Method for hydrogenating alkynes and / or diolefins in crude oil cracking gas stream

Abstract

The present invention relates to the field of hydrogenation, and discloses a method for hydrogenating alkynes and / or diolefins in a crude oil cracking gas stream. The method comprises: subjecting the crude oil cracking gas stream to catalytic desulfurization and hydrogenation respectively over a Ni-ZnO catalyst and a supported Pd-Ag catalyst, wherein the supported Pd-Ag catalyst comprises a second carrier, palladium, silver, and an optional modifying component, and contains a pyrrole adsorption in-situ infrared spectrum of the supported Pd-Ag catalyst at 40°C, wherein the pyrrole adsorption in-situ infrared spectrum of the supported Pd-Ag catalyst is 3200-3400 cm ‑1 The N-H bond stretching vibration absorption peak appeared in the range. After pyrrole adsorption, nitrogen was used to purge the in situ infrared spectra at 3160-3420 cm-1 at 0 and 15 minutes. ‑1 The ratio of the adsorption peak height within the range is more than 5. The method has good catalytic performance for the hydrogenation reaction of alkynes and diolefins in the crude oil cracking gas flow, and can remove trace organic sulfur, prevent the polymerization and coking of alkynes, and extend the service life of the catalyst.

Description

Technical Field

[0001] The present invention relates to the field of hydrogenation, and in particular to a method for hydrogenating alkynes and / or diolefins in a crude oil cracking gas stream. Background Art

[0002] Crude oil steam cracking technology is one of the "oil conversion" routes. It "skips" the traditional crude oil refining process and directly converts crude oil into chemicals such as ethylene and propylene. This will greatly shorten the production process, reduce production costs, and significantly reduce energy consumption and carbon emissions. Therefore, this technology has become the main research and development direction of major petrochemical companies.

[0003] The ethylene produced by crude oil steam cracking technology has accounted for more than 98% of the world's total ethylene production. The corresponding cryogenic separation technology is mainly divided into three categories, namely sequential separation technology, pre-depropanization pre-hydrogenation technology and pre-deethanization pre-hydrogenation technology.

[0004] In the pre-depropanization and pre-hydrogenation separation process, the cracked gas components include methane, CO, hydrogen, ethane, ethylene, acetylene, propylene, propane, and MAPD, which are directly hydrogenated to remove acetylenes and dienes without undergoing separation and distillation treatment. As one of the most important links in this separation process, the pre-depropanization and pre-hydrogenation reactor unit has strict index requirements for export acetylene, that is, after the cracked gas passes through the reactor, the acetylene content must be less than 1ppm, or even lower. This is because acetylene and ethylene are difficult to separate clearly through a distillation tower. Acetylene must be removed through selective hydrogenation or extraction methods; otherwise, it is impossible to obtain polymerization-grade ethylene. The requirements for the pre-depropanization and pre-hydrogenation reactor are to remove acetylene from the feedstock to at least less than 1ppm, convert as much MAPD as possible into propylene, and at the same time, the selectivity of ethylene and propylene is as high as possible.

[0005] The selective hydrogenation of acetylenes and diolefins in the cracked gas obtained through crude oil steam cracking using a pre-hydrogenation process offers advantages such as a simple process, increased ethylene and propylene production, and energy savings. With increasingly stringent requirements for acetylene content in the ethylene product and the emergence of trace impurities (such as organic sulfur) in the cracked gas composition, higher requirements are being placed on the technology and catalyst performance for the selective hydrogenation of crude oil cracked gas. Hydrogenation activity, selectivity, and stable operation are all areas of research and development.

[0006] Alkyne-supported Pd-Ag catalysts typically use the precious metal Pd as the active component, with effective additives added and loaded onto a support through methods such as impregnation. CN 1958155A discloses a method for preparing a Pd-Ag catalyst selectively supported on unsaturated alkynes. The method provides an alumina-coated support, on which the primary active component, Pd, and auxiliary active components are distributed, reducing the active component content and saving costs. However, some additives, such as Ag, in this technology can coat the surface of the Pd active sites, reducing Pd utilization. CN 1179788C discloses a catalyst for the selective hydrogenation of C2-C4 alkynes or dienes to the corresponding olefins. The catalyst comprises the primary active component, Pd, and auxiliary active components, such as Bi, loaded onto a support. The catalyst exhibits high activity and selectivity in high-space-velocity hydrogenation reactions. CN102249834B discloses a method for selectively hydrogenating alkynes and diolefins in an olefin stream. The olefin stream and hydrogen are introduced into a hydrogenation reactor equipped with a supported palladium catalyst to remove the alkynes and diolefins. The catalyst's active components are prepared by ionizing radiation irradiation at an inlet temperature of 10-80°C and a hydrogen / unsaturated hydrocarbon molar ratio of 1-10. CN102408916B discloses a method for selectively hydrogenating pyrolysis gas to remove alkynes and diolefins. Silylation treatment and grafting form silane groups on the surface of the supported Pd-Ag catalyst, improving the catalyst's adaptability to water or water content fluctuations in the pyrolysis gas feedstock and inhibiting carbon deposit formation.

[0007] Supported Pd-Ag catalysts can have both acidic and basic sites on their surfaces. Different acidic and basic sites play a crucial role in the catalyst's dehydrogenation activity, selectivity, and operating life. However, existing catalysts have not considered improving their catalytic performance from this perspective. Therefore, it is necessary to provide a supported Pd-Ag catalyst with specific catalytic sites that offers excellent selectivity, strong impurity resistance, and a long operating life. This would also allow for extended operating cycles when used to remove acetylene, MAPD, and trace organic sulfur from crude oil-to-cracked gas streams. Summary of the Invention

[0008] The present invention aims to provide a method for hydrogenating alkynes and / or diolefins in a crude oil cracking gas stream. The method utilizes a supported Pd-Ag catalyst having a specific basic center in combination with a two-stage catalytic process to selectively hydrogenate alkynes and / or diolefins in the crude oil cracking gas stream, thereby removing trace organic sulfur and achieving the beneficial effects of good selectivity, strong impurity resistance, and a long operating cycle.

[0009] In order to achieve the above object, the present invention provides a method for hydrogenating alkynes and / or diolefins in a crude oil cracking gas stream, the method comprising: desulfurizing and hydrogenating the crude oil cracking gas stream in a reactor equipped with a Ni-ZnO catalyst, and then selectively hydrogenating the resulting material in a reactor loaded with a supported Pd-Ag catalyst.

[0010] The supported Pd-Ag catalyst comprises a second support, palladium, silver and an optional modifying component; the supported Pd-Ag catalyst contains a basic center, wherein the basic center enables the supported Pd-Ag catalyst to have a pyrrole adsorption in-situ infrared spectrum at 40°C, with a wavelength of 3200-3400 cm -1 Moreover, after the supported Pd-Ag catalyst adsorbed pyrrole at 40 ° C, nitrogen was purged for 0 minutes and 15 minutes, and the in-situ infrared spectrum of 3160-3420 cm -1 The ratio of the peak heights of the adsorption peaks within the range is greater than 5;

[0011] The crude oil cracking gas stream contains acetylene, propadiene, propyne and organic sulfur.

[0012] Preferably, the preparation method of the supported Pd-Ag catalyst comprises the following steps:

[0013] (1) loading palladium, silver, and an optional modifying component onto a second carrier through a solution containing a palladium precursor, a solution containing a silver precursor, and an optional solution containing a modifying component precursor, and obtaining an intermediate after drying and calcining;

[0014] (2) The basic compound is loaded onto the intermediate in the form of a solution containing the basic compound, followed by drying and optionally calcining to obtain a catalyst.

[0015] The supported Pd-Ag catalyst of the present invention is characterized by its in-situ infrared spectrum of pyrrole adsorption, ensuring that the catalyst surface has basic centers of specific strength. The presence of these basic centers is further confirmed by the change in the height of specific adsorption peaks in the spectrum after a 15-minute purge. The in-situ infrared analysis of the catalyst allows for easy quantification, ensuring that the catalyst possesses specific catalytic activity and selectivity.

[0016] The preferred preparation method for the supported Pd-Ag catalyst of the present invention utilizes organic and / or inorganic basic compounds to provide effective basic centers in the catalyst, and quantitatively determines the strength of the basic centers through in-situ infrared analysis using pyrrole adsorption. This simple and easy preparation method obtains the basic centers required for the reaction, effectively improving the catalyst's ethylene and propylene selectivity. It also prevents Pd aggregation on the catalyst surface and coking from the polymerization of alkynes, thereby extending the catalyst's lifespan.

[0017] The present invention addresses the problem that trace organic sulfur in crude oil cracking gas can lead to rapid deactivation of a supported Pd-Ag catalyst and unqualified ethylene and propylene in the product. A multi-stage catalytic hydrogenation method is designed. Under high space velocity conditions, acetylene and MAPD can be removed, as well as organic sulfur. This solves the problem that a pre-hydrogenation reactor in crude oil cracking gas production cannot operate for a long period of time and that impurities in ethylene and propylene products exceed standards, and can also extend the operating cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The corresponding pyrrole adsorption in-situ infrared spectrum of catalyst 2 prepared in Example 2 is shown.

[0019] Figure 2 The in-situ infrared spectrum of pyrrole adsorption of catalyst 1 prepared in Example 1 over time is shown; in the spectrum, 0 min represents the infrared absorption curve at the end of nitrogen purge; 4 min, 6 min, and 10 min are the infrared absorption curves of pyrrole adsorption at the 4th, 6th, and 10th minutes; 25 min is the infrared absorption curve after 15 minutes of nitrogen purge at the end of pyrrole adsorption. DETAILED DESCRIPTION

[0020] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0021] The present invention provides a method for hydrogenating alkynes and / or diolefins in a crude oil cracking gas stream, the method comprising: desulfurizing and hydrogenating the crude oil cracking gas stream in a reactor equipped with a Ni-ZnO catalyst, and then selectively hydrogenating the resulting material in a reactor loaded with a supported Pd-Ag catalyst.

[0022] The supported Pd-Ag catalyst comprises a second support, palladium, silver and an optional modifying component; the supported Pd-Ag catalyst contains a basic center, wherein the basic center enables the supported Pd-Ag catalyst to have a pyrrole adsorption in-situ infrared spectrum at 40°C, with a wavelength of 3200-3400 cm -1 Moreover, after the supported Pd-Ag catalyst adsorbed pyrrole at 40 ° C, nitrogen was purged for 0 minutes and 15 minutes, and the in-situ infrared spectrum of 3160-3420 cm -1 The ratio of the peak heights of the adsorption peaks within the range is greater than 5;

[0023] The crude oil cracking gas stream contains acetylene, propadiene, propyne and organic sulfur.

[0024] The Ni-ZnO catalyst may be a supported catalyst or an unsupported catalyst, without any particular limitation.

[0025] If the Ni-ZnO catalyst is a supported catalyst, the supported Ni-ZnO catalyst comprises Ni, ZnO and a first carrier. Preferably, the Ni content in the supported Ni-ZnO catalyst is 2-20wt%, more preferably 8-10wt%; the ZnO content is 8-30wt%, more preferably 15-25wt%; and the content of the first carrier is 50-90wt%, more preferably 65-77wt%.

[0026] For example, the first support can be selected from at least one of aluminum oxide, titanium oxide, zirconium oxide, gallium oxide, silicon oxide, magnesium oxide, molecular sieves, zeolites, activated carbon, clay, bentonite, and polymer materials (such as polyacrylate, polystyrene, carbon supports, etc.). Its shape includes but is not limited to powder, granules, spheres, toothed spheres, Raschig rings, strips, cylinders, sheets, or clover leaves.

[0027] Preferably, the specific surface area of ​​the first carrier is 0.5-800m 2 / g, more preferably 4-200m 2 / g, more preferably 15-110m 2 / g.

[0028] When the catalyst is an unsupported catalyst, the Ni-ZnO catalyst does not contain a carrier. Preferably, the Ni content in the unsupported catalyst is 5-50wt% (for example, it can be 5, 8, 10, 15, 20, 30, 40, 50wt% and any range between any two values), more preferably 8-30wt%; the ZnO content is 50-95wt% (for example, it can be 50, 60, 70, 80, 90, 95wt% and any range between any two values), more preferably 70-92wt%.

[0029] The Ni-ZnO catalyst can be commercially available or homemade, and the preparation method can be conventional in the art. For example, an unsupported catalyst can be prepared by coprecipitation followed by drying and calcination; a supported catalyst can be prepared by impregnating a first support with Ni and Zn precursor compounds, followed by drying and calcination. It should be understood that the impregnation, drying, and calcination steps can be repeated multiple times to increase the loading.

[0030] The precursors of Ni and Zn can be selected from halogen compounds, nitric acid compounds, acetic acid compounds, carbonate compounds, oxalic acid compounds, acetic acid compounds, citric acid compounds, and the like.

[0031] Those skilled in the art can select a suitable method for preparation according to the circumstances, which will not be described in detail here. The temperature and time of drying and calcining can refer to the conditions of the hydrogenation catalyst.

[0032] Among them, desulfurization and hydrogenation treatment are carried out in an adiabatic bed reactor.

[0033] Preferably, the conditions for desulfurization and hydrotreating include: a reactor inlet temperature of 60-150°C (e.g., 60, 70, 80, 90, 100, 110, 120, 130, 140, 150°C, and any range between any two values); a reaction pressure of 1 MPa-4 MPa (e.g., 1, 1.5, 2, 2.5, 3, 3.5, 4 MPa, and any range between any two values); a gas phase space velocity of 5000-20000 h -1 (For example, it can be 5000, 6000, 7000, 8000, 10000, 12000, 14000, 16000, 18000, 20000h -1 and any range between any two values).

[0034] The desulfurized material can be selectively hydrogenated in a conventional selective hydrogenation reactor to remove MAPD. For example, the selective hydrogenation can be carried out in an adiabatic bed reactor. Those skilled in the art can select an appropriate number of reactors for the reaction as needed.

[0035] Preferably, the supported Pd-Ag catalyst has a wavelength of 3250-3390 cm -1 (For example, it can be 3250, 3260, 3280, 3300, 3310, 3320, 3330, 3340, 3350, 3355, 3360, 3365, 3370, 3375, 3380, 3385, 3390cm -1 And any range between any two values, preferably 3340-3390cm -1 ) range, an NH bond stretching vibration absorption peak (can be at least one).

[0036] The supported Pd-Ag catalyst can also be tested at 40°C for pyrrole adsorption in situ infrared spectrum at 3370-3400 cm -1 and 3200-3250cm -1The NH bond stretching vibration absorption peak appears simultaneously in the range, but due to its strong basic center, the service life and selectivity of the catalyst will be lost.

[0037] Preferably, the supported Pd-Ag catalyst is tested at 40°C for pyrrole adsorption in situ infrared spectrum, and the wavelength is less than 3250 cm -1 range (more preferably less than 3300cm -1 ) No NH bond stretching vibration absorption peak appears.

[0038] Preferably, the basic center makes the supported Pd-Ag catalyst absorb pyrrole at 40°C and then purge with nitrogen for 0 minutes, and the in-situ infrared spectrum of 3160-3420 cm -1 The peak height of the adsorption peak in the range is consistent with the peak at 3160-3420 cm in the in-situ infrared spectrum measured by nitrogen purge for 15 minutes. -1 The ratio of the adsorption peak height within the range is greater than 10.

[0039] In the present invention, the in-situ infrared spectrum of pyrolysis adsorption of the supported Pd-Ag catalyst can be measured by the following method:

[0040] a) placing a powdered catalyst sample in an infrared cell, vacuum-treating it, and then heating it to 350°C at a rate of 20°C / min;

[0041] b) keeping the temperature at 350°C for 2 h in a vacuum state, and then cooling to 40°C at a cooling rate of 20°C / min;

[0042] c) Maintaining the temperature at 40°C, introduce nitrogen gas for 30 minutes at a nitrogen flow rate of 5 mL / min;

[0043] d) maintaining the temperature at 40° C., introducing gaseous pyrrole for adsorption for 10 minutes at a gas flow rate of 5 mL / min, and recording the in situ infrared spectrum of the sample;

[0044] e) Maintaining the temperature at 40°C, purge with nitrogen at a flow rate of 5 mL / min for 30 minutes, and record the in situ infrared spectrum of the sample.

[0045] Before testing, the granular catalyst sample should be ground into powder and filled into the in-situ sample cell with the surface kept flat. The purpose of steps a to c is to remove water and impurities adsorbed on the catalyst surface.

[0046] In the pyrrole adsorption step (step d), the in-situ infrared spectrum of the sample can be recorded at different times as needed, for example, the in-situ infrared spectrum of the sample can be recorded at 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, and 10 minutes. In the in-situ infrared spectrum of pyrrole adsorption, 3160-3420 cm -1 The NH bond stretching vibration absorption peak appears in the range of 3160-3420cm, which corresponds to the base strength of the basic center on the catalyst surface. The higher the wave number of the peak position, the weaker the base strength of the basic center. -1 There are multiple NH bond stretching vibration absorption peaks in the range, indicating that the basic centers on the catalyst surface are diversified. The peak positions of pyrrole adsorption on different catalysts are quite different. Usually two or more peaks will overlap. In some cases, one peak will become the shoulder of another peak. In order to calculate the peak positions of each adsorption peak, the commonly used data processing software can be used to analyze the peak positions of 3160-3420cm -1 The absorption curve of the interval was fitted with peaks.

[0047] After purging with nitrogen, the intensity of the pyrrole infrared absorption peak gradually weakened. Spectrum 3160-3420cm after purging for 15 minutes -1 Absorption peak in the range 3160-3420cm and purge 0 minute spectrum -1 The peak height ratio of the absorption peaks within the range can be used to illustrate the adsorption capacity of the basic center on the catalyst surface for pyrrole, proving the existence of the basic center.

[0048] After the measurement, nitrogen purging can be maintained until the temperature drops to room temperature, with a nitrogen flow rate of 3-7 mL / min.

[0049] The supported Pd-Ag catalyst comprises a second support, palladium, silver and an optional modifying component.

[0050] The second support of the supported Pd-Ag catalyst can be selected from at least one of alumina, titanium oxide, zirconium oxide, gallium oxide, silicon oxide, magnesium oxide, molecular sieve, zeolite, activated carbon, clay, bentonite, and polymer materials. Its shape includes, but is not limited to, powder, granules, spheres, toothed spheres, Raschig rings, strips, cylinders, sheets, or clover leaves.

[0051] Preferably, the specific surface area of ​​the second carrier is 0.5-800m 2 / g, preferably 4-200m 2 / g, more preferably 15-110m 2 / g.

[0052] The palladium and silver may exist in the form of oxidation state, elemental state, alloy state, other compound state or a mixture of two or more thereof on the catalyst surface.

[0053] The supported Pd-Ag catalyst of the present invention may be a Pd-Ag supported catalyst, and may also contain a modifying component, wherein the modifying component may be a conventional modifying component in the art, for example, selected from Bi, Sb, Pb, Sn, Y, Zn, Co, W, Si, Group VIII elements other than palladium (such as Fe, Co, Ni, Ru, Rh, Os, Ir, Pt), Group IB elements other than Ag (such as Cu, Au), Group VIIB elements (such as Mn), Group III elements (such as Cu, Au), Group IV elements (such as Mn), Group VIII elements (such as Pd, VIII), and ... At least one of Group A elements (such as Ga, In, Tl), rare earth elements (such as La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Sc), alkali metal elements (such as Na, K), alkaline earth metal elements (such as Mg, Ca, Sr, Ba) and halogen elements (such as F, Cl, Br, I), more preferably at least one selected from Zn, La, Li, Cs, In, Y, Ga, Au and F. The modified component can be co-loaded on the second support with Pd and Ag as a co-active component, or can be used as a modifier of the second support and uniformly distributed in the second support. Preferably, the modified component is co-loaded on the second support with Pd and Ag as a co-active component.

[0054] Preferably, calculated as a metal element, the palladium content in the supported Pd-Ag catalyst is 0.01-20 wt% of the weight of the second carrier, for example, it can be 0.01, 0.02, 0.05, 0.1, 0.5, 1, 5, 10, 20 wt% and any range between any two values.

[0055] Preferably, calculated as metal element, the silver content in the supported Pd-Ag catalyst is 0.05-60wt% of the weight of the second support, for example, it can be 0.05, 0.1, 0.5, 1, 5, 10, 20, 40, 60wt% and any range between any two values.

[0056] Preferably, calculated as metal element, the content of the modifying component in the supported Pd-Ag catalyst is 0-20wt% of the weight of the second carrier, for example, it can be 0, 0.01, 0.02, 0.05, 0.1, 0.5, 1, 5, 10, 20wt% and any range between any two values.

[0057] The preparation method of the supported Pd-Ag catalyst can be a conventional preparation method in the art. Preferably, the preparation method of the supported Pd-Ag catalyst comprises the following steps:

[0058] (1) loading palladium, silver, and an optional modifying component onto a second carrier through a solution containing a palladium precursor, a solution containing a silver precursor, and an optional solution containing a modifying component precursor, and obtaining an intermediate after drying and calcining;

[0059] (2) The basic compound is loaded onto the intermediate in the form of a solution containing the basic compound, followed by drying and optionally calcining to obtain a catalyst.

[0060] In step (1), preferably, palladium is loaded in the form of a solution containing a palladium precursor, silver is loaded in the form of a solution containing a silver precursor, and the modifying component is loaded in the form of a solution containing a modifying component precursor.

[0061] The palladium, silver, and modifying component precursors can be pre-formulated into solutions simultaneously or separately and loaded onto the second support by spraying or impregnation. When the catalyst includes a modifying component, such as when it serves as a co-activating component, it can be loaded onto the second support alone or simultaneously with palladium and silver. If the modifying component serves as a modifier for the second support, it can be added during the preparation of the second support. Silver can also be used as a modifier for the second support and can be added during the preparation of the second support.

[0062] The palladium precursor can be a conventional acid or base or water-soluble substance in the art, such as one or more selected from palladium chloride, palladium nitrate, palladium acetate, palladium sulfate, palladium oxide and palladium metal organic compounds (such as palladium pivalate, octaethylporphyrin palladium, trimethylpalladium acetate, palladium trifluoroacetate, etc.).

[0063] The content of the palladium precursor in the solution containing the palladium precursor can be selected within a wide range, for example, the content of the palladium precursor in the solution containing the palladium precursor is 1-200 g / / L.

[0064] The silver precursor can be a conventional acid-, alkali-, or water-soluble substance in the art, such as at least one of silver nitrate, silver cyanide, silver oxalate, a silver ammonia complex, silver oxide, and a silver metal organic compound (such as silver oxalate). The content of the silver precursor in the solution containing the silver precursor can be selected within a wide range, such as 1-200 g / L.

[0065] Preferably, the precursor of the modifying component is selected from at least one of halides (such as chlorides, bromides, iodides), nitrates, acetates, carbonates, sulfates, hydroxides, ammonium compounds and metal organic compounds (such as citrates, oxalates, etc.).

[0066] The content of the precursor of the modifying component in the solution containing the precursor of the modifying component can be selected within a wide range, for example, the content of the precursor of the modifying component in the solution containing the precursor of the modifying component is 0.1-400 g / L.

[0067] The solvents in the solution of the precursor containing palladium, the solution of the precursor containing silver, and the optional solution of the precursor containing the modifying component can each independently be water, diethyl ether, ethanol, isobutyl alcohol, and the like.

[0068] Preferably, the amount of palladium used, calculated as the metal element, is such that the palladium content in the supported Pd-Ag catalyst is 0.01-20 wt% of the weight of the second carrier, for example, it can be 0.01, 0.02, 0.05, 0.1, 0.5, 1, 5, 10, 20 wt% and any range between any two values, more preferably 0.02-6 wt%.

[0069] Preferably, the amount of silver used, calculated as the metal element, is such that the silver content in the supported Pd-Ag catalyst is 0.05-60 wt % of the weight of the second support, for example, 0.05, 0.1, 0.5, 1, 5, 10, 20, 40, 60 wt % and any range between any two values, more preferably 0.05-10 wt %.

[0070] Preferably, the amount of the modifying component is such that, calculated as metal element, the content of the modifying component in the supported Pd-Ag catalyst is 0-20 wt% of the weight of the second carrier, for example, it can be 0, 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 15, 20 wt% and any range between any two values.

[0071] In the present invention, the loading method may be a conventional method in the art, for example, the loading method may be a spraying method or an immersion method, and the specific operation will not be described in detail.

[0072] In step (2), preferably, the amount of the alkaline compound used is 0.1-25 wt% compared to the weight of the second carrier, for example, it can be 0.1, 0.5, 1, 2, 4, 6, 8, 10, 15, 20, 25 wt% and any range between any two values.

[0073] Preferably, the basic compound is loaded in the form of a solution containing the basic compound. The basic compound can be an inorganic basic compound and / or an organic basic compound.

[0074] Preferably, the organic alkaline compound is selected from at least one of organic amines (such as aliphatic amines, alcoholamines, amides, aromatic amines), pyridine compounds, alkali metal alkoxides and alkali metal salts, and more preferably selected from at least one of dimethylamine, triethylamine, acetamide, trifluoroacetamide, aniline, pyridine, 4-dimethylaminopyridine, triethanolamine, triethylenediamine, tetramethylethylenediamine, N,N-diisopropylethylamine, N-methylmorpholine, sodium methoxide, potassium ethoxide, potassium tert-butoxide, sodium tert-butoxide and n-butyllithium.

[0075] Preferably, the inorganic alkaline compound is selected from at least one of ammonia, halides (such as KF or lithium chloride), citrates (such as sodium citrate or potassium citrate), oxalates (such as sodium oxalate, potassium oxalate), acetates (such as sodium acetate, potassium acetate) and carbonates (such as sodium carbonate, potassium carbonate), preferably at least one of KF, NaF, lithium chloride and sodium bicarbonate.

[0076] In a preferred embodiment of the present invention, the basic compound is selected from at least one of KF, trifluoroacetamide, sodium bicarbonate and NaF.

[0077] The solvent in the solution containing the alkaline compound can be any solution that can dissolve the alkaline compound, and is preferably selected from at least one of water, methanol, ethanol, ether, acetone, tetrahydrofuran and N,N-dimethylformamide.

[0078] Preferably, the content of the alkaline compound in the solution containing the alkaline compound is 0.1-70 wt %, for example, it can be 0.1, 0.5, 1, 5, 10, 20, 30, 40, 70 wt % and any range between any two values.

[0079] In a preferred embodiment of the present invention, the method comprises: (1) loading palladium and silver onto a second carrier, drying and calcining to obtain an intermediate; and (2) loading an alkaline compound onto the intermediate, drying and optionally calcining to obtain a catalyst.

[0080] In another preferred embodiment of the present invention, the method comprises: (1) loading palladium, silver and a modifying component onto a second carrier, and obtaining an intermediate after drying and calcining; and (2) loading an alkaline compound onto the intermediate, and obtaining a catalyst after drying and optionally calcining.

[0081] In another preferred embodiment of the present invention, the method comprises: (1) loading a first modifying component onto a second carrier, drying and calcining the carrier to obtain a modified second carrier; loading palladium, silver and an optional second modifying component onto the modified second carrier, drying and calcining the carrier to obtain an intermediate; and (2) loading an alkaline compound onto the intermediate, drying and optionally calcining the intermediate to obtain a catalyst.

[0082] In another preferred embodiment of the present invention, the method comprises: (1) loading silver and an optional first modifying component onto a second support, drying, and calcining to obtain a modified support; loading palladium and an optional second modifying component onto the modified support, drying, and calcining to obtain an intermediate; and (2) loading an alkaline compound onto the intermediate, drying, and optionally calcining to obtain a catalyst. The first modifying component and the second modifying component may be the same or different.

[0083] In steps (1) and (2), when preparing the intermediate, modified support, or catalyst, the drying temperature can be independently 60-180°C, for example, 60, 80, 120, 160, 180°C, and any range between any two values. The drying time can be independently 1-48 hours, for example, 1, 5, 10, 20, 30, 40, 48 hours, and any range between any two values. It should be understood that the drying can be performed at least once, and the drying conditions can be different each time.

[0084] In step (1), the calcination temperature may be 300-1500°C, for example, 300, 400, 600, 800, 1000, 1200, 1400, 1500°C, and any range between any two values. Preferably, in the process of preparing the intermediate, the calcination temperature is 600-1500°C, for example, 600, 800, 1000, 1200, 1400, 1500°C, and any range between any two values. In the process of preparing the modified support, the calcination temperature is preferably 300-1000°C, for example, 300, 400, 600, 800, 1000°C, and any range between any two values.

[0085] In step (2), the calcination temperature is preferably 250-500°C, for example, it can be 200, 250, 300, 350, 400, 450, 500°C and any range between any two values.

[0086] In steps (1) and (2), the calcination time can be independently 2-24 h, for example, 2, 4, 8, 12, 16, 20, 24 h and any range between any two values.

[0087] In the steps (1) and (2) of the preparation method of the present invention, the drying and calcining can be independently carried out in an air atmosphere or under vacuum, preferably independently carried out in an air atmosphere.

[0088] The method of the present invention is applicable to a crude oil cracking gas stream, wherein the crude oil cracking gas stream contains acetylene, propadiene, propyne and organic sulfur. In the crude oil cracking gas stream, the acetylene content is 0.01-1 mol%, the total content of propadiene and propyne is 0.1-1 mol% (for example, the content of propadiene is 0.05-0.5 mol%, and the content of propyne is 0.05-0.5 mol%), and the organic sulfur content is 0.01-10 ppm (preferably 0.2-1 ppm).

[0089] The number of adiabatic bed reactors is determined by the acetylene content in the cracked gas stream. When the acetylene content is less than 0.3 mol%, two adiabatic bed reactors are connected in series for selective hydrogenation, the first adiabatic bed reactor is loaded with a Ni-ZnO catalyst or a Ni-ZnO supported catalyst, and the last adiabatic bed is loaded with a palladium supported catalyst. When the acetylene content is 0.3-1 mol%, three adiabatic fixed bed reactors are connected in series for selective hydrogenation, the first adiabatic bed reactor is loaded with a Ni-ZnO catalyst or a Ni-ZnO supported catalyst, and the second and last adiabatic beds are loaded with palladium supported catalysts.

[0090] The material may further contain ethylene and propylene. The contents of ethylene and propylene may be selected within a wide range. Preferably, based on molar amount, the ethylene content in the crude oil cracked gas stream is 5-40 mol%, and the propylene content is 5-40 mol%.

[0091] Generally speaking, the crude oil cracking gas stream also contains hydrogen and CO. For example, based on molar amount, the hydrogen content in the crude oil cracking gas stream is 5-25 mol%, and the CO content is 0.05-0.3 mol%.

[0092] The organic sulfur in the crude oil cracked gas stream is preferably selected from at least one of COS, CS2, mercaptans and sulfides.

[0093] The present invention will be described in detail below through examples.

[0094] Unless otherwise specified, in the examples and comparative examples, the reagents used are all reagents commonly used in the art, and the methods adopted are all conventional methods in the art.

[0095] The Al2O3 carriers used below were purchased from Sinopec Catalyst (Beijing) Co., Ltd., with a specific surface area of ​​50-60m 2 / g.

[0096] Preparation Example 1

[0097] This preparation example is used to provide a method for preparing a Ni-ZnO / Al2O3 supported catalyst.

[0098] Prepare 500 ml of a Ni(NO3)2 aqueous solution containing 20 g of Ni and 50 g of Zn(NO3)2, impregnate 500 g of a spherical carrier Al2O3 into the solution, dry at 150°C, and calcine at 650°C to obtain intermediate 1.

[0099] Prepare 500 ml of a Ni(NO3)2 aqueous solution containing 20 g of Ni and 70 g of Zn in Zn(NO3)2, immerse the intermediate 1 in the solution, dry at 150°C, and calcine at 650°C to obtain the intermediate 2;

[0100] Prepare 500 ml of Ni(NO3)2 aqueous solution containing 10 g Ni and 80 g Zn, immerse the intermediate 2 in the solution, dry at 150°C, and calcine at 650°C to obtain a Ni-ZnO / Al2O3 supported catalyst, which is referred to as catalyst S.

[0101] Example 1

[0102] Prepare 250 ml of an aqueous solution of [(NH4)2Pd]Cl4 containing 0.3 g of Pd, [(NH4)2Ag]Cl3 containing 0.5 g of Ag, and ZnCl2 containing 1.1 g of Zn. Impregnate 500 g of a spherical Al2O3 support in the solution, dry at 105°C for 12 h, and calcine at 650°C for 15 h to obtain a Pd-Zn-Ag / Al2O3 intermediate.

[0103] 250 ml of an aqueous solution of KF containing 1.0 g of K was prepared, and the Pd-Zn-Ag / Al2O3 intermediate was immersed in the solution, dried at 160°C for 4 h, and calcined at 300°C for 4 h to obtain catalyst 1.

[0104] Example 2

[0105] Prepare 500 mL of an aqueous solution containing 5.0 g of La in La(NO3)3 and 1.0 g of Ag in AgNO3, impregnate 500 g of a clover-shaped support Al2O3 in the solution, dry at 160°C for 12 h, and calcine at 1100°C for 4 h to obtain a La-Ag / Al2O3 intermediate;

[0106] Prepare 250 mL of a tetrahydrofuran solution of palladium pivalate containing 0.15 g of Pd, immerse the La-Ag / Al2O3 intermediate in the solution, dry at 70°C for 8 h, and calcine at 350°C for 10 h to obtain a Pd-Ag-La / Al2O3 intermediate;

[0107] 200 mL of an aqueous solution containing 13 g of trifluoroacetamide was prepared, and the solution was sprayed onto the Pd-Ag-La / Al2O3 intermediate, dried at 100°C for 12 h, and secondary dried at 160°C for 8 h to obtain catalyst 2.

[0108] Example 3

[0109] Prepare 300 ml of AgNO3 aqueous solution containing 1.6 g of Ag, impregnate 500 g of spherical Al2O3 carrier into the solution, dry at 150°C for 15 h, and calcine at 650°C for 20 h to obtain Ag / Al2O3 intermediate;

[0110] Prepare 180 ml of a PdSO4 aqueous solution containing 1.25 g of Pd, spray the solution onto the Ag / Al2O3 intermediate, dry at 140°C for 12 h, and calcine at 620°C for 10 h to obtain a Pd-Ag / Al2O3 intermediate;

[0111] 180 ml of an aqueous solution of NaHCO 3 containing 0.6 g of Na was prepared and sprayed onto the Pd-Ag / Al 2 O 3 intermediate. The mixture was dried at 125° C. for 10 h and calcined at 445° C. for 16 h to obtain catalyst 3.

[0112] Example 4

[0113] Prepare 200 mL of a LiNO3 aqueous solution containing 5 g of Li, impregnate 500 g of a columnar Al2O3 support in the solution, dry at 110°C for 2 h, and calcine at 800°C for 6 h to obtain a Li / Al2O3 intermediate;

[0114] Prepare 400 mL of an aqueous solution of Pd(NO3)2 containing 0.2 g of Pd, AgNO3 containing 1.2 g of Ag, and Ga(NO3)3 containing 25 g of Ga, immerse the Li / Al2O3 intermediate in the solution, dry at 105°C for 12 h, and calcine at 610°C for 10 h to obtain a Pd-Ga-Ag-Li / Al2O3 intermediate;

[0115] 250 mL of an aqueous solution of NaF containing 2.5 g of Na was prepared, and the Pd-Ga-Ag-Li / Al2O3 intermediate was immersed in the solution, dried at 120°C for 4 h, and calcined at 280°C for 6 h to obtain catalyst 4.

[0116] Example 5

[0117] Prepare 400 ml of an ethanol solution of copper acetate containing 3.1 g of Cu, impregnate 500 g of a toothed spherical carrier Al2O3 into the solution, dry at 75°C for 40 h, and calcine at 1100°C for 20 h to obtain a Cu-modified carrier Al2O3.

[0118] Prepare 300 ml of an aqueous solution of Pd(NO3)2 containing 0.5 g of Pd and 0.8 g of Ag in AgNO3, impregnate the Cu-modified support Al2O3 in the solution, dry at 105°C for 6 h, and calcine at 700°C for 4 h to obtain a Pd-Cu-Ag / Al2O3 intermediate;

[0119] Prepare 250 ml of an aqueous solution containing 50 ml of tetramethylethylenediamine, immerse the Pd-Cu-Ag / Al2O3 intermediate in the solution, and dry at 75°C for 20 h to obtain catalyst 5.

[0120] Example 6

[0121] Prepare 300 ml of an aqueous solution of AgNO3 containing 1.2 g of Ag, impregnate 500 g of a clover-shaped carrier Al2O3 into the solution, dry at 150°C for 15 h, and calcine at 650°C for 20 h to obtain an Ag / Al2O3 intermediate;

[0122] Prepare 400 ml of ether solution containing 0.5 g of Pd in ​​Pd(Ac)2 solution and 5.0 g of Cs in Cs(Ac), immerse 500 g of Ag / Al2O3 intermediate in the solution, dry at 80°C for 48 h, and calcine at 450°C for 8 h to obtain Pd-Cs-Ag / Al2O3 intermediate;

[0123] 400 ml of an ethanol solution containing 2.0 g of K(Ac) was prepared, and the Pd-Cs-Ag / Al2O3 intermediate was immersed in the solution and dried at 80°C for 30 h to obtain catalyst 6.

[0124] Example 7

[0125] Prepare 265 ml of an isobutanol solution of HAuCl4 containing 0.5 g of Au, impregnate 500 g of a columnar Al2O3 support into the solution, dry at 110°C for 1 h, and calcine at 1270°C for 6 h to obtain an Au-modified Al2O3 support;

[0126] Prepare 300 ml of an aqueous solution of Pd(NO3)2 containing 2.0 g of Pd, AgNO3 containing 3.5 g of Ag, and Ga(NO3)3 containing 0.8 g of Ga. Impregnate the Au-modified support Al2O3 in this solution, dry at 140°C for 12 h, and calcine at 820°C for 14 h to obtain a Pd-Ga-Au-Ag / Al2O3 intermediate.

[0127] Prepare 300 ml of acetone solution containing 110 ml of 4-dimethylaminopyridine (DMAP), immerse the Pd-Ga-Au-Ag / Al2O3 intermediate in the solution, and dry it at 165°C for 20 h to obtain catalyst 7.

[0128] Comparative Example 1

[0129] Prepare 300 ml of an aqueous solution of AgNO3 containing 1.6 g of Ag, impregnate 500 g of a spherical carrier Al2O3 in the solution, dry at 150°C for 15 h, and calcine at 650°C for 20 h to obtain an Ag / Al2O3 intermediate;

[0130] 180 ml of a PdSO 4 aqueous solution containing 1.25 g of Pd was prepared, and the solution was sprayed onto the Ag / Al 2 O 3 intermediate, dried at 140° C. for 12 h, and calcined at 620° C. for 10 h to obtain catalyst D1.

[0131] Test Example 1

[0132] This test example is used to illustrate the in situ FTIR analysis of pyrrole adsorption on a supported palladium-silver catalyst.

[0133] The catalysts prepared in the examples and comparative examples were tested for pyrrole adsorption using a pyrrole in situ infrared analyzer (Thermo Nicolet 380). About 10 mg of powder sample was pressed into a thin sheet, fixed in an infrared cell, and first vacuum-purified (400°C, 1×10 -3 Pa) for 3 hours, cooled to 40°C, and the spectrum was scanned as background. The method for determining the in-situ infrared spectrum of pyrolyte adsorption of the catalyst is as follows:

[0134] a) placing a powdered catalyst sample in an infrared cell, vacuum-treating it, and then heating it to 350°C at a rate of 20°C / min;

[0135] b) maintaining the temperature at 350°C for 2 hours in a vacuum state, and then cooling the temperature to 40°C at a cooling rate of 20°C / min;

[0136] c) Maintaining the temperature at 40°C, introduce nitrogen gas for 30 minutes at a nitrogen flow rate of 5 mL / min;

[0137] d) Maintaining the temperature at 40°C, introduce gaseous pyrrole for 10 minutes at a gas flow rate of 5 mL / min, and record the sample's concentration at 1000-4000 cm-1 at 2, 4, 6, 8, and 10 minutes after the introduction of gaseous pyrrole. -1 In situ infrared spectra in wavenumber regions;

[0138] e) Maintaining the temperature at 40°C, purge with nitrogen at a flow rate of 5 mL / min for 30 minutes;

[0139] f) Maintain nitrogen purge until the temperature drops to room temperature with a nitrogen flow rate of 5 mL / min.

[0140] in, Figure 1 The corresponding in-situ infrared spectrum of pyrrole adsorption of catalyst 2 prepared in Example 2 is shown.

[0141] Figure 2The in situ infrared spectrum of pyrrole adsorption over time for catalyst 1 prepared in Example 1 is shown. In the spectrum, 0 min represents the infrared absorption curve at the end of nitrogen purge; 4 min, 6 min, and 10 min represent the infrared absorption curves at the 4th, 6th, and 10th minutes of pyrrole adsorption; and 25 min represents the infrared absorption curve after the end of pyrrole adsorption and the 15-minute nitrogen purge.

[0142] The in situ infrared spectrum of pyrrole adsorption was analyzed, and the results are shown in Table 1. Table 1 shows the infrared spectrum of 3160-3420 cm at 10 minutes. -1 Within the range, the peak positions of the infrared absorption peaks of pyrrole of the catalysts prepared in the examples and comparative examples, as well as the peak height ratio H 10min / H 25min , where H 10min 3160-3420 cm-1 at 10 min of pyrrole adsorption -1 The highest peak height within the range (when there are two or more peaks, the highest peak height is used for calculation), H 25min 3160-3420 cm-1 at the end of pyrrole adsorption and nitrogen purge for 15 min -1 The highest peak height within the range (when there are two or more peaks, the highest peak height is used for calculation).

[0143] Table 1

[0144]

[0145] The calculation results show that the infrared peak position of pyrrole adsorption of the catalyst prepared in the example is at a wavelength of 3200-3400 cm -1 The pyrrole adsorption infrared peak position of the catalyst prepared in the comparative example is 3417.3cm -1 , which means that the catalyst has no basic center on its surface and has no effect on the ν(NH) peak position of pyrrole. However, the catalyst prepared in Example has a basic center, which affects the ν(NH) peak position of pyrrole, causing the peak position to shift to 3200-3400 cm -1 Within this range, the stronger the basicity of the basic center, the greater the red shift distance. After pyrrole adsorption ends and nitrogen purge is applied, the pyrrole adsorbed on the catalyst surface rapidly desorbs, resulting in peak height ratios greater than 10 for each catalyst, confirming the presence of the basic center.

[0146] Test Example 2

[0147] This test example is used to illustrate the effect evaluation of hydrogenation of cracked gas stream produced from crude oil.

[0148] The acetylene hydrogenation process for removing acetylene from a crude oil cracked gas stream utilizes three adiabatic reactors connected in series, with heat exchangers between each stage to control the feed temperature. The crude oil cracked gas stream comprises 15.5 mol% hydrogen, 687 ppm CO, 34 mol% ethylene, 0.55 mol% acetylene, 19 mol% propylene, 0.3 mol% MA, 0.3 mol% PD, 870 ppb COS, and the remainder methane, ethane, and propane. The space velocity in the first reactor is 7000 h / min. -1 The inlet temperature of the first stage reactor was 82°C, the outlet temperature was 93°C, and the pressure was 2.6 MPa. The catalyst used was the Ni-ZnO catalyst described in Preparation Example 1. The space velocity of the second and final stages was 15000 h -1 , pressure 2.6MPa; the inlet temperature of the second stage reactor is 61℃, and the outlet temperature of the second stage is 79℃; the inlet temperature of the third stage reactor is 64℃, and the outlet temperature of the third stage is 70℃. The catalysts used in the second and final stages are supported Pd-Ag catalysts, the types of which are shown in Table 2.

[0149] Among them, the commercially available catalyst in Table 2 is the hydrogenation catalyst BC-H-20A purchased from Sinopec Catalyst Branch, and its operating cycle in industrial use is about 3 years.

[0150] The catalysts prepared in the examples and comparative examples and the above-mentioned catalyst were used for selective hydrogenation, and the acetylene content at the outlet of the final reactor was controlled to be less than 0.2 ppm. The outlet COS content, MAPD conversion (%), operating cycle (h), ethylene selectivity (%), propylene selectivity (%) and C4+ production (mol%) were measured. The results are shown in Table 2.

[0151] The operating cycle refers to the time the system can operate when the total acetylene content at the outlet of the final reactor is controlled below 0.2 ppm.

[0152] The selectivity to ethylene is calculated as:

[0153]

[0154] The calculation method for MAPD conversion rate is:

[0155]

[0156] The selectivity to propylene is calculated as:

[0157]

[0158] The amount of C4+ generated is the sum of the contents of C4 and above components in the component analysis at the outlet of the second-stage reactor.

[0159] Table 2

[0160]

[0161] As can be seen from the selective hydrogenation reaction results in the cracked gas stream given in Table 2, in order to ensure that the export acetylene is less than 0.2ppm, the operating cycle, MAPD conversion rate, ethylene and propylene selectivity, and C4+ production of each catalyst are different. Compared with the comparative example and commercially available catalysts, the catalyst prepared in the embodiment has a longer operating time, can remove COS to below 20ppb, has better selectivity for ethylene and propylene, has a higher MAPD conversion rate, and has a lower C4+ production. This shows that the hydrogenation method for alkynes and diolefins in the crude oil cracked gas stream provided in the present invention can effectively remove acetylene and trace organic sulfur under conditions of higher space velocity, and obtain higher ethylene selectivity, propylene selectivity and MAPD conversion rate, and achieve long-term stable operation.

[0162] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for hydrogenating alkynes and / or diolefins in a crude oil cracking gas stream, characterized in that: The method comprises: desulfurizing and hydrogenating the crude oil cracking gas stream in a reactor equipped with a Ni-ZnO catalyst, and then selectively hydrogenating the obtained material in a reactor loaded with a supported Pd-Ag catalyst. The supported Pd-Ag catalyst comprises a second support, palladium, silver and an optional modifying component; the supported Pd-Ag catalyst contains a basic center, wherein the basic center enables the supported Pd-Ag catalyst to have a pyrrole adsorption in-situ infrared spectrum at 40°C, with a wavelength of 3200-3400 cm -1 Moreover, after the supported Pd-Ag catalyst adsorbed pyrrole at 40 ° C, nitrogen was used to purge the catalyst for 0 minutes and 15 minutes, and the in-situ infrared spectrum at 3160-3420 cm -1 The ratio of the peak heights of the adsorption peaks within the range is greater than 5; The crude oil cracking gas stream contains acetylene, propadiene, propyne and organic sulfur; The pyrrole adsorption in-situ infrared spectrum of the supported Pd-Ag catalyst was measured using the following method: a) The powdered catalyst sample was placed in an infrared cell, vacuum treated, and then heated to 350°C at a rate of 20°C / min. b) Keep at 350°C for 2 h in a vacuum state, then cool to 40°C at a cooling rate of 20°C / min; c) Maintain the temperature at 40°C and introduce nitrogen purge for 30 minutes at a nitrogen flow rate of 5 mL / min; d) Maintaining the temperature at 40°C, introduce gaseous pyrrole for adsorption for 10 minutes at a gas flow rate of 5 mL / min, and record the in situ infrared spectrum of the sample; e) Maintaining the temperature at 40°C, switch to nitrogen purge for 30 minutes at a nitrogen flow rate of 5 mL / min, and record the in situ FTIR spectrum of the sample.

2. The method according to claim 1, wherein The Ni-ZnO catalyst is a supported Ni-ZnO catalyst and / or an unsupported Ni-ZnO catalyst.

3. The method according to claim 2, wherein: The supported Ni-ZnO catalyst comprises Ni, ZnO and a first carrier, wherein the content of Ni in the supported Ni-ZnO catalyst is 2-20 wt %, the content of ZnO is 8-30 wt %, and the content of the first carrier is 50-90 wt %; and / or The content of Ni in the non-supported Ni-ZnO catalyst is 5-50wt%, and the content of ZnO is 50-95wt%.

4. The method according to claim 3, wherein: In the supported Ni-ZnO catalyst, the content of Ni is 8-10 wt %; the content of ZnO is 15-25 wt %; the content of the first carrier is 65-77 wt %; and / or The content of Ni in the non-supported Ni-ZnO catalyst is 8-30wt%; the content of ZnO is 70-92wt%.

5. The method according to claim 1, wherein Desulfurization and hydrotreating are carried out in an adiabatic bed reactor.

6. The method according to claim 5, wherein: The conditions for desulfurization and hydrogenation treatment include: reactor inlet temperature of 60-150°C; reaction pressure of 1MPa-4MPa; gas phase space velocity of 5000-20000h -1 .

7. The method according to claim 1, wherein The basic center makes the supported Pd-Ag catalyst have at least 3250-3390 cm-1 in the pyrrole adsorption in-situ infrared spectrum tested at 40°C. -1 NH bond stretching vibration absorption peak appears in the range; and / or The basic center enables the supported Pd-Ag catalyst to adsorb pyrrole at 40°C, and then nitrogen is used to purge for 0 minutes. The in-situ infrared spectrum at 3160-3420 cm -1 The peak height of the adsorption peak in the range is consistent with the peak at 3160-3420 cm in the in-situ infrared spectrum measured by nitrogen purge for 15 minutes. -1 The ratio of the adsorption peak height within the range is greater than 10.

8. The method according to claim 1, wherein The second carrier of the supported Pd-Ag catalyst is selected from at least one of aluminum oxide, titanium oxide, zirconium oxide, gallium oxide, silicon oxide, magnesium oxide, molecular sieves, activated carbon, clay and polymer materials; and / or The modified component in the supported Pd-Ag catalyst is selected from at least one of Bi, Sb, Pb, Sn, Y, Zn, W, Si, Group VIII elements other than palladium, Group IB elements other than Ag, Group VIIB elements, Group IIIA elements, rare earth elements, alkali metal elements, alkaline earth metal elements and halogen elements.

9. The method according to claim 8, wherein The specific surface area of ​​the second carrier is 0.5-800 m 2 / g; and / or The modified component in the supported Pd-Ag catalyst is selected from at least one of Zn, La, Li, Cs, In, Y, Ga, Au and F; and / or Calculated as elements, the palladium content in the supported Pd-Ag catalyst is 0.01-20wt% of the weight of the second carrier, the silver content is 0.05-60wt% of the weight of the second carrier, and the content of the modifying component is 0-20wt% of the weight of the second carrier.

10. The method according to claim 9, wherein: The specific surface area of ​​the second carrier is 4-200m 2 / g.

11. The method according to claim 10, wherein: The specific surface area of ​​the second carrier is 15-110m 2 / g.

12. The method according to any one of claims 1 to 11, wherein: The preparation method of the supported Pd-Ag catalyst comprises the following steps: (1) loading palladium, silver, and an optional modifying component onto a second carrier by using a solution containing a palladium precursor, a solution containing a silver precursor, and an optional solution containing a modifying component precursor, and obtaining an intermediate after drying and calcining; (2) The basic compound is loaded onto the intermediate in the form of a solution containing the basic compound, followed by drying and optionally calcining to obtain a catalyst.

13. The method according to claim 12, wherein: The palladium precursor is selected from at least one of palladium chloride, palladium nitrate, palladium acetate, palladium sulfate, palladium oxide and a metal organic compound of palladium; and / or The silver precursor is selected from at least one of silver nitrate, silver cyanide, silver ammonia complex, silver oxide and silver metal organic compound; and / or The precursor of the modifying component is selected from at least one of halides, nitrates, acetates, carbonates, sulfates, hydroxides, ammonium compounds and metal organic compounds of the modifying component.

14. The method according to claim 12, wherein: The amount of palladium used, calculated as the element, is such that the content of palladium in the supported Pd-Ag catalyst is 0.01-20 wt % of the weight of the second support, the content of silver is 0.05-60 wt % of the weight of the second support, and the content of the modifying component is 0-20 wt % of the weight of the second support; and / or Compared to the weight of the second carrier, the amount of the basic compound is 0.1-25 wt %.

15. The method according to claim 12, wherein: The basic compound is an inorganic basic compound and / or an organic basic compound.

16. The method according to claim 15, wherein The organic basic compound is at least one selected from organic amines, pyridine compounds and alkali metal salts; and / or The inorganic alkaline compound is selected from at least one of ammonia, halides, bicarbonates and carbonates.

17. The method according to claim 16, wherein: The organic alkaline compound is selected from at least one of dimethylamine, triethylamine, acetamide, trifluoroacetamide, aniline, pyridine, 4-dimethylaminopyridine, triethanolamine, triethylenediamine, tetramethylethylenediamine, N,N-diisopropylethylamine, N-methylmorpholine, sodium methoxide, potassium ethoxide, potassium tert-butoxide, citrate, oxalate, acetate, sodium tert-butoxide and n-butyllithium.

18. The method according to claim 12, wherein: The solvent in the solution containing the basic compound is selected from at least one of water, methanol, ethanol, ether, acetone, tetrahydrofuran and N,N-dimethylformamide; and / or The content of the alkaline compound in the alkaline compound-containing solution is 0.1-70 wt %.

19. The method according to claim 12, wherein: In step (1), the drying conditions include: temperature of 60-180°C; time of 1-48h; and / or The calcination temperature is 300-1500°C; the calcination time is 2-24h; and / or Wherein, in step (2), the drying temperature is 60-180°C; the drying time is 1-48h; and / or The calcination temperature is 250-500° C. and the calcination time is 2-24 hours.

20. The method according to claim 1, wherein Calculated by mole, the acetylene content in the crude oil cracking gas stream is 0.01-1 mol%, the total content of propadiene and propyne is 0.1-1 mol%, and the organic sulfur content is 0.01-10 ppm.

21. The method according to claim 20, wherein The crude oil cracking gas stream also contains hydrogen, CO, ethylene and propylene.

22. The method according to claim 21, wherein In terms of molar amount, the crude oil cracking gas stream has a hydrogen content of 5-25 mol%, a CO content of 0.05-0.3 mol%, an ethylene content of 5-40 mol%, and a propylene content of 5-40 mol%.

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