Nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, preparation method and application thereof

Abstract

The present invention belongs to the technical field of heterogeneous catalysts, and particularly relates to a nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, a preparation method and an application thereof. A nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, the catalyst is composed of a main active component, a first co-metal, a second co-metal and a composite carrier, the main active component is nickel, accounting for 0.5% to 5.0% of the mass of the composite carrier; the first co-metal accounts for 0.5% to 5.0% of the mass of the composite carrier based on the total mass of metal atoms; the second co-metal accounts for 0.5% to 5.0% of the mass of the composite carrier based on the total mass of metal atoms. The catalyst prepared by the method has the advantages of small active metal nickel grains, high specific surface area, good sulfur resistance, etc., and can show excellent conversion rate and propylene selectivity in the reaction of selective hydrogenation of propyne to propylene.

Description

Technical Field

[0001] The invention belongs to the technical field of heterogeneous catalysts, and particularly relates to a nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, a preparation method and an application thereof. Background Art

[0002] Propylene is one of the most basic chemical raw materials, and its use among low-carbon olefins is second only to ethylene. It is mainly used to produce chemical products such as polypropylene, acrylonitrile, propylene oxide, acrylic acid and esters, and has a wide range of applications in the fields of construction, daily necessities, automobiles, medical care, etc. With the growth of propylene market demand, the process of producing propylene by catalytic dehydrogenation of propane has advantages such as short investment cycle, low energy consumption and high efficiency. In the past two years, the number of PDH (propane direct catalytic dehydrogenation) units invested in China has doubled, and the market share has grown fastest.

[0003] The catalytic dehydrogenation of propane to produce propylene is a highly endothermic reaction that requires a large amount of additional heat. If the energy required for the reaction is not replenished in time during the reaction, a reverse reaction is very likely to occur, resulting in the loss of product propylene. However, in a high-temperature reaction environment, a deep dehydrogenation reaction will inevitably occur to produce propyne and propadiene, which will also cause the loss of product propylene. The "SHP reactor" is often installed in the downstream separation equipment of the PDH unit, that is, propyne and propadiene are selectively hydrogenated to produce propylene. The core of this reactor is the catalyst. In actual industrial production, fluctuations in the upstream process parameters of the unit will cause trace penetration of hydrogen sulfide adsorbents. Hydrogen sulfide enters the SHP reactor with the process materials and is adsorbed on the active metal surface of the catalyst to form a stable metal-sulfur compound form that permanently poisons the catalyst. As time goes by, the catalyst activity eventually decreases significantly. Therefore, the catalyst for the selective hydrogenation of propyne and propadiene also needs to have a certain sulfur resistance. At present, the most studied selective hydrogenation catalysts are palladium, platinum, rhodium and other precious metal catalysts. The most industrially used are palladium-based catalysts. Due to their high prices, they have increased the company's operating costs. However, non-precious metal nickel-based catalysts are cheap and easy to obtain, and have good catalytic hydrogenation performance. There are few reports on the research and application of propyne and propadiene selective hydrogenation. In response to this phenomenon, we have explored the research work on the selective hydrogenation performance and sulfur resistance of nickel-based catalysts for propyne and propadiene, and filled the gap in the relevant technical field. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene. The catalyst prepared by the method has the advantages of small active metal nickel grains, high specific surface area, good sulfur resistance, etc., and can show excellent conversion rate and propylene selectivity in the reaction of selective hydrogenation of propyne to propylene.

[0005] The invention provides a nickel-based sulfur-resistant catalyst for synthesizing propylene by selective hydrogenation of propyne. The catalyst has a long service life and has no obvious decrease in selective hydrogenation performance.

[0006] The technical solution of the present invention is achieved by the following measures:

[0007] A nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, the catalyst comprising a main active component, a first co-metal, a second co-metal and a composite carrier.

[0008] The main active component is nickel, which accounts for 0.5% to 5.0% of the composite support mass;

[0009] The first auxiliary metal accounts for 0.5% to 5.0% of the mass of the composite support based on the total mass of metal atoms;

[0010] The second auxiliary metal accounts for 0.5% to 5.0% of the mass of the composite support based on the total mass of metal atoms;

[0011] The first auxiliary metal is selected from one or more of inorganic iron salts, inorganic copper salts, inorganic zinc salts, and inorganic chromium salts, the second auxiliary metal is selected from one or more of inorganic lithium salts, inorganic sodium salts, inorganic potassium salts, and inorganic magnesium salts, and the composite carrier is a mixture of one or more of titanium dioxide, zirconium dioxide, manganese dioxide, cobalt oxide, and molybdenum trioxide and aluminum oxide (γ type).

[0012] Preferably, the main active component nickel precursor is Ni(NO3)2·6H2O.

[0013] Preferably, the first auxiliary metal inorganic iron salt, inorganic copper salt, inorganic zinc salt, and inorganic chromium salt are Fe(NO3)3·9H2O, Cu(NO3)2·3H2O, Zn(NO3)2, and Cr(NO3)3·9H2O, respectively. Cu(NO3)2·3H2O is further preferred, which can improve the dispersion of the main active metal nickel and reduce the adsorption energy of propylene on the catalyst surface.

[0014] Preferably, the second auxiliary metal inorganic lithium salt, inorganic sodium salt, inorganic potassium salt, and inorganic magnesium salt are LiCl·H2O, NaCl, KF·2H2O, and MgCl2, respectively. KF·2H2O is further preferred, because it can make the catalyst show better sulfur resistance and enhanced anti-toxicity.

[0015] Preferably, the corresponding oxide precursors of titanium dioxide, zirconium dioxide, manganese dioxide, cobalt oxide and molybdenum trioxide added to the catalyst composite carrier are: butyl titanate, Zr(HPO4)2·H2O, Mn(NO3)2·6H2O, Co(NO3)2·6H2O, Na2MoO4·10H2O. Butyl titanate is further preferred.

[0016] Preferably, in the catalyst, the molar ratio of the main active component nickel, the first auxiliary metal copper, and the second auxiliary metal potassium is 1:(1-5):(1-8) by metal atomic weight, and the molar ratio of n(Al) to n(Ti) in the composite carrier is 1:(0.5-5). The optimal molar ratio of the main active component nickel, the first auxiliary metal copper, and the second auxiliary metal potassium is 1:(1-3):(1-3). The optimal molar ratio of n(Al) to n(Ti) in the composite carrier is 1:(0.5-2.5).

[0017] A method for preparing a nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, the method comprising the following steps:

[0018] (1) According to the Al / Ti molar ratio in the composite support, butyl titanate was weighed and dissolved in anhydrous ethanol, and the mixture was stirred thoroughly to obtain solution A; appropriate amounts of anhydrous ethanol, water, glacial acetic acid, and a small amount of acetylacetone were weighed and stirred thoroughly to obtain solution B;

[0019] The volume ratio of butyl titanate, anhydrous ethanol, water and glacial acetic acid is 1:(3~10):(0.1~1):(0.1~1);

[0020] (2) slowly adding solution B in step (1) dropwise into solution A while stirring, and after solution B is added, slowly adding 10-30 mmol / L dilute nitric acid solution, adjusting the pH value of the solution to 2-5, and stirring into a colloid;

[0021] (3) According to the Al / Ti molar ratio in the composite carrier, weigh dry γ-Al2O3, add an appropriate amount of anhydrous ethanol and stir to form a suspension, then slowly add all of it to the colloid obtained in step (2), stirring while adding, and after stirring for 2 to 6 hours, it becomes a gel, and then it is aged at room temperature, dried, and calcined in sequence to obtain a γ-Al2O3-TiO2 composite carrier;

[0022] (4) Weighing the main active component nickel precursor, the first auxiliary metal, and the second auxiliary metal and dissolving them in a 10-30 mmol / L dilute nitric acid solution to obtain a mixed metal impregnation liquid;

[0023] (5) While stirring, slowly drip the mixed metal impregnation liquid in step (4) onto the composite support in step (3), and perform impregnation aging, filtering, washing, separation, drying, and calcination in sequence to obtain a catalyst precursor.

[0024] Preferably, in step (1), the volume ratio of butyl titanate, anhydrous ethanol, water and glacial acetic acid is 1:(3-5):(0.1-0.5):(0.1-0.5).

[0025] Preferably, in step (3), the standing aging time is 12 to 24 hours, the drying temperature is 120 to 150°C, the drying time is 12 to 24 hours, and the roasting conditions are: heating rate: 3 to 10°C / min, from room temperature to 450 to 650°C, and constant temperature for 3 to 5 hours.

[0026] Preferably, in step (5), the immersion aging time is 18-36 h, the pH value of washing with deionized water is neutral, the drying temperature is 120-150°C, the drying time is 12-24 h, and the roasting conditions are: heating rate: 3-10°C / min, from room temperature to 450-650°C, and constant temperature for 3-5 h.

[0027] The present invention also provides an application of the nickel-based sulfur-resistant catalyst of the present invention in the selective hydrogenation of propyne to propylene. The application comprises the following specific steps: activating the catalyst with hydrogen / nitrogen, cooling the catalyst to room temperature after reduction is completed, and then catalyzing a hydrogenation reaction between a mixed liquid of propane, propylene, propyne, and hydrogen sulfide and hydrogen in a reactor.

[0028] Preferably, the nickel-based sulfur-resistant catalyst precursor is loaded into a tubular fixed bed reactor, a quantitative catalyst is loaded into the middle constant temperature zone of the tubular fixed bed, and the remaining space is filled with quartz sand. After the fixed tube is connected completely and airtight, the catalyst is activated with hydrogen / nitrogen. After the catalyst reduction is completed, the fixed bed is naturally cooled to room temperature; then a mixed liquid of propane, propylene, propyne and hydrogen sulfide is transported to the tubular fixed bed reactor to undergo a hydrogenation reaction with hydrogen.

[0029] Preferably, the catalyst reduction conditions are: hydrogen / nitrogen volume ratio (1~3):(7~9), pressure: 0.2~2MPa, reduction temperature: 350~500°C, heating rate: 5°C / min, reduction time: 3~8h. Under these conditions, it can be ensured that after the active components are fully reduced, the active particles will not agglomerate and grow, and the dispersion is better.

[0030] Preferably, the hydrogenation reaction conditions are: reaction pressure: 1-5 MPa, reaction temperature: 30-80°C, reaction substrate propane, propylene, propyne molar concentrations: 65%, 34.9%, 0.1%, respectively, hydrogen sulfide content: 10-500 ppm (mol), hydrogen to propyne molar ratio: 1.05-1.2, liquid hourly space velocity: 15-40 h -1 .

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The first auxiliary metal (especially Cu) doped in the catalyst of the present invention can well induce the dispersion of the main active metal Ni, improve the Ni dispersion, and transfer the charge to the metal Ni, which helps to reduce the adsorption capacity of propylene on the catalyst surface and avoid excessive hydrogenation of propylene;

[0033] (2) The second promoter metal (especially K) doped in the catalyst of the present invention and the composite carrier γ-Al2O3-TiO2 can improve the activation ability of hydrogen on the catalyst surface, enhance the sulfur resistance of the catalyst, greatly reduce the adsorption of hydrogen sulfide on the catalyst surface, and extend the service life of the catalyst;

[0034] (3) The catalyst of the present invention is cheap and readily available, has good propyne selective hydrogenation performance, high mechanical strength, and has good industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work.

[0036] Figure 1 is a schematic diagram of the service life of the catalyst prepared in Example 1;

[0037] Figure 2 This is a schematic diagram of the conversion rate and selectivity of selective hydrogenation of propyne at different hydrogen sulfide concentrations in Example 9. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described in detail below through specific embodiments. It should be understood that the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0039] In the present invention, unless otherwise specified, all parts and percentages are weight units, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments, unless otherwise specified, are commonly used methods in the art. The reagents used in the following embodiments, unless otherwise specified, can be purchased from conventional biochemical reagent stores.

[0040] Since propadiene is extremely unstable in chemical properties and is easily decomposed, it only exists in small amounts during large-scale industrial production. Therefore, the selective hydrogenation performance and sulfur resistance of the nickel-based catalyst prepared in the present invention are evaluated by using propyne as a raw material model to carry out research activities.

[0041] Example 1

[0042] A method for preparing a nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, comprising the following steps:

[0043] 1. Place an appropriate amount of γ-Al2O3 powder in a drying oven at 120°C for 12 hours, and then place it in a closed dryer to cool naturally to room temperature. Weigh 3g of dried γ-Al2O3, add an appropriate amount of anhydrous ethanol and stir to a suspension to obtain a mixture C. According to the Al / Ti molar ratio of 1:2 in the composite carrier, measure a specified volume of butyl titanate and dissolve it in 10mL of anhydrous ethanol to obtain solution A; measure 30mL of anhydrous ethanol, 2mL of deionized water, 5mL of glacial acetic acid, and 0.5mL of acetylacetone and mix them, and stir them thoroughly to obtain solution B. Slowly add solution B to solution A while stirring. After adding solution B, slowly add 10mmol / L dilute nitric acid solution, adjust the pH value of the solution to about 4, and stir to form a colloid D. Slowly add mixture C into colloid D while stirring. Stir for about 5 hours until it becomes a gel. Then age it at room temperature for 12 hours, dry it in a drying oven at 130°C for 12 hours, then transfer the carrier precursor to a crucible, and calcine it in a muffle furnace from room temperature to 550°C at 5°C / min, keep the temperature constant for 5 hours, and then cool it down to room temperature to obtain a γ-Al2O3-TiO2 composite carrier. Put it into a closed desiccator for use.

[0044] 2. Weigh 3g of γ-Al2O3-TiO2 composite carrier for standby use. According to the nickel loading of 2wt%, the molar mass ratio of nickel, copper and potassium is 1:2:1, weigh Ni(NO3)2·6H2O, Cu(NO3)2·3H2O and KF·2H2O and dissolve them in 10mmol / L dilute nitric acid solution. Slowly add the composite carrier to the metal mixture, stirring while adding, and then soak and age at room temperature for 24h, filter, wash the filter cake with deionized water until the filtrate is neutral, dry it in a drying oven at 130℃ for 12h, then transfer the catalyst precursor to a crucible, place it in a muffle furnace for roasting, raise it from room temperature to 550℃ at 5℃ / min, keep the temperature constant for 3h, and then reduce it to room temperature to obtain the catalyst to be activated, put it in a closed dryer for standby use.

[0045] An application of a nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, comprising the following specific steps:

[0046] Weigh 0.3g of the catalyst to be activated, press and crush (about 20 mesh particles) and place it in the constant temperature zone of the tubular fixed bed reactor. Fill the remaining space with quartz sand. After the fixed tube is connected completely and airtight, start the program temperature rise from room temperature to 450℃ at 5℃ / min, keep the temperature constant for 4h, and the reducing gas is a mixture of hydrogen and nitrogen with a volume flow ratio of 2:8 and a pressure of 0.5MPa. After the catalyst is completely reduced, the tubular fixed bed reactor is naturally cooled to room temperature. At a reaction temperature of 60℃ and a reaction pressure of 3MPa, a reaction substrate consisting of 65mol% propane, 34.9mol% propylene, 0.1mol% propyne, and 100ppm (mol) hydrogen sulfide is mixed with hydrogen and injected into the fixed bed reactor. The molar ratio of hydrogen to propyne is 1.1:1, and the liquid hourly space velocity is 25h -1 After the reaction reaches the set conditions, the liquid product is collected with a high-pressure sampling bottle every two hours and analyzed with a gas chromatograph. Multiple samples are taken in parallel, and the average value is taken to calculate the conversion rate and selectivity under the current reaction conditions. According to calculations, the conversion rate of propyne is 98.5% and the selectivity of propylene is 90.3%.

[0047] Example 2

[0048] The Al / Ti molar ratio in the composite support was 1:1 instead of 1:2 in the composite support, and the other steps were the same as in Example 1. According to calculation, the conversion rate of propyne was 98.8%, and the selectivity of propylene was 81.4%.

[0049] Example 3

[0050] Cr(NO3)3·9H2O was used to replace Cu(NO3)2·3H2O in Example 1, and the other steps were the same as in Example 1. According to calculation, the conversion rate of propyne was 86.0%, and the selectivity of propylene was 88.9%.

[0051] Example 4

[0052] LiCl·H2O was used to replace KF·2H2O in Example 1, and the other steps were the same as in Example 1. According to calculation, the conversion rate of propyne was 96.2%, and the selectivity of propylene was 75.6%.

[0053] Example 5

[0054] The nickel loading amount was 2 wt % instead of 5 wt % in Example 1, and the other steps were the same as in Example 1. According to calculation, the propyne conversion rate was 99.5%, and the propylene selectivity was 83.6%.

[0055] Example 6

[0056] The molar mass ratio of nickel, copper and potassium in Example 1 was replaced by 1:1:2, and the other steps were the same as in Example 1. According to calculation, the conversion rate of propyne was 92.0%, and the selectivity of propylene was 87.0%.

[0057] Example 7

[0058] The reducing gas in Example 1 was replaced by a mixture of hydrogen and nitrogen with a volume flow ratio of 4:6, and the other steps were the same as in Example 1. According to calculation, the conversion rate of propyne was 97.9%, and the selectivity of propylene was 79.5%.

[0059] Example 8

[0060] The molar ratio of hydrogen to propyne in Example 1 was replaced by a molar ratio of hydrogen to propyne of 1.2:1, and the other steps were the same as in Example 1. According to calculation, the conversion rate of propyne was 99.4%, and the selectivity of propylene was 78.4%.

[0061] Example 9

[0062] The reaction substrate composed of 100 ppm (mol) of hydrogen sulfide in Example 1 was replaced by the reaction substrate composed of 50 ppm (mol), 200 ppm (mol), 300 ppm (mol), 400 ppm (mol), and 500 ppm (mol) of hydrogen sulfide in turn, and the other steps were the same as in Example 1. After calculation, the propyne conversion rate and propylene selectivity were as follows: Figure 2 shown.

[0063] Comparative Example 1

[0064] 1. Weigh 3g of the dried γ-Al2O3 carrier for standby use. According to the nickel loading of 2wt%, the molar mass ratio of nickel, copper and potassium is 1:2:1, weigh Ni(NO3)2·6H2O, Cu(NO3)2·3H2O and KF·2H2O and dissolve them in 10mmol / L dilute nitric acid solution. Slowly add the carrier to the metal mixture, stirring while adding, and then soak and age at room temperature for 24h, filter, wash the filter cake with deionized water until the filtrate is neutral, dry it in a drying oven at 130℃ for 12h, then transfer the catalyst precursor to a crucible, place it in a muffle furnace for roasting, raise it from room temperature to 550℃ at 5℃ / min, keep the temperature constant for 3h, and then reduce it to room temperature to obtain the catalyst to be activated, put it in a closed dryer for standby use.

[0065] An application of a nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, comprising the following specific steps:

[0066] Weigh 0.3g of the catalyst to be activated, press and crush (about 20 mesh particles) and place it in the constant temperature zone of the tubular fixed bed reactor. Fill the remaining space with quartz sand. After the fixed tube is connected completely and airtight, start the program temperature rise from room temperature to 450℃ at 5℃ / min, keep the temperature constant for 4h, and the reducing gas is a mixture of hydrogen and nitrogen with a volume flow ratio of 2:8 and a pressure of 0.5MPa. After the catalyst is completely reduced, the tubular fixed bed reactor is naturally cooled to room temperature. At a reaction temperature of 60℃ and a reaction pressure of 3MPa, a reaction substrate consisting of 65mol% propane, 34.9mol% propylene, 0.1mol% propyne, and 100ppm (mol) hydrogen sulfide is mixed with hydrogen and injected into the fixed bed reactor. The molar ratio of hydrogen to propyne is 1.1:1, and the liquid hourly space velocity is 25h -1 After the reaction reaches the set conditions, the liquid product is collected with a high-pressure sampling bottle every two hours and analyzed with a gas chromatograph. Multiple samples are taken in parallel, and the average value is taken to calculate the conversion rate and selectivity under the current reaction conditions. According to calculations, the conversion rate of propyne is 87.9% and the selectivity of propylene is 62.0%.

[0067] Comparative Example 2

[0068] 1. Place an appropriate amount of γ-Al2O3 powder in a drying oven at 120°C for 12 hours, and then place it in a closed dryer to cool naturally to room temperature. Weigh 3g of dried γ-Al2O3, add an appropriate amount of anhydrous ethanol and stir to a suspension to obtain a mixture C. According to the Al / Ti molar ratio of 1:2 in the composite carrier, measure a specified volume of butyl titanate and dissolve it in 10mL of anhydrous ethanol to obtain solution A; measure 20mL of anhydrous ethanol, 2mL of deionized water, 5mL of glacial acetic acid, and 0.5mL of acetylacetone and mix them, and stir them thoroughly to obtain solution B. Slowly add solution B to solution A while stirring. After adding solution B, slowly add 10mmol / L dilute nitric acid solution, adjust the pH value of the solution to about 4, and stir to form a colloid D. Slowly add mixture C into colloid D while stirring. Stir for about 5 hours until it becomes a gel. Then age it at room temperature for 12 hours, dry it in a drying oven at 130°C for 12 hours, then transfer the carrier precursor to a crucible, and calcine it in a muffle furnace from room temperature to 550°C at 5°C / min, keep the temperature constant for 5 hours, and then cool it down to room temperature to obtain a γ-Al2O3-TiO2 composite carrier. Put it into a closed desiccator for use.

[0069] 2. Weigh 3g of γ-Al2O3-TiO2 composite carrier for standby use. According to the nickel loading of 2wt%, the weighed Ni(NO3)2·6H2O is dissolved in 10mmol / L dilute nitric acid solution. Slowly add the composite carrier to the metal mixture, stirring while adding, and then immerse and age at room temperature for 24h, filter, wash the filter cake with deionized water until the filtrate is neutral, dry it in a drying oven at 130℃ for 12h, then transfer the catalyst precursor to a crucible, and calcine it in a muffle furnace, raising the temperature from room temperature to 550℃ at 5℃ / min, keeping the temperature constant for 3h, and then lowering it to room temperature to obtain the catalyst to be activated, which is placed in a closed dryer for standby use.

[0070] An application of a nickel-based sulfur-resistant catalyst for selective hydrogenation of propyne to propylene, comprising the following specific steps:

[0071] Weigh 0.3g of the catalyst to be activated, press and crush (about 20 mesh particles) and place it in the constant temperature zone of the tubular fixed bed reactor. Fill the remaining space with quartz sand. After the fixed tube is connected completely and airtight, start the program temperature rise from room temperature to 450℃ at 5℃ / min, keep the temperature constant for 4h, and the reducing gas is a mixture of hydrogen and nitrogen with a volume flow ratio of 2:8 and a pressure of 0.5MPa. After the catalyst is completely reduced, the tubular fixed bed reactor is naturally cooled to room temperature. At a reaction temperature of 60℃ and a reaction pressure of 3MPa, a reaction substrate consisting of 65mol% propane, 34.9mol% propylene, 0.1mol% propyne, and 100ppm (mol) hydrogen sulfide is mixed with hydrogen and injected into the fixed bed reactor. The molar ratio of hydrogen to propyne is 1.1:1, and the liquid hourly space velocity is 25h -1 After the reaction reaches the set conditions, the liquid product is collected with a high-pressure sampling bottle every two hours and analyzed with a gas chromatograph. Multiple samples are taken in parallel, and the average value is taken to calculate the conversion rate and selectivity under the current reaction conditions. According to calculations, the conversion rate of propyne is 95.6% and the selectivity of propylene is 63.0%.

[0072] According to the above experimental results, the catalyst prepared by the present invention, which uses non-precious metal nickel as the main active center, metal copper and potassium as additives, and γ-Al2O3-TiO2 composite oxide as a carrier, has good catalytic activity for the selective hydrogenation of propyne to produce propylene in a high hydrogen sulfide environment, and has good industrial application prospects. Metallic copper can well induce the dispersion of the main active metal nickel, improve the nickel dispersion, and transfer the charge to the metallic nickel, which helps to reduce the adsorption capacity of propylene on the catalyst surface and avoid excessive hydrogenation of propylene. Metallic potassium and the composite carrier γ-Al2O3-TiO2 can improve the activation ability of hydrogen on the catalyst surface and enhance the catalyst's sulfur resistance (sulfur resistance performance such as Figure 2 As shown), it greatly reduces the adsorption of hydrogen sulfide on the catalyst surface and prolongs the service life of the catalyst (the service life of the catalyst is shown in Figure 1 as shown).

[0073] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0074] The above is a detailed introduction to the nickel-based sulfur-resistant catalyst, preparation method and application thereof for the selective hydrogenation of propyne to propylene provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. Application of a nickel-based sulfur-resistant catalyst in the selective hydrogenation of propyne to propylene, characterized in that The specific steps are: activating the nickel-based sulfur-resistant catalyst with hydrogen and nitrogen, cooling the catalyst to room temperature after reduction; and then catalyzing a mixed liquid of propane, propylene, propyne and hydrogen sulfide to undergo a hydrogenation reaction with hydrogen in a reactor; The nickel-based sulfur-resistant catalyst is composed of a main active component, a first auxiliary metal, a second auxiliary metal and a composite carrier. The main active component is nickel, which accounts for 0.5% to 5.0% of the composite support mass; The first auxiliary metal accounts for 0.5% to 5.0% of the mass of the composite support based on the total mass of metal atoms; The second auxiliary metal accounts for 0.5% to 5.0% of the mass of the composite support based on the total mass of metal atoms; The first auxiliary metal is selected from one or both of inorganic copper salts and inorganic chromium salts, the second auxiliary metal is selected from one or both of inorganic lithium salts and inorganic potassium salts, the composite carrier is a mixture of titanium dioxide and γ-type alumina; the main active component nickel precursor is Ni(NO3)2·6H2O, The first auxiliary metal inorganic copper salt and inorganic chromium salt are Cu(NO3)2·3H2O and Cr(NO3)3·9H2O respectively. The second auxiliary metal inorganic lithium salt and inorganic potassium salt are LiCl·H2O and KF·2H2O respectively; In the catalyst, the molar ratio of the main active component nickel, the first auxiliary metal copper, and the second auxiliary metal potassium is 1:(1-5):(1-8) based on the weight of metal atoms, and the molar ratio of n(Al) to n(Ti) in the composite carrier is: 1:(0.5-5).

2. The use according to claim 1, characterized in that: The catalyst reduction conditions are: hydrogen / nitrogen volume ratio (1~3):(7~9), pressure: 0.2~2MPa, reduction temperature: 350~500℃, heating rate: 5℃ / min, reduction time: 3~8h.

3. The use according to claim 1, characterized in that: The hydrogenation reaction conditions are: reaction pressure: 1~5MPa, reaction temperature: 30~80℃, reaction substrate propane, propylene, propyne molar concentrations: 65%, 34.9%, 0.1%, hydrogen sulfide content: 10~500ppm(mol), hydrogen to propyne molar ratio: 1.05~1.2, liquid hourly space velocity: 15~40h -1 .

4. The use according to claim 1, characterized in that The preparation method of the nickel-based sulfur-resistant catalyst comprises the following steps: (1) According to the Al / Ti molar ratio in the composite support, butyl titanate was weighed and dissolved in anhydrous ethanol, and the mixture was stirred thoroughly to obtain solution A; appropriate amounts of anhydrous ethanol, water, glacial acetic acid, and a small amount of acetylacetone were weighed and stirred thoroughly to obtain solution B; The volume ratio of butyl titanate, anhydrous ethanol, water and glacial acetic acid is 1:(3~10):(0.1~1):(0.1~1); (2) slowly adding solution B in step (1) dropwise into solution A while stirring, and after solution B is added, slowly adding 10-30 mmol / L dilute nitric acid solution, adjusting the pH value of the solution to 2-5, and stirring into a colloid; (3) According to the Al / Ti molar ratio in the composite carrier, weigh dry γ-Al2O3, add an appropriate amount of anhydrous ethanol and stir to form a suspension, then slowly add all of it to the colloid obtained in step (2), stirring while adding, and after stirring for 2 to 6 hours, it becomes a gel, and then it is aged at room temperature, dried, and calcined in sequence to obtain a γ-Al2O3-TiO2 composite carrier; (4) Weighing the main active component nickel precursor, the first auxiliary metal, and the second auxiliary metal and dissolving them in a 10-30 mmol / L dilute nitric acid solution to obtain a mixed metal impregnation liquid; (5) While stirring, slowly drip the mixed metal impregnation liquid in step (4) onto the composite support in step (3), and perform impregnation aging, filtering, washing, separation, drying, and calcination in sequence to obtain a catalyst precursor.

5. The use according to claim 4, characterized in that: In the catalyst, the molar ratio of the main active component nickel, the first auxiliary metal copper, and the second auxiliary metal potassium is 1:(1-3):(1-3) based on the weight of metal atoms; the molar ratio of n(Al) to n(Ti) in the composite carrier is: 1:(0.5-2.5).

6. The use according to claim 4, characterized in that: In step (3), the standing aging time is 12 to 24 hours, the drying temperature is 120 to 150°C, the drying time is 12 to 24 hours, and the roasting conditions are: heating rate: 3 to 10°C / min, from room temperature to 450 to 650°C, and constant temperature for 3 to 5 hours.

7. The use according to claim 4, characterized in that: In step (1), the volume ratio of butyl titanate, anhydrous ethanol, water and glacial acetic acid is 1:(3-5):(0.1-0.5):(0.1-0.5).

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