Preparation method of ZrO2-SiO2 aerogel supported nickel catalyst
By preparing a ZrO2-SiO2 aerogel-supported nickel catalyst, the problems of low UV transmittance and high aldehyde content in ethylene glycol products were solved, resulting in more efficient ethylene glycol production, extended catalyst lifespan, and reduced costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-16
- Publication Date
- 2026-03-10
AI Technical Summary
In existing ethylene glycol production facilities, the ethylene glycol products have low ultraviolet transmittance, high aldehyde content, short catalyst life and high cost, and are environmentally unfriendly.
A ZrO2-SiO2 aerogel-supported nickel catalyst was prepared by supercritical fluid drying and equal-volume impregnation to form a Ni/ZrO2-SiO2 catalyst with high specific surface area and porosity, which was then applied to the liquid-phase hydrogenation process of an ethylene glycol production unit.
It improves the UV transmittance of ethylene glycol products and reduces aldehyde content, increases the yield of polyester-grade ethylene glycol products, extends catalyst lifespan, reduces pollution, and lowers costs.
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Figure CN121623795A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of catalysts for ethylene glycol products, and specifically to a method for preparing a ZrO2-SiO2 aerogel-supported nickel catalyst. Background Technology
[0002] In recent years, the load on ethylene glycol production facilities in my country has been continuously increasing, and the service life of dimethyl oxalate hydrogenation catalysts has also been continuously extending. This has resulted in ethylene glycol products having lower ultraviolet transmittance at wavelengths of 220nm and 275nm compared to similar products from abroad. Liquid-phase hydrogenation is an effective method to solve the problem of low transmittance in ethylene glycol products. After its application, the proportion of polyester-grade ethylene glycol products can reach 100%, the yield of ethylene glycol products can be increased from 90% to 96.5%–97%, and the aldehyde content of ethylene glycol products can be stabilized below 8×10⁻⁶.
[0003] However, liquid-phase hydrogenation catalysts are still in the early stages of development, and their catalytic performance has many problems, such as significant pollution during production, short service life, high unit cost, and environmental unfriendliness. To address these issues, some scholars have conducted extensive research. For example, Liu Zhen, based on the ethylene glycol project of Guoneng Yulin Chemical, attempted to improve catalyst lifespan by increasing operational stability. Zhao Hui focused on Pb-based carbonylation synthesis catalysts, investigating their deep utilization effects. Li Suxian et al. improved the UV transmittance of ethylene glycol products through self-made additives, enabling the prepared ethylene glycol to meet the technical indicators in GB / T4649-2018. The research of these scholars provides a reference for improving the efficiency of syngas-to-ethylene glycol production, but the improvement effect is still not ideal. Therefore, this invention prepares a novel nickel-based liquid-phase hydrogenation catalyst and verifies its performance and industrial application. Summary of the Invention
[0004] In order to solve one or more technical problems existing in the prior art, one of the objectives of this application is to provide a method for preparing a nickel catalyst supported on ZrO2-SiO2 aerogel, which can improve the ultraviolet transmittance of ethylene glycol solution while reducing the aldehyde content of polyester-grade ethylene glycol product, and has good catalytic effect to improve its utilization efficiency.
[0005] The second objective of this application is to provide an application of a Ni / ZrO2-SiO2 catalyst in the liquid-phase hydrogenation process of an ethylene glycol production unit, which can increase the yield of polyester-grade ethylene glycol in the syngas-to-ethylene glycol unit by 1.5%, and has a better UV enhancement effect on 98% ethylene glycol product and a better aldehyde removal effect; it can also be used for a longer period of time in the same production unit, reducing the pollution of the liquid-phase hydrogenation catalyst in the later stage.
[0006] To address the aforementioned technical problems, one of the objectives of this application is achieved through the following technical solution: A method for preparing a ZrO2-SiO2 aerogel-supported nickel catalyst, the method comprising: S1. Add ethanol and ZrO(NO3)2 to the reaction flask in sequence, and stir until they are completely dissolved to form a ZrO(NO3)2 / ethanol solution; S2. Tetraethyl orthosilicate, water, and AcOH are added sequentially to a ZrO(NO3)2 / ethanol solution under stirring, and the mixture is stirred at room temperature for 6 hours to obtain a mixed solution; this ensures that the solution reacts and mixes thoroughly. S3. Pour the mixed solution obtained in step S2 into an autoclave for supercritical fluid drying. Using this method, the powder surface area and porosity obtained under the same conditions are lower than those obtained by conventional drying methods, and the specific surface area difference between the two can be as many as tens of times. S4. After the reaction is complete, the liquid is discharged at a constant rate and cooled to room temperature with nitrogen gas to obtain a ZrO2-SiO2 composite oxide with a ZrO2 content of 4.5-5.5%; this avoids the situation where the product structure is damaged due to excessively fast reaction. S5. The composite oxide prepared in step S4 is impregnated with Ni(NO3)2 aqueous solutions of different concentrations in equal volumes. After a period of time, the composite is taken out and calcined and reduced to obtain Ni / ZrO2-SiO2 catalysts with different mass fractions. The catalyst with the best catalytic effect can be found by using this method.
[0007] Preferably, the molar ratio of ethanol to ZrO(NO3)2 in step S1 is 1.1~1.3:1.
[0008] Preferably, the molar ratio of tetraethyl orthosilicate, water and AcOH in step S2 is 1.3:2:1.
[0009] Preferably, the calcination temperature and time in step S5 are 400±2℃ and 3~3.5h, respectively, and after calcination, the temperature is maintained and the reduction is carried out under nitrogen for 3h.
[0010] Preferably, the high-pressure reactor heating process in step S3 is as follows: heating to 270°C at a heating rate of 5°C / min, reaction pressure of 8MPa, and reaction time of 30min.
[0011] Preferably, the solution stirring speed in steps S1 and S2 is 200 r / min.
[0012] Preferably, the concentration of the Ni(NO3)2 aqueous solution in step S5 is 6%, 13%, 30%, 40%, or 50%.
[0013] Preferably, the time for the medium-volume immersion treatment in step S5 is not less than 2 hours.
[0014] To solve the aforementioned existing technical problems, the second objective of this application is achieved by the following technical solution: The application of a Ni / ZrO2-SiO2 catalyst in the liquid-phase hydrogenation process of an ethylene glycol production unit involves adding the Ni / ZrO2-SiO2 catalyst in an equal proportion to the liquid-phase hydrogenation process of an ethylene glycol production unit.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The nickel content is relatively low compared to traditional catalysts, resulting in lower preparation costs.
[0016] Compared to traditional catalysts used in the liquid-phase hydrogenation of ethylene glycol from syngas, the Ni / ZrO2-SiO2 catalyst can increase the yield of polyester-grade ethylene glycol in syngas-to-ethylene glycol plants from 96.5%–97% to 98%–98.5%, and improve the ethylene glycol product yield by 1.5%, resulting in superior technical specifications for the ethylene glycol product. Furthermore, replacing the catalyst with Ni / ZrO2-SiO2 leads to better UV enhancement of the 98% ethylene glycol product and improved aldehyde removal; it also allows for a longer service life in equivalent production facilities.
[0017] Based on an ethylene glycol plant capacity of 600,000 tons / year and an ethylene glycol price of 4,200 yuan / ton (including tax), the increase in ethylene glycol product yield can increase the production of polyester-grade ethylene glycol by 9,000 tons and generate an additional 37.8 million yuan in revenue annually. Attached Figure Description
[0018] Figure 1 The TPR spectrum of the N / S catalyst in this invention; Figure 2 This is the TPR spectrum of the N / ZS catalyst in this invention. Detailed Implementation
[0019] The present application will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.
[0020] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0021] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0022] A method for preparing a ZrO2-SiO2 aerogel-supported nickel catalyst, the method comprising: Step 1: Add ethanol and a certain amount of ZrO(NO3)2 to the reaction flask in sequence, and stir at 200 r / min until completely dissolved to form a ZrO(NO3)2 / ethanol solution; Add tetraethyl orthosilicate, water and AcOH in sequence to the ZrO(NO3)2 / ethanol solution under stirring, maintain the stirring speed and stir at room temperature for 6 hours to obtain a mixed solution; The second step involves pouring the mixed solution into an autoclave and drying it using ethanol as the medium through supercritical fluid drying. The heating process involves a heating rate of 5°C / min to 270°C, a reaction pressure of 8 MPa, and a reaction time of 30 min. Using this method, under the same conditions, the powder obtained can have a lower surface area and porosity than that obtained by conventional drying methods; the specific surface area difference between the two can be tens of times. Third step: After the reaction is complete, the liquid is discharged at a constant rate and then cooled to room temperature with nitrogen gas to obtain a ZrO2-SiO2 composite oxide with a ZrO2 content of 5%; named ZS. Step 4: The composite oxide prepared in step S4 was impregnated with Ni(NO3)2 aqueous solutions of different concentrations at equal volumes. The concentrations of the Ni(NO3)2 aqueous solutions were 6%, 13%, 30%, 40%, and 50%. After a period of time, the composite was removed and calcined and reduced. The calcination temperature and time were 400℃ and 3h, respectively. After calcination, the temperature was maintained and the composite was reduced under H2 conditions for 3h to obtain Ni / ZrO2-SiO2 catalysts with different mass fractions; these were labeled as XN / ZS (X represents the mass percentage of nickel). The catalyst with the best catalytic effect was found by using this method. The molar ratio of ethanol to ZrO(NO3)2 was 1.1~1.3:1; the molar ratio of tetraethyl orthosilicate, water, and AcOH was 1.3:2:1.
[0023] The existing Ni / SiO2 catalyst was prepared using the same method and named XN / S.
[0024] Depend on Figure 1 As can be seen, the TPR spectrum of the N / S catalyst shows two hydrogen consumption peaks, indicating that N / S is more easily reduced. From Figure 2 It is evident that the N / ZS catalysts with Ni contents of 6% and 13% exhibit only a single, gradual hydrogen consumption peak in their TPR spectra, with hydrogen consumption beginning at 330℃ and not fully completed by 630℃, indicating a complex morphology of the active component in the reaction. At a Ni content of 30%, a more pronounced hydrogen consumption peak exists, with near-complete hydrogen consumption by 420℃. This may be due to excess Ni agglomerating within the system, affecting the interaction between the active component and the support, thus influencing the catalyst properties. These conclusions demonstrate that the novel 6N / ZS and 13N / ZS catalysts prepared in this experiment possess more stable chemical properties and a longer service life.
[0025] Using the traditional liquid-phase hydrogenation catalyst used in the ethylene glycol unit of Qianxi Chemical as a control, the results of the hydrogenation ultraviolet transmittance of the synthesis catalyst and the aldehyde content of the ethylene glycol solution were compared in the laboratory. The results are shown in Tables 1 and 2 below.
[0026] Table 1 Table 1 compares the improvement in UV transmittance of 98% ethylene glycol solution at 220nm, 250nm, and 350nm compared to traditional liquid-phase hydrogenation catalysts. As shown in Table 1, traditional liquid-phase hydrogenation catalysts increase the UV transmittance of 98% ethylene glycol solution by 36.3% at 220nm, 86.2% at 275nm, and 2.6% at 350nm. In contrast, the Ni / ZrO2-SiO2 catalyst of this application increases the UV transmittance of 98% ethylene glycol solution by 38.6% at 220nm, 89.5% at 275nm, and 3.1% at 350nm, demonstrating a superior UV enhancement effect.
[0027] Table 2 Table 2 compares the aldehyde removal efficiency of the present invention and a traditional liquid-phase hydrogenation catalyst in removing aldehydes from a 98% ethylene glycol solution. As shown in Table 2, the aldehyde content in the inlet sample from the traditional liquid-phase hydrogenation catalyst was 17.6 × 10⁻⁶. -6 The aldehyde content in the exhaust sample was 6.47 × 10⁻⁶. -6 The aldehyde reduction was 11.13 × 10⁻⁶. -6 The aldehyde content in the inlet sample of the Ni / ZrO2-SiO2 catalyst of this invention was 18.53 × 10⁻⁶. -6 The aldehyde content in the exhaust sample was 2.33 × 10⁻⁶. -6 The aldehyde reduction was 16.20 × 10⁻⁶. -6Liquid-phase hydrogenation can significantly improve the UV transmittance of the product and reduce its aldehyde content. Furthermore, the Ni / ZrO2-SiO2 nickel-based liquid-phase hydrogenation catalyst presented in this application demonstrates superior performance compared to traditional liquid-phase hydrogenation catalysts used in syngas-to-ethylene glycol production units. This is because the Ni / ZrO2-SiO2 nickel-based liquid-phase hydrogenation catalyst prepared in this experiment exhibits highly dispersed NiO grains on its surface, resulting in a higher specific surface area and pore volume, increasing the opportunity for contact with reactant molecules and thus enhancing its catalytic performance.
[0028] The novel Ni / ZrO2-SiO2 liquid-phase hydrogenation catalyst prepared by this invention exhibits excellent catalytic performance and can be used as a liquid-phase hydrogenation catalyst. Compared with conventional liquid-phase hydrogenation catalysts used in traditional syngas-to-ethylene glycol plants, it shows better improvement in product UV transmittance and superior aldehyde removal. Furthermore, this development lays the foundation for reducing contamination and improving the efficiency of liquid-phase hydrogenation catalysts in the future.
[0029] The above embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of protection of this application. Any non-substantial changes and substitutions made by those skilled in the art based on this application shall fall within the scope of protection claimed by this application.
Claims
1. A process for the preparation of a Zr02-Si02 aerogel supported nickel catalyst, characterized in that: The preparation method comprises: S1, adding ethanol and ZrO(NO3)2 into a reaction bottle in sequence, and forming a ZrO(NO3)2 / ethanol solution by stirring to completely dissolve ZrO(NO3)2; S2, adding tetraethyl orthosilicate, water and AcOH into the ZrO(NO3)2 / ethanol solution under stirring in sequence, and obtaining a mixed solution after stirring at room temperature for 6 hours; S3, pouring the mixed solution prepared in step S2 into an autoclave for supercritical fluid drying; S4, after the reaction is completed, discharging the liquid at a constant speed, cooling the liquid to room temperature by nitrogen, and obtaining a ZrO2-SiO2 composite oxide with a ZrO2 content of 4.5-5.5%; S5, using a Ni(NO3)2 aqueous solution with different concentrations to carry out equal-volume impregnation treatment on the composite oxide prepared in step S4, taking out the composite after a period of time, and carrying out calcination and reduction to obtain a Ni / ZrO2-SiO2 catalyst with different mass fractions.
2. The preparation method of Zr02-Si02 aerogel supported nickel catalyst according to claim 1, characterized in that: The molar ratio of ethanol to ZrO(NO3)2 in step S1 is 1.1-1.3:
1.
3. The preparation method of Zr02-Si02 aerogel supported nickel catalyst according to claim 1, characterized in that: The molar ratio of tetraethyl orthosilicate, water and AcOH in step S2 is 1.3:2:
1.
4. The method for preparing Zr02-Si02 aerogel supported nickel catalyst according to claim 1, characterized in that: The calcination temperature and time in step S5 are 400±2°C and 3-3.5 hours respectively, and after calcination, the temperature is maintained at 3 hours under nitrogen reduction.
5. The method for preparing a Zr02-Si02 aerogel supported nickel catalyst according to claim 1, characterized by: The autoclave temperature rising process in step S3 is: rising to 270°C at a temperature rising rate of 5°C / min, the reaction pressure is 8 MPa, and the reaction time is 30 min.
6. The method for preparing Zr02-Si02 aerogel supported nickel catalyst according to claim 1, characterized in that: The stirring speed of the solution in steps S1 and S2 is 200 r / min.
7. The method according to claim 1, wherein the method is characterized by: The concentration of the Ni(NO3)2 aqueous solution in step S5 is 6%, 13%, 30%, 40% and 50%.
8. The method for preparing a Zr02-Si02 aerogel supported nickel catalyst according to claim 1, characterized by: The time of equal-volume impregnation treatment in step S5 is not less than 2 hours.
9. Use of a Ni / Zr02-Si02 catalyst in a liquid phase hydrogenation process in an ethylene glycol production plant, characterized in that: The Ni / ZrO2-SiO2 catalyst is applied to the liquid-phase hydrogenation process of an ethylene glycol production device and is added in equal proportions.