Method for preparing butene from gamma-valerolactone
By using metal cation modified FAU molecular sieve catalysts, the problem of poor reaction stability of solid acid catalysts in the prior art at high aerial speeds was solved, and efficient conversion and selectivity of butenes prepared by γ-valerolactone were achieved, showing good results stability of reaction.
Patent Information
- Application Number
- CN202411259786.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2025-01-17
AI Technical Summary
The existing solid acid catalysts can only show good conversion and selectivity at low aerial speeds in the preparation of butene of γ-valerolide, and it is difficult to maintain reaction stability and high efficiency at high aerial speeds.
FAU-type molecular sieve catalyst modified with metal cations, including alkali metals, alkaline earth metals, rare earth elements and transition metal-modified Y zeolites, used for the preparation of butene reaction of γ-valerolide, and treated through a fixed bed reactor. In the catalyst The metal element content is 1 to 30 wt%, the silicon-aluminum ratio is 0.5 to 10, the reaction temperature is 300 to 500°C, the pressure is 0.02 to 5 MPa, and diluted with an inert gas.
The high conversion rate of γ-valerolide and high selectivity of butene were achieved at high aerial speeds, with good reaction stability and the catalyst showed excellent performance.
Abstract
Description
Technical Field
[0001] The present application relates to a method for preparing butene from γ-valerolactone, belonging to the field of heterogeneous catalysis. Background Art
[0002] Butene is an important organic chemical raw material and has a wide range of applications in the fields of energy and material synthesis. Butene can be used directly as a gas fuel or it can be polymerized to produce C8-C 16 liquid fuel. In addition, 1-butene and 2-butene can also be used to produce high value-added products such as butanol, butadiene, and butene copolymers. At present, the production of butene relies on fossil resources and is mainly produced by steam cracking of naphtha. The production of butene using renewable biomass-based raw materials is a very promising research direction. γ-Valerolactone is a highly promising biomass platform compound that can undergo a ring-opening decarboxylation reaction under the action of a solid acid catalyst to produce butene and carbon dioxide. This reaction provides a way to obtain butene from renewable biomass resources.
[0003] In 2010, the Dumesic research group of the University of Wisconsin-Madison reported in an article (Science, 2010, 327, 1110-1114) that amorphous SiO2-Al2O3 was used as a catalyst and heated at 375°C for 0.22 h. -1 Under the condition of mass space velocity of 36 bar, the butene yield reached 98% using 80% γ-valerolactone aqueous solution as raw material.
[0004] In 2019, Zhang Suojiang's research group at the Institute of Process Engineering, Chinese Academy of Sciences reported in an article (Ind. Eng. Chem. Res., 2019, 58, 11841-11848) that they used Beta molecular sieves with a silicon-aluminum molar ratio of 5, reacted in an intermittent reactor at 300°C, 1.8 MPa, 1 gram of γ-valerolactone raw material, and 0.1 gram of catalyst. The reaction lasted for 4.5 hours, and the γ-valerolactone conversion rate was 99.5%, and the butene yield was 98%.
[0005] In 2020, Yang Sihai's research group at the University of Manchester reported in an article (Nat. Mater, 2020, 19, 86-93) that NbAlS-1 was used as a catalyst at 320°C, atmospheric pressure, and 0.18h -1 Under the mass space velocity condition, using 30% γ-valerolactone aqueous solution as raw material, the γ-valerolactone conversion rate reached 100% and the butene yield was 99.3%.
[0006] In 2020, Ding Mingyue's research group at Wuhan University reported in an article (Mol. Catal, 2020, 497, 111218) that an amorphous SiO2-Al2O3 catalyst with a silicon-aluminum ratio of 4 was used to produce a 375°C, 4.0 MPa, 0.18 h -1 Under the above conditions, with 60wt% γ-valerolactone aqueous solution as raw material, the conversion rate reached 99.5%, the butene yield reached 97%, and the process ran stably for 50 hours.
[0007] At present, the solid acid catalysts used in the reaction of γ-valerolactone to butene mainly include amorphous SiO2-Al2O3 and hydrogen-type molecular sieves. γ-戊内酯 ·g cat -1 ·h -1 Good conversion rate and selectivity can only be achieved at a certain space velocity. Summary of the invention
[0008] The present invention provides an application of a metal cation-modified FAU type molecular sieve catalyst in the preparation of butene from γ-valerolactone, specifically a Y zeolite modified by an alkali metal, an alkaline earth metal, a rare earth element and a transition metal. In the reaction of γ-valerolactone to butene, at a high space velocity, the catalyst has a high conversion rate and butene selectivity and good reaction stability.
[0009] According to one aspect of the present application, a method for preparing butene from γ-valerolactone is provided, comprising the following steps:
[0010] In a fixed bed reactor, the pretreated catalyst is mixed with a raw material containing γ-valerolactone to react to obtain a product containing butene;
[0011] The mass space velocity of the raw material containing γ-valerolactone is 0.1 to 10 g γ-戊内酯 ·g cat -1 ·h -1 ;
[0012] The catalyst has a FAU topology;
[0013] The catalyst contains a metal element;
[0014] The metal element is selected from at least one of alkali metals, alkaline earth metals, rare earth elements, and transition metals;
[0015] In the catalyst, the content of the metal element is 1 to 30 wt%.
[0016] In the catalyst, the content of the metal element is 2 to 25 wt%.
[0017] Optionally, in the catalyst, the content of the metal element is at least one of 2wt%, 5wt%, 10wt%, 15wt%, 20wt%, 25wt% or a range value between any two of them.
[0018] The silicon-to-aluminum ratio of the catalyst is 0.5-10.
[0019] Optionally, the silicon-to-aluminum ratio of the catalyst is at least one of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or a range value between any two of them.
[0020] The metal element is selected from at least one of Li, Na, K, Rb, Cs, Mg, Ca, La, and Re.
[0021] The metal element is introduced into the catalyst by a hydrothermal synthesis method, an ion exchange method or an impregnation method.
[0022] Optionally, the mass space velocity of the raw material containing γ-valerolactone is 1.4 to 10 g γ-戊内酯 ·g cat -1 ·h -1 .
[0023] Optionally, the mass space velocity of the raw material containing γ-valerolactone is 1.4g γ-戊内酯 ·g cat -1 ·h -1 , 1.5g γ-戊内酯 ·g cat -1 ·h -1 , 2g γ-戊内酯 ·g cat -1 ·h -1 , 3g γ-戊内酯 ·g cat -1 ·h -1 , 4g γ-戊内酯 ·g cat -1 ·h -1 、5g γ-戊内酯 ·g cat -1 ·h -1 , 6g γ-戊内酯 ·g cat -1 ·h -1 , 7g γ-戊内酯 ·g cat -1 ·h -1 , 8g γ-戊内酯 ·g cat -1·h -1 , 9g γ-戊内酯 ·g cat -1 ·h -1 , 10g γ-戊内酯 ·g cat -1 ·h -1 At least one of or a range of values between any two of .
[0024] The reaction temperature is 300-500°C.
[0025] Optionally, the reaction temperature is 375-400°C.
[0026] The reaction pressure is 0.02-5 MPa.
[0027] Optionally, the reaction pressure is at least one of 0.02 MPa, 0.05 MPa, 0.1 MPa, 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, or a range value between any two of them.
[0028] The raw material containing gamma-valerolactone is a gamma-valerolactone aqueous solution with a mass fraction of 60-80wt%.
[0029] The reaction uses an inert gas as a diluent, including but not limited to nitrogen and helium.
[0030] The pretreatment temperature is 400-600°C.
[0031] Optionally, the pretreatment temperature is at least one of 400° C., 500° C., 600° C., or a range between any two of them.
[0032] The pretreatment atmosphere is helium, nitrogen, air, or hydrogen.
[0033] The catalyst is formed by an extrusion method or a tableting method;
[0034] In the extrusion method, a binder is used, and the binder is alumina or silica.
[0035] In the tableting method, the pressure is 10 to 30 MPa.
[0036] The beneficial effects of this application include:
[0037] 1) The catalyst provided in the present application can achieve good conversion rate and selectivity at high space velocity in the process of preparing butene from γ-valerolactone. DETAILED DESCRIPTION
[0038] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.
[0039] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.
[0040] The reaction performance evaluation of the catalyst was carried out in a conventional fixed bed reactor, the inner diameter of the reaction tube was 12 mm, and the length was 30 cm. The catalyst was loaded in the center of the reaction tube, and the rest of the reaction tube was filled with 20-40 mesh quartz sand, and quartz wool was placed on the top and bottom of the catalyst bed.
[0041] The gas phase products were analyzed online using an Agilent 8860 chromatograph, the hydrocarbon components were analyzed using an HP-PLOT Al2O3KCL column and an FID detector, and CO and CO2 were analyzed using a Hayesep Q column and a TCD detector.
[0042] Comparative Example 1
[0043] The reaction tube was filled with inert quartz sand, no catalyst was added, and the reactor pressure was 0.1 MPa. Pretreatment was carried out at 500°C for 2 hours under a helium atmosphere, and then the temperature was lowered to 375°C. After the temperature stabilized, a constant flow pump was used to feed 60wt% of the γ-valerolactone raw material into the reactor, and the raw material passed through the catalyst bed from top to bottom, and the flow rate of γ-valerolactone was 0.01mL / min. Helium was used as the reaction diluent, and the helium flow rate was 30mL / min. After reacting for 4 hours, the conversion rate of γ-valerolactone was less than 5%, and the yield of butene was 0.
[0044] Example 1
[0045] Take 5g of NaY molecular sieve, and the X-ray fluorescence spectrum (XRF) measured the Na2O% content to be 8.1%, and the SiO2 / Al2O3 to be 5.0. Press it into tablets, and crush and sieve it into solid particles of 20-40 mesh. Then load the catalyst into a fixed bed reactor with a reactor pressure of 0.1MPa. The catalyst is pretreated at 500℃ for 2h in a helium atmosphere, and then cooled to 375℃. After the temperature stabilizes, a constant flow pump is used to feed 60wt% of γ-valerolactone raw material into the reactor. The raw material passes through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone is 2.88g·g cat -1 ·h -1 Helium was used as the reaction diluent gas, and the helium flow rate was 30 mL / min. After 4 hours of reaction, the conversion rate of γ-valerolactone was 99.9%, and the selectivity of butene was 99.1%.
[0046] Example 2
[0047] The synthesized NaY molecular sieve was placed in a 1 mol / L potassium chloride solution, where the mass ratio of the NaY molecular sieve to the potassium chloride solution was 1:10, and ion exchange was performed three times under 80°C water bath heating conditions, each lasting 2 hours; after each ion exchange, the sample was washed and centrifuged, and repeated three times. The molecular sieve after ion exchange was dried in an oven at 120°C for 24 hours to obtain a KY molecular sieve.
[0048] Take 2g of KY molecular sieve prepared by ion exchange method, X-ray fluorescence spectrum (XRF) measured K2O content of 13.5%, SiO2 / Al2O3 = 5.0, press it into tablets, break and sieve into solid particles of 10-30 mesh. Then load the catalyst into a fixed bed reactor with a reactor pressure of 0.1MPa. The catalyst is pretreated at 500℃ for 2h in a helium atmosphere and then cooled to 375℃. After the temperature stabilizes, a constant flow pump is used to feed 60wt% of γ-valerolactone raw material into the reactor. The raw material passes through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone is 2.88g·g cat -1 ·h -1 Helium was used as the reaction diluent gas, and the helium flow rate was 30 mL / min. After 4 hours of reaction, the conversion rate of γ-valerolactone was 97.7%, and the selectivity of butene was 98.6%.
[0049] Example 3
[0050] Take 2g of LiY molecular sieve prepared by ion exchange method, and the X-ray fluorescence spectrum (XRF) measures the Li2O content to be 4.7%, SiO2 / Al2O3=5.0, press it into tablets, and crush and sieve it into solid particles of 20-40 mesh. Then load the catalyst into a fixed bed reactor with a reactor pressure of 0.1MPa. The catalyst is pretreated at 500℃ for 2h in a helium atmosphere, and then cooled to 375℃. After the temperature stabilizes, a constant flow pump is used to feed 60wt% of γ-valerolactone raw material into the reactor. The raw material passes through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone is 3.88g·g cat -1 ·h -1 Helium was used as the reaction diluent gas, and the helium flow rate was 30 mL / min. After 4 hours of reaction, the conversion rate of γ-valerolactone was 97.3%, and the selectivity of butene was 95.1%.
[0051] Example 4
[0052] Take 2g of RbY molecular sieve prepared by ion exchange method, and the X-ray fluorescence spectrum (XRF) measures the Rb2O content to be 15.4%, SiO2 / Al2O3=10.0, press it into tablets, and crush and sieve it into solid particles of 10-30 mesh. Then the catalyst is loaded into a fixed bed reactor with a reactor pressure of 0.1MPa. The catalyst is pretreated at 500℃ for 2h in a helium atmosphere, and then cooled to 375℃. After the temperature stabilizes, a constant flow pump is used to feed 60wt% of γ-valerolactone raw material into the reactor. The raw material passes through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone is 1.44g·g cat -1 ·h -1 Helium was used as the reaction diluent gas, and the helium flow rate was 60 mL / min. After 4 hours of reaction, the conversion rate of γ-valerolactone was 95.6%, and the selectivity of butene was 94.7%.
[0053] Example 5
[0054] Take 2g of CsY molecular sieve prepared by impregnation method, and the X-ray fluorescence spectrum (XRF) measures the Cs2O content to be 21.5%, SiO2 / Al2O3=10, and extrude it into strips with a diameter of 2mm using alumina as a binder, and sieve to obtain solid particles of 10-30 mesh. The catalyst is then loaded into a fixed bed reactor with a reactor pressure of 0.1MPa. The catalyst is pretreated at 500℃ for 2h in a helium atmosphere, and then cooled to 375℃. After the temperature stabilizes, a constant flow pump is used to feed 80wt% of the γ-valerolactone raw material into the reactor, and the raw material passes through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone is 1.4g·g cat -1 ·h -1 Helium was used as the reaction diluent gas, and the helium flow rate was 60 mL / min. After 4 hours of reaction, the conversion rate of γ-valerolactone was 93.2%, and the selectivity of butene was 92.1%.
[0055] Example 6
[0056] Take 2g of MgY molecular sieve prepared by ion exchange method, and the X-ray fluorescence spectrum (XRF) measures the MgO content to be 3.2%, SiO2 / Al2O3=5. Use alumina as a binder to extrude it into strips with a diameter of 3mm, and sieve to obtain solid particles of 10-30 mesh. The catalyst is then loaded into a fixed bed reactor with a reactor pressure of 0.1MPa. The catalyst is pretreated at 500℃ for 2h in a helium atmosphere, and then cooled to 375℃. After the temperature stabilizes, a constant flow pump is used to feed 60wt% of γ-valerolactone raw material into the reactor. The raw material passes through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone is 5.51g·g cat -1 ·h -1Helium was used as the reaction diluent gas, and the helium flow rate was 30 mL / min. After 4 hours of reaction, the conversion rate of γ-valerolactone was 60.8%, and the selectivity of butene was 32.1%.
[0057] Example 7
[0058] Take 2g of CaY molecular sieve prepared by ion exchange method, and the CaO content is 4.5% and SiO2 / Al2O3=5 measured by X-ray fluorescence spectrum (XRF). Use silicon oxide as a binder to extrude it into strips with a diameter of 2mm, and sieve to obtain solid particles of 10-30 mesh. Then the catalyst is loaded into a fixed bed reactor with a reactor pressure of 0.1MPa. The catalyst is pretreated at 500℃ for 2h in a helium atmosphere and then cooled to 375℃. After the temperature stabilizes, a constant flow pump is used to feed 60wt% of γ-valerolactone raw material into the reactor. The raw material passes through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone is 8.92g·g cat -1 ·h -1 Helium was used as the reaction diluent gas, and the helium flow rate was 30 mL / min. After 4 hours of reaction, the γ-valerolactone conversion rate was 40.4%, and the butene selectivity was 25.0%.
[0059] Example 8
[0060] Take 2g of LaY molecular sieve prepared by ion exchange method, and the La2O3 content is 9.5% and SiO2 / Al2O3=10 measured by X-ray fluorescence spectrum (XRF). Press it into tablets, break it and sieve it into solid particles of 20-40 mesh. Then load the catalyst into a fixed bed reactor with a reactor pressure of 1MPa. The catalyst is pretreated at 500℃ for 2h in a helium atmosphere and then cooled to 320℃. After the temperature stabilizes, a constant flow pump is used to feed 60wt% of γ-valerolactone raw material into the reactor. The raw material passes through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone is 7.40g·g cat -1 ·h -1 Helium was used as the reaction diluent gas, and the helium flow rate was 90 mL / min. After 4 hours of reaction, the conversion rate of γ-valerolactone was 52.2%, and the selectivity of butene was 45.2%.
[0061] Example 9
[0062] Take 2g of ReY molecular sieve prepared by ion exchange method, and the Re2O7 content is 6.3% and SiO2 / Al2O3=10 measured by X-ray fluorescence spectrum (XRF). Press it into tablets and sieve them into solid particles of 20-40 mesh. Then load the catalyst into a fixed bed reactor with a reactor pressure of 5MPa. The catalyst is pretreated at 500℃ for 2h in a helium atmosphere and then cooled to 300℃. After the temperature stabilizes, a constant flow pump is used to feed 30wt% of γ-valerolactone raw material into the reactor. The raw material passes through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone is 9.80g·g cat -1 ·h -1 Helium was used as the reaction diluent gas, and the helium flow rate was 90 mL / min. After 4 hours of reaction, the conversion rate of γ-valerolactone was 61.2%, and the selectivity of butene was 37.6%.
[0063] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing butene from γ-valerolactone, characterized in that: The following steps are involved: The raw material containing γ-valerolactone is contacted with a catalyst to react and obtain a product containing butene; The catalyst is a Y-type zeolite molecular sieve modified by metal elements; The metal element is selected from at least one of alkali metals, alkaline earth metals, rare earth elements, and transition metals; In the catalyst, the content of the metal element is 1 to 30 wt%; The mass space velocity of the raw material containing γ-valerolactone is 0.1 to 10 g γ-戊内酯 ·g cat -1 ·h -1 .
2. The method according to claim 1, characterized in that In the catalyst, the content of the metal element is 2-25 wt%.
3. The method according to claim 1, characterized in that: The silicon-aluminum ratio of the Y-type zeolite molecular sieve is 0.5-10.
4. The method according to claim 1, characterized in that The metal element is selected from at least one of Li, Na, K, Rb, Cs, Mg, Ca, La, and Re.
5. The method according to claim 1, characterized in that The metal element is introduced into the Y-type zeolite molecular sieve by hydrothermal synthesis, ion exchange or impregnation.
6. The method according to claim 1, characterized in that The mass space velocity of the raw material containing γ-valerolactone is 1.4 to 10 g γ-戊内酯 ·g cat -1 ·h -1 .
7. The method according to claim 1, characterized in that The reaction temperature is 300-500°C.
8. The method according to claim 1, characterized in that The reaction temperature is 375-400°C.
9. The method according to claim 1, characterized in that: The reaction pressure is 0.02-5 MPa.
10. The method according to claim 1, characterized in that The catalyst is pretreated under an inactive atmosphere; The pretreatment temperature is 400-600°C.