Process for the preparation of biobased toluene

Abstract

The present application relates to the field of catalysis, in particular to a preparation method of bio-based toluene, which comprises: contacting methylfuran with ethylene in the presence of a catalyst in the presence of an optional organic solvent, wherein the catalyst contains a solid acid. The preparation method of bio-based toluene provided by the present application can efficiently convert methylfuran into toluene under mild reaction conditions, and both the conversion rate and the selectivity of the product toluene are very high. Meanwhile, the content of key impurities (such as polyalkyltoluene and dimers) in the obtained product is extremely low, which greatly reduces the energy consumption of separation, and the stability of the catalyst in the recycling use is outstanding. In addition, the zinc-based solid acid used as the catalyst has very high stability, and no obvious change in the performance of the catalyst is found after four cycles of recycling use.

Description

Technical Field

[0001] This invention relates to the field of catalysis, and more specifically to a method for preparing bio-based toluene. Background Technology

[0002] Due to rapid economic development and global population growth, the world's energy demand has increased dramatically. Meanwhile, fossil fuels, primarily coal and oil, face a series of problems including overconsumption, increasing scarcity, and severe environmental pollution. Therefore, in recent years, countries worldwide have shifted their energy development strategies to seeking clean, new energy sources. Conversely, biomass, as a green and renewable energy source, is abundant on Earth, and its conversion and utilization process does not pollute the environment. Therefore, many scholars have focused on using biomass to supplement fossil fuels.

[0003] Toluene is mainly used as an organic solvent, an additive to adjust the octane number of gasoline, and in the preparation of benzoic acid, and is currently primarily produced through petrochemical routes. To utilize biomass resources for green and sustainable toluene production, alternative methods for preparing toluene from bio-based methyl furan (MF) reacting with ethylene are under investigation. Furfural can be prepared from biomass through hydrolysis, and further hydrogenolysis can convert it into methyl furan (Green Chemistry. 2018, 20, 2027-2037).

[0004] Jungho Jae's group (Fuel, 2016, 182, 588-596) achieved complete conversion of methylfuran and ethylene at 250℃ for 24 h using metal chloride catalysis, with a toluene yield as high as 75%. However, metal chloride catalysts all caused some degree of equipment corrosion, environmental pollution, and excessively high separation costs. Subsequently, Dauenhauer's group (Green Chemistry. 2014, 16, 585-588; Applied Catalysis B: Environmental. 2016, 180, 487-496) studied the effect of different molecular sieves on the reaction performance. The experimental results showed that H-Beta molecular sieves were the most effective catalyst. At 250℃, the toluene selectivity was only 46% at its highest, and a large amount of polymers were produced, increasing the cost of product purification and separation, which is difficult to meet the needs of large-scale production. In conclusion, the development of high-performance, low-cost, and environmentally friendly solid acid catalysts has become a current research focus. Summary of the Invention

[0005] The technical problem this invention aims to solve is the low product selectivity or poor catalyst cycling stability in the preparation of toluene. It provides a method for the catalytic conversion of methylfuran to toluene. This method features high efficiency in the conversion of methylfuran under mild reaction conditions, high selectivity for the toluene product, and outstanding catalyst cycling stability.

[0006] To achieve the above objectives, the present invention provides a method for preparing bio-based toluene, the method comprising: contacting methyl furan with ethylene in the presence of a catalyst in the optional presence of an organic solvent, said catalyst containing a solid acid.

[0007] The bio-based toluene preparation method provided by this invention enables the efficient conversion of methylfuran to toluene under mild reaction conditions, with both high conversion rate and toluene selectivity. Simultaneously, the resulting product exhibits extremely low levels of key impurities (e.g., polyalkyltoluene, dimers), significantly reducing separation energy consumption, and demonstrates outstanding catalyst stability during recycling. Furthermore, the zinc-based solid acid catalyst exhibits high stability, showing no significant change in catalyst performance after four cycles of recycling. Attached Figure Description

[0008] Figure 1 The image shows the NH3-TPD of the solid acid catalyst obtained in Example 1.

[0009] Figure 2 The image shows the Py-FTIR spectrum of the solid acid catalyst obtained in Example 1.

[0010] Figure 3 Example 33 describes the MF conversion and toluene selectivity under the catalyst recycling conditions of Example 1. Detailed Implementation

[0011] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0012] This invention provides a method for preparing bio-based toluene, comprising: reacting methylfuran with ethylene in the presence of a catalyst, optionally in the presence of an organic solvent, wherein the catalyst contains a solid acid. This method features high efficiency in the conversion of methylfuran under mild reaction conditions, high selectivity for the toluene product, and outstanding stability of the catalyst during recycling.

[0013] According to a preferred embodiment of the present invention, the solid acid is a metal composite oxide; preferably, the solid acid includes a silica support and an active component, wherein the active component is zinc oxide and a second metal oxide; using a zinc-based solid acid as a catalyst has high stability, and no significant change in catalyst performance was observed after four cycles of use.

[0014] According to the present invention, the range of types of the second metal oxide is relatively wide, such as transition metal oxides, alkaline earth metal oxides, etc. For the present invention, it is preferably selected from at least one of tin oxide, lanthanum oxide, zirconium oxide, niobium oxide, and magnesium oxide; preferably, the second metal oxide is tin oxide and / or magnesium oxide. Using this preferred zinc-based solid acid as a catalyst exhibits high stability, and no significant change in catalyst performance was observed after four cycles of use.

[0015] According to the present invention, the molar ratio of zinc oxide, the second metal oxide, and silicon dioxide in the solid acid has a wide selectable range and can be adjusted as needed. For the present invention, the preferred molar ratio of zinc oxide, the second metal oxide, and silicon dioxide is (0.01-0.8):(0.005-0.10):1, more preferably (0.02-0.5):(0.008-0.05):1. Using this preferred zinc-based solid acid as a catalyst exhibits high stability; no significant change in catalyst performance was observed after four cycles of use.

[0016] According to a preferred embodiment of the present invention, the solid acid has an acid content of 255-780 μmol / g, preferably 350-700 μmol / g. Using this preferred solid acid as a catalyst exhibits high stability, and no significant change in catalyst performance was observed after four cycles of use.

[0017] According to a preferred embodiment of the present invention, the specific surface area of ​​the solid acid is 470-840 m². 2 / g, preferably 550-800m 2 / g. Using this preferred solid acid as a catalyst, it exhibits high stability, and no significant change in catalyst performance was observed after four cycles of use.

[0018] According to a preferred embodiment of the present invention, by ammonia gas temperature-programmed desorption analysis, the content of the solid acid as a weak acid is 25-60%, preferably 30-55%. Using this preferred solid acid as a catalyst exhibits high stability, and no significant change in catalyst performance was observed after four cycles of use.

[0019] According to a preferred embodiment of the present invention, by ammonia temperature-programmed desorption analysis, the strong acid content in the solid acid is 25-60%, preferably 30-55%. Using this preferred solid acid as a catalyst exhibits high stability, and no significant change in catalyst performance was observed after four cycles of use.

[0020] According to a preferred embodiment of the present invention, the content of the solid acid strong acid is 0-20%, preferably 2-10%, as determined by ammonia temperature-programmed desorption analysis. Using this preferred solid acid as a catalyst exhibits high stability, and no significant change in catalyst performance was observed after four cycles of use.

[0021] According to a preferred embodiment of the present invention, by ammonia-programmed temperature desorption analysis, the ratio of L-acid content to Brønsted acid content in the solid acid is 5-50:1, preferably 10-40:1, and more preferably 15-35:1. Using this preferred solid acid as a catalyst exhibits high stability, and no significant change in catalyst performance was observed after four cycles of use.

[0022] According to the present invention, the catalyst only needs to contain the solid acid of the present invention to achieve the purpose of the present invention. For the present invention, it is preferred that the solid acid content in the catalyst is 50% by weight or more (e.g., containing solid acid and binder), preferably 50-100% by weight, more preferably 100% by weight.

[0023] According to the present invention, the range of organic solvents that can be selected is relatively wide, such as aromatic hydrocarbons, aliphatic hydrocarbons, ethers and ketones. For the present invention, the organic solvent is preferably selected from one or more of methyl isobutyl ketone, n-hexane, n-heptane, n-octane, tetrahydrofuran, and 1,4-dioxane.

[0024] In this invention, the amount of catalyst can be selected from a wide range and can be used as needed. According to a preferred embodiment of the present invention, the mass ratio of methylfuran to catalyst is 0.1-10.0:1, preferably 0.2-5.0:1.

[0025] In this invention, the amount of organic solvent can be selected from a wide range and can be used as needed. According to a preferred embodiment of this invention, the mass ratio of the organic solvent to methyl furan is 10-100:1, preferably 15-60:1.

[0026] According to the present invention, the reaction conditions can be conventionally selected. For the present invention, the preferred reaction conditions include: a reaction temperature of 150-300°C, preferably 200-280°C, and more preferably 230-260°C.

[0027] According to the present invention, the reaction time can be determined based on the reaction temperature. For the present invention, the preferred reaction conditions include a reaction time of 6-64 h, more preferably 12-48 h, and more preferably 14-36 h.

[0028] According to a preferred embodiment of the present invention, the reaction conditions are as follows: the reaction temperature is 150-300℃, preferably 200-280℃; and / or the reaction time is 6-64h, preferably 12-48h.

[0029] According to the present invention, the preferred reaction conditions include a reaction pressure of 1-8 MPa, more preferably 2-6 MPa, and more preferably 2-4 MPa.

[0030] In this invention, solid acid catalysts with the aforementioned properties can achieve the purpose of this invention; in view of this invention, this invention provides a method for preparing the solid acid, the method comprising mixing a zinc source, a second metal source, a silicon source, a dispersant, a complexing agent and water uniformly to form a gel, optionally drying the gel and then calcining it.

[0031] In this invention, the range of amounts of various substances is relatively wide, and the specific amounts can be adjusted according to needs. According to a preferred embodiment of this invention, the zinc source is calculated as ZnO, and the second metal source is calculated as MO. x The molar ratio of silicon source (SiO2), dispersant, complexing agent and water is (0.01-0.8):(0.005-0.10):1:(0.002-0.5):(0.001-0.4):(2-80), preferably (0.02-0.5):(0.008-0.05):1:(0.05-0.2):(0.02-0.3):(5-50), where M is a metal element and x changes according to the metal valence state.

[0032] In this invention, there are no special requirements for the type of zinc source or silicon source; commonly used types can be used in this invention.

[0033] According to a preferred embodiment of the present invention, the zinc source is at least one of zinc nitrate, zinc acetate, zinc acetylacetonate, zinc sulfate, and zinc chloride, preferably at least one of zinc nitrate and zinc acetate.

[0034] According to a preferred embodiment of the present invention, the second metallic element is selected from at least one of tin, lanthanum, zirconium, niobium and magnesium.

[0035] According to a preferred embodiment of the present invention, the silicon source is selected from at least one of silica, tetraethyl orthosilicate and silica sol, preferably tetraethyl orthosilicate.

[0036] In this invention, the type of dispersant can be selected from a wide range, such as carbohydrates. According to a preferred embodiment of this invention, the dispersant is at least one of glucose, fructose, xylose, sucrose, cellobiose and inulin, preferably one or more of sucrose, inulin and glucose.

[0037] In this invention, the range of types of complexing agents is relatively wide, such as organic acids and organic amines. According to a preferred embodiment of this invention, the complexing agent is at least one of citric acid, oxalic acid, acetic acid, propionic acid, glycolic acid and adipic acid, preferably citric acid and / or oxalic acid.

[0038] According to a preferred embodiment of the present invention, in the solid acid preparation process, the drying and calcination can be carried out in a conventional manner, preferably the drying temperature is 50-140℃, more preferably 70-110℃; the drying time is 4-24 hours, more preferably 10-12 hours.

[0039] According to a preferred embodiment of the present invention, in the solid acid preparation process, the calcination temperature is preferably 300-650℃, more preferably 500-550℃; the calcination time is 1-12 hours, more preferably 4-10 hours.

[0040] According to a preferred embodiment of the present invention, in the solid acid preparation process, the calcination atmosphere is oxygen or air.

[0041] In this invention, the reaction product toluene was qualitatively analyzed by gas chromatography-mass spectrometry (GC-MS), and the conversion rate of the substrate methylfuran and the yield of the reaction product toluene were analyzed by gas chromatography (GC). The GC-MS system was an Agilent 7890A from Agilent Technologies, USA, with an HP-5 nonpolar capillary column (30m, 0.53mm). The gas chromatograph was an Agilent 7890B, with a flame ionization detector (FID) and an SE-54 capillary column (30m, 0.53mm).

[0042] In this invention, an inductively coupled plasma atomic emission spectrometer (ICP) model Varian725-ES is used to dissolve the analytical sample in hydrofluoric acid to detect the element content.

[0043] In this invention, the NH3 temperature-programmed desorption (NH3-TPD) experiment was conducted on a TPD / TPR Altamira AMI-3300 instrument. The total acid content was calculated by fitting and peaking the obtained spectrum. Acids with desorption temperatures of 100-250℃ were defined as weak acids, acids with desorption temperatures of 250-400℃ were defined as medium-strong acids, and acids with desorption temperatures of 400-550℃ were defined as strong acids. The proportions of weak, medium-strong, and strong acids were thus calculated.

[0044] The acid content, acid type, and acid strength of the catalyst were determined using the pyridine adsorption infrared method (Nicolet Model 710 spectrometer). The specific operational steps are as follows: a) Sample pretreatment: The sample (approximately 30 mg) was compressed into thin discs with a diameter of 13 mm and placed in the infrared sample cell. The sample was then pretreated in a vacuum chamber at 400 °C for 1 hour. After the sample cell cooled to room temperature, the infrared data of the sample was scanned as background. b) Pyridine adsorption: Pyridine vapor was introduced into the in-situ under room temperature and vacuum conditions until adsorption reached equilibrium, with an adsorption time of 1 hour. c) Pyridine desorption: After adsorption, a vacuum was applied at 100 °C until the internal pressure no longer changed. The desorption time was 40 minutes, and the infrared absorption spectrum was scanned and recorded. The difference spectrum before and after pyridine adsorption is the obtained pyridine adsorption-infrared absorption spectrum. When the desorption temperature was 100 °C, the acid content calculated from the spectrum was the total acid content.

[0045] The difference spectrum before and after pyridine adsorption is the obtained pyridine adsorption-infrared absorption spectrum. Based on the spectrum, a semi-quantitative calculation of the acidity of the sample was performed.

[0046]

[0047]

[0048] Where r and w are the diameter (cm) and mass (g) of the catalyst disc, respectively, and A is the integral absorbance value at the specified wavenumber peak based on the scanned pyridine adsorption-infrared absorption spectrum. IMEC is the integral molar extinction coefficient. L Version 2.22, IMEC B It is 1.67.

[0049] In this invention, the formula for methylfuran conversion rate is:

[0050] The conversion rate of methylfuran (%) = (molar amount of methylfuran participating in the reaction) / (molar amount of methylfuran substrate) × 100%.

[0051] In this invention, the formula for calculating the yield of toluene is as follows:

[0052] The yield % of the product toluene = (molar amount of toluene produced in the reaction) / (molar amount of the reaction substrate methylfuran) × 100%.

[0053] In this invention, the formula for calculating the selectivity of the product toluene is:

[0054] Selectivity of toluene as a product % = (molar amount of toluene produced in the reaction) / (molar amount of methylfuran produced in the reaction) × 100%.

[0055] To facilitate understanding of the present invention, the following embodiments are provided. However, these embodiments are merely for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0056] Example 1

[0057] According to the molar ratio of 0.05ZnO:0.03MgO:1SiO2:0.1sucrose:0.1oxalic acid:20H2O, 36g (2mol) deionized water, 0.95g (0.005mol) zinc nitrate, 0.44g (0.003mol) magnesium nitrate, 3.6g (0.01mol) sucrose, and 0.9g (0.01mol) oxalic acid were mixed to form a homogeneous solution. 20.8g (0.1mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 100℃ for 12 hours. The ZnMgSi-O solid acid catalyst was obtained by calcination at 550℃ for 5 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.05ZnO·0.03MgO·1SiO2, with a specific surface area of ​​633 m². 2 / g. The NH3-TPD of the sample is as follows: Figure 1 As shown, the total acid content is 573 μmol·g. -1 The sample contained 39% weak acid, 53% moderately strong acid, and 8% strong acid. The pyridine infrared spectroscopy of the sample was as follows: Figure 2 As shown, the ratio of L acid to B acid is 30:1.

[0058] Example 2

[0059] According to the molar ratio of 0.03ZnO:0.05MgO:1SiO2:0.08sucrose:0.2citric acid:30H2O, 54g (3mol) deionized water, 0.57g (0.003mol) zinc nitrate, 0.74g (0.005mol) magnesium nitrate, 2.9g (0.008mol) sucrose, and 3.8g (0.02mol) citric acid were mixed to form a homogeneous solution. 20.8g (0.1mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 90℃ for 10 hours. The ZnMgSi-O solid acid catalyst was obtained by calcination at 550℃ for 4 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.03ZnO·0.05MgO·1SiO2, and the specific surface area is 593 m². 2 / g. The NH3-TPD of the sample and such Figure 1Similarly, the total acid content was 636 μmol·g. -1 The sample contained 42% weak acid, 52% moderately strong acid, and 6% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 25:1.

[0060] Example 3

[0061] According to the molar ratio of 0.1 ZnO: 0.01 MgO: 1 SiO2: 0.09 inulin: 0.25 citric acid: 25 H2O, 45 g (2.5 mol) deionized water, 1.89 g (0.01 mol) zinc nitrate, 0.08 g (0.001 mol) magnesium carbonate, 4.5 g (0.009 mol) inulin, and 4.8 g (0.025 mol) citric acid were mixed to form a homogeneous solution. 20.8 g (0.1 mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 110 °C for 10 hours. The ZnMgSi-O solid acid catalyst was obtained by calcination at 550 °C for 5 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.1 ZnO·0.01 MgO·1 SiO2, with a specific surface area of ​​623 m². 2 / g. The NH3-TPD of the sample and such Figure 1 Similarly, the total acid content was 420 μmol·g. -1 The sample contained 51% weak acid, 44% moderately strong acid, and 5% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 28:1.

[0062] Example 4

[0063] According to the molar ratio of 0.08ZnO:0.04MgO:1SiO2:0.15g glucose:0.04oxalic acid:20H2O, 36g (2mol) deionized water, 1.47g (0.008mol) zinc acetate, 0.34g (0.004mol) magnesium carbonate, 2.7g (0.015mol) glucose, and 0.36g (0.004mol) oxalic acid were mixed to form a homogeneous solution. 20.8g (0.1mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 110℃ for 10 hours. The ZnMgSi-O solid acid catalyst was obtained by calcination at 550℃ for 5 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.08ZnO·0.04MgO·1SiO2, with a specific surface area of ​​710 m². 2 / g. The NH3-TPD of the sample and such Figure 1 Similarly, the total acid content was 612 μmol·g. -1 The sample contained 47% weak acid, 46% moderately strong acid, and 7% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 20:1.

[0064] Example 5

[0065] According to the molar ratio of 0.07ZnO:0.04MgO:1SiO2:0.1g glucose:0.05citric acid:35H2O, 63g (3.5mol) deionized water, 1.28g (0.007mol) zinc acetate, 0.59g (0.004mol) magnesium nitrate, 1.8g (0.01mol) glucose, and 0.96g (0.005mol) citric acid were mixed to form a homogeneous solution. 20.8g (0.1mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 80℃ for 10 hours. The ZnMgSi-O solid acid catalyst was obtained by calcination at 550℃ for 5 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.07ZnO·0.04MgO·1SiO2, with a specific surface area of ​​615 m². 2 / g. The NH3-TPD of the sample and such Figure 1 Similarly, the total acid content was 633 μmol·g. -1 The sample contained 52% weak acid, 42% moderately strong acid, and 6% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 23:1.

[0066] Example 6

[0067] According to the molar ratio of 0.09ZnO:0.02MgO:1SiO2:0.08g glucose:0.15citric acid:40H2O, 72g (4mol) deionized water, 1.70g (0.009mol) zinc nitrate, 0.30g (0.002mol) magnesium nitrate, 1.44g (0.008mol) glucose, and 2.88g (0.015mol) citric acid were mixed to form a homogeneous solution. 20.8g (0.1mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 70℃ for 12 hours. The ZnMgSi-O solid acid catalyst was obtained by calcination at 550℃ for 6 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.09ZnO·0.02MgO·1SiO2, with a specific surface area of ​​732 m². 2 / g. The NH3-TPD of the sample and such Figure 1 Similarly, the total acid content was 583 μmol·g. -1 The sample contained 42% weak acid, 50% moderately strong acid, and 8% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 17:1.

[0068] Example 7

[0069] According to the molar ratio of 0.03ZnO:0.03SnO2:1SiO2:0.07g glucose:0.2citric acid:20H2O, 36g (2mol) deionized water, 0.57g (0.003mol) zinc nitrate, 1.06g (0.003mol) tin acetate, 1.26g (0.007mol) glucose, and 3.84g (0.02mol) citric acid were mixed to form a homogeneous solution. 20.8g (0.1mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 90℃ for 10 hours. The ZnSnSi-O solid acid catalyst was obtained by calcination at 550℃ for 8 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.03ZnO·0.03SnO2·1SiO2, with a specific surface area of ​​704 m². 2 / g. The NH3-TPD of the sample and such Figure 1 Similarly, the total acid content was 390 μmol·g. -1The sample contained 52% weak acid, 45% moderately strong acid, and 3% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 16:1.

[0070] Example 8

[0071] According to the molar ratio of 0.05ZnO:0.017SnO2:1SiO2:0.09g glucose:0.06citric acid:25H2O, 45g (2.5mol) deionized water, 0.92g (0.005mol) zinc acetate, 0.60g (0.0017mol) tin tetrachloride, 1.62g (0.009mol) glucose, and 1.15g (0.006mol) citric acid were mixed to form a homogeneous solution. 20.8g (0.1mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 110℃ for 10 hours. The ZnSnSi-O solid acid catalyst was obtained by calcination at 500℃ for 10 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.03ZnO·0.017SnO2·1SiO2, with a specific surface area of ​​614 m². 2 / g. The NH3-TPD of the sample and such Figure 1 Similarly, the total acid content was 520 μmol·g. -1 The sample contained 51% weak acid, 42% moderately strong acid, and 7% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 22:1.

[0072] Example 9

[0073] According to the molar ratio of 0.3ZnO:0.01SnO2:1SiO2:0.14sucrose:0.13citric acid:20H2O, 36g (2mol) deionized water, 5.51g (0.03mol) zinc acetate, 0.35g (0.001mol) tin tetrachloride, 5.04g (0.014mol) sucrose, and 2.50g (0.013mol) citric acid were mixed to form a homogeneous solution. 20.8g (0.1mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 100℃ for 12 hours. The ZnSnSi-O solid acid catalyst was obtained by calcination at 550℃ for 7 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.07ZnO·0.01SnO2·1SiO2, with a specific surface area of ​​671 m².2 / g. The NH3-TPD of the sample and such Figure 1 Similarly, the total acid content was 563 μmol·g. -1 The sample contained 52% weak acid, 43% moderately strong acid, and 5% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 18:1.

[0074] Example 10

[0075] According to the molar ratio of 0.4 ZnO: 0.02 SnO2: 1 SiO2: 0.16 glucose: 0.15 citric acid: 28 H2O, 50.4 g (2.8 mol) deionized water, 12.8 g (0.04 mol) zinc nitrate, 0.70 g (0.002 mol) tin tetrachloride, 2.88 g (0.016 mol) glucose, and 2.88 g (0.015 mol) citric acid were mixed to form a homogeneous solution. 20.8 g (0.1 mol) tetraethyl orthosilicate was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 100°C for 12 hours. The ZnSnSi-O solid acid catalyst was obtained by calcination at 550°C for 6 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.4ZnO·0.02SnO2·1SiO2, with a specific surface area of ​​579 m². 2 / g. The NH3-TPD of the sample and such Figure 1 Similarly, the total acid content was 685 μmol·g. -1 The sample contained 51% weak acid, 42% moderately strong acid, and 7% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 23:1.

[0076] Example 11

[0077] According to the molar ratio of 0.4 ZnO: 0.08 SnO2: 1 SiO2: 0.16 glucose: 0.15 citric acid: 28 H2O, 50.4 g (2.8 mol) deionized water, 12.8 g (0.04 mol) zinc nitrate, 2.80 g (0.008 mol) tin tetrachloride, 0.016 mol fructose, and 2.88 g (0.015 mol) acetic acid were mixed to form a homogeneous solution. 0.1 mol of silica was continuously added dropwise to the solution. The mixture was heated and stirred at room temperature until a gel was completely formed. Then, it was placed in an oven to remove moisture and volatiles at 100°C for 12 hours. The ZnSnSi-O solid acid catalyst was obtained by calcination at 550°C for 6 hours under air conditions. The schematic chemical composition of the sample, determined by inductively coupled plasma atomic emission spectrometry (ICP), is 0.4ZnO·0.08SnO2·1SiO2, with a specific surface area of ​​523 m². 2 / g. The NH3-TPD of the sample and such Figure 1 Similarly, the total acid content was 763 μmol·g. -1 The sample contained 26% weak acid, 58% moderately strong acid, and 16% strong acid. The pyridine infrared spectroscopy of the sample was compared with... Figure 2 Similarly, the ratio of L acid to Brønsted acid is 30:1.

[0078] Examples 12-22

[0079] Heptane was used as the reaction solvent, with a heptane to methylfuran (MF) mass ratio of 20 and an MF to catalyst mass ratio of 2. The reaction temperature was 250°C, and the reaction time was 24 h. 0.5 g of the catalyst from Examples 1-10 above, 1.0 g of MF, and 20 g of heptane were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 2.0 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 250°C for 24 h. The MF conversion and toluene selectivity were calculated by gas phase analysis of the reaction liquid, as shown in Table 1.

[0080] Table 1. Catalytic evaluation results of Examples 12-22.

[0081]

[0082]

[0083] The data in the table may differ from the implementation examples; the implementation examples shall prevail.

[0084] Example 23

[0085] Using the ZnMgSi-O material from Example 1 as the catalyst and n-heptane as the reaction solvent, the mass ratio of n-heptane to MF was 30, and the mass ratio of MF to catalyst was 1. The reaction temperature was 240℃, and the reaction time was 20 h. 0.5 g of the catalyst from Example 1, 0.5 g of MF, and 15 g of n-heptane were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 3 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 240℃ for 20 h. Gas phase analysis of the reaction liquid showed an MF conversion of 97% and a toluene selectivity of 95%.

[0086] Example 24

[0087] Using the ZnMgSi-O material from Example 1 as the catalyst and n-heptane as the reaction solvent, the mass ratio of n-heptane to MF was 60, the mass ratio of MF to catalyst was 0.5, the reaction temperature was 250℃, and the reaction time was 12 h. 0.5 g of the catalyst from Example 1, 0.25 g of MF, and 15 g of n-heptane were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 2 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 250℃ for 12 h. Gas phase analysis of the reaction liquid showed an MF conversion rate >99% and a toluene selectivity of 97%.

[0088] Example 25

[0089] Using the ZnMgSi-O material from Example 1 as the catalyst and methyl isobutyl ketone (MOH) as the reaction solvent, the mass ratio of MOH to MF was 20, the mass ratio of MF to catalyst was 1, the reaction temperature was 230°C, and the reaction time was 16 h. 0.5 g of the catalyst from Example 1, 0.5 g of MF, and 10 g of MOH were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 2 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 230°C for 16 h. Gas phase analysis of the reaction liquid showed an MF conversion of 91% and a toluene selectivity of 94%.

[0090] Example 26

[0091] Using the ZnMgSi-O material from Example 1 as the catalyst and methyl isobutyl ketone (MOH) as the reaction solvent, the mass ratio of MOH to MF was 30, the mass ratio of MF to catalyst was 2, the reaction temperature was 240°C, and the reaction time was 30 h. 0.5 g of the catalyst from Example 1, 1.0 g of MF, and 30 g of MOH were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 3 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 240°C for 30 h. Gas phase analysis of the reaction liquid showed an MF conversion of 92% and a toluene selectivity of 96%.

[0092] Example 27

[0093] Using the ZnMgSi-O material from Example 1 as the catalyst and n-heptane as the reaction solvent, the mass ratio of n-heptane to MF was 40, and the mass ratio of MF to catalyst was 3. The reaction temperature was 260℃, and the reaction time was 36 h. 0.5 g of the catalyst from Example 1, 1.5 g of MF, and 60 g of n-heptane were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 4 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 260℃ for 36 h. Gas phase analysis of the reaction liquid showed an MF conversion rate of 88% and a toluene selectivity of 95%.

[0094] Example 28

[0095] Using the ZnMgSi-O material from Example 1 as the catalyst and n-hexane as the reaction solvent, the mass ratio of n-hexane to MF was 35, and the mass ratio of MF to catalyst was 2. The reaction temperature was 250℃, and the reaction time was 30 h. 0.5 g of the catalyst from Example 1, 1.0 g of MF, and 35 g of n-hexane were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 3 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 250℃ for 30 h. Gas phase analysis of the reaction liquid showed that the MF conversion was 90%, and the toluene selectivity was 94%.

[0096] Example 29

[0097] Using the ZnMgSi-O material from Example 1 as the catalyst and n-hexane as the reaction solvent, the mass ratio of n-hexane to MF was 30, and the mass ratio of MF to catalyst was 1. The reaction temperature was 230℃, and the reaction time was 20 h. 0.5 g of the catalyst from Example 1, 0.5 g of MF, and 15 g of n-hexane were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 2 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 230℃ for 20 h. Gas phase analysis of the reaction liquid showed an MF conversion of 94% and a toluene selectivity of 93%.

[0098] Example 30

[0099] Using the ZnMgSi-O material from Example 1 as the catalyst and n-heptane as the reaction solvent, the mass ratio of n-heptane to MF was 60, the mass ratio of MF to catalyst was 0.5, the reaction temperature was 230℃, and the reaction time was 14 h. 0.5 g of the catalyst from Example 1, 0.25 g of MF, and 15 g of n-heptane were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 2 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 230℃ for 14 h. Gas phase analysis of the reaction liquid showed an MF conversion rate >99% and a toluene selectivity of 92%.

[0100] Example 31

[0101] Using the ZnMgSi-O material from Example 1 as the catalyst and tetrahydrofuran as the reaction solvent, the mass ratio of tetrahydrofuran to MF was 25, and the mass ratio of MF to catalyst was 2. The reaction temperature was 240℃, and the reaction time was 30 h. 0.5 g of the catalyst from Example 1, 1.0 g of MF, and 25 g of tetrahydrofuran were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 3 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 240℃ for 30 h. Gas phase analysis of the reaction liquid showed an MF conversion rate of 89% and a toluene selectivity of 96%.

[0102] Example 32

[0103] Using the ZnMgSi-O material from Example 1 as the catalyst and tetrahydrofuran as the reaction solvent, the mass ratio of tetrahydrofuran to MF was 40, and the mass ratio of MF to catalyst was 1. The reaction temperature was 240℃, and the reaction time was 24 h. 0.5 g of the catalyst from Example 1, 0.5 g of MF, and 20 g of tetrahydrofuran were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 3 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 240℃ for 24 h. Gas phase analysis of the reaction liquid showed that the MF conversion rate was 97%, and the toluene selectivity was 97%.

[0104] To more intuitively describe the reaction conditions and results of Examples 23-32 above, the parameters and results are listed in Table 2.

[0105] Table 2 Catalytic performance results of Examples 23-32.

[0106]

[0107]

[0108] The data in the table may differ from the implementation examples; the implementation examples shall prevail.

[0109] Example 33

[0110] Heptane was used as the reaction solvent, with a heptane to methylfuran (MF) mass ratio of 20 and an MF to catalyst mass ratio of 2. The reaction temperature was 250°C, and the reaction time was 24 h. 0.5 g of the catalyst from Example 1, 1.0 g of MF, and 20 g of heptane were added to a high-pressure reactor equipped with a stirrer, and ethylene was introduced at 2.0 MPa. The temperature was raised to the preset temperature using a programmed heating mantle, and then stirred magnetically. The reaction was carried out at 250°C for 24 h. The MF conversion and toluene selectivity were calculated by gas phase analysis of the reaction liquid. The used catalyst was washed, dried, and then used in the next reaction cycle, for a total of 4 cycles. The results are as follows. Figure 3 As shown in the figure. The results show that after four reactions, the MF conversion remained above 90%, and the pX selectivity remained at 94%, indicating that the catalyst has good cycle stability.

[0111] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing bio-based toluene, characterized in that, The method comprises: contacting methylfuran with ethylene in the presence of a catalyst in the optional presence of an organic solvent, said catalyst containing a solid acid, said solid acid comprising a silica support and an active component, said active component containing zinc oxide and a second metal oxide, said second metal oxide being an oxide of tin and / or an oxide of magnesium, wherein the molar ratio of zinc oxide, the second metal oxide and silica in the solid acid is (0.01-0.8):(0.005-0.10):1; said solid acid has an acid content of 255-780 μmol / g and a specific surface area of ​​470-840 m². 2 / g; Ammonia temperature-programmed desorption analysis showed that the solid acid had a weak acid content of 25-60%, the solid acid had a medium-strong acid content of 25-60%, the solid acid had a strong acid content of 0-20%, and the ratio of L acid content to B acid content in the solid acid was 5-50:

1.

2. The preparation method according to claim 1, wherein, In the solid acid, the molar ratio of zinc oxide, the second metal oxide, and silicon dioxide is (0.02-0.5):(0.008-0.05):

1.

3. The preparation method according to claim 1, wherein, The solid acid has an acid content of 350-700 μmol / g; and / or The specific surface area of ​​the solid acid is 550-800 m². 2 / g.

4. The preparation method according to any one of claims 1-3, wherein, Ammonia temperature-programmed desorption analysis showed that The solid acid has a weak acid content of 30-55%; and / or The solid acid contains 30-55% strong acid; and / or The content of the solid acid strong acid is 2-10%; and / or The ratio of L acid content to B acid content in the solid acid is 10-40:

1.

5. The preparation method according to claim 4, wherein, Ammonia temperature-programmed desorption analysis showed that The ratio of L acid content to B acid content in the solid acid is 15-35:

1.

6. The preparation method according to any one of claims 1-3, wherein, The catalyst contains more than 50% by weight of solid acid; and / or The organic solvent includes one or more of methyl isobutyl ketone, n-hexane, n-heptane, n-octane, tetrahydrofuran, and 1,4-dioxane.

7. The preparation method according to claim 6, wherein, The catalyst contains 50-100% solid acid by weight.

8. The preparation method according to claim 7, wherein, The catalyst contains 100% solid acid by weight.

9. The preparation method according to any one of claims 1-3, wherein, The mass ratio of methylfuran to catalyst is 0.1-10.0:1; and / or The mass ratio of the organic solvent to methyl furan is 10-100:

1.

10. The preparation method according to claim 9, wherein, The mass ratio of methylfuran to catalyst is 0.2-5.0:1; and / or The mass ratio of the organic solvent to methyl furan is 15-60:

1.

11. The preparation method according to any one of claims 1-3, wherein, The reaction conditions include: The reaction temperature is 150-300℃; and / or The reaction time is 6-64 hours; and / or The reaction pressure is 1-8 MPa.

12. The preparation method according to claim 11, wherein, The reaction conditions include: The reaction temperature is 200-280℃; and / or The reaction time is 12-48 hours; and / or The reaction pressure is 2-6 MPa.

13. The preparation method according to claim 12, wherein, The reaction conditions include: The reaction temperature is 230-260℃; and / or The reaction time is 14-36 hours; and / or The reaction pressure is 2-4 MPa.

14. The preparation method according to any one of claims 1-3, wherein, The method for preparing the solid acid includes: mixing a zinc source, a second metal source, a silicon source, a dispersant, a complexing agent, and water uniformly to form a gel; optionally drying the gel and then calcining it; wherein the zinc source is calculated as ZnO and the second metal source is calculated as MO. x The molar ratio of silicon source (SiO2), dispersant, complexing agent, and water is (0.01-0.8):(0.005-0.10):1:(0.002-0.5):(0.001-0.4):(2-80), the second metal source is a tin source and / or a magnesium source, where M is a metal element, x changes according to the metal valence state, the dispersant is at least one of glucose, fructose, xylose, sucrose, cellobiose, and inulin, and the complexing agent is at least one of citric acid, oxalic acid, acetic acid, propionic acid, glycolic acid, and adipic acid.

15. The preparation method according to claim 14, wherein, The zinc source is calculated as ZnO, and the second metal source is calculated as MO. x The molar ratio of silicon source (calculated as SiO2), dispersant, complexing agent, and water is (0.02-0.5):(0.008-0.05):1:(0.05-0.2):(0.02-0.3):(5-50), where the second metal source is a tin source and / or a magnesium source, where M is a metal element and x varies according to the metal valence state; and / or The zinc source is at least one selected from zinc nitrate, zinc acetate, zinc acetylacetone, zinc sulfate, and zinc chloride; and / or The silicon source is selected from at least one of silica, tetraethyl orthosilicate, and silica sol; and / or The dispersant is one or more selected from sucrose, inulin, and glucose; and / or The complexing agent is citric acid and / or oxalic acid.

16. The preparation method according to claim 15, wherein, The zinc source is at least one of zinc nitrate and zinc acetate; and / or The silicon source is tetraethyl orthosilicate.

17. The preparation method according to claim 14, wherein, The drying temperature is 50-140℃; and / or the drying time is 4-24 hours; and / or The roasting temperature is 300-650℃; and / or the roasting time is 1-12 hours; and / or the roasting atmosphere is oxygen or air.

18. The preparation method according to claim 17, wherein, The drying temperature is 70-110℃; and / or the drying time is 10-12 hours; and / or The roasting temperature is 500-550℃; and / or the roasting time is 4-10 hours.

Images