A catalyst for producing low-carbon oxygenates, and a method for preparing the same and use thereof

Abstract

The application discloses a catalyst for preparing low-carbon oxygen-containing compounds and a preparation method and application thereof. The catalyst comprises a carrier, a main catalyst and a cocatalyst. The carrier is InN, the main catalyst is Ag, and the cocatalyst is In2O3. The application further discloses a preparation method of the catalyst. The method comprises the following steps: preparing an In2O3 / InN mixture by using an ammonia nitrogenization method. Finally, the catalyst is obtained by impregnating silver ammine solution into the In2O3 / InN mixture and then calcining the mixture to decompose silver ammine complexes into metallic silver. The application further discloses that the catalyst is used in a reaction for preparing low-carbon oxygen-containing compounds.

Description

Technical Field

[0001] This application relates to a catalyst for preparing low-carbon oxygen-containing compounds, its preparation method, and its application, belonging to the field of chemical engineering. Background Technology

[0002] The gas-phase oxidation of olefins can produce many useful organic compounds, among which the epoxidation of ethylene to ethylene oxide is relatively important. Ethylene oxide is the third most important organic chemical product in the ethylene industry after polyethylene and polyvinyl chloride. Besides being used in the manufacture of nonionic surfactants, amino alcohols, and ethylene glycol ethers, it is mainly used to produce ethylene glycol, which is a major raw material for polyester resins and is also widely used as an antifreeze. Currently, almost all ethylene oxide production is combined with ethylene glycol production; most or all of ethylene oxide is used to produce ethylene glycol, with only a small portion used to produce other chemical products.

[0003] There are two methods for producing ethylene oxide: the chlorohydrin process and the direct oxidation process. The chlorohydrin process was first industrialized by Union Carbide Corporation (UCC) in 1925. It can use low-concentration ethylene as raw material, has low ethylene consumption, simple equipment, and is easy to control. Sometimes it can also co-produce propylene oxide. However, its production cost is high, and it also causes equipment corrosion and serious environmental pollution. Since the 1950s, it has been gradually replaced by the direct oxidation process.

[0004] The research and development focus of ethylene oxidation to produce low-carbon oxygen-containing compounds (ethylene oxide) technology is on catalysts. Currently, there are three types of industrial catalysts: highly active silver catalysts; moderately selective catalysts; and highly selective silver catalysts. Foreign companies providing silver catalyst technology for ethylene oxide mainly include Shell, Scientific Design (SD), Dow Chemical, and Nippon Shokubai. Domestically, the YS series silver catalysts (YS-4, YS-5, YS-6) developed by Sinopec's Yanshan Branch have performance comparable to similar foreign catalysts. Furthermore, its recently developed YS-7, YS-8520, and YS-8810 silver catalysts exhibit good performance and have achieved excellent application results in China. Summary of the Invention

[0005] This application employs an impregnation method to prepare highly selective silver catalysts, using InN as the support, Ag as the main catalyst, and In2O3 as the co-catalyst to improve catalyst activity and stability, thus producing highly selective silver catalysts. These highly selective silver catalysts meet market development requirements and have significant practical implications and economic benefits for reducing production costs and promoting the development of the domestic petrochemical industry.

[0006] This application discloses a catalyst comprising a support, a main catalyst, and a co-catalyst, wherein the support is InN, the main catalyst is Ag, and the co-catalyst is In2O3.

[0007] This application also discloses a method for preparing the catalyst, the method comprising preparing an In₂O₃ / InN mixture using an ammonia nitridation method. Finally, the In₂O₃ / InN mixture is impregnated with a silver amine solution and then calcined to decompose the silver amine complex into metallic silver, thereby obtaining the catalyst. This application also discloses the use of the catalyst in reactions for preparing low-carbon oxygen-containing compounds.

[0008] According to one aspect of this application, a catalyst for preparing low-carbon oxygen-containing compounds is provided, comprising a support, an active component, and an auxiliary agent;

[0009] The carrier is InN;

[0010] The active component is Ag;

[0011] The auxiliary agent is In2O3;

[0012] The catalyst is characterized by the active component Ag being distributed on the In2O3 / InN surface.

[0013] In the catalyst, the content of the active component is 10-50 wt%;

[0014] Optionally, in the catalyst, the content of the active component is any value among 10wt%, 20wt%, 30wt%, 40wt%, and 50wt%, or a range between any two.

[0015] In the catalyst, the content of the auxiliary agent is 10-30 wt%;

[0016] Optionally, in the catalyst, the content of the auxiliary agent is any value among 10wt%, 20wt%, and 30wt%, or a range between any two.

[0017] According to another aspect of this application, a method for preparing the above-mentioned catalyst for preparing low-carbon oxygen-containing compounds is provided, comprising the following steps:

[0018] (1) Preparation of In2O3 / InN mixture by ammonia nitridation;

[0019] (2) The In2O3 / InN mixture obtained in (1) is mixed with silver ammonia solution, dried and calcined to obtain the catalyst used to prepare low-carbon oxygen-containing compounds.

[0020] The preparation of the In2O3 / InN mixture by ammonia nitridation includes the following steps:

[0021] In2O3 was placed in an ammonia atmosphere and calcined to obtain the In2O3 / InN mixture.

[0022] The roasting temperature is 550–650°C;

[0023] Optionally, the roasting temperature is any value or a range between 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C, and 650°C.

[0024] The heating rate of the roasting is 4–10 °C / min;

[0025] Optionally, the heating rate of the calcination is any value or a range between 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, and 10℃ / min.

[0026] The roasting time is 0.5 to 4 hours.

[0027] Optionally, the roasting time is any value among 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, and 4h, or a range between any two.

[0028] The roasting is carried out in an open tube furnace.

[0029] The solid-liquid ratio of the In2O3 / InN mixture obtained in (1) to the silver ammonia solution is 1:(40-100)g / ml;

[0030] Optionally, the solid-liquid ratio of the In2O3 / InN obtained in (1) to the silver ammonia solution is any value among 1:40 g / ml, 1:50 g / ml, 1:60 g / ml, 1:70 g / ml, 1:80 g / ml, 1:90 g / ml, and 1:100 g / ml, or any range between two of these values. The mixing is performed by vacuum excess impregnation in a vacuum container.

[0031] The vacuum degree of the mixture is 5-15 mmHg;

[0032] Optionally, the vacuum degree of the mixture is any value among 5 mmHg, 10 mmHg, and 15 mmHg, or a range between any two.

[0033] The mixing time is 0.5 to 1 hour;

[0034] Optionally, the mixing time is any value among 0.5h, 0.75h, and 1h, or a range between any two.

[0035] The drying temperature is 100–120°C;

[0036] Optionally, the drying temperature is any value among 100°C, 110°C, and 120°C, or a range between any two.

[0037] The drying time is 8–12 hours;

[0038] Optionally, the drying time is any value among 8h, 9h, 10h, 11h, and 12h, or a range between any two.

[0039] The calcination temperature is 100–200°C;

[0040] Optionally, the calcination temperature is any value among 100°C, 150°C, and 200°C, or a range between any two.

[0041] The calcination time is 2 to 60 minutes;

[0042] Optionally, the calcination time is any value among 2 min, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, and 60 min, or a range between any two.

[0043] The calcination atmosphere is a non-reactive gas atmosphere;

[0044] The inactive gas atmosphere is selected from at least one of nitrogen, helium, and argon.

[0045] The method for preparing the silver amine solution includes adding a certain amount of silver nitrate solution to deionized water I, heating the deionized water to 50°C, and then adding ammonium oxalate (molar ratio of silver nitrate to ammonium oxalate 2:1). After the two solutions react, a white silver oxalate precipitate is formed. After a period of time, the solution is washed with deionized water until nitrate ions are no longer present. Deionized water II, a certain amount of ethylenediamine, and ethanolamine are added to the filtered cake. After continuous stirring, the filter cake completely dissolves, yielding the silver amine solution.

[0046] Optionally, the volume ratio of silver nitrate to deionized water I is 1:(3-5);

[0047] Optionally, the upper limit of the volume ratio of silver nitrate to deionized water I is selected from 1:3 and 1:4, and the lower limit is selected from 1:5 and 1:4.

[0048] Optionally, the molar ratio of silver oxalate, ethylenediamine, ethanolamine and deionized water II is 1:(1-2):(1-2):(20-30).

[0049] Optionally, the upper limit of the molar ratio of silver oxalate, ethylenediamine, ethanolamine and deionized water II is selected from 1:1:1:20 and 1:1.5:1.5:25, and the lower limit is selected from 1:2:2:30 and 1:1.5:1.5:25.

[0050] According to another aspect of this application, a method for preparing low-carbon oxygen-containing compounds is provided, comprising the following steps:

[0051] In a reactor, a raw material containing ethylene and oxygen is introduced, which comes into contact with a catalyst and reacts to obtain a product containing ethylene oxide.

[0052] The catalyst is selected from the catalysts described above for preparing low-carbon oxygen-containing compounds or the catalysts prepared by the methods described above for preparing low-carbon oxygen-containing compounds.

[0053] In the raw material containing ethylene and oxygen, the molar ratio of ethylene to oxygen is 10 to 15:1;

[0054] Optionally, in the raw material containing ethylene and oxygen, the molar ratio of ethylene to oxygen is any value among 10:1, 11:1, 12:1, 13:1, 14:1, and 15:1, or any range between the two.

[0055] The volume hourly space velocity (VHSV) of the feedstock containing ethylene and oxygen is 2500–5000 h⁻¹. -1 .

[0056] Optionally, the volume hourly space velocity (VHSV) of the feedstock containing ethylene and oxygen is 2500 h⁻¹. -1 3000h -1 3500h -1 4000h -1 4500h -1 5000h -1 Any value in the range or any value between the two.

[0057] The reaction temperature is 230–270°C;

[0058] Optionally, the temperature of the reaction is any value of 230°C, 240°C, 250°C, 260°C, or 270°C, or a range between any two.

[0059] The reaction time is 3–6 hours;

[0060] Optionally, the reaction time is any value among 3h, 4h, 5h, and 6h, or a range between any two.

[0061] The reaction is carried out at a pressure of 1–3 MPa.

[0062] Optionally, the pressure of the reaction is any value of 1 MPa, 2 MPa, 3 MPa, or a range between any two.

[0063] The reactor is a fixed-bed reactor.

[0064] The beneficial effects that this application can produce include:

[0065] 1) The catalyst provided in this application can be applied to the reaction for preparing low-carbon oxygen-containing compounds and improves the selectivity of the generated ethylene oxide.

[0066] 2) The preparation method of the catalyst provided in this application is stable, controllable, and reproducible.

[0067] 3) The method for preparing low-carbon oxygen-containing compounds by oxidation provided in this application uses the catalyst provided in this application, which has a fast reaction rate and high yield, and can be applied to large-scale production. Attached Figure Description

[0068] Figure 1 Catalyst 1 # and 15 # X-ray powder diffraction pattern of In2O3 / InN.

[0069] Figure 2 Catalyst 1 # Scanning electron microscope image of In2O3 / InN. Detailed Implementation

[0070] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0071] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially. The gas chromatograph used was an Agilent 7890B gas chromatograph.

[0072] Examples 1-28

[0073] Preparation of catalysts

[0074] Taking item 1 in Table 1 as an example, In₂O₃ was placed in an open tube furnace and heated to 600℃ with ammonia gas introduced, at a heating rate of 4℃ / min. This mixture was then heated at this temperature for 30 minutes to obtain an In₂O₃ / InN mixture. A certain amount of silver nitrate solution (volume ratio 1:5) was added to deionized water I. After heating deionized water I to 50℃, ammonium oxalate (molar ratio of silver nitrate to ammonium oxalate 2:1) was added. The two solutions reacted to form a white precipitate of silver oxalate. After a period of time, the mixture was washed with deionized water until nitrate ions were no longer present. Deionized water II, ethylenediamine, and ethanolamine (the molar ratio of silver oxalate, ethylenediamine, ethanolamine, and deionized water II is 1:2:2:30) are added to the filtered cake. After continuous stirring, the filter cake is completely dissolved to obtain a silver amine solution. In₂O₃ / InN is placed in a vacuum container and evacuated using a vacuum pump (vacuum degree is 9 mmHg). The silver amine solution (the solid-liquid ratio of the In₂O₃ / InN mixture to the silver ammonia solution is 1:50 g / ml) is poured into the prepared In₂O₃ / InN and allowed to stand for 30 min. The excess solution is filtered off. The mixture is dried at 100℃ for 10 h and calcined at 180℃ in argon for 40 min to obtain the Ag / In₂O₃ / InN catalyst (Ag accounts for 20 wt% of the catalyst mass, and In₂O₃ accounts for 20 wt% of the catalyst mass). This is denoted as Catalyst 1. # .

[0075] Following the steps below, adjust the type and amount of each raw material and the reaction parameters to obtain a series of catalysts numbered 2 to 28, denoted as catalyst 2. # ~Catalyst 28 # As shown in Table 1-2 below:

[0076] Table 1

[0077]

[0078]

[0079] Table 2

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] XRD characterization

[0086] Catalyst 1 was analyzed using a Miniflex 600 X-ray diffractometer with a Cu target. # and 15 # Powder diffraction of In2O3 / InN yielded catalyst 1. # and 15 # The diffraction peaks of In2O3 / InN conform to the characteristic peaks of In2O3 / InN (e.g., Figure 1 (As shown).

[0087] SEM characterization

[0088] Scanning electron microscopy (SEM) (JSM-7800F) on catalyst 1 # Morphology analysis of In2O3 / InN (e.g.) Figure 2 As shown in the figure, In2O3 / InN exhibits rectangular structures of varying sizes.

[0089] Application Example 1

[0090] The catalyst is used in the oxidation reaction to prepare low-carbon oxygen-containing compounds (ethylene oxide).

[0091] Catalysts 1-28 prepared in Examples 1-28 # ~Catalyst 28 # It is used in the oxidation process to prepare ethylene oxide at a reaction temperature of 230℃, a reaction pressure of 2 MPa, a reaction time of 5 h, and a volume hourly space velocity of 4000 h⁻¹. -1 .

[0092] Composition of reactant gases (mol%)

[0093] Ethylene (C2H4) 28.0% ± 1.0%

[0094] Oxygen (O2) 2.4% ± 0.2%

[0095] Carbon dioxide (CO2) < 1.0%

[0096] Stabilizing gas (N2) balance

[0097]

[0098] ΔEO represents the difference in ethylene oxide concentration between the outlet gas and the inlet gas. The average of three or more sets of test data is taken as the test result for that day.

[0099] After the reaction stabilized, both the reactants and products were analyzed using online gas chromatography. The results are shown in Table 3.

[0100] Table 3

[0101]

[0102]

[0103] As can be seen from the table, the synthesized catalysts exhibit high selectivity for ethylene oxide in the oxidation reaction.

[0104] Application Example 2

[0105] Catalyst 1 prepared using the catalysts in Tables 1-2 # An oxidation reaction was carried out to prepare low-carbon oxygen-containing compounds (ethylene oxide). Reaction parameters were varied, and after the reaction stabilized, both the reactants and products were analyzed using online gas chromatography. The results are shown in Table 4.

[0106] Table 4

[0107]

[0108] The table shows that the reaction temperature has a significant impact on the selectivity of ethylene oxide.

[0109] 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 catalyst for preparing low-carbon oxygen-containing compounds, characterized in that, Includes carrier, active ingredient, and auxiliaries; The carrier is InN; The active component is Ag; The additive is In2O3.

2. The catalyst according to claim 1, characterized in that, In the catalyst, the content of the active component is 10-50 wt%; The catalyst contains 10-30 wt% of the auxiliary agent.

3. A method for preparing a catalyst for preparing low-carbon oxygen-containing compounds as described in claim 1 or 2, characterized in that, Includes the following steps: (1) Preparation of In2O3 / InN mixture by ammonia nitridation; (2) The In2O3 / InN mixture obtained in (1) is mixed with silver ammonia solution, dried and calcined to obtain the catalyst used to prepare low-carbon oxygen-containing compounds.

4. The preparation method according to claim 3, characterized in that, The preparation of the In2O3 / InN mixture by ammonia nitridation includes the following steps: In2O3 was placed in an ammonia atmosphere and calcined to obtain the In2O3 / InN mixture.

5. The preparation method according to claim 4, characterized in that, The roasting temperature is 550–650°C; The heating rate of the roasting is 4–10 °C / min; The roasting time is 0.5 to 4 hours.

6. The preparation method according to claim 3, characterized in that, The solid-liquid ratio of the In2O3 / InN mixture obtained in (1) to the silver ammonia solution is 1:(40-100)g / mL; The mixing is a vacuum excess impregnation; The vacuum degree of the mixture is 5-15 mmHg; The mixing time is 0.5 to 1 hour; The drying temperature is 100–120°C; The drying time is 8–12 hours; The calcination temperature is 100–200°C; The calcination time is 2 to 60 minutes; The calcination atmosphere is a non-reactive gas atmosphere; The inactive gas atmosphere is selected from at least one of nitrogen, helium, and argon.

7. A method for preparing low-carbon oxygen-containing compounds, characterized in that, Includes the following steps: In a reactor, a raw material containing ethylene and oxygen is introduced, which comes into contact with a catalyst and reacts to obtain a product containing ethylene oxide. The catalyst is selected from the catalyst for preparing low-carbon oxygen-containing compounds according to any one of claims 1 or 2, or the catalyst for preparing low-carbon oxygen-containing compounds prepared by the preparation method according to any one of claims 3 to 6.

8. The method according to claim 7, characterized in that, In the raw material containing ethylene and oxygen, the molar ratio of ethylene to oxygen is 10 to 15:1; The volume hourly space velocity (VHSV) of the feedstock containing ethylene and oxygen is 2500–5000 h⁻¹. -1 .

9. The method according to claim 7, characterized in that, The reaction temperature is 230–270°C; The reaction time is 3–6 hours; The reaction is carried out at a pressure of 1–3 MPa.

10. The method according to claim 7, characterized in that, The reactor is a fixed-bed reactor.

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