in water, the volume of the solution is equivalent to the water absorption amount of the carrier, adjusting the pH to 1.2-2.7, adding the semi-finished catalyst B into the salt solution of Pd, drying after the solution is completely absorbed, and calcining at 400-550°C to obtain a semi-finished catalyst C;

[0041] (4) dissolving a precursor salt of Pd in water, adding an oil phase, a surfactant and a co-surfactant, and stirring to form a microemulsion; the conditions for preparing the microemulsion are: the mass ratio of the water phase to the oil phase is 2.0-4.5, the mass ratio of the surfactant to the oil phase is 0.10-0.4, and the mass ratio of the surfactant to the co-surfactant is 1.0-1.5; dipping the semi-finished catalyst C into the prepared microemulsion, and drying after the solution is completely absorbed, and then calcining at 400-550 ℃ to obtain the catalyst required by the semi-finished catalyst;

[0042] Wherein, step (1) and step (2) can be interchanged; step (3) and step (4) can be interchanged, step (4) is after step (1), and step (3) is after step (2).

[0043] The precursor salt of the metal in each step is a soluble salt, which can be a nitrate salt, a chloride salt or other soluble salt, such as the precursor salt of Pd can be selected from any one of the soluble palladium salts such as palladium chloride and palladium nitrate; the precursor salt of Ni can be selected from any one of the soluble nickel salts such as nickel chloride and nickel nitrate; and the precursor salt of Fe can be selected from any one of the soluble iron salts such as ferric nitrate and ferric chloride.

[0044] Optionally, in the C1-C3 fraction selective hydrogenation method provided by the present application, before the catalyst is put into the selective hydrogenation reaction, the reducing atmosphere is pure hydrogen or a mixture of hydrogen and nitrogen, and the reduction time is 2-15 h.

[0045] Compared with the prior art, the present application has the following beneficial effects:

[0046] Beneficial effect 1: The C1-C3 fraction selective hydrogenation method provided by the present application has good hydrogenation selectivity and long-period operation characteristics, which not only reduces the catalyst preparation cost, but also improves the target product yield, and greatly reduces the coking rate. Specifically, the main active component in the catalyst used is non-noble metal Fe, which reduces the content of Pd, reduces the cost of the catalyst, and makes the catalyst more convenient to produce and replace. Fe as the main active component, its adsorption strength of CO is lower than that of the main active component Pd of the traditional catalyst, which reduces the sensitivity of the reaction temperature to the CO content in the hydrogenation process, which is conducive to the stability of the acetylene removal reaction. Moreover, due to the significant reduction of the catalyst cost, the reaction can be operated at a lower space velocity to ensure that the reaction result is qualified.

[0047] Beneficial effect 2: In the C1-C3 fraction selective hydrogenation method provided by the application, the main active component of the catalyst used is Fe, and a small amount of Pd plays the role of adsorbing and transferring hydrogen. Due to the reduction of the content of noble metal, the cost of the catalyst is greatly reduced. Moreover, the ability of the catalyst to resist CO fluctuation is improved. Specifically, the outer electron arrangement of the main active component Fe is close to half full, and its empty orbital can accept π electrons or lone pair electrons from olefin molecules or CO. Therefore, CO can play a role in adjusting the selectivity of the active center. In addition, the number of outer empty orbitals of Fe atoms is lower than that of Pd atoms, and the adsorption strength of CO on Fe atoms is lower than that on Pd atoms. Therefore, the active center composed of Fe as the main active component has lower sensitivity to CO content fluctuation than the active center composed of Pd as the main active component. Therefore, the former active center no longer needs to add Ag, so the preparation cost of the catalyst can be reduced, and the range of CO that can be adapted is larger.

[0048] More importantly, when Pd is usually used as a hydrogenation catalyst, the temperature exceeds 130°C, which has the risk of flying temperature. The reason is that at this temperature, ethylene may undergo a polymerization reaction, releasing a large amount of reaction heat, which promotes the rapid increase of the temperature in the reactor. In addition, there is a large amount of hydrogen in the material, which accelerates the hydrogenation reaction and the polymerization reaction, so that the temperature cannot be controlled and the temperature flies. In the present application, the active center composed of Fe as the main active component has lower hydrogenation activity and will not cause rapid self-polymerization of ethylene when the temperature exceeds 120°C, so it is not easy to cause the reactor to fly. Therefore, the highest temperature in the reactor can reach 135°C, that is, the activity temperature range is also wider. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 Particle size distribution diagram of the iron microemulsion prepared for step (1) of Example 1 of the application. DETAILED DESCRIPTION

[0050] The application will be described in detail below by means of examples. It is necessary to point out here that the following examples are only used to further illustrate the application and cannot be understood as limiting the protection scope of the application. Those skilled in the art can make some non-essential improvements and adjustments to the application according to the above content of the application.

[0051] If the specific experimental steps or conditions are not specified in the examples, they can be carried out according to the conventional experimental steps described in the literature in the art or the operation or conditions. If the reagents or instruments used are not specified by the manufacturer, they are all conventional reagent products that can be obtained by purchase.

[0052] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, and these corresponding changes and modifications shall all belong to the protection scope of the claims of the present application.

[0053] The experimental instruments, raw materials and chemical reagents involved in the following examples and comparative examples are shown in Table 1 and Table 2.

[0054] Table 1 Experimental instruments

[0055]

[0056]

[0057] Table 2 Experimental raw materials and chemical reagents

[0058]

[0059] Analytical test method:

[0060] Specific surface: GB / T-5816;

[0061] Active component content in catalyst: atomic absorption method;

[0062] Ni, Pd microemulsion particle size distribution: dynamic light scattering particle size analyzer;

[0063] The hydrogen and acetylene contents at the outlet and inlet of the reactor were measured by using Agilent 7890A gas chromatograph.

[0064] The conversion rate and selectivity were calculated according to the following formula:

[0065] Acetylene conversion rate (%) = [(acetylene content at the inlet of the reactor - acetylene content at the outlet of the reactor) / acetylene content at the inlet of the reactor] x 100%

[0066] Ethylene selectivity = [(ethylene content at the outlet of the reactor - ethylene content at the inlet of the reactor) / (acetylene content at the inlet of the reactor - acetylene content at the outlet of the reactor)] x 100%

[0067] The initial conversion rate refers to the acetylene conversion rate within 24 hours from the start of feeding into the reactor.

[0068] The present application is further illustrated by the following examples, but it is not considered to be limited to this.

[0069] Example 1

[0070] Support: A commercially available bimodal pore size distribution spherical support with a diameter of 4 mm was weighed. After calcination at 1350°C, the pore size distribution ranges were 45-65 nm and 410-560 nm, respectively, the water absorption was 35%, and the specific surface area was 3 m 2 / g. 100 g of the support was weighed.

[0071] Catalyst preparation:

[0072] (1) 3.11 g of nickel nitrate was weighed and dissolved in 30 ml of deionized water, 14 g of cyclohexane, 3.08 g of Triton X-100, and 2.57 g of n-butanol were added, and the mixture was stirred to form a microemulsion. 100 g of the support was immersed in the prepared microemulsion, and after the emulsion was completely absorbed, the mixture was dried at 60°C and calcined at 600°C for 5 h to obtain a semi-finished catalyst A.

[0073] (2) 2.17 g of iron nitrate was weighed and dissolved in 35 g of deionized water, and then the semi-finished catalyst A was added to the Ni salt solution. After the solution was completely absorbed, the mixture was aged for 4 h, dried at 120°C, and calcined at 400°C for 6 h to obtain a semi-finished catalyst B.

[0074] (3) 16.67 mg of palladium chloride was weighed and dissolved in 35 g of deionized water, and the pH was adjusted to 1.5. Then, the semi-finished catalyst B was added to the Pd salt solution, and the mixture was aged for 10 h, dried at 120°C, and calcined at 400°C for 4 h to obtain a semi-finished catalyst C.

[0075] (4) 8.33 mg of palladium chloride was weighed and dissolved in 30 ml of deionized water, 14 g of cyclohexane, 3.08 g of Triton X-100, and 2.57 g of n-butanol were added, and the semi-finished catalyst C was immersed in the prepared microemulsion. After the emulsion was completely absorbed, the mixture was dried at 60°C for 6 h and calcined at 450°C for 4 h to obtain the desired catalyst.

[0076] The particle sizes of the microemulsion emulsions prepared in steps (1) and (4) were both 400 nm. Among them, Figure 1 is the particle size distribution graph of the iron microemulsion prepared in step (1). It can be seen from Figure 1 that the particle sizes of the iron microemulsion are mostly in a narrow range of 390-410 nm, indicating that the particle size distribution of the microemulsion reaches an ideal degree, which is beneficial to the loading of active components.

[0077] By atomic absorption spectrometry, the Pd content in the catalyst was 0.015%, the Ni content was 1.0%, and the Fe content was 0.5%, based on the mass of the support being 100%. Among them, the Pd content loaded by the solution method was 0.01%, and the Pd content loaded by the emulsion method was 0.005%.

[0078] The catalyst was placed in a fixed bed reactor and reduced at 180°C for 4 hours in an atmosphere of hydrogen / nitrogen (molar ratio) = 1:1, the reduction space velocity being 200 / h.

[0079] Comparative Example 1

[0080] Support: same as in Example 1.

[0081] Catalyst preparation: similar to Example 1, except that in Comparative Example 1 no Fe was loaded, and the preparation of the catalyst in this comparative example was as follows:

[0082] (1) 3.11 g of nickel nitrate was dissolved in 35 g of deionized water, and then 100 g of the support was added to the Ni salt solution. After the solution was completely absorbed, it was aged for 4 hours, dried at 120°C, and calcined at 400°C for 6 hours to obtain semi-finished catalyst A1.

[0083] (2) 16.67 mg of palladium chloride was dissolved in 35 g of deionized water, and the pH was adjusted to 1.5. The semi-finished catalyst A1 was then added to the Pd salt solution, aged for 10 hours, dried at 120°C, and calcined at 400°C for 4 hours to obtain semi-finished catalyst B1.

[0084] (3) 8.33 mg of palladium chloride was dissolved in 30 ml of deionized water, and 14 g of cyclohexane, 3.08 g of Triton X-100, and 2.57 g of n-butanol were added to the 30 ml of deionized water. The semi-finished catalyst B1 was then immersed in the prepared microemulsion, and after the emulsion was completely absorbed, it was dried at 60°C for 6 hours and calcined at 450°C for 4 hours to obtain the desired catalyst.

[0085] The particle size of the microemulsion prepared in step (3) was 400 nm as determined by dynamic light scattering.

[0086] The Pd content of the catalyst was 0.015% and the Ni content was 1.0% based on the mass of the support being 100%, as determined by atomic absorption spectrometry. The Pd content loaded by the solution method was 0.01%, and the Pd content loaded by the emulsion method was 0.005%.

[0087] The catalyst was placed in a fixed bed reactor and reduced at 180°C for 4 hours in an atmosphere of hydrogen / nitrogen (molar ratio) = 1:1, the reduction space velocity being 200 / h.

[0088] Experimental Example 1

[0089] The composition of the hydrogenation material is shown in Table 3 below.

[0090] Table 3

[0091]

[0092] Evaluation process conditions: space velocity 6000 / h, reactor inlet temperature: 130°C, reaction process is single-stage isothermal. The evaluation results are shown in Table 4.

[0093] Table 4 Evaluation results

[0094]

[0095] From the results of Example 1 and Comparative Example 1, it can be seen that in Example 1, the isothermal single-stage reactor can completely remove acetylene at an inlet temperature of 130°C. And the selectivity reaches 78.54%. After 1500 hours, the reaction results change very little; while in the comparative example, the initial acetylene conversion rate is only 23.14%, although the change after 1500 hours is also very small, but the acetylene conversion efficiency of Comparative Example 1 is significantly lower than that of Example 1. The reason is that there is no Fe loaded in the comparative example, and the active center aggregate formed by a small amount of Pd has a spatial scale smaller than the optimal scale, which makes the hydrogenation activity of the catalyst insufficient.

[0096] Example 2

[0097] Support: A commercially available bimodal pore size distribution spherical support with an alumina content of 90% and a titania content of 10% and a diameter of 4 mm was weighed. After calcination at 1310°C, the pore size distribution ranges were 55-80 nm and 500-800 nm, respectively, the water absorption rate was 35%, and the specific surface area was 3.1 m 2 / g. 100 g of the support was weighed.

[0098] Catalyst preparation:

[0099] (1) 1.55 g of nickel nitrate was weighed and dissolved in 30 ml of deionized water, 6.67 g of n-hexane, 0.67 g of CTAB, and 0.47 g of n-pentanol were added, and the mixture was stirred to form a microemulsion. The calcined 100 g of the support was immersed in the prepared microemulsion, and after the emulsion was completely absorbed, it was dried at 100°C, and calcined at 500°C for 5h to obtain a semi-finished catalyst D.

[0100] (2) 2.17 g of iron nitrate was weighed and dissolved in 35 g of deionized water, and the semi-finished catalyst D was added to the prepared Fe salt solution. After the solution was completely absorbed, it was aged for 4 hours, dried at 100°C, and calcined at 250°C for 6 hours to obtain a semi-finished catalyst E;

[0101] (3) 15.15 mg of palladium nitrate was dissolved in 45 g of deionized water, and the pH was adjusted to 1.7. Then the semi-finished catalyst E was added to the Pd salt solution, aged for 10 hours, dried at 120°C, and calcined at 450°C for 4 hours to obtain a semi-finished catalyst F;

[0102] (4) Weigh 3.33 mg of palladium chloride into 30 ml of deionized water, add 6.67 g of n-hexane, 0.67 g of CTAB, and 0.47 g of n-pentanol, and fully stir to form a microemulsion. Immerse the semi-finished catalyst F into the prepared microemulsion, and fully stir until the emulsion is completely absorbed. Dry at 100°C, and calcine at 550°C for 4 hours to obtain the desired catalyst.

[0103] The particle size of the microemulsion prepared in steps (1) and (4) is 800 nm, as determined by dynamic light scattering.

[0104] The prepared catalyst is determined by atomic absorption spectrometry, and the Pd content is 0.009%, the Ni content is 0.5%, and the Fe content is 0.5%, calculated based on 100% of the carrier. The Pd content loaded by the solution method is 0.007%, and the Pd content loaded by the emulsion method is 0.002%.

[0105] Before use, place in a fixed bed reaction device, and reduce at a temperature of 190°C for 12 h using a mixed gas with a molar ratio of N2:H2=1:1, and a reduction space velocity of 150 / h.

[0106] Comparative Example 2

[0107] Carrier: The same as in Example 2.

[0108] Catalyst preparation: Similar to Example 2, except that in Comparative Example 2, the Pd was not loaded by the solution method. Catalyst preparation:

[0109] Catalyst preparation:

[0110] (1) Weigh 1.55 g of nickel nitrate into 30 ml of deionized water, add 6.67 g of n-hexane, 0.67 g of CTAB, and 0.47 g of n-pentanol, and fully stir to form a microemulsion. Immerse the 100 g of calcined carrier into the prepared microemulsion, and fully stir until the emulsion is completely absorbed. Dry at 100°C, and calcine at 500°C for 5 h to obtain the semi-finished catalyst D1.

[0111] (2) Weigh 2.17 g of iron nitrate into 35 g of deionized water, and add the semi-finished catalyst D1 into the prepared Fe salt solution. After the solution is completely absorbed, age for 4 hours, dry at 100°C, and calcine at 250°C for 6 hours to obtain the semi-finished catalyst E1.

[0112] (3) Weigh 3.33 mg of palladium chloride into 30 ml of deionized water, add 6.67 g of n-hexane, 0.67 g of CTAB, and 0.47 g of n-pentanol, and stir thoroughly to form a microemulsion. Immerse the semi-finished catalyst E1 into the prepared microemulsion, and dry at 100°C until the emulsion is completely absorbed. Then, calcine at 550°C for 4 hours to obtain the desired catalyst.

[0113] The particle size of the microemulsion prepared in steps (1) and (3) is 800 nm, as determined by dynamic light scattering.

[0114] The prepared catalyst is determined by atomic absorption spectrometry, and the Pd content is 0.002%, the Ni content is 0.5%, and the Fe content is 0.5%, based on 100% of the carrier.

[0115] Before use, place it in a fixed bed reaction device, and reduce it at a temperature of 190°C for 12 hours using a mixed gas with a molar ratio of N2:H2=1:1, and a reduction space velocity of 150 / h.

[0116] Experimental Example 2

[0117] The composition of the hydrogenated material is shown in Table 5 below.

[0118] Table 5

[0119]

[0120] Evaluation process conditions: 2-stage adiabatic reactor, inlet temperature of the first stage 95°C, inlet temperature of the second stage reactor 120°C, and space velocity 8000 / h. The evaluation results are shown in Table 6.

[0121] Table 6 Evaluation Results

[0122]

[0123]

[0124] From the evaluation results in the above table, in Example 2, the acetylene at the outlet of the second stage has been completely converted, and the ethylene selectivity after 2000 hours has decreased very little compared to the initial value. In Comparative Example 2, the acetylene conversion, ethylene and propylene selectivity after 2000 hours have all decreased very little, indicating that the performance of the catalyst in this hydrogenation method is well maintained, especially since the butadiene content in the material is as high as 0.15%, which is a relatively high amount.

[0125] The low acetylene conversion in Comparative Example 2 indicates that the pure active component Fe is insufficient in adsorbing and activating hydrogen, resulting in insufficient hydrogenation activity.

[0126] Example 3

[0127] Catalyst Preparation:

[0128] Commercially available bimodal pore size distribution spherical alumina support, diameter 4mm, 80% alumina, 20% magnesia. After calcination at 1250°C, the pore size distribution ranges are 30-55nm and 310-460nm respectively, water absorption 50%, specific surface area 15m 2 / g, 100g of the support was weighed.

[0129] Catalyst preparation:

[0130] (1) 2.49g of nickel nitrate was weighed and dissolved in 50ml of deionized water, 20.g of n-hexane, 8.0g of CTAB, and 8.0g of n-pentanol were added, and the mixture was stirred to form a microemulsion. 100g of the support was immersed in the prepared microemulsion, and after the emulsion was completely absorbed, the mixture was calcined at 400°C for 7h to obtain a semi-finished catalyst H.

[0131] (2) 6.52g of iron nitrate was weighed and dissolved in 50g of deionized water, and then the semi-finished catalyst H was added to the prepared Fe salt solution. After the solution was completely absorbed, it was aged for 6 hours, dried at 120°C, and calcined at 400°C for 6 hours to obtain a semi-finished catalyst J.

[0132] (3) 8.66mg of palladium nitrate was weighed and dissolved in 50ml of deionized water, 20.g of n-hexane, 8..0g of CTAB, and 8.0g of n-pentanol were added, and the mixture was stirred to form a microemulsion. The semi-finished catalyst J was immersed in the prepared microemulsion, and after the emulsion was completely absorbed, it was dried at 60°C, and calcined at 550°C for 6 hours to obtain a semi-finished catalyst K.

[0133] (4) 16.67mg of palladium chloride was weighed and dissolved in 51g of deionized water, and the pH was adjusted to 2.0. Then the semi-finished catalyst K was added to the Pd salt solution, aged for 10 hours, dried at 120°C, and calcined at 400°C for 4 hours to obtain the desired catalyst.

[0134] The particle size of the microemulsion prepared in steps (1) and (3) was 80nm, as determined by dynamic light scattering.

[0135] The prepared catalyst was determined by atomic absorption spectrometry, and the Pd content was 0.014%, the Ni content was 0.8%, and the Fe content was 1.5%, based on 100% of the support. Among them, the Pd content loaded by the solution method was 0.010%, and the Pd content loaded by the emulsion method was 0.004%.

[0136] Before use, it was placed in a fixed bed reaction device and reduced at a temperature of 210°C for 12h using a mixed gas with a molar ratio of N2:H2=1:1, and the reduction space velocity was 350 / h.

[0137] Comparative Example 3

[0138] Support: same as example 3.

[0139] Catalyst preparation: similar to example 3, except that in comparative example 3 no Ni was supported.

[0140] Catalyst preparation:

[0141] (1) 6.52 g of iron nitrate was weighed into 50 g of deionized water, and 100 g of the calcined support was added to the prepared Fe salt solution. After the solution was completely absorbed, it was aged for 6 hours, dried at 120°C, and calcined at 400°C for 6 hours to obtain a semi-finished catalyst J1.

[0142] (2) 8.66 mg of palladium nitrate was weighed into 50 ml of deionized water, 20 g of n-hexane, 8.0 g of CTAB, and 8.0 g of n-pentanol were added, and the mixture was stirred to form a microemulsion. The semi-finished catalyst J1 was immersed in the prepared microemulsion, and after the emulsion was completely absorbed, it was dried at 60°C and calcined at 550°C for 6 hours to obtain a semi-finished catalyst K1.

[0143] (3) 16.67 mg of palladium chloride was weighed into 51 g of deionized water, and the pH was adjusted to 2.0. The semi-finished catalyst K1 was added to the Pd salt solution, aged for 10 hours, dried at 120°C, and calcined at 400°C for 4 hours to obtain the desired catalyst.

[0144] The particle size of the microemulsion prepared in step (2) was 80 nm, as determined by dynamic light scattering.

[0145] The prepared catalyst was determined by atomic absorption spectrometry, and the Pd content was 0.014%, the Fe content was 1.5%, based on 100% of the support. Among them, the Pd content loaded by the solution method was 0.010%, and the Pd content loaded by the emulsion method was 0.004%.

[0146] Before use, it was placed in a fixed bed reaction device and reduced at a temperature of 210°C for 12 h with a mixed gas of molar ratio N2:H2=1:1, and the reduction space velocity was 350 / h.

[0147] Experimental example 3

[0148] The raw material composition was evaluated, as shown in Table 7.

[0149] Table 7 Hydrogenation material composition

[0150]

[0151] Evaluation of process conditions:

[0152] Three adiabatic reactors, the inlet temperature of the first reactor is 90°C, the inlet temperature of the second reactor is 110°C, the inlet temperature of the third reactor is 115°C, and the space velocity is 15000 / h.

[0153] Table 8 test results

[0154]

[0155] From the results of Table 8, it can be seen that in Example 3, the second reactor can still convert acetylene completely after 1500 hours, while in the comparative example, the second reactor can convert acetylene completely in the initial stage, but the acetylene conversion rate of the second reactor is only 98.52% after 1500 hours, and the third reactor can convert acetylene completely, and the acetylene conversion rate of the first reactor decreases by nearly 10 percentage points, indicating that the catalyst coking is serious. From the material composition, the butadiene content is 0.14%, which should be a relatively high content of butadiene, causing the catalyst to coke.

[0156] Under the same material composition, the acetylene and PDMA conversion rates and ethylene and propylene selectivity of the three reactors in the example only have a small decrease, indicating that the catalyst coking is very little.

[0157] The reason for the difference between the two should be that the catalyst in the comparative example does not load Ni, and the catalyst does not have the function of saturating and hydrogenating butadiene or butadiene polymers, and these heavy fractions can continue to polymerize, eventually forming coke, causing the catalyst performance to decrease.

[0158] Example 4

[0159] Carrier: A commercially available bimodal pore size distribution spherical alumina carrier with a diameter of 3 mm is used. After calcination at 1330°C, the bimodal pore size distribution ranges from 50 to 70 nm and 430 to 720 nm, the water absorption rate is 38%, and the specific surface area is 5 m 2 / g. 100 g of the carrier is weighed.

[0160] Catalyst preparation:

[0161] (1) 5.52 g of nickel chloride is dissolved in 35 ml of deionized water, 8.75 g of n-hexane, 1.4 g of Triton X-100, and 1.08 g of n-octanol are added, and the mixture is stirred to form a microemulsion. The weighed 100 g of the carrier is immersed in the prepared microemulsion, and after the emulsion is completely absorbed, it is dried at 120°C for 6 hours and calcined at 550°C for 3 hours to obtain a semi-finished catalyst M.

[0162] (2) 3.49 g of ferric chloride is weighed and dissolved in 38 g of deionized water, and then the semi-finished catalyst M is added to prepare a good Fe salt solution. After the solution is completely absorbed, it is aged for 1 hour, dried at 100°C, and calcined at 350°C for 8 hours to obtain a semi-finished catalyst N.

[0163] (3) Weigh 12.5 mg of palladium chloride into 38 g of deionized water, adjust the pH to 2.5, and then add the semi-finished catalyst N into the prepared Pd salt solution, age for 12 hours, dry at 100°C, and calcine at 450°C for 6 hours to obtain the semi-finished catalyst O;

[0164] (4) Weigh 27.17 mg of palladium nitrate into 40 ml of deionized water, add 8.75 g of n-hexane, 1.4 g of Triton X-100, and 1.08 g of n-octanol, and fully stir to form a microemulsion. Dip the semi-finished catalyst O into the prepared microemulsion, and after 4 hours of immersion, filter out the remaining liquid. Wash with deionized water until neutral, dry at 120°C for 6 hours, and calcine at 450°C for 6 hours to obtain the desired catalyst.

[0165] The particle size of the microemulsion prepared in steps (1) and (4) is 600 nm, as determined by dynamic light scattering.

[0166] The prepared catalyst is determined by atomic absorption spectrometry, and the Pd content is 0.020%, the Ni content is 2.5%, and the Fe content is 1.2%, calculated based on the carrier being 100%. Among them, the Pd content loaded by the solution method is 0.0075%, and the Pd content loaded by the emulsion method is 0.0125%.

[0167] Before use, place it in a fixed bed reaction device, use a mixed gas with a molar ratio of N2:H2 = 1:1, reduce at a temperature of 200°C for 12 hours, and the reduction space velocity is 200 / h.

[0168] Comparative Example 4

[0169] Carrier: The same as in Example 4.

[0170] Catalyst: Similar to Example 4, except that the emulsion method for loading Pd is omitted.

[0171] Catalyst preparation:

[0172] (1) Weigh 5.52 g of nickel chloride into 35 ml of deionized water, add 8.75 g of n-hexane, 1.4 g of Triton X-100, and 1.08 g of n-octanol, and fully stir to form a microemulsion. Dip 100 g of the carrier into the prepared microemulsion, and after the emulsion is completely absorbed, dry at 120°C for 6 hours, and calcine at 550°C for 3 hours to obtain the semi-finished catalyst M1.

[0173] (2) Weigh 3.49 g of ferric chloride into 38 g of deionized water, and then add the semi-finished catalyst M1 into the prepared Fe salt solution. After the solution is completely absorbed, age for 1 hour, dry at 100°C, and calcine at 350°C for 8 hours to obtain the semi-finished catalyst N1.

[0174] (3) Weigh 12.5 mg of palladium chloride into 38 g of deionized water, adjust the pH to 2.5, and then add the semi-finished catalyst N1 into the prepared Pd salt solution, age for 12 hours, dry at 100°C, and calcine at 450°C for 6 hours to obtain the desired catalyst.

[0175] The particle size of the microemulsion emulsion prepared in step (1) is 600 nm, as determined by dynamic light scattering.

[0176] The prepared catalyst is determined by atomic absorption spectrometry, and the Pd content is 0.0075%, the Ni content is 2.5%, and the Fe content is 1.2%, calculated based on 100% of the carrier.

[0177] Before use, place in a fixed bed reaction device, reduce at a temperature of 200°C for 12 h using a mixed gas with a molar ratio of N2:H2=1:1, and the reduction space velocity is 200 / h.

[0178] Experimental Example 4

[0179] The material composition is evaluated, and Table 9 shows the results.

[0180] Table 9 Hydrogenation material composition

[0181]

[0182] The process conditions are evaluated as follows: single-stage isothermal reactor, reactor inlet temperature 110°C, space velocity 10000 / h, and the specific evaluation results are shown in Table 10.

[0183] Table 10 Evaluation results

[0184] Example 4 Comparative Example 4 Initial acetylene conversion; % 100 100 Initial PDMA conversion, % 64.25 64.34 Initial ethylene selectivity, % 78.64 78.49 Initial propylene selectivity, % 93.14 93.27 2000 hour acetylene conversion, % 100 97.31 2000 hour PDMA conversion, % 63.87 58.23 2000 hour ethylene selectivity, % 76.53 68.29 2000 hour propylene selectivity, % 92.67 89.71 Catalyst weight gain after 2000 hours, % 3.27 8.92

[0185] From the results in Table 10, it can be seen that the acetylene conversion rates of both Example 4 and Comparative Example 4 reach 100% at the beginning of the reaction, and there is little difference in ethylene selectivity, PDMA conversion rate, and propylene selectivity. However, after 2000 hours, the acetylene conversion rate of Example 4 is still 100%, while the acetylene conversion rate of Comparative Example 4 is only 97.31%, and the acetylene at the reactor outlet is significantly over-standard, and the reaction results are already unqualified. In addition, the PDMA conversion rate, ethylene selectivity, and propylene selectivity in the comparative example all decrease significantly. From the catalyst weight gain, the catalyst weight gain in Comparative Example 4 is more than 1 time that of Example 4. The results show that without loading Pd using the emulsion method, the catalyst cokes seriously. The reason is that the catalyst reduction temperature is 200°C, and without Pd, the reduction temperature of NiO on the surface is generally 450°C. At the given reduction temperature in this experiment, NiO is not reduced and does not have the function of hydrogenating butadiene, etc., resulting in serious coking of the catalyst in Comparative Example 4 and a significant decrease in catalyst performance.

[0186] Example 5

[0187] Support: A commercially available bimodal pore size distribution spherical support with a diameter of 3.5 mm was used, which was composed of 95% alumina and 5% magnesia. The support was calcined at 1310°C, and had a specific surface area of 12 m 2 / g, a water absorption of 48%, a small pore size of 40-60 nm, and a large pore size of 360-500 nm. 100 g of the support was weighed.

[0188] Preparation of the catalyst:

[0189] (1) 2.65 g of nickel chloride was weighed and dissolved in 45 ml of deionized water, 15.51 g of cyclohexane, 5.12 g of Triton X-10, and 4.66 g of n-butanol were added, and the mixture was stirred to form a microemulsion. 100 g of the support was immersed in the prepared microemulsion, and after the emulsion was completely absorbed, the mixture was dried at 120°C for 6 hours and calcined at 450°C for 5 hours to obtain a semi-finished catalyst P.

[0190] (2) 3.91 g of iron nitrate was weighed and dissolved in 48 g of deionized water, and the semi-finished catalyst P was added to the prepared Fe salt solution. After the solution was completely absorbed, the mixture was aged for 4 hours, dried at 110°C, and calcined at 350°C for 2 hours to obtain a semi-finished catalyst Q.

[0191] (3) 5.67 mg of palladium chloride was weighed and dissolved in 48 g of deionized water, and the pH was adjusted to 1.9. The semi-finished catalyst Q was added to the prepared Pd salt solution, and after the solution was completely absorbed, the mixture was aged for 12 hours, dried at 100°C, and calcined at 400°C for 8 hours to obtain a semi-finished catalyst R.

[0192] (4) 6 mg of palladium chloride was weighed and dissolved in 45 ml of deionized water, 15.51 g of cyclohexane, 5.12 g of Triton X-10, and 4.66 g of n-butanol were added, and the mixture was stirred to form a microemulsion. The semi-finished catalyst R was immersed in the prepared microemulsion, and after the emulsion was completely absorbed, the mixture was dried at 120°C for 6 hours and calcined at 480°C for 6 hours to obtain the desired catalyst.

[0193] The particle size of the microemulsion prepared in steps (1) and (4) was 200 nm, as determined by dynamic light scattering.

[0194] The prepared catalyst was measured by atomic absorption spectrometry, and the Pd content was 0.007%, the Ni content was 1.2%, and the Fe content was 0.9%, based on 100% of the support. Among them, the Pd content loaded by the solution method was 0.0034%, and the Pd content loaded by the emulsion method was 0.0036%.

[0195] Before use, place in a fixed bed reaction device, reduce for 12 h at 190°C using a mixed gas of N2:H2=1:1, reduction space velocity: 150 / h.

[0196] Comparative Example 5

[0197] Support: same as Example 5.

[0198] Catalyst: same as Example 5.

[0199] The particle size of the microemulsion emulsion prepared in steps (1), (4) was 200 nm, as determined by dynamic light scattering.

[0200] The prepared catalyst was determined by atomic absorption spectrometry, and the Pd content was 0.007%, the Ni content was 1.2%, and the Fe content was 0.9%, calculated based on the support being 100%. Among them, the Pd content loaded by the solution method was 0.0034%, and the Pd content loaded by the emulsion method was 0.0036%.

[0201] Before use, place in a fixed bed reaction device, reduce for 12 h at 190°C using a mixed gas of N2:H2=1:1, reduction space velocity: 150 / h.

[0202] Experimental Example 5

[0203] The material composition was evaluated, and is shown in Table 11.

[0204] Table 11 Evaluation results of comparative examples

[0205]

[0206] Evaluation of process conditions

[0207] Example 5: single-stage adiabatic reactor, reactor inlet temperature 95°C, space velocity 10000 / h,

[0208] Comparative Example 5: single-stage adiabatic reactor, reactor inlet temperature 85°C, space velocity 10000 / h,

[0209] The evaluation results are shown in Table 12.

[0210] Table 12 Evaluation results

[0211] Example 5 Comparative Example 5 Initial acetylene conversion; % 100 98.64 Initial PDMA conversion, % 54.32 48.69 1000 hour acetylene conversion, % 100 98.51 1000 hour PDMA conversion, % 53.65 47.85 Catalyst weight gain after 1000 hours, % 2.60 2.14

[0212] From Table 12, in Example 5, the single-stage adiabatic reaction can completely convert acetylene, and still maintains good acetylene removal effect after 1000 hours of operation; the reactor inlet temperature of the comparative example is 85℃, and acetylene cannot be completely converted. After 1000 hours, the coking amount of the catalyst in Comparative Example 5 is still lower than that of the example (catalyst weight gain), indicating that the catalyst coking is not the factor affecting the reaction result, and the catalyst activity in the comparative example is insufficient, which is inferred to be caused by the low reactor inlet temperature, resulting in low catalyst activity in the comparative example. That is, the low reactor inlet temperature leads to low catalyst activity in the comparative example. Compared with the traditional method using Pd as the hydrogenation active component, the reactor inlet temperature of the hydrogenation method of the present application is significantly higher.

[0213] Example 6

[0214] Support: commercially available bimodal pore size distribution spherical support with a diameter of 4 mm. After calcination at 1325℃, the specific surface area is 12m 2 / g, the water absorption rate is 48%, the small pore size is 40-65 nm, and the large pore size is 390-540 nm. 100 g of the support is weighed.

[0215] Catalyst preparation:

[0216] (1) 4.35 g of iron nitrate is dissolved in 48 g of deionized water, and 100 g of the weighed support is added to the prepared Fe salt solution. After the solution is completely absorbed, it is aged for 6 hours, dried at 120℃, and calcined at 600℃ for 8 hours to obtain semi-finished catalyst S.

[0217] (2) 2.21 g of nickel chloride is dissolved in 40 ml of deionized water, 15.38 g of n-hexane, 5.69 g of Triton X-10, and 4.07 g of n-octanol are added, and the mixture is stirred to form a microemulsion. Then, the semi-finished catalyst S is immersed in the prepared microemulsion, and after the emulsion is completely absorbed, it is dried at 80℃ and calcined at 600℃ for 8 hours to obtain semi-finished catalyst T.

[0218] (3) 21.7 mg of palladium nitrate is dissolved in 48 g of deionized water, and the pH is adjusted to 2.3. Then, the semi-finished catalyst T is added to the Pd salt solution, aged for 10 hours, dried at 120℃, and calcined at 550℃ for 4 hours to obtain semi-finished catalyst U.

[0219] (4) 15.0 mg of palladium nitrate is dissolved in 40 ml of deionized water, 15.38 g of n-hexane, 5.69 g of Triton X-10, and 4.07 g of n-pentanol are added, and the mixture is stirred to form a microemulsion. Then, the semi-finished catalyst U is immersed in the prepared microemulsion, and after the emulsion is completely absorbed, it is dried at 80℃ and calcined at 400℃ for 4 hours to obtain the desired catalyst.

[0220] The particle size of the microemulsion emulsion prepared in steps (2), (4) was 100 nm, as determined by dynamic light scattering.

[0221] The prepared catalyst was determined by atomic absorption spectrometry, and the Pd content was 0.017%, the Ni content was 1.0%, and the Fe content was 1.0% based on 100% of the carrier. Among them, the Pd content loaded by the solution method was 0.010%, and the Pd content loaded by the emulsion method was 0.007%.

[0222] Before use, it was placed in a fixed bed reaction device, reduced with pure hydrogen at a temperature of 210°C for 8h, and the reduction space velocity was 150 / h.

[0223] Comparative Example 6

[0224] Carrier: the same as Example 6, catalyst preparation: the same as Example 6.

[0225] The particle size of the microemulsion emulsion prepared in steps (2), (4) was 100 nm, as determined by dynamic light scattering.

[0226] The prepared catalyst was determined by atomic absorption spectrometry, and the Pd content was 0.017%, the Ni content was 1.0%, and the Fe content was 1.0% based on 100% of the carrier. Among them, the Pd content loaded by the solution method was 0.010%, and the Pd content loaded by the emulsion method was 0.007%.

[0227] Before use, it was placed in a fixed bed reaction device, reduced with pure hydrogen at a temperature of 210°C for 8h, and the reduction space velocity was 150 / h.

[0228] Experimental Example 6

[0229] The hydrogenation material composition is shown in Table 13.

[0230] Table 13 Hydrogenation material composition

[0231]

[0232]

[0233] Process conditions:

[0234] Two-stage adiabatic reactor, space velocity 12000 / h.

[0235] Temperature: before 1500 hours, the inlet temperature of the first reactor was 95°C, and the inlet temperature of the second reactor was 110°C; after 1500 hours, the inlet temperature of the first reactor was 95°C, and the inlet temperature of the second reactor was 125°C.

[0236] The evaluation results are shown in Table 14.

[0237] Evaluation results of Table 14

[0238]

[0239] From the results of Table 14, the conversion of Example 6 in the first stage is 68.61%, and the conversion of Comparative Example 6 in the first stage is 46.28%, which is more than 20 percentage points lower than Example 6; the second stage of Example 6 completely converts acetylene, and the second stage of Comparative Example 6 does not completely convert acetylene. Since the catalysts are the same and the reaction process conditions are also the same, the difference in the reaction results should be caused by the difference in the materials. As shown in Table 13, the CO content in the reaction material of Comparative Example 6 is 1 time higher than that of Example 6. Although Fe has lower sensitivity to CO than Pd, too high CO still seriously inhibits the hydrogenation activity of Fe, or the competition of high CO content and hydrogen for adsorption on Pd atoms intensifies, which inhibits the transfer of hydrogen to the Fe active center, resulting in that acetylene cannot be completely converted in the second stage reactor of the comparative example; after 1500 hours, the inlet temperature of the second stage reactor is increased by 10°C, and the ethylene selectivity in the second stage of Example 6 is more than 6 percentage points lower than that at 1000 hours, while the decrease in Comparative Example 6 is only 2 percentage points, indicating that high CO content is still beneficial to improving selectivity. However, if the CO content is too high, even if the inlet temperature of the second stage is increased by 15°C, Comparative Example 6 still cannot completely convert acetylene. From the catalyst weight gain after 2000 hours, the weight gain of the catalysts in the comparative example and the example is not significant, which does not seriously affect the performance of the catalyst. Therefore, it can be concluded that the reason why acetylene is not completely converted in the second stage of the comparative example is that the CO content in the material is too high.

[0240] Example 7

[0241] Support: commercially available spherical alumina support with a diameter of 2 mm. After calcination at 1300°C for 4h, the water absorption rate is 44%, the small pore size is 40-65 nm, the large pore size is 390-540 nm, and the specific surface area is 9 m 2 / g. 100 g of the support was weighed.

[0242] Catalyst preparation:

[0243] (1) 6.22 g of nickel nitrate was weighed and dissolved in 40 ml of deionized water, 11.42 g of cyclohexane, 3.08 g of Triton X-10, and 2.8 g of n-butanol were added, and the mixture was stirred to form a microemulsion. 100 g of the weighed support was immersed in the prepared microemulsion, and after the emulsion was completely absorbed, the mixture was dried at 120°C for 6 hours and calcined at 550°C for 5h to obtain a semi-finished catalyst P.

[0244] (2) Weigh 6.52 g of ferric nitrate into 48 g of deionized water, then add the semi-finished catalyst P to prepare the Fe salt solution, and after the solution is completely absorbed, age for 4 hours, dry at 110°C, and calcine at 280°C for 4 hours to obtain the semi-finished catalyst Q;

[0245] (3) Weigh 16.67 mg of palladium chloride into 48 g of deionized water, adjust the pH to 1.9, then add the semi-finished catalyst Q into the prepared Pd salt solution, and after the solution is completely absorbed, age for 12 hours, dry at 100°C, and calcine at 520°C for 8 hours to obtain the semi-finished catalyst R;

[0246] (4) Weigh 16.67 mg of palladium chloride into 40 ml of deionized water, add 11.42 g of cyclohexane, 3.08 g of Triton X-10, and 2.8 g of n-butanol, and fully stir to form a microemulsion, then immerse the semi-finished catalyst R into the prepared microemulsion, and after the emulsion is completely absorbed, dry at 120°C for 6 hours, and calcine at 500°C for 6 hours to obtain the desired catalyst.

[0247] The particle size of the microemulsion prepared in steps (1) and (4) is 300 nm, as determined by dynamic light scattering.

[0248] The prepared catalyst is determined by atomic absorption spectrometry, and the Pd content is 0.02%, the Ni content is 2.0%, and the Fe content is 1.5%, calculated based on the carrier being 100%. Among them, the Pd content loaded by the solution method is 0.010%, and the Pd content loaded by the emulsion method is 0.01%.

[0249] Before use, place it in a fixed bed reaction device, reduce it with pure hydrogen at a temperature of 220°C for 8h, and the reduction space velocity is 150 / h.

[0250] Comparative Example 7

[0251] The carrier and the catalyst are the same as in Example 7.

[0252] The particle size of the microemulsion prepared in steps (1) and (4) is 300 nm, as determined by dynamic light scattering.

[0253] The prepared catalyst is determined by atomic absorption spectrometry, and the Pd content is 0.02%, the Ni content is 2.0%, and the Fe content is 1.5%, calculated based on the carrier being 100%. Among them, the Pd content loaded by the solution method is 0.010%, and the Pd content loaded by the emulsion method is 0.01%.

[0254] Before use, place it in a fixed bed reaction device, reduce it with pure hydrogen at a temperature of 220°C for 8h, and the reduction space velocity is 150 / h.

[0255] Experimental Example 7

[0256] The material composition is evaluated and shown in Table 15.

[0257] Table 15 Material composition

[0258]

[0259] Process conditions: The reaction process is three-stage adiabatic, the first-stage reactor inlet temperature is 90°C, the second-stage inlet temperature is 100°C, and the third-stage inlet temperature is 120°C.

[0260] The space velocity of Example 7 is 20000 / h, and the space velocity of Comparative Example 7 is 5000 / h. The specific evaluation results are shown in Table 16.

[0261] Table 16 Evaluation results

[0262]

[0263] As can be seen from Table 16, in the initial stage of the reaction, the acetylene conversion rate of the first stage of the comparative example reaches 79.54%, which is very high, but the selectivity is already lower than 70%; the acetylene is completely converted in the second stage of Comparative Example 7, and the selectivity is close to 50%, that is, among the converted acetylene, 50% of the ethylene is also hydrogenated to ethane, and the tendency of ethylene hydrogenation is very obvious. After the third stage, there is no inhibition of acetylene hydrogenation of ethylene, and the temperature is too high, CO cannot effectively inhibit the hydrogenation of ethylene, resulting in a runaway temperature.

[0264] In Example 7, when the CO content is high, the acetylene conversion rate in the first stage cannot reach 50%, and the selectivity is as high as more than 94%. The acetylene is completely converted in the third stage, and the selectivity of the third stage is also more than 60%. This shows that under the conditions of high CO and high space velocity, the hydrogenation activity of acetylene is obviously inhibited, but the selectivity is very high. That is, the space velocity of 5000 / h in the comparative example is lower than the minimum (critical) space velocity at which the reaction can be stably operated, the reaction activity is too high and the selectivity is too low, resulting in a runaway temperature. Since the third stage of Comparative Example 7 runs away, the temperature of the second stage of Example 7 and Comparative Example 7 is reduced to 95°C, and the temperature of the third stage is reduced to 105°C. That is, the reduction is as much as 15°C, and the evaluation is carried out again, and the results are shown in Table 17.

[0265] Table 17 Evaluation results of Example 7 and Comparative Example 7 after temperature reduction

[0266]

[0267]

[0268] From the data in the above table, it can be seen that after 1500 hours, the activity and selectivity of the first and second stages of Example 7 slightly decreased; but the activity and selectivity of the first stage of Comparative Example 7 decreased very obviously, and the activity of the second stage of Comparative Example 7 also decreased very obviously. The reason is that under the condition of very low space velocity, the activity of the first stage of Comparative Example 7 is too high, and butadiene polymerizes before being hydrogenated. As shown in Table 17, after 1500 hours, the weight of the catalyst of the first stage of Comparative Example 7 increased by more than 13%, that is, butadiene formed a large amount of coking in the first reactor of Comparative Example 7, resulting in a significant decrease in the activity and selectivity. Part of the macromolecules formed by the polymerization of butadiene also entered the second reactor, affecting the performance of the catalyst in the second reactor. If the running time is long enough, the activity and selectivity of the second reactor will decrease, and the selectivity of the third reactor will also decrease, eventually resulting in the leakage of acetylene.

[0269] Therefore, the space velocity index is a relatively key index for the hydrogenation reaction of the C1-C3 fraction.

[0270] Compared with the conventional hydrogenation method of the C1-C3 fraction, the minimum space velocity in the hydrogenation method of the present application is significantly lower, which is of great significance for ensuring the safety of the hydrogenation reaction. In the selective hydrogenation of the C1-C3 fraction in an industrial device, a lower space velocity is generally used at the initial stage of operation to avoid the waste of burning materials. If the critical (minimum) space velocity value is high, the actual space velocity is likely to be lower than the critical space velocity, and a temperature runaway accident will occur, resulting in great economic losses and even a serious safety accident of device explosion.

[0271] Example 8 and Comparative Example 8

[0272] The catalysts used in Example 8 and Comparative Example 8 are the same as those in Example 7.

[0273] Experimental Example 8

[0274] The composition of the evaluation material is shown in Table 18

[0275] Table 18 Composition of the evaluation material of Example 8 and Comparative Example 8

[0276]

[0277]

[0278] Process conditions: The reaction process is three-stage adiabatic, the inlet temperature of the first reactor is 90°C, the inlet temperature of the second reactor is 100°C, and the inlet temperature of the third reactor is 105°C.

[0279] Preparation of hydrogenation feedstock: The carbon 2 fraction, carbon 3 fraction, methane, hydrogen and CO from the industrial plant pipe network were proportionally prepared on-line, wherein the CO was separately prepared and its content was changed at a rate of from 0.015% (v) to 0.03% (v) within 15 minutes.

[0280] Sampling and analysis method: The feedstock was analyzed once before the CO content adjustment and once after the CO content adjustment. The sampling interval was the adjustment time of the CO content.

[0281] The space velocity of Example 8 was 15000 / h and the space velocity of Comparative Example 8 was 5500 / h.

[0282] The evaluation results are shown in Table 19.

[0283] Table 19 Evaluation results of Example 8 and Comparative Example 8

[0284]

[0285] During the evaluation, the feedstock used in Example 8 and Comparative Example 8 was the same feedstock prepared uniformly.

[0286] After being measured by different flow meters, the feedstock entered different reactors, and the space velocities of the reactors were different.

[0287] As shown in Table 19, when the CO content was 0.15%, the acetylene conversion rate of the first reactor of Comparative Example 8 was obviously higher than that of the first reactor of Example, and the acetylene conversion rate of the second reactor of Comparative Example 8 reached 100%. However, the third reactor did not have a temperature runaway. When the CO content was reduced, the acetylene conversion rate of the first reactor of Example 8 reached more than 90%, the acetylene conversion rate of the second reactor reached 100%, and the third reactor did not have a temperature runaway. After the CO content was reduced, the ethylene selectivity of each reactor in Example decreased by about 10 percentage points, but the selectivity of the third reactor was still more than 50%, indicating that a large fluctuation in CO content would not cause a large change in the selectivity of the hydrogenation reaction.

[0288] In Comparative Example 8, when the CO content changed greatly, the first reactor could completely convert acetylene, but the selectivity was less than 55%, and the second and third reactors had a temperature runaway. This indicates that when the CO content is greatly reduced at a low space velocity or a space velocity lower than the critical value, a reactor temperature runaway is inevitable. This indicates that for this hydrogenation method, the space velocity is still a key parameter.

[0289] For the front-end hydrogenation process, the sharp change of CO content in the hydrogenation feed mainly occurs in the following situations: 1) a new cracking furnace is put into operation; 2) on-line decoking of the cracking furnace; and 3) the cracking furnace is changed to use a different feedstock. However, it is still relatively rare for CO to change sharply from 0.15% (V) to 0.03% (V) or from 0.03% (V) to 0.15% (V) within a short time, such as 15 minutes. The examples 8 and comparative example 8 show that the hydrogenation process of the present application has good ability to resist CO fluctuation under normal space velocity.

[0290] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications to the present application without departing from the spirit and essence of the present application. However, these corresponding changes and modifications shall all belong to the protection scope of the claims of the present application.

Claims

1. A method for selective hydrogenation of C1-C3 fractions, wherein the C1-C3 fractions originate from the top of a propane removal column in an ethylene plant, and the C1-C3 fractions undergo a selective hydrogenation reaction with hydrogen in a fixed-bed reactor containing a catalyst, characterized in that... The process conditions for the selective hydrogenation reaction are as follows: reactor inlet temperature of 90–130°C and gas hourly space velocity of 6000–20000 h⁻¹. -1 The volume content of CO in the C1-C3 fraction is 0.03% to 0.2%. The catalyst used in the selective hydrogenation reaction is supported on alumina or mainly alumina, with a specific surface area of ​​3–15 m². 2 / g, exhibiting a bimodal pore size distribution, with micropores ranging from 30 to 80 nm and macropores from 300 to 800 nm; the active components include Pd, Ni, and Fe, with Pd loaded via both microemulsion and solution methods, Ni loaded via microemulsion, and Fe loaded via solution method; solution-loaded Pd follows solution-loaded Fe, and microemulsion-loaded Pd follows microemulsion-loaded Ni; microemulsion-loaded Pd and Ni are located in the macropores, while solution-loaded Fe and Pd are located in the micropores; Based on the mass of the carrier (100%), the Ni content is 0.5%–2.5%, the Fe content is 0.5%–1.5%, and the Pd content is 0.007%–0.020%; the Pd content loaded by the microemulsion method is 0.002%–0.007% of the Ni content. The catalyst is reduced at 180–230 °C before being added to the selective hydrogenation reaction; The main active component of the catalyst is Fe, while Pd plays a role in adsorbing and transferring hydrogen.

2. The selective hydrogenation method for C1-C3 fractions as described in claim 1, characterized in that, Based on the total volume of the C1~C3 fractions as 100%, the H2 content is 10%~30%, the C2H4 content is 25%~40%, the C2H2 content is 0.4%~0.9%, the C3H6 content is 5%~11%, the PDMA content is 0.2%~1.2%, the CO content is 0.03%~0.2%, the butadiene content is ≤0.2%, and the balance is methane, ethane and propane.

3. The selective hydrogenation method for C1-C3 fractions as described in claim 1, characterized in that, The selective hydrogenation reaction is a single-stage hydrogenation, a two-stage hydrogenation, or a three-stage hydrogenation.

4. The selective hydrogenation method for C1-C3 fractions as described in claim 1, characterized in that, The process of loading Ni or Pd using the microemulsion method includes the following steps: dissolving the precursor salt of Ni or the precursor salt of Pd in ​​water to obtain an aqueous phase, and then adding an oil phase, a surfactant, and a co-surfactant to the aqueous phase and stirring to form a microemulsion.

5. The selective hydrogenation method for C1-C3 fractions as described in claim 4, characterized in that, The mass ratio of the aqueous phase to the oil phase is 2.0 to 4.5, the mass ratio of the surfactant to the oil phase is 0.10 to 0.4, and the mass ratio of the surfactant to the co-surfactant is 1.0 to 1.

5.

6. The selective hydrogenation method for C1-C3 fractions as described in claim 4, characterized in that, The oil phase is C6-C8 saturated alkanes or cycloalkanes.

7. The selective hydrogenation method for C1-C3 fractions as described in claim 4, characterized in that, The surfactant is an ionic surfactant and / or a nonionic surfactant.

8. The selective hydrogenation method for C1-C3 fractions as described in claim 4, characterized in that, The co-surfactant is an organic alcohol.

9. The selective hydrogenation method for C1-C3 fractions as described in claim 1, characterized in that, The order of loading the active component into the carrier includes the following steps: Ni loaded using microemulsion method, Fe loaded using solution method, Pd loaded using solution method, and Pd loaded using microemulsion method; or Ni loaded using microemulsion method, Fe loaded using solution method, Pd loaded using microemulsion method, Pd loaded using solution method; or Solution-loaded Fe, microemulsion-loaded Ni, solution-loaded Pd, microemulsion-loaded Pd; or Ni loaded by microemulsion method, Pd loaded by microemulsion method, Fe loaded by solution method, and Pd loaded by solution method.

10. The selective hydrogenation method for C1-C3 fractions as described in claim 1, characterized in that, Before the catalyst is introduced into the selective hydrogenation reaction, the reduction atmosphere is pure hydrogen or a mixture of hydrogen and nitrogen.

11. The selective hydrogenation method for C1-C3 fractions as described in claim 6, characterized in that, The oil phase is cyclohexane or n-hexane.

12. The selective hydrogenation method for C1-C3 fractions as described in claim 7, characterized in that, The surfactant is a nonionic surfactant.

13. The selective hydrogenation method for C1-C3 fractions as described in claim 7, characterized in that, The surfactant is polyethylene glycol octylphenyl ether or hexadecyltrimethylammonium bromide.

14. The selective hydrogenation method for C1-C3 fractions as described in claim 8, characterized in that, The co-surfactant is a C4-C6 alcohol.

15. The selective hydrogenation method for C1-C3 fractions as described in claim 14, characterized in that, The co-surfactant is n-butanol and / or n-pentanol.

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