Catalyst for synthesizing 1-butene through selective hydrogenation of butadiene as well as preparation and application of catalyst

Abstract

The invention discloses a catalyst for synthesizing 1-butene through selective hydrogenation of butadiene as well as preparation and application of the catalyst. The catalyst is prepared by taking palladium chloride, a platinum-containing precursor, an iridium-containing precursor and silicon nitride as raw materials through a flame jet cracking method in one step, and the platinum-containing precursor, the iridium-containing precursor, the palladium chloride and the silicon nitride are fed according to the element molar ratio of Pt: Ir: Pd: N being 1: (1-1.5): 1: (77-163); wherein the molar weight of the N element is based on the total molar weight of the platinum-containing precursor, the iridium-containing precursor and the N element in the silicon nitride. A flame jet cracking device is used in the preparation process of the catalyst, and the catalyst is good in structural characteristic, high in component regulation and control performance, simple and convenient in preparation process, high in catalytic activity and good in stability.

Description

TECHNICAL FIELD

[0001] The present application relates to a catalyst for the selective hydrogenation of butadiene to 1-butene and its preparation and application. BACKGROUND

[0002] Butadiene hydrogenation is an important reaction in the field of petroleum chemical industry, and its products such as 1-butene are basic chemical raw materials. The selectivity control of butadiene hydrogenation is particularly crucial, because excessive hydrogenation will generate by-products such as butane, reducing the yield and purity of target products. Supported metal catalysts improve the dispersion and utilization of metals by dispersing active metal components on carriers with high specific surface area, thereby enhancing the catalytic performance. Silicon nitride is an excellent carrier material with high hardness, high wear resistance, good thermal stability and chemical stability, which is suitable as a catalyst carrier. Palladium is a noble metal catalyst widely used in hydrogenation reactions, which has excellent hydrogenation performance for olefin compounds. However, its high cost limits large-scale application, so it is often supported to reduce the cost. Platinum is also an important hydrogenation catalyst, similar to palladium, with high activity and selectivity, but also faces cost problems. Although iridium is less used directly in hydrogenation reactions, it can exhibit unique catalytic performance under certain conditions or in combination with other metals, such as improving the stability and resistance to poisoning of the catalyst.

[0003] The present application aims to develop a preparation method for introducing multiple auxiliary metals into Pd-based catalysts, adjusting the geometric and electronic structure of Pd nanoparticles and producing a synergistic effect, improving its selectivity and yield in butadiene hydrogenation reaction, while reducing production costs. SUMMARY

[0004] The present application aims to overcome the problems of short service life of Pd-based catalysts used in catalytic reactions, immature application and research of supported non-noble metal catalysts, poor stability of supported noble metals, and high cost of use, and to provide a catalyst for catalyzing butadiene hydrogenation reaction to synthesize 1-butene and its preparation method and application.

[0005] The technical solutions adopted by the present application are described below.

[0006] In a first aspect, the present application provides a catalyst for the selective hydrogenation of butadiene to 1-butene, which is prepared by flame spray pyrolysis (FSP) using palladium chloride, platinum-containing precursor, iridium-containing precursor and silicon nitride as raw materials. The molar ratio of Pt:Ir:Pd:N is 1:1-1.5:1:77-163, and the molar amount of N is based on the total molar amount of N in the platinum-containing precursor, iridium-containing precursor and silicon nitride.

[0007] Furthermore, the platinum-containing precursor is selected from one or more of chloroplatinic acid, platinum oxide, platinum nitrate, platinum chloride, and platinum acetylacetonate. Furthermore, the platinum-containing precursor is platinum nitrate.

[0008] Furthermore, the iridium-containing precursor is selected from one or more of chloroiridic acid, iridium oxide, iridium nitrate, iridium chloride, and iridium acetylacetonate. Furthermore, the iridium-containing precursor is iridium nitrate.

[0009] Furthermore, the average particle size of the silicon nitride is between 50 and 5000 nm.

[0010] Furthermore, the silicon nitride is α-type Si3N4.

[0011] Furthermore, during the one-step preparation of the catalyst by flame spray pyrolysis (FSP), the nozzle temperature is controlled at 1500-3000°C, the filter temperature is controlled at 100-500°C, and the reaction time is controlled at 5-15 minutes. Furthermore, the nozzle temperature is controlled at 2000-2800°C, preferably 2000-2300°C, the filter temperature is controlled at 200-500°C, preferably 200-400°C, and the reaction time is controlled at 8-12 minutes.

[0012] In a second aspect, the present invention provides a method for preparing the catalyst for selective hydrogenation of butadiene to 1-butene according to the first aspect, comprising the following steps:

[0013] Step 1: fully mix platinum nitrate, iridium nitrate, palladium chloride, silicon nitride and solvent in proportion, and stir evenly to obtain a precursor mixture;

[0014] Step 2: The flame jet cracker generates a flame by burning a mixture of CH4 and O2;

[0015] Step 3: The precursor mixture obtained in step 1) is pumped into the nozzle of the flame jet cracking device. The precursor mixture is sprayed out from the nozzle, dispersed into droplets by the dispersion gas, and introduced into the flame for combustion. During the reaction process, the nozzle temperature is controlled at 1500-3000° C., the filter temperature is controlled at 100-500° C., and the reaction time is 5-15 minutes.

[0016] Step 4: After cooling, the catalyst particles formed after combustion are collected from the filter and ground to obtain a catalyst for selective hydrogenation of butadiene to 1-butene.

[0017] Furthermore, the solvent in step 1 is a mixed solvent consisting of acetic acid (AA), 2-ethylhexanoic acid (EHA) and methanol (MeOH) in a volume ratio of 1:0.5-1.5:1-3 (preferably 1:1:2).

[0018] Further, in step 1, the concentration of the palladium chloride in the precursor mixture is 0.01-1 mol / L, and more preferably, the concentration of the palladium chloride is 0.01-0.03 mol / L.

[0019] Further, in step 2, the flow rate of CH4 and O2 is 0.5-5 L / min and 1-10 L / min, respectively, and more preferably, the flow rate of CH4 and O2 is 0.5-1 L / min and 1.5-2.5 L / min, respectively.

[0020] Further, in step 3, the pump-in flow rate of the precursor mixture is 1-15 mL / min, and more preferably, the pump-in flow rate is 4-6 mL / min.

[0021] Further, in step 3, the dispersing gas is oxygen, and the input rate of the oxygen is 1-10 L / min, and more preferably, the input rate is 2-5 L / min.

[0022] Further, in step 3, the temperature of the nozzle is controlled at 2000-2800 ℃, and preferably, the temperature of the nozzle is controlled at 2000-2300 ℃, and the temperature of the filter is controlled at 200-500 ℃, and preferably, the temperature of the filter is controlled at 200-400 ℃; and the reaction time is 8-12 min.

[0023] Further, in step 4, the catalyst particles are ground into powders with a desired particle size, and the powders can also be pressed into blocks according to requirements.

[0024] The reaction time in the present application refers to the input time of the dispersing gas, and generally, the input time of the dispersing gas is required to be greater than the pump-in time of the precursor mixture.

[0025] In a third aspect, the present application provides an application of the catalyst in the selective hydrogenation of butadiene to synthesize 1-butene.

[0026] The application is specifically as follows: the catalyst is loaded into a fixed bed reactor, and a raw gas is inputted, the reaction temperature is 90-200 ℃, the reaction pressure is 0.1-0.5 MPa, and 1-butene is generated by the reaction; the raw gas comprises hydrogen and butadiene.

[0027] The raw gas in the present application can also comprise N2 and C4H8.

[0028] Further, in the raw gas, the molar ratio n(H2) / n(C4H6) is 0.8-1.2 / 1.

[0029] Further, the butadiene gas space velocity is 30-370 h -1 .

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] (1) The preparation method of the catalyst used in the present application is in-situ synthesis of Pd-Pt-Ir / silicon nitride material catalyst, and the material itself has relatively high activity.

[0032] (2) The flame jet cracking device is used in the preparation process of the catalyst, and has the advantages of good structural characteristics, strong component regulation, simple preparation process, high catalytic activity and good stability.

[0033] (3) The Pd-Pt-Ir / silicon nitride material has many advantages, the dispersion degree of the active center on the surface of the catalyst is obviously improved, the introduction of the additives Pt and Ir promotes the dispersion of the metal Pd, inhibits the agglomeration of the Pd species in the reaction process, and improves the catalytic performance of the catalyst in the reaction of preparing 1-butene by selectively hydrogenating butadiene.

[0034] (4) The Pd-Pt-Ir / silicon nitride catalyst prepared by the present application has good catalytic activity in the butadiene hydrogenation reaction under a wide range of space velocities. DETAILED DESCRIPTION

[0035] The present application will be described in detail below with specific examples. It should be pointed out that the examples are only used to further illustrate the present application, and cannot be understood as limiting the scope of protection of the present application. The skilled person in the art can make some non-essential improvements and adjustments according to the content of the above-mentioned application.

[0036] In the examples of the present application, the specific conditions are not specified, and the conventional conditions or the conditions recommended by the manufacturer are used. The reagents or instruments used are not specified by the manufacturer, and are conventional products that can be obtained by conventional technical means or purchased on the market.

[0037] The silicon nitride used in the examples of the present application is α-type Si3N4, and the average particle size is 500 nm.

[0038] Example 1

[0039] (1) 0.323 g of platinum nitrate, 0.4322 g of iridium nitrate, 0.1774 g of palladium chloride, and 6 g of silicon nitride were weighed, and 50 ml of a mixture of acetic acid (AA), 2-ethylhexanoic acid (EHA) and methanol (MeOH) in a volume ratio of 1:1:2 was added, and stirred for 2 h to make them fully mixed;

[0040] (2) In the flame jet cracking device, first, 0.6 L / min of CH4 was introduced for 8 minutes, and then 1.9 L / min of O2 was introduced after the gas in the device was stabilized, and the flame was ignited and burned for 10 minutes;

[0041] (3) The metal precursor solution obtained in step 1) was pumped into the nozzle at a flow rate of 5 ml / min through a syringe pump, and the precursor mixture was ejected from the nozzle. At the same time, O2 was introduced into the gap around the nozzle at a rate of 3.5 L / min. The precursor mixture was dispersed into droplets by O2 and introduced into the flame for combustion. The ventilation was continued for 10 minutes. The temperature of the flame nozzle was controlled at 1500°C and the temperature of the filter was controlled at 100°C using two cooling water pipes.

[0042] (4) After cooling the FSP system for 15 minutes, carefully collect the sediment particles from the filter and grind them to 80 mesh;

[0043] (5) Butadiene hydrogenation reaction evaluation in a fixed bed reactor: Butadiene hydrogenation reaction at 130 ° C, reaction pressure of 0.45 MPa, butadiene space velocity of 80 h -1 The reaction was carried out under a hydrogen:butadiene volume ratio of 1.2:1. Gas samples were taken every hour for content analysis by gas chromatography. Over a 10-hour reaction, the conversion rate showed an upward trend during the first two to three hours, then stabilized. The stable conversion and selectivity were recorded, yielding 82% conversion and 76% 1-butene selectivity.

[0044] Example 2

[0045] (1) Weigh 0.323 g of platinum nitrate, 0.4322 g of iridium nitrate, 0.1774 g of palladium chloride, and 3.51 g of silicon nitride, add 50 ml of a mixture of acetic acid (AA), 2-ethylhexanoic acid (EHA), and methanol (MeOH) in a volume ratio of 1:1:2, and stir for 2 h to mix thoroughly;

[0046] (2) In the flame jet cracking device, CH4 was first introduced at a flow rate of 0.6 L / min for 8 minutes. After the gas in the device stabilized, O2 was introduced at a flow rate of 1.9 L / min, and the flame was ignited at the same time and continued to burn for 10 minutes;

[0047] (3) The metal precursor solution obtained in step 1) was pumped into the nozzle at a flow rate of 5 ml / min through a syringe pump, and the precursor mixture was ejected from the nozzle. At the same time, O2 was introduced into the gap around the nozzle at a rate of 3.5 L / min. The precursor mixture was dispersed into droplets by O2 and introduced into the flame for combustion. The ventilation was continued for 10 minutes. The temperature of the flame nozzle was controlled at 2000°C and the temperature of the filter was controlled at 200°C using two cooling water pipes.

[0048] (4) After cooling the FSP system for 25 minutes, carefully collect the sediment particles from the filter and grind them to 80 mesh;

[0049] (5) Butadiene hydrogenation reaction evaluation was carried out on a fixed bed reactor device: butadiene hydrogenation reaction was carried out at 110°C, reaction pressure was 0.4 MPa, butadiene space velocity was 60 h -1 , hydrogen:butadiene volume ratio was 1.2:1; using the same observation method as in Example 1, the reaction conversion rate was 91%, and the 1-butene selectivity was 95%.

[0050] Example 3

[0051] (1) 0.323 g of platinum nitrate, 0.4322 g of iridium nitrate, 0.1774 g of palladium chloride, and 4.419 g of silicon nitride were weighed, and 50 ml of a mixture of acetic acid (AA), 2-ethylhexanoic acid (EHA), and methanol (MeOH) in a volume ratio of 1:1:2 was added, and stirred for 2 h to allow them to be mixed well;

[0052] (2) In the flame spray pyrolysis device, CH4 with a flow rate of 0.6 L / min was first introduced for 5 min, and then O2 with a flow rate of 1.9 L / min was introduced, and the flame was ignited and burned for 10 min;

[0053] (3) The metal precursor solution obtained in step 1) was pumped into the nozzle at a flow rate of 5 ml / min by an injection pump, and the precursor mixture was sprayed from the nozzle, and at the same time, O2 was introduced into the gap around the nozzle at a rate of 3.5 L / min, and the precursor mixture was dispersed into droplets by O2, and introduced into the flame for combustion, and the gas was continuously introduced for 10 min; two cooling water pipes were used to control the temperature of the flame nozzle at 2300°C, and the temperature of the filter was controlled at 400°C;

[0054] (4) After the FSP system was cooled for 30 min, the deposited particles were carefully collected from the filter, and the particle size was ground to 80 mesh;

[0055] (5) Butadiene hydrogenation reaction evaluation was carried out on a fixed bed reactor device: butadiene hydrogenation reaction was carried out at 110°C, reaction pressure was 0.3 MPa, butadiene space velocity was 30 h -1 , hydrogen:butadiene volume ratio was 1.2:1; using the same observation method as in Example 1, the reaction conversion rate was 97%, and the 1-butene selectivity was 99%.

[0056] Example 4

[0057] (1) 0.323 g of platinum nitrate, 0.4322 g of iridium nitrate, 0.1774 g of palladium chloride, and 4.419 g of silicon nitride were weighed, and 50 ml of a mixture of acetic acid (AA), 2-ethylhexanoic acid (EHA), and methanol (MeOH) in a volume ratio of 1:1:2 was added, and stirred for 2 h to allow them to be mixed well;

[0058] (2) In the flame spray pyrolysis device, first introduce CH4 with a flow rate of 0.6 L / min for 8 minutes, and then introduce O2 with a flow rate of 1.9 L / min after the gas in the device is stabilized, and ignite to produce a flame and continue to burn for 10 minutes;

[0059] (3) Pump the metal precursor solution obtained in step (1) into the nozzle at a flow rate of 5 ml / min by an injection pump, and spray the precursor mixture from the nozzle, while introducing O2 into the gap around the nozzle at a rate of 3.5 L / min, so that the precursor mixture is dispersed into droplets by O2, and introduced into the flame for combustion, and continue to introduce air for 10 minutes; use two cooling water pipes to control the temperature of the flame nozzle at 2800℃, and control the temperature of the filter at 500℃;

[0060] (4) After cooling the FSP system for 40 minutes, carefully collect the deposited particles from the filter, and grind the particle size to 80 mesh;

[0061] (5) Perform butadiene hydrogenation reaction evaluation on a fixed bed reactor device: butadiene hydrogenation reaction is carried out at 140℃, the reaction pressure is 0.5 MPa, the butadiene space velocity is 100 h -1 , and the volume ratio of hydrogen to butadiene is 1:1; using the same observation method as in Example 1, the reaction conversion rate is 85%, and the 1-butene selectivity is 95%.

[0062] Example 5

[0063] (1) Weigh 0.323g of platinum nitrate, 0.4322g of iridium nitrate, 0.1774g of palladium chloride, and 4.419g of silicon nitride, add 50ml of a mixture of acetic acid (AA), 2-ethylhexanoic acid (EHA) and methanol (MeOH) in a volume ratio of 1:1:2, stir for 2h to make them fully mixed;

[0064] (2) In the flame spray pyrolysis device, first introduce CH4 with a flow rate of 0.6 L / min for 8 minutes, and then introduce O2 with a flow rate of 1.9 L / min after the gas in the device is stabilized, and ignite to produce a flame and continue to burn for 10 minutes;

[0065] (3) Pump the metal precursor solution obtained in step (1) into the nozzle at a flow rate of 5 ml / min by an injection pump, and spray the precursor mixture from the nozzle, while introducing O2 into the gap around the nozzle at a rate of 3.5 L / min, so that the precursor mixture is dispersed into droplets by O2, and introduced into the flame for combustion, and continue to introduce air for 10 minutes; use two cooling water pipes to control the temperature of the flame nozzle at 2800℃, and control the temperature of the filter at 500℃;

[0066] (4) After cooling the FSP system for 40 minutes, carefully collect the deposited particles from the filter, and grind the particle size to 80 mesh;

[0067] (5) The hydrogenation reaction of butadiene was carried out in a fixed bed reactor at 90°C, a reaction pressure of 0.5 MPa, a butadiene space velocity of 150 h"1, and a hydrogen:butadiene volume ratio of 1:0.8. The conversion rate of the reaction was 89% and the selectivity of 1-butene was 92% using the same observation method as in Example 1. -1

[0068] Comparative Example 1: Comparison with Example 2

[0069] The catalyst was prepared according to Example 2, except that no iridium nitrate and platinum nitrate were added. The hydrogenation reaction of butadiene was carried out in a fixed bed reactor at 110°C, a reaction pressure of 0.4 MPa, a butadiene space velocity of 60 h"1, and a hydrogen:butadiene volume ratio of 1.2:1. The conversion rate of the reaction was 70% and the selectivity of 1-butene was 58% using the same observation method as in Example 1. -1

[0070] As shown by the comparison between Comparative Example 1 and Example 2, the introduction of platinum and iridium can significantly improve the catalytic performance of the catalyst, and the conversion rate of butadiene and the selectivity of 1-butene are both significantly improved.

[0071] Comparative Example 2

[0072] The catalyst was prepared according to Example 2, except that no iridium nitrate was added. The hydrogenation reaction of butadiene was carried out in a fixed bed reactor at 110°C, a reaction pressure of 0.4 MPa, a butadiene space velocity of 60 h"1, and a hydrogen:butadiene volume ratio of 1.2:1. The conversion rate of the reaction was 83% and the selectivity of 1-butene was 75% using the same observation method as in Example 1. -1

[0073] Comparative Example 3

[0074] The catalyst was prepared according to Example 1, except that no platinum nitrate was added. The hydrogenation reaction of butadiene was carried out in a fixed bed reactor at 110°C, a reaction pressure of 0.4 MPa, a butadiene space velocity of 60 h"1, and a hydrogen:butadiene volume ratio of 1.2:1. The conversion rate of the reaction was 79% and the selectivity of 1-butene was 69% using the same observation method as in Example 1. -1

[0075] Comparative Example 4 (impregnation method)

[0076] ​​​​(1) Preparation of impregnation solution: 0.323 g of platinum nitrate, 0.4322 g of iridium nitrate and 0.1774 g of palladium chloride were weighed and dissolved in 50 ml of deionized water by ultrasonic stirring;

[0077] (2) The impregnation solution in (1) was added to 4.419 g of silicon nitride, and static impregnation was carried out at room temperature for 10 h;

[0078] (3) The impregnated carrier in (2) was placed in a vacuum oven and dried at 120°C for 10 h;

[0079] (4) The catalyst obtained in (3) was placed in a muffle furnace and calcined at 500°C for 4 h, and the particle size was ground to 80 mesh;

[0080] (5) The catalyst obtained in (4) was placed in a hydrogen reduction furnace and reduced at 400°C for 2 h;

[0081] (6) Butadiene hydrogenation reaction evaluation was carried out on a fixed bed reactor device: butadiene hydrogenation reaction was carried out at 110°C, the reaction pressure was 0.3 MPa, the butadiene space velocity was 30 h -1 , and the volume ratio of hydrogen to butadiene was 1.2:1; the same observation method as in Example 1 was used, and the reaction conversion rate was 63% and the 1-butene selectivity was 82%.

[0082] Table 1 summarizes

[0083]

[0084] Note: The catalyst evaluation conditions in each example and comparative example are the best evaluation conditions for the respective catalysts

Claims

1. A catalyst for selective hydrogenation of butadiene to 1-butene, characterized by: The catalyst is prepared in one step by a flame jet pyrolysis method using palladium chloride, a platinum-containing precursor, an iridium-containing precursor and silicon nitride as raw materials. The platinum-containing precursor, the iridium-containing precursor, the palladium chloride and the silicon nitride are added according to an element molar ratio of Pt:Ir:Pd:N=1:1-1.5:1:77-163, wherein the molar amount of the N element is calculated based on the total molar amount of the N element in the platinum-containing precursor, the iridium-containing precursor and the silicon nitride.

2. The catalyst according to claim 1, wherein: The platinum-containing precursor is selected from one or more of chloroplatinic acid, platinum oxide, platinum nitrate, platinum chloride, and platinum acetylacetonate; the iridium-containing precursor is selected from one or more of chloroiridic acid, iridium oxide, iridium nitrate, iridium chloride, and iridium acetylacetonate.

3. The catalyst according to claim 1, wherein: The average particle size of the silicon nitride is between 50 and 5000 nm.

4. The catalyst according to claim 1, wherein: The silicon nitride is α-type Si3N4.

5. The catalyst according to claim 1, wherein: In the process of preparing the catalyst in one step by flame spray cracking, the nozzle temperature is controlled at 1500-3000°C, preferably 2000-2800°C, more preferably 2000-2300°C; the filter temperature is 100-500°C, preferably 200-500°C, more preferably 200-400°C; and the reaction time is 5-15 minutes, preferably 8-12 minutes.

6. A method for preparing a catalyst for selective hydrogenation of butadiene to 1-butene according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: Step 1: fully mix platinum nitrate, iridium nitrate, palladium chloride, silicon nitride and solvent in proportion, and stir evenly to obtain a precursor mixture; Step 2: The flame jet cracker generates a flame by burning a mixture of CH4 and O2; Step 3: The precursor mixture obtained in step 1) is pumped into the nozzle of the flame jet cracking device. The precursor mixture is sprayed out from the nozzle, dispersed into droplets by the dispersion gas, and introduced into the flame for combustion. During the reaction process, the nozzle temperature is controlled at 1500-3000° C., the filter temperature is controlled at 100-500° C., and the reaction time is 5-15 minutes. Step 4: After cooling, the catalyst particles formed after combustion are collected from the filter and ground to obtain a catalyst for selective hydrogenation of butadiene to 1-butene.

7. The preparation method according to claim 6, wherein: The solvent in step 1 is a mixed solvent consisting of acetic acid, 2-ethylhexanoic acid and methanol in a volume ratio of 1:0.5-1.5:1-3; the concentration of palladium chloride in the precursor mixture is 0.01-1 mol / L.

8. The preparation method according to claim 6, wherein: In step 2, the flow rates of CH4 and O2 are 0.5-5 L / min and 1-10 L / min, respectively. Preferably, the flow rates of CH4 and O2 are 0.5-1 L / min and 1.5-2.5 L / min, respectively.

9. The preparation method according to claim 6, wherein: In step 3, the pumping flow rate of the precursor mixture is 1 to 15 mL / min, preferably 4 to 6 mL / min; the dispersed gas is oxygen, and the input rate of oxygen is 1 to 10 L / min, preferably 2 to 5 L / min.

10. Use of the catalyst according to any one of claims 1 to 5 in the selective hydrogenation of butadiene to synthesize 1-butene.

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