Preparation method for generating 1-butene from 2-butene through isomerization

Abstract

The invention discloses a preparation method for generating 1-butene by isomerization of 2-butene, and the preparation method comprises the following steps: activating a catalyst, and reacting with 2-butene to obtain 1-butene; the catalyst is a metal-ZSM-22 molecular sieve catalyst. According to the present invention, the 1-butene is generated through the 2-butene isomerization, such that the ideal 2-butene conversion activity and the excellent 1-butene selectivity are provided; the catalyst is simple in composition and easy for large-scale application, and has a good industrial application prospect.

Description

Technical Field

[0001] This application relates to a method for preparing 1-butene by isomerization of 2-butene, which belongs to the field of chemical engineering technology. Background Technology

[0002] 1-Butene is an important chemical raw material for the production of linear low-density polyethylene resin, high-density polyethylene, 1-octene, dodecene, butadiene, isoprene, and synthetic rubber, with wide applications and high industrial value. However, traditional chemical synthesis methods require valuable ethylene resources, resulting in high costs. Therefore, to make more rational use of C4 resources, the technology of isomerizing 1-butene from 2-butene has greater economic significance.

[0003] ZSM molecular sieves, with their unique mesoporous channels and three-dimensional structure, exhibit good stability and isomerization selectivity in catalytic olefin reactions, making them ideal materials for olefin isomerization. Theoretical calculations show that butene on ZSM-48 is prone to skeletal isomerization, not double bond isomerization. ZSM-35 is also a promising catalyst, but its hydrothermal stability is poor. In contrast, patent CN102649084 A discloses that ZSM-5 molecular sieves are prone to double bond isomerization with high selectivity, but its conversion rate is low. The double bond isomerization reaction of butene requires acidic conditions for catalysis, so optimizing the number and distribution of acid centers is the main research direction. Introducing heteroatoms into the molecular sieve framework is an effective method to modulate the type and strength of its acid centers and improve catalytic performance. In the same literature (Petroleum Refining and Chemical Engineering 47(8), 2016:1-6), the study on the isomerization of 1-heptene confirmed that the acid strength of the acid center is the active site, which can effectively promote the double bond isomerization of olefins.

[0004] Therefore, developing catalysts that combine high selectivity and stability for butene double bond isomers remains an urgent problem to be solved. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide an application of a catalyst for the conversion of 2-butene to 1-butene, which exhibits excellent selectivity in the catalytic isomerization reaction of 2-butene to 1-butene. To achieve the above objective, the catalyst modulates the acid properties of ZSM-22 molecular sieve by introducing specific metals Co and Ni and subsequent acid treatment. Under the synergistic effect of Co and Ni with ZSM-22 molecular sieve, the skeletal isomerization reaction between 2-butene and 1-butene is significantly suppressed, thereby improving the selectivity for the isomerization of 2-olefin double bonds to 1-butene.

[0006] According to one aspect of this application, a method for preparing 1-butene by isomerization of 2-butene is provided, the method comprising:

[0007] The catalyst was activated and reacted with 2-butene to obtain 1-butene;

[0008] The catalyst is a metal-ZSM-22 molecular sieve catalyst;

[0009] The metal-ZSM-22 molecular sieve catalyst contains 0.5% to 5% metal by mass.

[0010] The metal is cobalt and / or nickel.

[0011] Optionally, the mass percentage of metal in the metal-ZSM-22 molecular sieve catalyst is independently selected from any value of 0.5%, 1%, 2%, 3%, 4%, 5% or a range between any two of the above.

[0012] Optionally, the preparation method of the metal-ZSM-22 molecular sieve catalyst includes:

[0013] A mixture containing ZSM-22 molecular sieve and metal salt solution is aged, dried (I), acid-treated, dried (II), and calcined to obtain a metal-ZSM-22 molecular sieve catalyst.

[0014] Optionally, the metal salt solution is selected from at least one of Co(NO3)2, Ni(NO3)2, and NiSO4·7H2O.

[0015] Optionally, the silicon-to-aluminum ratio of the ZSM-22 molecular sieve is 50 to 200.

[0016] Optionally, the silica-alumina ratio of the ZSM-22 molecular sieve is independently selected from any value of 50, 80, 100, 120, 150, 180, 200 or a range between any two of the above.

[0017] Optionally, the ratio of the ZSM-22 molecular sieve to the metal salt solution is 1:1 to 2.

[0018] Optionally, the aging time is 1 to 12 hours.

[0019] Optionally, the temperatures of drying I and drying II are independently selected from 100 to 120°C, and the times of drying I and drying II are independently selected from 6 to 12 hours.

[0020] Optionally, the acid used for acid treatment is selected from at least one of nitric acid, hydrochloric acid, and sulfuric acid.

[0021] Optionally, the concentration of the acid is 1 to 5 mol / L.

[0022] Optionally, the calcination temperature is 500–600°C, and the calcination time is 4–8 hours.

[0023] Optionally, the activation temperature is 400–500°C, and the activation time is 2–5 hours.

[0024] Optionally, the activation temperature is independently selected from any value of 400°C, 420°C, 440°C, 460°C, 480°C, 500°C, or a range between any two of the above.

[0025] Optionally, the feed space velocity of the 2-butene is 10–25 h⁻¹. -1 .

[0026] Optionally, the feed space velocity of the 2-butene is independently selected from 10 h⁻¹. -1 12h -1 15h -1 18h -1 20h -1 25h -1 Any value in or a range between any two of the above.

[0027] Optionally, the reaction temperature is 200–400°C, and the reaction pressure is 0.1–3 MPa.

[0028] Optionally, the temperature of the reaction is independently selected from any value of 200°C, 250°C, 300°C, 350°C, 400°C, or a range between any two of the above.

[0029] Optionally, the pressure of the reaction is independently selected from any value of 0.1 MPa, 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, or a range between any two of the above.

[0030] As an optional implementation, this application is achieved through the following technical solution:

[0031] The preparation method of metal-ZSM-22 molecular sieve catalyst includes the following steps:

[0032] a) Prepare a solution containing a certain amount of active metal salt.

[0033] b) Add a certain mass of ZSM-22 molecular sieve to a);

[0034] c) After aging for a certain period of time, the catalyst is dried and calcined to obtain the metal-ZSM-22 molecular sieve catalyst.

[0035] The beneficial effects that this application can produce include:

[0036] 1) The metal-molecular sieve catalyst provided in this application improves the selectivity of 2-butene to 1-butene through double bond isomerization by introducing specific metals Co and nickel into ZSM-22 molecular sieve and subsequent acid treatment.

[0037] 2) The method for preparing the metal-ZSM-22 molecular sieve catalyst provided in this application is simple and efficient, and the catalyst is inexpensive and readily available.

[0038] 3) The 2-butene isomerization to 1-butene provided in this application has ideal 2-butene conversion activity and excellent 1-butene selectivity, is easy to scale up for large-scale application, and has good industrial application prospects. Detailed Implementation

[0039] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0040] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0041] Conversion rate = ((initial moles of 2-butene - remaining moles of 2-butene) / initial moles of 2-butene) × 100%;

[0042] Selectivity = (moles of 1-butene produced / (initial moles of 2-butene - remaining moles of 2-butene)) × 100%.

[0043] Example 1

[0044] Preparation and application of Co / ZSM-22 (silicon-to-aluminum ratio 100) catalyst

[0045] 1g of Co(NO3)2·6H2O was added to 20mL of deionized water and stirred to dissolve. Then, 5g of ZSM-22 (silicon-to-aluminum ratio 100) molecular sieve was added and aged for 6 hours. The mixture was then dried at 120℃ overnight. The sample was then acid-washed with 1mol / L nitric acid for 30 hours, washed with deionized water until neutral, and dried in a 120℃ oven for 12 hours. After that, it was ground evenly and calcined in a muffle furnace at 550℃ for 6 hours to obtain Co / ZSM-22 (silicon-to-aluminum ratio 100) molecular sieve with a Co mass percentage of 3.9%.

[0046] 1 g of the prepared Co / ZSM-22 catalyst was loaded into a fixed-bed reactor, and the temperature was increased to 450 °C at a rate of 10 °C / min with 50 ml / min N2, and activated for 4 h. The reactor was then activated at 380 °C, 0.2 MPa, and a feed space velocity of 15 h⁻¹ for 2-butene. -1 The reaction was carried out under specific conditions. The specific reaction results are listed in Table 1.

[0047] Example 2

[0048] Preparation and application of Ni / ZSM-22 (silicon-to-aluminum ratio 100) catalyst

[0049] 1.2 g of Ni(NO3)2·6H2O was added to 20 mL of deionized water and stirred to dissolve. Then, 5 g of ZSM-22 (silicon-to-aluminum ratio 100) molecular sieve was added to the solution. The mixture was aged for 6 h and then dried at 120 °C overnight. The sample was then acid-washed with 3 mol / L hydrochloric acid for 10 h, washed with deionized water until neutral, and dried in an oven at 120 °C for 10 h. After that, the sample was ground evenly and calcined in a muffle furnace at 550 °C for 6 h to obtain Ni / ZSM-22 (silicon-to-aluminum ratio 100) molecular sieve with a Ni mass percentage of 4.6%.

[0050] 1 g of the prepared Ni / ZSM-22 catalyst was loaded into a fixed-bed reactor, and the temperature was increased to 450 °C at a rate of 10 °C / min with 50 ml / min N2, and activated for 4 h. The reactor was then activated at 380 °C, 0.2 MPa, and a feed space velocity of 12 h⁻¹ for 2-butene. -1 The reaction was carried out under specific conditions. The specific reaction results are listed in Table 1.

[0051] Example 3

[0052] Preparation and application of Ni-Co / ZSM-22 (silicon-to-aluminum ratio 100) catalyst

[0053] 0.1g Ni(NO3)2·6H2O and 0.05g Co(NO3)2·6H2O were added to 10mL of deionized water and stirred to dissolve. Then, 1g of ZSM-22 (silicon-to-aluminum ratio 100) molecular sieve was added and aged for 12h. Then, the sample was dried at 120℃ overnight. After that, the sample was acid-washed with 3mol / L sulfuric acid for 10h, washed with deionized water until neutral, and dried in an oven at 120℃ for 12h. After that, it was ground evenly and calcined in a muffle furnace at 550℃ for 6h to obtain Ni-Co / ZSM-22 (silicon-to-aluminum ratio 100) molecular sieve, in which the mass percentage of Co was 1% and the mass percentage of Ni was 1.9%.

[0054] The prepared 1g Ni-Co / ZSM-22 catalyst was loaded into a fixed-bed reactor, and the temperature was increased to 450℃ at a rate of 10℃ / min with 50ml / min N2, and activated for 4h. The reactor was then activated at 390℃, 0.2MPa, and a feed space velocity of 10h for 2-butene. -1 The reaction was carried out under the specified conditions. The specific reaction results are listed in Table 1.

[0055] Example 4

[0056] Preparation and application of Ni / ZSM-22 (silicon-to-aluminum ratio 130) catalyst

[0057] 0.05 g of Ni(NO3)2·6H2O was added to 10 mL of deionized water and stirred to dissolve. Then, 1 g of ZSM-22 (silicon-to-aluminum ratio 130) molecular sieve was added to the solution. The mixture was aged for 10 h and then dried at 120 °C overnight. The sample was then acid-washed with 3 mol / L nitric acid for 10 h, washed with deionized water until neutral, and dried in an oven at 120 °C for 6 h. After that, the sample was ground evenly and calcined in a muffle furnace at 550 °C for 6 h to obtain Ni / ZSM-22 (silicon-to-aluminum ratio 130) molecular sieve, wherein the mass percentage of Ni was 1%.

[0058] 1 g of the prepared Ni / ZSM-22 catalyst was loaded into a fixed-bed reactor, and the temperature was increased to 450 °C at a rate of 10 °C / min with 50 ml / min N2, and activated for 4 h. The reactor was then activated at 390 °C, 0.2 MPa, and a feed space velocity of 12 h⁻¹ for 2-butene. -1 The reaction was carried out under the specified conditions. The specific reaction results are listed in Table 1.

[0059] Example 5

[0060] Preparation and application of Co / ZSM-22 (silicon-to-aluminum ratio 130) catalyst

[0061] 0.15 g of NiSO4·7H2O was added to 20 mL of deionized water and stirred to dissolve. Then, 2 g of ZSM-22 (silicon-to-aluminum ratio 130) molecular sieve was added and aged for 6 h. After that, it was dried at 120 °C overnight. The sample was then acid-washed with 2 mol / L nitric acid for 20 h, washed with deionized water until neutral, and dried in an oven at 120 °C for 6 h. After that, it was ground evenly and calcined in a muffle furnace at 550 °C for 6 h to obtain Co / ZSM-22 (silicon-to-aluminum ratio 130) molecular sieve, in which the mass percentage of Co was 1.5%.

[0062] 1 g of the prepared Co / ZSM-22 catalyst was loaded into a fixed-bed reactor, and the temperature was increased to 500 °C at a rate of 10 °C / min with 50 ml / min N2, and activated for 4 h. The reactor was then activated at 390 °C, 0.1 MPa, and a feed space velocity of 10 h⁻¹ for 2-butene. -1 The reaction was carried out under specific conditions. The specific reaction results are listed in Table 1.

[0063] Example 6

[0064] Preparation and application of Ni-Co / ZSM-22 (silicon-to-aluminum ratio 130) catalyst

[0065] 0.1 g NiSO4·7H2O and 0.05 g Co(NO3)2·6H2O were added to 30 mL of deionized water and stirred to dissolve. Then, 2 g of ZSM-22 (silicon-to-aluminum ratio 130) molecular sieve was added. The mixture was aged for 8 h, then dried at 120 °C overnight. The sample was then acid-washed with 2 mol / L nitric acid for 20 h, washed with deionized water until neutral, and dried in a 120 °C oven for 12 h. After that, it was ground evenly and calcined in a muffle furnace at 550 °C for 6 h to obtain Ni-Co / ZSM-22 (silicon-to-aluminum ratio 130) molecular sieve, wherein the mass percentage of Co was 0.5% and the mass percentage of Ni was 1%.

[0066] The prepared 1g Ni-Co / ZSM-22 catalyst was loaded into a fixed-bed reactor, and the temperature was increased to 450℃ at a rate of 10℃ / min with 50ml / min N2, and activated for 4h. The reactor was then activated at 390℃, 0.2MPa, and a 2-butene feed space velocity of 10h⁻¹. -1 The reaction was carried out under specific conditions. The specific reaction results are listed in Table 1.

[0067] Comparative Example 1

[0068] Application of ZSM-22 (silicon-to-aluminum ratio 100) catalyst

[0069] 1 g of ZSM-22 (silicon-to-aluminum ratio 100) catalyst was loaded into a fixed-bed reactor, and the temperature was increased to 500 °C at a rate of 10 °C / min using 50 ml / min N2, and activated for 4 h. The reactor was then activated at 380 °C, 0.1 MPa, and a feed space velocity of 12 h⁻¹ for 2-butene. -1 The reaction was carried out under specific conditions. The specific reaction results are listed in Table 1.

[0070] Comparative Example 2

[0071] Application of ZSM-22 (silicon-to-aluminum ratio 130) catalyst

[0072] 1 g of ZSM-22 (silicon-to-aluminum ratio 130) catalyst was loaded into a fixed-bed reactor, and the temperature was increased to 500 °C at a rate of 10 °C / min using 50 ml / min N2, and activated for 4 h. The reactor was then activated at 400 °C, 0.1 MPa, and a feed space velocity of 10 h⁻¹ for 2-butene. -1 The reaction was carried out under specific conditions. The specific reaction results are listed in Table 1.

[0073] Table 1. Experimental results for catalyst activity evaluation

[0074]

[0075]

[0076] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing 1-butene by isomerization of 2-butene, characterized in that, The preparation method includes: The catalyst was activated and reacted with 2-butene to obtain 1-butene; The catalyst is a metal-ZSM-22 molecular sieve catalyst; The metal-ZSM-22 molecular sieve catalyst has a metal content of 0.5% to 5% by mass. The metal is one or both of cobalt and nickel.

2. The preparation method according to claim 1, characterized in that, The preparation method of the metal-ZSM-22 molecular sieve catalyst includes: A mixture containing ZSM-22 molecular sieve and metal salt solution is aged, dried (I), acid-treated, dried (II), and calcined to obtain a metal-ZSM-22 molecular sieve catalyst.

3. The preparation method according to claim 2, characterized in that, The metal salt solution is selected from at least one of Co(NO3)2, Ni(NO3)2, and NiSO4·7H2O.

4. The preparation method according to claim 2, characterized in that, The silicon-to-aluminum ratio of the ZSM-22 molecular sieve is 50–200; Preferably, the volume ratio of the ZSM-22 molecular sieve to the metal salt solution is 1:1 to 2.

5. The preparation method according to claim 2, characterized in that, The aging time is 1 to 12 hours; Preferably, the temperatures of drying I and drying II are independently selected from 100 to 120°C, and the times of drying I and drying II are independently selected from 6 to 12 hours.

6. The preparation method according to claim 2, characterized in that, The acid used in the acid treatment is selected from at least one of nitric acid, hydrochloric acid, and sulfuric acid; Preferably, the concentration of the acid is 1 to 5 mol / L.

7. The preparation method according to claim 2, characterized in that, The roasting temperature is 500-600℃, and the roasting time is 4-8 hours.

8. The preparation method according to claim 1, characterized in that, The activation temperature is 400–500℃, and the activation time is 2–5 hours.

9. The preparation method according to claim 1, characterized in that, The feed space velocity of the 2-butene is 10–25 h⁻¹. -1 .

10. The preparation method according to claim 1, characterized in that, The reaction temperature is 200–400℃, and the reaction pressure is 0.1–3 MPa.

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