Method for preparing 1, 3-butadiene

Abstract

The invention discloses a method for preparing 1, 3-butadiene, and the method comprises the following steps: enabling a raw material containing gamma-valerolactone to be in contact and react with a catalyst to obtain the 1, 3-butadiene, the catalyst is a hydrogen type molecular sieve with a ten-membered ring topological structure, and the typical topological structure types of the catalyst comprise FER, TON, MTT, EUO, * MRE, MEL and MWW. In a fixed bed reactor, gamma-valerolactone is taken as a raw material and passes through the reactor from top to bottom. The target product 1, 3-butadiene can be efficiently prepared under the condition of 300-450 DEG C by using the catalyst.

Description

Technical Field

[0001] The present application relates to a method for preparing 1,3-butadiene, belonging to the field of heterogeneous catalysis. Background Art

[0002] 1,3-Butadiene is a key polymer monomer. Through polymerization reactions, butadiene can produce synthetic rubbers and polymer resins, such as butadiene rubber, styrene-butadiene rubber, nitrile rubber, etc. Currently, butadiene is mainly produced as a by-product in the steam cracking of naphtha to produce ethylene. Therefore, the price of butadiene is greatly affected by the supply and demand relationship of ethylene. In addition, the development of shale gas has led to a reduction in the supply of butadiene, and there may be a shortage of butadiene in the future. Preparing butadiene products from biomass-based raw materials provides a green and sustainable path for its production.

[0003] Currently, the main method for preparing butadiene from biomass-based raw materials is the conversion of ethanol to butadiene, i.e., the Lebedev process. In 1985, Ryuichiro Ohnishi et al. reported in an article (J. Chem. Soc., Chem. Commun., 1985, 1613 - 1614) that a catalyst with a molar ratio of 1:1 of MgO - SiO 2 was prepared by the wet kneading method, and 0.1 wt% Na 2 O was added as an auxiliary agent. At 350 °C, the ethanol conversion rate reached 100%, and the butadiene selectivity reached 87%.

[0004] γ-Valerolactone is a highly potential biomass platform compound. It is itself a green solvent and can also be directly mixed with gasoline for combustion. Through chemical conversion, important compounds such as methyltetrahydrofuran and dimethyl adipate can be prepared from it. Under the action of a solid acid catalyst, γ-valerolactone can undergo a ring-opening decarboxylation reaction to obtain butene, which provides a way to obtain renewable butene resources. In 2010, the Dumesic research group at the University of Wisconsin - Madison in the United States reported in an article (Science, 2010, 327, 1110 - 1114) that amorphous SiO 2 -Al 2 O 3 was used as a catalyst. At 375 °C, with a mass space velocity of 0.22 h -1 , and at 36 bar, using 80% γ-valerolactone as the raw material, the butene yield reached 98%. In 2020, the Yang Sihai 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, under atmospheric pressure, with a mass space velocity of 0.18 h -1Under the condition of mass space velocity, using 30 wt% aqueous solution of γ-valerolactone as raw material, the conversion rate of γ-valerolactone reaches 100%, and the yield of butene reaches 99.3%.

[0005] The molecular formula of γ-valerolactone is C 5 H 8 O 2 , and theoretically γ-valerolactone can also be decomposed into equimolar amounts of butadiene (C 4 H 6 ), carbon monoxide (CO) and water (H 2 O). For the reaction of γ-valerolactone to produce butadiene, Chinese Patent CN 113754510 A uses HZSM-5 zeolite with an MFI topological structure and a silica-alumina ratio of 50 as the catalyst. In a fixed-bed reactor, at 0.1 MPa and a γ-valerolactone space velocity of 0.4 h -1 -1, using 60 wt% γ-valerolactone solution as raw material, the conversion rate of γ-valerolactone reaches 97.6%, and the selectivity of 1,3-butadiene reaches 70.6%, but it needs to be achieved under the condition of 400 - 450 °C. Below 350 °C, the yield of butadiene is relatively low, only reaching 29.4%. Summary of the Invention

[0006] In view of the experimental results of high yield and stability of hydrogen-type zeolites with a ten-membered ring topological structure in the reaction of γ-valerolactone to produce butadiene, the present application provides a method for preparing 1,3-butadiene. This method uses a hydrogen-type zeolite with a ten-membered ring topological structure and has a relatively high selectivity for butadiene.

[0007] According to one aspect of the present application, a method for preparing 1,3-butadiene is provided. The method includes: contacting a raw material containing γ-valerolactone with a catalyst, reacting, and obtaining the 1,3-butadiene;

[0008] The catalyst is a hydrogen-type zeolite with a ten-membered ring topological structure.

[0009] In the present application, the catalyst is a zeolite with a ten-membered ring topological structure obtained through various synthesis routes.

[0010] Optionally, the topological structure of the hydrogen-type zeolite is selected from at least one of FER, TON, MTT, EUO, *MRE, MEL, MWW.

[0011] Optionally, the silica-alumina ratio of the hydrogen-type zeolite is: SiO 2 / Al 2 O 3 = 20 - 600

[0012] Optionally, the silica-alumina ratio of the hydrogen-type molecular sieve is independently selected from any value among 20, 27, 30, 40, 58, 60, 76, 100, 200, 300, 400, 500, 600 or any range value between any two of the above.

[0013] Optionally, the method further includes the forming pretreatment of the catalyst:

[0014] The hydrogen-type molecular sieve is formed by an extrusion forming process or a tabletting forming process, sieved, and pretreated to obtain the catalyst.

[0015] Optionally, the binder used in the extrusion forming process is selected from at least one of alumina and silica.

[0016] Optionally, the pressure in the tabletting forming process is 10 - 30 MPa.

[0017] Optionally, the pressure in the tabletting forming process is independently selected from any value among 10 MPa, 20 MPa, 30 MPa or any range value between any two of the above.

[0018] Optionally, the particles after sieving can be of any size, preferably 20 - 40 mesh.

[0019] Optionally, the temperature of the pretreatment is 400 - 600 °C.

[0020] Optionally, the temperature of the pretreatment is independently selected from any value among 400 °C, 500 °C, 600 °C or any range value between any two of the above.

[0021] Optionally, the temperature of the pretreatment is 500 °C.

[0022] Optionally, the time of the pretreatment is 1 - 5 h.

[0023] Optionally, the time of the pretreatment is independently selected from any value among 1 h, 2 h, 3 h, 4 h, 5 h or any range value between any two of the above.

[0024] Optionally, the pretreatment is carried out in an inert atmosphere;

[0025] The inert atmosphere includes at least one of helium, nitrogen, and air.

[0026] Optionally, the temperature of the reaction is 300 - 450 °C.

[0027] Optionally, the temperature of the reaction is 375 - 400 °C.

[0028] Optionally, the temperature of the reaction is independently selected from any value among 300 °C, 320 °C, 375 °C, 400 °C, 450 °C or any range value between any two of the above.

[0029] Optionally, the pressure of the reaction is 0.02 - 1 MPa.

[0030] Optionally, the pressure of the reaction is independently selected from any value among 0.02 MPa, 0.05 MPa, 0.1 MPa, 0.2 MPa, 0.4 MPa, 0.6 MPa, 0.8 MPa, 1 MPa or any range value between any two of the above.

[0031] Optionally, the pressure of the reaction is 0.1 MPa.

[0032] Optionally, the raw material containing γ-valerolactone is γ-valerolactone or its aqueous solution with any concentration.

[0033] Optionally, the raw material containing γ-valerolactone is an aqueous solution containing γ-valerolactone.

[0034] Optionally, the raw material containing γ-valerolactone is an aqueous solution of γ-valerolactone with a mass concentration of 60 - 80 wt%.

[0035] Optionally, the mass hourly space velocity of γ-valerolactone is 0.1 - 10 g γ-戊内酯 ·g cat -1 ·h -1 。

[0036] Optionally, the mass hourly space velocity of γ-valerolactone is 0.18 - 0.9 g γ-戊内酯 ·g cat -1 ·h -1 。

[0037] Optionally, the mass hourly space velocity of γ-valerolactone is independently selected from 0.1 g γ-戊内酯 ·g cat -1 ·h -1 、0.18 g γ-戊内酯 ·g cat -1 ·h -1 、0.36 g γ-戊内酯 ·g cat -1 ·h -1 、0.54 g γ-戊内酯 ·g cat -1 ·h -1 、0.72 g γ-戊内酯 ·g cat-1 ·h -1 、0.9 g γ-戊内酯 ·g cat -1 ·h -1 、1.2 g γ-戊内酯 ·g cat -1 ·h -1 、1.4 g γ-戊内酯 ·g cat -1 ·h -1 、2 g γ-戊内酯 ·g cat -1 ·h -1 、4 g γ-戊内酯 ·g cat -1 ·h -1 、6 g γ-戊内酯 ·g cat -1 ·h -1 、8 g γ-戊内酯 ·g cat -1 ·h -1 、10 g γ-戊内酯 ·g cat -1 ·h -1 Any value within the above range or any range value between any two of the above points.

[0038] Optionally, an inert gas is used as the diluent gas in the reaction, including but not limited to nitrogen and helium.

[0039] As a specific embodiment, the method for preparing 1,3-butadiene comprises the following specific steps:

[0040] (1) Take a certain mass of molecular sieve catalyst and exchange it to obtain a hydrogen form sample;

[0041] (2) Shape the sample obtained in step (1) by extrusion or tabletting, and screen it to obtain catalyst particles;

[0042] (3) Load the sample obtained in step (2) into a fixed bed reactor and pretreat it for a certain time under a certain temperature and atmosphere;

[0043] (4) Lower the reactor to the reaction temperature, and after the temperature stabilizes, introduce the raw materials to start the reaction.

[0044] The beneficial effects that can be produced by this application include:

[0045] In the method provided by this application, the catalyst uses a hydrogen-type molecular sieve with a ten-membered ring topological structure obtained through various synthesis routes. Its typical topological structure types include: FER, TON, MTT, EUO, *MRE, MEL, MWW. In a fixed-bed reactor, γ-valerolactone is used as the raw material and passes through the reactor from top to bottom. Using the above catalyst, the target product 1,3-butadiene can be efficiently prepared under the conditions of 300-450 °C. Detailed implementation manners

[0046] The following elaborates on this application in combination with examples, but this application is not limited to these examples.

[0047] Unless otherwise specified, the raw materials and catalysts in the examples of this application are all purchased through commercial channels.

[0048] Comparative example 1

[0049] The reaction tube was filled with inert quartz sand, no catalyst was added, and the reactor pressure was 0.1 MPa. It was pretreated at 500 °C for 2 h in a helium atmosphere and then cooled to 375 °C. After the temperature stabilized, a 60 wt% γ-valerolactone raw material was fed into the reactor using a constant flow pump. The raw material passed through the catalyst bed layer from top to bottom, and the γ-valerolactone flow rate was 0.01 mL / min. Helium was used as the reaction diluent gas with a helium flow rate of 30 mL / min. During the reaction plateau period, the γ-valerolactone conversion rate was less than 5%, and the selectivity for 1,3-butadiene was 0.

[0050] Example 1

[0051] Take 2 g of hydrogen-type ZSM-35 molecular sieve with a FER topological structure, SiO 2 / Al 2 O 3 = 30, and it was tableted into solid particles of 20-40 mesh under a pressure of 20 Mpa. Subsequently, the catalyst was loaded into a fixed-bed reactor with a reactor pressure of 0.1 MPa. The catalyst was pretreated at 500 °C for 2 h in a helium atmosphere and then cooled to 320 °C. After the temperature stabilized, a 60 wt% γ-valerolactone raw material was fed into the reactor using a constant flow pump. The raw material passed through the catalyst bed layer from top to bottom, and the γ-valerolactone mass space velocity was 0.18 g·g cat -1 ·h -1 . Helium was used as the reaction diluent gas with a helium flow rate of 30 mL / min. During the reaction plateau period, the γ-valerolactone conversion rate was 90.69%, and the selectivity for 1,3-butadiene was 61.39%.

[0052] Example 2

[0053] Take 2 g of hydrogen-type ZSM-22 molecular sieve with a TON topological structure, SiO 2 / Al2 O 3 = 76, and it is tableted into solid particles of 40 - 60 mesh at a pressure of 20 Mpa. Subsequently, the catalyst is loaded into a fixed - bed reactor with a reactor pressure of 0.1 MPa. The catalyst is pretreated at 500 °C for 2 h in a helium atmosphere and then cooled to 375 °C. After the temperature is stabilized, a constant - flow pump is used to feed a 60 wt% 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 0.9 g·g cat -1 ·h -1 . Helium is used as the reaction diluent gas with a helium flow rate of 30 mL / min. During the reaction plateau, the conversion rate of γ - valerolactone is 98.50%, and the selectivity of 1,3 - butadiene is 61.14%.

[0054] Example 3

[0055] Take 2 g of hydrogen - form ZSM - 23 molecular sieve with MTT topological structure, SiO 2 / Al 2 O 3 = 60, and it is tableted into solid particles of 20 - 40 mesh at a pressure of 20 Mpa. Subsequently, the catalyst is loaded into a fixed - bed reactor with a reactor pressure of 1 MPa. The catalyst is pretreated at 500 °C for 2 h in a helium atmosphere and then cooled to 400 °C. After the temperature is stabilized, a constant - flow pump is used to feed an 80 wt% 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 1.2 g·g cat -1 ·h -1 . Helium is used as the reaction diluent gas with a helium flow rate of 60 mL / min. During the reaction plateau, the conversion rate of γ - valerolactone is 96.45%, and the selectivity of 1,3 - butadiene is 59.27%.

[0056] Example 4

[0057] Take 2 g of hydrogen - form EU - 1 molecular sieve with EUO topological structure, SiO 2 / Al 2 O 3 = 40, and it is tableted into solid particles of 10 - 30 mesh at a pressure of 20 Mpa. Subsequently, the catalyst is loaded into a fixed - bed reactor with a reactor pressure of 0.1 MPa. The catalyst is pretreated at 500 °C for 2 h in a helium atmosphere and then cooled to 300 °C. After the temperature is stabilized, a constant - flow pump is used to feed a 40 wt% 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 1.4 g·g cat -1 ·h -1Helium was used as the reaction diluent gas with a helium flow rate of 80 mL / min. During the reaction plateau, the conversion rate of γ-valerolactone was 94.30%, and the selectivity for 1,3-butadiene was 55.54%.

[0058] Example 5

[0059] 2 g of hydrogen-form ZSM-48 zeolite with an *MRE topological structure, SiO 2 / Al 2 O 3 = 58, was extruded into solid particles of 20 - 40 mesh with an alumina binder. Subsequently, the catalyst was loaded into a fixed-bed reactor with a reactor pressure of 0.1 MPa. The catalyst was pretreated at 500 °C for 2 h in a helium atmosphere and then cooled to 375 °C. After the temperature stabilized, a 90 wt% γ-valerolactone raw material was fed into the reactor using a constant-flow pump. The raw material passed through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone was 0.9 g·g cat -1 ·h -1 −1. Helium was used as the reaction diluent gas with a helium flow rate of 80 mL / min. During the reaction plateau, the conversion rate of γ-valerolactone was 98.07%, and the selectivity for 1,3-butadiene was 39.61%.

[0060] Example 6

[0061] 2 g of hydrogen-form ZSM-11 zeolite with an MEL topological structure, SiO 2 / Al 2 O 3 = 30, was extruded into solid particles of 20 - 40 mesh with a silica binder. Subsequently, the catalyst was loaded into a fixed-bed reactor with a reactor pressure of 0.05 MPa. The catalyst was pretreated at 500 °C for 2 h in a helium atmosphere and then cooled to 375 °C. After the temperature stabilized, a 60 wt% γ-valerolactone raw material was fed into the reactor using a constant-flow pump. The raw material passed through the catalyst bed from top to bottom, and the mass space velocity of γ-valerolactone was 0.18 g·g cat -1 ·h -1 −1. Helium was used as the reaction diluent gas with a helium flow rate of 80 mL / min. During the reaction plateau, the conversion rate of γ-valerolactone was 95.52%, and the selectivity for 1,3-butadiene was 15.33%.

[0062] Example 7

[0063] 2 g of hydrogen-form MCM-22 zeolite with an MWW topological structure, SiO 2 / Al 2 O 3= 27, and it was tableted into solid particles with a particle size of 20 - 40 mesh under a pressure of 20 MPa. Subsequently, the catalyst was loaded into a fixed - bed reactor with a reactor pressure of 0.1 MPa. The catalyst was pretreated at 500 °C for 2 h in a helium atmosphere and then cooled to 320 °C. After the temperature stabilized, a 60 wt% γ - valerolactone raw material was fed into the reactor using a constant - flow pump. The raw material passed through the catalyst bed from top to bottom, and the mass space velocity of γ - valerolactone was 0.18 g·g cat -1 ·h -1 . Helium was used as the reaction diluent gas with a helium flow rate of 30 mL / min. During the reaction plateau, the conversion rate of γ - valerolactone was 95.17%, and the selectivity of 1,3 - butadiene was 11.82%.

[0064] Reaction evaluation and product analysis of Comparative Example 1 and Examples 1 - 7:

[0065] The reaction performance evaluation of the catalyst was carried out on 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 quartz sand with a particle size of 20 - 40 mesh. Quartz wool was placed on the top and bottom of the catalyst bed.

[0066] The gaseous products were analyzed online using an Agilent 8860 chromatograph. Hydrocarbon components were analyzed using an HP - PLOT Al 2 O 3 KCL chromatographic column and an FID detector, and CO and CO 2 were analyzed using a Hayesep Q chromatographic column and a TCD detector. To quantitatively analyze the gaseous products, a certain amount of methane was added to the reaction tail gas as an internal standard. The liquid products were quantitatively analyzed using an Agilent 8860 chromatograph and an HP - INNOWax chromatographic column. The liquid products were collected at regular intervals. Since they were divided into an oil phase and a water phase, they were dissolved into a homogeneous phase with excessive isopropanol, and a certain amount of cyclohexanone was added as an internal standard.

[0067] As described above, these are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed with preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the relevant art, without departing from the technical solutions of the present application, making some changes or modifications using the disclosed technical content is equivalent to equivalent implementation cases and all fall within the scope of the technical solutions.

Claims

1. A method for preparing 1,3-butadiene, characterized in that, the method comprises: contacting a raw material containing γ-valerolactone with a catalyst, reacting to obtain the 1,3-butadiene; the catalyst is a hydrogen-type molecular sieve having a ten-membered ring topological structure.

2. The method according to claim 1, characterized in that, the topological structure of the hydrogen-type molecular sieve is selected from at least one of FER, TON, MTT, EUO, *MRE, MEL, MWW.

3. The method according to claim 1, characterized in that, The silica-alumina ratio of the hydrogen form molecular sieve is: SiO 2 / Al 2 O 3 = 20 to 600.

4. The method according to claim 1, characterized in that, the method further comprises a shaping pretreatment of the catalyst: shaping the hydrogen-type molecular sieve by an extrusion molding process or a tableting molding process, sieving, and pretreatment to obtain the catalyst.

5. The method according to claim 4, characterized in that, the binder used in the extrusion molding process is selected from at least one of alumina and silica; preferably, the pressure in the tableting molding process is 10 - 30 MPa.

6. The method according to claim 4, characterized in that, the temperature of the pretreatment is 400 - 600 °C; the time of the pretreatment is 1 - 5 h; the pretreatment is carried out in an inert atmosphere; the inert atmosphere includes at least one of helium, nitrogen, and air.

7. The method according to claim 1, characterized in that, the temperature of the reaction is 300 - 450 °C; preferably, the temperature of the reaction is 375 - 400 °C.

8. The method according to claim 1, characterized in that, the pressure of the reaction is 0.02 - 1 MPa.

9. The method according to claim 1, characterized in that, the raw material containing γ-valerolactone is an aqueous solution containing γ-valerolactone; preferably, the raw material containing γ-valerolactone is an aqueous solution of γ-valerolactone with a mass concentration of 60 - 80 wt%.

10. The method according to claim 1, characterized in that, The mass space velocity of the γ-valerolactone is 0.1 to 10 g γ-戊内酯 ·g cat -1 ·h -1 ; Preferably, the mass hourly space velocity of the γ-valerolactone is 0.18 to 0.9 g γ-戊内酯 ·g cat -1 ·h -1 .