Maleic anhydride hydrogenation catalyst and method for preparing the same

Abstract

This invention provides a maleic anhydride hydrogenation catalyst for use in the process of hydrogenating maleic anhydride to prepare succinic anhydride. The catalyst comprises nickel, copper, tin oxide, and aluminum oxide. Based on the mass percentage of the catalyst, the nickel content is 10-20%, the copper content is 2-7%, the tin oxide content is 1-4%, and the aluminum oxide content is 67-87%. The catalyst has a specific surface area of ​​100-200 m² / g, a pore volume of 0.3-0.5 cm³ / g, and a bulk density of 0.6-1.0 g / cm³. By rationally designing the contents of nickel, copper, tin oxide, and aluminum oxide, and combining them with appropriate bulk density, specific surface area, pore size distribution, and pore volume, the preparation of succinic anhydride from maleic anhydride is facilitated. This invention also provides a method for preparing the aforementioned maleic anhydride hydrogenation catalyst.

Description

Technical Field

[0001] This invention relates to the field of maleic anhydride hydrogenation technology, and more particularly to maleic anhydride hydrogenation catalysts and their preparation methods. Background Technology

[0002] Succinic anhydride, also known as succinic anhydride, is an important organic synthesis intermediate and fine chemical raw material, widely used in food, surfactants, coatings, pharmaceuticals, agriculture, plastics, and other industrial fields. In recent years, high-performance polybutylene succinate (PBS) biodegradable plastics can be synthesized from succinic anhydride and butanediol via polycondensation. The market prospects for PBS are very broad, greatly stimulating and driving the market demand for succinic anhydride.

[0003] Currently, the main methods for synthesizing succinic anhydride include succinic acid dehydration and maleic anhydride hydrogenation. The succinic acid dehydration method involves heating succinic acid in the presence of a dehydrating agent to produce succinic anhydride. However, this method results in unstable yields, with product purity typically ranging from 85-94%. It also suffers from high energy consumption and equipment susceptibility to corrosion. The maleic anhydride hydrogenation method, on the other hand, uses maleic anhydride as a raw material and employs a highly efficient catalyst for direct hydrogenation to produce succinic anhydride. This method boasts advantages such as a simple process flow, convenient operation, high equipment utilization, low operating costs, and high product purity, making it the most widely adopted industrial process for succinic anhydride production. The main challenge in preparing succinic anhydride via maleic anhydride hydrogenation is controlling the hydrogenation reaction at the C=C double bond hydrogenation stage. Deep hydrogenation reduces the selectivity of succinic anhydride, thus requiring the search for suitable catalysts to achieve high selectivity. Currently, the main hydrogenation catalyst systems for preparing succinic anhydride via maleic anhydride hydrogenation include noble metal, copper-based, and nickel-based catalysts.

[0004] US Patent No. SU1541210, Russian Patent No. RU2058311, and EU Patent No. EP0691335 disclose a method for one-step hydrogenation of maleic anhydride to succinic anhydride using noble metal catalysts in the presence of a solvent. The catalysts used have a noble metal palladium content as high as 2-10%, which makes the catalyst cost too high.

[0005] Chinese patent CN101502802 discloses a catalyst for the continuous hydrogenation of maleic anhydride to produce succinic anhydride and its preparation method. The catalyst is prepared using an equal-volume impregnation method, with a nickel content of 13-20%, a promoter content of 1-7%, and a support of SiO2, Al2O3, or a SiO2-Al2O3 composite oxide. This catalyst suffers from drawbacks such as high energy consumption and high cost.

[0006] Chinese patents CN1078716 and CN1063484 disclose a method for the catalytic hydrogenation of molten maleic anhydride to succinic anhydride using a Raney nickel catalyst in a solvent-free state. The catalyst dosage is 4-10% of the weight of maleic anhydride, the reaction pressure is 1.2-2.0 MPa, the reaction temperature is 160-210℃, and the yield of succinic anhydride is 89%. Due to the large amount of catalyst used, the catalyst and product are not easily separated.

[0007] Chinese patent CN101502802 discloses a method for preparing a catalyst for the continuous hydrogenation of maleic anhydride to succinic anhydride. The catalyst is prepared using an equal-volume impregnation method, with Ni as the active component and 1-7 wt% of a promoter added. The support is SiO2, Al2O3, or a SiO2-Al2O3 composite support. The preparation method involves preparing an impregnation solution using ammonia and an active metal nitrate, and then impregnating the solution onto the support. However, this impregnation method results in ammonia reacting with nitrate ions to form a large amount of ammonium nitrate, a highly explosive substance. This can cause the catalyst to break apart during calcination, leading to extremely low yields and a high risk of explosion. Furthermore, γ-butyrolactone was used as a solvent in the catalyst evaluation, requiring distillation to obtain succinic anhydride.

[0008] Chinese Patent 03122336.2 discloses a method for the catalytic hydrogenation of maleic anhydride to produce succinic anhydride under both solvent-containing and solvent-free conditions. The molar ratio of nickel to support in the catalyst is Ni:SiO2:Al2O3 = 1:(1.47-5.98):(0-3.3), the reaction pressure is 0.5-3 MPa, the reaction temperature is 120-180℃, the reaction time is 1-3 h, and the molar ratio of nickel to maleic anhydride is 0.3-1.6:100. The efficiency of maleic anhydride conversion per unit nickel in this system is not high. Summary of the Invention

[0009] The purpose of this invention is to provide a maleic anhydride hydrogenation catalyst with good activity, high selectivity and excellent stability, and its preparation method, which is mainly used for the catalytic hydrogenation of maleic anhydride to prepare succinic anhydride under solvent-free conditions.

[0010] To achieve the above objectives, the maleic anhydride hydrogenation catalyst of the present invention is applied to the process of preparing succinic anhydride by hydrogenation of maleic anhydride, wherein the maleic anhydride hydrogenation catalyst comprises nickel, copper, tin oxide and aluminum oxide;

[0011] The content of nickel is 10-20%, the content of copper is 2-7%, the content of tin oxide is 1-4%, and the content of aluminum oxide is 67-87% by mass percentage of the maleic anhydride hydrogenation catalyst.

[0012] The maleic anhydride hydrogenation catalyst has a specific surface area of ​​100-200 m² / g, a pore volume of 0.3-0.5 cm³ / g, and a bulk density of 0.6-1.0 g / cm³.

[0013] The beneficial effects of the maleic anhydride hydrogenation catalyst of the present invention are as follows: the maleic anhydride hydrogenation catalyst contains nickel, copper, tin oxide, and aluminum oxide, but does not contain precious metals such as palladium and ruthenium, thus reducing costs. Furthermore, the addition of tin oxide improves the structural stability of the aluminum oxide and simultaneously fixes the nickel, which is beneficial for improving the distribution of nickel on the aluminum oxide surface and inhibiting the growth of nickel grains at high temperatures. This enhances the thermal stability of the maleic anhydride hydrogenation catalyst, thereby giving it better high-temperature reactivity. The catalyst contains 10-20% nickel, 2-7% copper, 1-4% tin oxide, and 67-87% aluminum oxide by mass percentage. The maleic anhydride hydrogenation catalyst has a specific surface area of ​​100-200 m² / g, a pore volume of 0.3-0.5 cm³ / g, and a bulk density of 0.6-1.0 g / cm³. By rationally designing the contents of nickel, copper, tin oxide, and aluminum oxide, and combining them with reasonable bulk density, specific surface area, pore size distribution, and pore volume, it is beneficial to prepare succinic anhydride by maleic anhydride hydrogenation.

[0014] Preferably, the maleic anhydride hydrogenation catalyst further includes a promoter oxide, the content of which is less than or equal to 2% by mass percentage of the maleic anhydride hydrogenation catalyst. The beneficial effect is that the active component nickel in the maleic anhydride hydrogenation catalyst interacts with the promoter oxide, thereby reducing the interaction force between nickel and the alumina support, increasing the dispersion of nickel in the maleic anhydride hydrogenation catalyst, and thus improving the hydrogenation activity of the maleic anhydride hydrogenation catalyst.

[0015] Preferably, the auxiliary oxide includes one or more of lanthanum, cerium, and zirconium, and the content of the auxiliary oxide is 0.5-1.5% by mass percentage of the maleic anhydride hydrogenation catalyst.

[0016] Another object of the present invention is to provide a method for preparing a maleic anhydride hydrogenation catalyst, comprising the following steps:

[0017] S1: Provide a mixed solution containing nickel and copper, an alkaline salt solution, and a tin-aluminum source slurry; use the alkaline salt solution as a precipitant to co-precipitate the mixed solution to obtain a nickel-copper source slurry;

[0018] S2: Mix the nickel-copper source slurry and the tin-aluminum source slurry to obtain a mixed slurry;

[0019] S3: The mixed slurry is subjected to a first aging treatment at 30-60 degrees Celsius for 30-80 minutes to obtain an aged slurry with a pH value of 9-10;

[0020] S4: The aged slurry is filtered and washed until the content of alkaline salt cations in the filtrate is less than 1%, and then the obtained filtered product is dried to remove free water to obtain dried powder.

[0021] S5: After molding the dried powder with excipients, the resulting molded product is dried to remove free water and the excipients, thereby obtaining the maleic anhydride hydrogenation catalyst;

[0022] In step S1:

[0023] Based on nickel oxide, each liter of the mixed solution contains 40-100 grams of the nickel oxide;

[0024] Based on copper oxide, each liter of the mixed solution contains 5-30 grams of copper oxide;

[0025] Each liter of the alkaline salt aqueous solution contains 70-160 grams of acid radical ions, and the volume ratio of the mixed solution to the alkaline salt aqueous solution is 1:1-5:1;

[0026] The volume ratio of the nickel-copper source slurry to the tin-aluminum source slurry is 1:1 to 5:1.

[0027] The beneficial effects of the preparation method of the maleic anhydride hydrogenation catalyst of the present invention are as follows: In step S1, the mixed solution contains 40-100 grams of nickel oxide per liter, and 5-30 grams of copper oxide per liter; the alkaline salt solution contains 70-160 grams of anion ions per liter; the volume ratio of the mixed solution to the alkaline salt solution is 1:1-5:1; and the volume ratio of the nickel-copper source slurry to the tin-aluminum source slurry is 1:1-5:1. Combined with the first aging treatment of the mixed slurry at 30-60 degrees Celsius for 30-80 minutes in step S3, it is beneficial to control the interaction between the nickel-copper source slurry and the tin-aluminum source slurry to regulate the grain size of the obtained maleic anhydride hydrogenation catalyst, thereby ensuring that the maleic anhydride hydrogenation catalyst has better maleic anhydride hydrogenation performance.

[0028] Preferably, the mixed solution further includes an auxiliary oxide, with each liter of the mixed solution containing 0-5 grams of the auxiliary oxide. The beneficial effect is that it allows the active component nickel in the maleic anhydride hydrogenation catalyst to interact with the auxiliary oxide, thereby reducing the interaction force between nickel and the alumina support, increasing the dispersion of nickel in the maleic anhydride hydrogenation catalyst, and thus improving the hydrogenation activity of the maleic anhydride hydrogenation catalyst.

[0029] Preferably, the pH value of the alkaline salt solution is 11-13.

[0030] More preferably, the mixed solution is prepared by dissolving a nickel compound, a copper compound, and an auxiliary oxide in water, wherein the nickel compound is nickel nitrate, the copper compound is copper nitrate, the auxiliary oxide is a nitrate, the alkaline salt solution is either a sodium carbonate solution or a sodium bicarbonate solution, and the acid radical is a carbonate ion.

[0031] More preferably, the auxiliary oxide is one or more of lanthanum nitrate, cerium nitrate, and zirconium nitrate.

[0032] Further preferably, in step S1, the step of using the alkaline salt solution as a precipitant to co-precipitate the mixed solution to obtain the nickel-copper source slurry includes: mixing the mixed solution and the alkaline salt solution in parallel flow; during the parallel flow mixing, the mixed solution obtained by the parallel flow mixing is subjected to a neutralization treatment at a stirring rate of not less than 250 rpm at a neutralization temperature of 30-60 degrees Celsius for a neutralization time of 30-90 minutes; the pH value is adjusted using deionized water to obtain a neutralized slurry with a pH of 8-10; and the neutralized slurry is then subjected to a second aging treatment at an aging temperature of 30-60 degrees Celsius for an aging time of 5-30 minutes.

[0033] Preferably, the step of co-current mixing of the mixed solution and the alkaline saline solution includes: controlling the mixed solution and the alkaline saline solution to be co-currently mixed at a flow rate of 10-40 ml / min respectively.

[0034] Preferably, in step S1, the method for preparing the tin-aluminum source slurry includes: introducing a mixed gas containing carbon dioxide into a flowing aqueous solution of aluminate and an aqueous solution containing tin compound to carry out a gelling reaction until a gelling slurry with a pH of 9.0-10.5 is obtained, and then subjecting the gelling slurry to a third aging treatment to obtain the tin-aluminum source slurry.

[0035] More preferably, the volumetric flow rate of the carbon dioxide-containing mixed gas is 1-8 standard cubic meters per hour, the volume percentage of carbon dioxide in the carbon dioxide-containing mixed gas is 20-80%, the concentration of the aluminate aqueous solution is calculated as alumina, and each liter of the aluminate aqueous solution contains 80-200 grams of alumina; the concentration of the tin-containing compound aqueous solution is calculated as tin oxide, and each liter of the tin-containing compound aqueous solution contains 2-10 grams of tin oxide.

[0036] More preferably, the temperature of the gelation reaction and the third aging treatment are both 30-65 degrees Celsius, the sum of the time of the gelation reaction and the time of the third aging treatment is less than 90 minutes, and the time of the third aging treatment is 20-40 minutes.

[0037] More preferably, the aluminate aqueous solution is prepared from the waste liquid after activation by powdered Raney nickel catalyst, the tin-containing compound aqueous solution is prepared from sodium stannate, and the tin-aluminum source slurry is a tin-containing pseudoboehmite slurry.

[0038] Preferably, in step S5, the excipient is composed of nitric acid, water and guar gum powder, and the drying process includes removing the free water from the molded product and then calcining the obtained product at 300-600 degrees Celsius for 3-6 hours.

[0039] In preparing the tin-aluminum source slurry, the aluminate aqueous solution used in this invention is the waste liquid after activation by powdered Raney nickel catalyst, which not only fully realizes waste utilization and creates value, but also reduces environmental pollution caused by wastewater discharge.

[0040] The maleic anhydride hydrogenation catalyst prepared by this invention can flexibly control the content of active components nickel and copper, improving the utilization rate and dispersion of active components, while maintaining the performance of the alumina support, thus overcoming the problem of pore blockage in traditional co-precipitation methods. By rationally designing the content of nickel, copper, tin oxide, and alumina, and combining it with reasonable bulk density, specific surface area, pore size distribution, and pore volume, it is beneficial to prepare succinic anhydride by maleic anhydride hydrogenation.

[0041] The maleic anhydride hydrogenation catalyst prepared by this invention has a simple operation process, can carry out maleic anhydride hydrogenation to prepare succinic anhydride under solvent-free conditions, has excellent hydrogenation activity and stability, and has low operating cost, which is beneficial for industrial applications. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0043] This invention provides a maleic anhydride hydrogenation catalyst comprising nickel, copper, tin oxide, and aluminum oxide. Nickel and copper are the active components, tin oxide is the auxiliary agent, and aluminum oxide is the support.

[0044] In some embodiments of the present invention, the maleic anhydride hydrogenation catalyst is composed of nickel, copper, tin oxide and aluminum oxide, but does not contain precious metals such as palladium and ruthenium, thereby reducing costs.

[0045] In some embodiments of the present invention, the nickel content is 10-20% by mass percentage of the maleic anhydride hydrogenation catalyst. In other embodiments of the present invention, the nickel content is 13-20% by mass percentage of the maleic anhydride hydrogenation catalyst.

[0046] In some embodiments of the present invention, the copper content is 2-7%. In other embodiments of the present invention, the copper content is 3-7%.

[0047] In some embodiments of the present invention, the content of the auxiliary oxide is 0-2%. In other embodiments of the present invention, the content of the auxiliary oxide is 0.5-1.5%.

[0048] In some embodiments of the present invention, the tin oxide content is 1-4%. In other embodiments of the present invention, the tin oxide content is 2-4%.

[0049] In some embodiments of the present invention, the alumina content is 67-87%. In other embodiments of the present invention, the alumina content is 67-85%.

[0050] In some embodiments of the present invention, the specific surface area of ​​the maleic anhydride hydrogenation catalyst is 100-200 m² / g, the pore volume of the maleic anhydride hydrogenation catalyst is 0.3-0.5 cm³ / g, and the bulk density of the maleic anhydride hydrogenation catalyst is 0.6-1.0 g / cm³.

[0051] The bulk density is determined by freely filling the maleic anhydride hydrogenation catalyst into a container and measuring the mass per unit volume immediately after filling. The volume basis for calculating the bulk density is the sum of the volume occupied by the maleic anhydride hydrogenation catalyst itself, the volume of the voids inside the maleic anhydride hydrogenation catalyst, and the interstitial volume between adjacent maleic anhydride hydrogenation catalysts.

[0052] The present invention also provides a method for preparing the maleic anhydride hydrogenation catalyst, comprising the following steps:

[0053] S1: Provide a mixed solution containing nickel and copper, an alkaline salt solution, and a tin-aluminum source slurry; use the alkaline salt solution as a precipitant to co-precipitate the mixed solution to obtain a nickel-copper source slurry;

[0054] S2: Mix the nickel-copper source slurry and the tin-aluminum source slurry to obtain a mixed slurry;

[0055] S3: The mixed slurry is subjected to a first aging treatment at 30-60 degrees Celsius for 30-80 minutes to obtain an aged slurry with a pH value of 9-10;

[0056] S4: The aged slurry is filtered and washed until the content of alkaline salt cations in the filtrate is less than 1%, and then the obtained filtered product is dried to remove free water to obtain dried powder.

[0057] S5: After molding the dried powder with an excipient, the resulting molded product is dried to remove free water and the excipient, thereby obtaining the maleic anhydride hydrogenation catalyst.

[0058] In some embodiments of the present invention, the aluminate aqueous solution is prepared from the waste liquid after activation by powdered Raney nickel catalyst, the tin-containing compound aqueous solution is prepared from sodium stannate, and the tin-aluminum source slurry is a tin-containing pseudoboehmite slurry.

[0059] In some embodiments of the present invention, the tin-containing pseudoboehmite slurry includes monohydrate pseudoboehmite and trihydrate pseudoboehmite.

[0060] The mixing process of the nickel-copper source slurry and the tin-aluminum source slurry differs from the co-precipitation mixing of nickel, copper, tin, and aluminum, and also from the deposition of metallic nickel and copper into the structures of monohydrated and trihydrated boehmite. Mixing the two materials facilitates the interaction between nickel and copper and the monohydrated and trihydrated boehmite; it also effectively controls the appropriate ratio between the monohydrated and trihydrated boehmite, thus controlling the crystal transformation and grain size of the product. To achieve a highly ideal state, the control of pH, aging temperature, and aging time is crucial to the obtained product. By adjusting and controlling the pH, aging temperature, and aging time, catalyst powders with the required specific properties can be obtained.

[0061] In some embodiments of the present invention, the pH value of the alkaline salt aqueous solution is 11-13, and each liter of the alkaline salt aqueous solution contains 70-160 grams of acid anions. In other embodiments of the present invention, each liter of the alkaline salt aqueous solution contains 100-160 grams of acid anions.

[0062] In some specific embodiments of the present invention, the alkaline salt solution is either a sodium carbonate solution or a sodium bicarbonate solution, and the acid radical is a carbonate ion, i.e., CO32-. 2- .

[0063] In some embodiments of the present invention, the mixed solution is prepared by dissolving a nickel compound, a copper compound, and an auxiliary oxide in water.

[0064] In some embodiments of the present invention, the mixed solution contains 40-100 grams of nickel oxide per liter. In other embodiments of the present invention, the mixed solution contains 50-100 grams of nickel oxide per liter. More specifically, the nickel oxide is NiO.

[0065] In some specific embodiments of the present invention, the nickel compound used to prepare the mixed solution is nickel nitrate.

[0066] In some embodiments of the present invention, the mixed solution contains 5-30 grams of copper oxide per liter. In other embodiments of the present invention, the mixed solution contains 10-30 grams of copper oxide per liter. More specifically, the copper oxide is CuO.

[0067] In some embodiments of the present invention, each liter of the mixed solution contains 0-5 grams of the auxiliary oxide, calculated as an auxiliary oxide.

[0068] In some specific embodiments of the present invention, the auxiliary oxide used to prepare the mixed solution is one or more of lanthanum nitrate, cerium nitrate, and zirconium nitrate.

[0069] In some embodiments of the present invention, the volume ratio of the mixed solution to the alkaline salt solution is 1:1 to 5:1.

[0070] In Examples 1-9, the nickel compound is nickel nitrate, the copper compound is copper nitrate, and the alkaline salt solution is an aqueous sodium carbonate solution. The pH value of the aqueous sodium carbonate solution is 11-13.

[0071] Specifically, the aqueous solutions of nickel nitrate and copper nitrate are uniformly mixed and placed in the first container, while the aqueous solution of sodium carbonate is placed in the second container for subsequent co-precipitation treatment.

[0072] In Examples 1-9, the volume V1 of the mixed solution and the concentration C, expressed as NiO content, are... NiO Concentration C, expressed as CuO content CuO Concentration C, expressed as La2O3 content La2O3 Concentration C, expressed as CeO2 content CeO2 Concentration C, expressed as ZrO2 content ZrO2 The volume V3 of the sodium carbonate aqueous solution and the amount of CO3 2- Concentration C of the content meter CO3 2- Please refer to Table 1. The units for V1 and V3 are liters (C). NiO C CuO C La2O3 C CeO2 C ZrO2 and C CO32- The unit is grams per liter.

[0073] Table 1

[0074] 1 1 1 70 14 0 0 0 70 2 0.5 0.5 49 18.5 0 0 0 100 3 0.5 0.5 100 11 0 0 0 110 4 0.5 0.5 60 30 0 0 0 130 5 1 1 70 25 0 0 0 160 6 1.5 1.5 50 8 4 0 0 100 7 1 2 70 10 0 0 0 110 8 1 1 40 18 0 1 0 127 9 1 1 50 10 0 0 2 120

[0075] In some embodiments of the present invention, the coprecipitation treatment includes a neutralization treatment and a second aging treatment.

[0076] In some embodiments of the present invention, the mixed solution and the alkaline salt aqueous solution are neutralized at a certain stirring rate and a certain flow rate, and the pH value is adjusted using deionized water during the neutralization process. After the neutralization process is completed, the second aging process is performed at the neutralization temperature.

[0077] In some specific embodiments of the present invention, the mixed solution and the alkaline salt solution are respectively mixed in parallel at a certain flow rate into deionized water used to adjust the pH value. During the parallel mixing process, neutralization is carried out at a certain stirring rate to facilitate the uniform composition of the formed crystal particles.

[0078] In some embodiments of the present invention, the stirring rate is not less than 250 rpm.

[0079] In some embodiments of the present invention, the flow rate of the mixed solution and the alkaline salt solution is 10-40 ml / min.

[0080] In some embodiments of the present invention, the flow rate of the mixed solution is the same as or different from that of the alkaline salt solution.

[0081] In some embodiments of the present invention, the neutralization temperature of the neutralization treatment is 30-60 degrees Celsius, and the neutralization time is 30-90 minutes.

[0082] In some embodiments of the present invention, the volume of deionized water used for pH adjustment in the neutralization treatment is 1-2 liters.

[0083] In some embodiments of the present invention, a neutralized slurry with a pH of 8-10 is obtained after the neutralization treatment.

[0084] In some embodiments of the present invention, after the neutralization treatment is completed, stirring is stopped, and the mixture is allowed to stand for 5-30 minutes to complete the second aging treatment. In some embodiments of the present invention, the aging temperature in the second aging treatment is 30-60 degrees Celsius, and the aging time is 5-30 minutes. In other embodiments of the present invention, the aging time in the second aging treatment is 5-15 minutes.

[0085] In Examples 1-9, the mixed solution in the first container and the sodium carbonate aqueous solution in the second container are respectively pumped by peristaltic pumps into a stainless steel container equipped with a stirrer and containing deionized water for pH adjustment for neutralization treatment until the pH of the neutralized slurry in the stainless steel container is 8-10. The temperature controlled inside the stainless steel container is the neutralization temperature, and the stirring speed in the stainless steel container is 250 rpm. After the neutralization treatment is completed, the stirring speed is maintained at the neutralization temperature for the second aging treatment.

[0086] In Examples 1-9, the volume V of deionized water used for pH adjustment in the stainless steel container... pH The flow rate Q of the mixed solution from the first container into the stainless steel container. Ni-Cu-助剂氧化物 The flow rate Q of the sodium carbonate aqueous solution from the second container into the stainless steel container. Na2co3 The temperature T of the neutralization treatment neu The neutralization time t neu The pH value of the obtained neutralized slurry and the time t of the second aging treatment. age2 Please refer to Table 2. Wherein, V pH The unit is liter, Q Ni-Cu and Q Na2co3 The unit is milliliters per minute; T neu The unit is Celsius; t neu and t age2 All units are minutes.

[0087] Table 2

[0088]

[0089]

[0090] In some embodiments of the present invention, the preparation method of the tin-aluminum source slurry in step S1 includes: passing a mixed gas containing carbon dioxide into a flowing aqueous solution of aluminate and an aqueous solution containing tin compound to carry out a gelling reaction until a gelling slurry with a pH of 9.0-10.5 is obtained, and then subjecting the gelling slurry to a third aging treatment to obtain the tin-aluminum source slurry.

[0091] Specifically, if the pH value of the gelling slurry is lower than 9.0, the tin-aluminum source slurry formed is prone to forming an insoluble sulphite structure, which affects the washing process of alkaline ions and ultimately affects the hydrogenation effect of the catalyst.

[0092] Specifically, if the pH of the gelling slurry is too high, the resulting maleic anhydride hydrogenation catalyst is prone to contain a high content of impurities such as gibbsite, which significantly reduces the catalyst's specific surface area, pore volume, and pore size.

[0093] In some embodiments of the present invention, the carbon dioxide-containing mixed gas is composed of carbon dioxide and air, wherein the carbon dioxide accounts for not less than 20% by volume of the carbon dioxide-containing mixed gas, specifically 20%-80%. In other embodiments of the present invention, the carbon dioxide accounts for 40-80% by volume of the carbon dioxide-containing mixed gas.

[0094] In some embodiments of the present invention, the volumetric flow rate of the carbon dioxide-containing mixed gas is 1-8 standard cubic meters per hour.

[0095] In some embodiments of the present invention, the carbon dioxide-containing gas mixture is introduced in an intermittent or continuous manner.

[0096] In some embodiments of the present invention, the concentration of the aluminate aqueous solution is calculated as aluminum oxide, and each liter of the aluminate aqueous solution contains 80-200 grams of aluminum oxide, wherein the chemical formula of the aluminum oxide is Al2O3.

[0097] In some embodiments of the present invention, the concentration of the tin-containing compound aqueous solution is calculated as tin oxide, and each liter of the tin-containing compound aqueous solution contains 2-10 grams of tin oxide.

[0098] In some embodiments of the present invention, the volume of the aluminate aqueous solution is 1-2 liters.

[0099] In some embodiments of the present invention, the temperature of the gelation reaction and the temperature of the third aging treatment are both 30-65 degrees Celsius. In some specific embodiments of the present invention, the temperature of the gelation reaction and the temperature of the third aging treatment are both 30-50 degrees Celsius.

[0100] In some embodiments of the present invention, the temperature of the gelation reaction and the temperature of the third aging treatment are the same or different.

[0101] In some embodiments of the present invention, the sum of the gelation reaction time and the third aging treatment time is less than 90 minutes.

[0102] In some embodiments of the present invention, the third aging treatment takes 20-40 minutes.

[0103] In some embodiments of the present invention, the aluminate aqueous solution is the waste liquid after activation by powdered Raney nickel catalyst, the tin compound in the tin-containing aqueous solution is sodium stannate, and the tin-aluminum source slurry is a tin-containing pseudoboehmite slurry.

[0104] In Examples 1-9, the aluminate aqueous solution is the waste liquid after activation by powdered Raney nickel catalyst. The waste liquid after activation by powdered Raney nickel catalyst and the sodium stannate aqueous solution are placed in a container and continuously stirred. The temperature inside the container is controlled at the gelation reaction temperature. A mixed gas containing carbon dioxide is continuously introduced into the container until the pH value of the tin-containing pseudoboehmite slurry obtained in the container reaches 10. After the gelation reaction is completed, stirring continues under gelation conditions for a third aging treatment. The mixed gas containing carbon dioxide is a mixture of carbon dioxide and air.

[0105] In Examples 1-9, the volume V4 of the mixed aqueous solution of the waste liquid after activation by powdered Raney nickel catalyst and sodium stannate aqueous solution, and the concentration C based on the alumina content. 活化废液 Concentration C, expressed as tin oxide content Na2SnO3 The volume percentage of carbon dioxide in the gas mixture, Vt co2 and carbon dioxide flow rate Q co2 The temperature T of the gelation reaction Gel The gelation reaction time t Gel The pH value of the gelling slurry and the time t of the third aging treatment. age3 Please refer to Table 3. The unit for V4 is liters (C). 活化废液 and C Na2SnO3 The unit is grams per liter, Q co2 The unit is standard cubic meters per hour, T Gel The unit is Celsius, t age3 The unit is minutes.

[0106] Table 3

[0107] 1 2 100 5 50 3 40 50 9.5 25 2 1 110 4.6 40 1 30 50 10 20 3 1 150 8 30 2 40 25 9 30 4 1 160 2 50 5 50 50 9.5 25 5 2 91 5 70 8 50 25 9.5 35 6 1.5 200 9 40 4 35 50 10 30 7 2 100 3 80 5 50 40 10.5 25 8 2 93 3 60 6 40 40 10 25 9 1 145 5 50 5 45 45 10 30

[0108] In some embodiments of the present invention, in step S2, the nickel-copper source slurry and the tin-aluminum source slurry are mixed to obtain a mixed slurry.

[0109] In some embodiments of the present invention, the nickel-copper source slurry and the tin-aluminum source slurry are mixed in parallel flow.

[0110] In some embodiments of the present invention, one of the nickel-copper source slurry and the tin-aluminum source slurry is added to the other for mixing.

[0111] In Examples 1-9, the tin-aluminum source slurry is a tin-containing boehmite slurry. During the mixing process of the nickel-copper source slurry and the tin-containing boehmite slurry, nickel, copper, and tin-containing boehmite interact. By controlling the ratio of the tin-containing boehmite slurry to the nickel-copper source slurry, the appropriate ratio between monohydrated and trihydrated boehmite can be effectively controlled, thereby controlling the crystal transformation of the product and effectively controlling the size of the product grains.

[0112] In some embodiments of the present invention, in step S3, the mixed slurry is subjected to a first aging treatment at 30-60 degrees Celsius for 30-80 minutes to obtain an aged slurry with a pH value of 9-10. By controlling the pH value, aging temperature, and aging time during the first aging treatment, it is beneficial for the particles to recrystallize and undergo crystal transformation, as well as for grain growth and impurity removal.

[0113] In Examples 1-9, the nickel-copper source slurry and the tin-aluminum source slurry are mixed and then subjected to a first aging treatment under stirring. The volume ratio V of the nickel-copper source slurry to the tin-aluminum source slurry is... Ni-Cu :V Al-Sn The temperature T of the first aging treatment age1 and time t age1 Please refer to Table 4 for the pH of the aged slurry. Among them, T... age1 The unit is Celsius, t age1 The unit is minutes.

[0114] Table 4

[0115] 1 4:2 40 40 9.4 2 2:1 45 45 9.7 3 3:1 35 30 9.1 4 3:1 55 50 9.0 5 4:2 50 60 9.2 6 2:1 35 80 9.8 7 4:2 50 75 9.7 8 3:2 40 70 9.6 9 3:1 45 65 10

[0116] In some embodiments of the present invention, in step S4, the aged slurry is filtered and washed until the content of alkaline salt cations in the filtrate is less than the content threshold, and then the obtained filtered product is dried to remove free water to obtain dried powder.

[0117] In some embodiments of the present invention, the content threshold is 0.5%-1%.

[0118] In some embodiments of the present invention, the drying temperature in step S4 is 80-120 degrees Celsius, and the drying time is 4-15 hours.

[0119] In step S4 of Examples 1-9, since the nickel-copper source slurry is prepared using sodium carbonate as a precipitant, the cation of the alkaline salt detected in the filtrate is sodium ion. The threshold value of sodium ion content in the filtrate and the drying temperature T... dry1 and drying time t dry1 Please refer to Table 5. The content thresholds are expressed in %, T. dry1 The unit is Celsius, t dry1 The unit is hours.

[0120] Table 5

[0121] Content threshold 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 <![CDATA[T dry1 ]]> 80 100 120 110 110 110 120 120 110 <![CDATA[t dry1 ]]> 12 10 6 9 7 8 5 5 8

[0122] In some embodiments of the present invention, in step S5, the excipient is composed of nitric acid, water and guar gum powder.

[0123] In some embodiments of the present invention, in step S5, the drying process includes drying the molded product at 80-140 degrees Celsius until free water is removed, and then calcining the obtained product at 300-600 degrees Celsius for 3-6 hours to remove the guar gum powder.

[0124] In Examples 1-9, 7 ml of nitric acid, 9 g of guar gum powder, and 280 g of water were added to every 300 g of dried powder and mixed evenly to achieve the desired shape.

[0125] In Examples 1-9, the drying temperature T during the drying process dry2 and drying time t dry2 and calcination temperature T bake and roasting time t bake Please refer to Table 6. Where T... dry2 and T bake The unit is Celsius, t dry2 and t bake The unit is hours.

[0126] Table 6

[0127] <![CDATA[T dry2 ]]> 110 110 110 110 120 120 120 120 110 <![CDATA[t dry2 ]]> 8 8 8 8 12 12 12 12 9 <![CDATA[T bake ]]> 400 450 450 300 500 350 400 350 350 <![CDATA[t bake ]]> 4 3 3 6 3 5 3 5 4

[0128] The present invention also provides comparative examples 1-6 for preparing reference adsorbents.

[0129] In Comparative Examples 1-4, nickel-copper source slurries were prepared using aqueous solutions of nickel nitrate, copper nitrate, and sodium carbonate. The second aging treatment was carried out at a neutralization temperature.

[0130] Specifically, the concentration C of the nickel nitrate aqueous solution, expressed as NiO. c-NiO The volume V of nickel nitrate aqueous solution c-NiO and the flow rate Q flowing into the stainless steel container c-NiO The concentration of copper nitrate aqueous solution, expressed as CuO, is C. c-CuO The volume V of copper nitrate aqueous solution c-CuO and the flow rate Q flowing into the stainless steel container c-CuO The concentration of sodium carbonate aqueous solution, expressed as carbonate ions, is C. c-CO3 And the volume V of the sodium carbonate aqueous solution c-Na2CO3 The volume V of deionized water used to adjust pH c-pH The pH value of the neutralized slurry and the temperature T of the neutralization reaction. c-neu The time t for the neutralization reaction c-neu and aging time t c-age Please refer to Table 7. The units for concentration are grams per liter, flow rate is standard cubic meters per hour, volume is liters, temperature is degrees Celsius, and time is minutes.

[0131] Table 7

[0132]

[0133]

[0134] The drying temperature T of the reference dry powders obtained in Comparative Examples 1-4 after being shaped with excipients c-dry Drying time t c-dry Calcination temperature T c-bake and roasting time t c-bake Please refer to Table 8. Temperature is in degrees Celsius, and time is in hours.

[0135] Table 8

[0136] <![CDATA[T c-dry ]]> 110 120 110 120 <![CDATA[t c-dry ]]> 8 12 8 12 <![CDATA[T c-bake ]]> 300 400 450 500 <![CDATA[t c-bake ]]> 6 3 3 3

[0137] For the specific method of preparing the reference adsorbent in Comparative Example 1, please refer to Example 4; for the specific method of preparing the reference adsorbent in Comparative Example 2, please refer to Example 7; for the specific method of preparing the reference adsorbent in Comparative Example 3, please refer to Example 3; for the specific method of preparing the reference adsorbent in Comparative Example 4, please refer to Example 5.

[0138] In Comparative Example 5, 68g of alumina powder calcined at 750℃ was first placed in a stainless steel container, and 1L of deionized water was added and stirred until homogeneous. Then, 1L of aqueous solutions of nickel nitrate (calculated as NiO) at a concentration of 70 g / L and copper nitrate (calculated as CuO) at a concentration of 14 g / L were placed in separate containers. Next, 1L of an aqueous solution of sodium carbonate (calculated as carbonate ions) at a concentration of 70 g / L was prepared and placed in the stainless steel container. Finally, the solutions in the first container were pumped into the stainless steel container at a flow rate of 20 mL / min under the control of a peristaltic pump, and stirred. The neutralization reaction temperature in the stainless steel container was controlled at 40℃, and the neutralization reaction was stopped when the pH of the neutralized slurry reached 10.0. After aging at the neutralization reaction temperature for 30 minutes, the mixture was filtered and washed until the Na+ ion content in the filtrate was less than 0.5%. The collected filtered solid product was then dried at 120℃ for 12 hours to obtain the reference adsorbent powder. The reference adsorbent powder was mixed and kneaded with nitric acid, guar gum powder, and water, with the specific proportions described in Example 1. After extrusion molding, it was dried at 110 degrees Celsius for 8 hours and finally calcined at 400 degrees Celsius for 4 hours to obtain the reference adsorbent.

[0139] The catalyst for the hydrogenation of maleic anhydride to prepare succinic anhydride provided in Comparative Example 6 is Ni-Cu / SiO2-Al2O3, with Ni content of 13%, Cu content of 5%, SiO2 content of 3.28%, and the remainder being Al2O3. For the specific preparation method, please refer to Example 3 of ZL200910073975.6.

[0140] The catalyst for the hydrogenation of maleic anhydride to prepare succinic anhydride provided in Comparative Example 7 is Ni / SiO2-Al2O3, with Ni content of 12.58%, SiO2 content of 74.9%, and Al2O3 content of 12.5%. For the specific preparation method, please refer to Example 10 of ZL03122336.2.

[0141] The samples of maleic anhydride hydrogenation catalysts obtained in Examples 1-9 are numbered C1-C9, and the samples of reference adsorbents provided in Comparative Examples 1-6 are numbered D1-D7.

[0142] Table 9 shows the composition and physical parameters of the maleic anhydride hydrogenation catalysts and reference adsorbents for Examples 1-9 and Comparative Examples 1-5. Specific surface area is expressed in square meters per gram (m² / g), pore volume in cubic centimeters per gram (cm³ / g), and nickel, copper, tin oxide, and aluminum oxide contents are all mass percentages. Bulk density is expressed in grams per cubic centimeter (g / cm³).

[0143] Table 9

[0144]

[0145] The application of the present invention will be further illustrated below with examples of catalysts in Examples 1-9 and Comparative Examples 1-6 in the liquid-phase hydrogenation reaction of maleic anhydride.

[0146] The catalysts of Examples 1-9 and Comparative Examples 1-7 were reduced with hydrogen at 300-350 degrees Celsius for 6-16 hours, and then loaded into a fixed-bed reactor to carry out the process of hydrogenating maleic anhydride to succinic anhydride. No solvent dilution was used, and the inlet temperature was controlled at 150 degrees Celsius, the pressure at 5 MPa, the molar ratio of H2 to maleic anhydride at 3, the dilution ratio of maleic anhydride to succinic anhydride at 1:17, and the fresh oil volume hourly space velocity at 1.0 h⁻¹. -1 The specific results are shown in Table 10.

[0147] Table 10

[0148] C1 100 99.95 99.55 C2 100 99.85 99.64 C3 100 99.98 99.65 C4 100 99.85 99.78 C5 100 100 99.52 C6 100 99.85 99.67 C7 100 100 99.50 C8 100 99.90 99.85 C9 100 99.82 99.70 D1 50 98.0 94.56 D2 50 100 94.5 D3 40 98.5 94.5 D4 40 99.8 94.7 D5 40 98.0 93.2 D6 50 98.5 94.3 D7 30 87.7 78.5

[0149] The catalyst evaluation results clearly show that the catalyst prepared in this invention has better hydrogenation activity, selectivity, and stability. Under solvent-free dilution conditions, after 100 hours of performance evaluation, the average maleic anhydride conversion rate exceeded 99.8%, and the catalyst selectivity exceeded 99.5%, demonstrating significantly better overall performance than the comparative catalyst.

[0150] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A maleic anhydride hydrogenation catalyst, characterized in that, The catalyst is used in the hydrogenation of maleic anhydride to prepare succinic anhydride using a fixed-bed reactor, wherein the maleic anhydride hydrogenation catalyst comprises nickel, copper, tin oxide and aluminum oxide; Based on the mass percentage of the maleic anhydride hydrogenation catalyst, the nickel content is 10-20%, the copper content is 2-7%, the tin oxide content is 1-4%, and the aluminum oxide content is 67-87%. The maleic anhydride hydrogenation catalyst has a specific surface area of ​​100-200 m² / g, a pore volume of 0.3-0.5 cm³ / g, and a bulk density of 0.6-1.0 g / cm³. The preparation method of the maleic anhydride hydrogenation catalyst includes the following steps: S1: Provide a mixed solution containing nickel and copper, an alkaline salt solution, and a tin-aluminum source slurry; use the alkaline salt solution as a precipitant to co-precipitate the mixed solution to obtain a nickel-copper source slurry; S2: Mix the nickel-copper source slurry and the tin-aluminum source slurry to obtain a mixed slurry; S3: The mixed slurry is subjected to a first aging treatment at 30-60 degrees Celsius for 30-80 minutes to obtain an aged slurry with a pH value of 9-10; S4: The aged slurry is filtered and washed until the content of alkaline salt cations in the filtrate is less than 1%, and then the obtained filtered product is dried to remove free water to obtain dried powder. S5: After molding the dried powder with excipients, the resulting molded product is dried and calcined to remove free water and the excipients, thereby obtaining the maleic anhydride hydrogenation catalyst; In step S1: Based on nickel oxide, each liter of the mixed solution contains 40-100 grams of the nickel oxide; Based on copper oxide, each liter of the mixed solution contains 5-30 grams of copper oxide; Each liter of the alkaline salt aqueous solution contains 70-160 grams of acid radical ions, and the volume ratio of the mixed solution to the alkaline salt aqueous solution is 1:1-5:1; The steps of using the alkaline salt aqueous solution as a precipitant to co-precipitate the mixed solution to obtain the nickel-copper source slurry include: The mixed solution is mixed with the alkaline salt solution in a parallel flow. During the parallel flow mixing, the mixture obtained by the parallel flow mixing is subjected to a neutralization treatment at a stirring rate of not less than 250 rpm at a temperature of 30-60 degrees Celsius for a neutralization time of 30-90 minutes. The pH value is adjusted using deionized water to obtain a neutralized slurry with a pH of 8-10. The neutralized slurry is then subjected to a second aging treatment at a temperature of 30-60 degrees Celsius for an aging time of 5-30 minutes. The method for preparing the tin-aluminum source slurry includes: A mixed gas containing carbon dioxide is introduced into a flowing aqueous solution of aluminate and an aqueous solution containing tin compounds to carry out a gelation reaction until a gelling slurry with a pH of 9.0-10.5 is obtained. The gelling slurry is then subjected to a third aging treatment to obtain the tin-aluminum source slurry. The volume ratio of the nickel-copper source slurry to the tin-aluminum source slurry is 1:1 to 5:

1.

2. The maleic anhydride hydrogenation catalyst according to claim 1, characterized in that, It also includes auxiliary oxides, which, by mass percentage of the maleic anhydride hydrogenation catalyst, contain less than or equal to 2% of the auxiliary oxides, and the auxiliary oxides include one or more oxides of lanthanum, cerium and zirconium.

3. The maleic anhydride hydrogenation catalyst according to claim 1, characterized in that, The mixed solution also includes the auxiliary agent nitrate, and each liter of the mixed solution contains 0-5 grams of the auxiliary agent oxide, calculated as an auxiliary agent oxide, and the auxiliary agent oxide is not zero.

4. The maleic anhydride hydrogenation catalyst according to claim 1, characterized in that, The pH value of the alkaline salt solution is 11-13.

5. The maleic anhydride hydrogenation catalyst according to claim 3, characterized in that, The mixed solution is prepared by dissolving a nickel compound, a copper compound, and an auxiliary agent nitrate in water. The nickel compound is nickel nitrate, the copper compound is copper nitrate, the alkaline salt solution is either a sodium carbonate solution or a sodium bicarbonate solution, and the acid radical is a carbonate ion.

6. The maleic anhydride hydrogenation catalyst according to claim 1, characterized in that, The step of mixing the mixed solution with the alkaline salt aqueous solution in a parallel flow includes: The mixed solution and the alkaline salt solution are controlled to be mixed in parallel at a flow rate of 10-40 mL / min.

7. The maleic anhydride hydrogenation catalyst according to claim 1, characterized in that, The volumetric flow rate of the carbon dioxide-containing mixed gas is 1-8 standard cubic meters per hour, and the volume percentage of carbon dioxide in the carbon dioxide-containing mixed gas is 20-80%. The concentration of the aluminate aqueous solution is based on alumina, with 80-200 grams of alumina per liter of the aluminate aqueous solution. The concentration of the tin-containing compound aqueous solution is based on tin oxide, with 2-10 grams of tin oxide per liter of the tin-containing compound aqueous solution.

8. The maleic anhydride hydrogenation catalyst according to claim 1, characterized in that, The temperature of the gelation reaction and the third aging treatment are both 30-65 degrees Celsius, the sum of the gelation reaction time and the third aging treatment time is less than 90 minutes, and the third aging treatment time is 20-40 minutes.

9. The maleic anhydride hydrogenation catalyst according to claim 1, characterized in that, The aluminate aqueous solution is prepared from the waste liquid after activation by powdered Raney nickel catalyst, the tin-containing compound aqueous solution is prepared from sodium stannate, and the tin-aluminum source slurry is a tin-containing pseudoboehmite slurry.

10. The maleic anhydride hydrogenation catalyst according to claim 1, characterized in that, In step S5, the excipient is composed of nitric acid, water and guar gum powder. The drying and calcination treatment includes drying to remove the free water of the molded product and then calcining the obtained product at 300-600 degrees Celsius for 3-6 hours.

Images