Catalyst for polyether polyol amination and preparation method thereof

Abstract

The invention relates to a catalyst for polyether polyol amination and a preparation method thereof. The catalyst comprises an active component and an auxiliary agent, wherein the active component comprises an oxide of Co, an oxide of Cu and an oxide of Al; the auxiliary agent is selected from one or more of Zn, Zr, Cr, Mo, Ce, La, Cr, Sb and Mg metal oxides. The modified graphene is loaded on the catalyst, so that the contact efficiency of raw materials and active sites of the catalyst is improved, meanwhile, water generated in the reaction is removed in time, the conversion rate and selectivity of the reaction are greatly improved, and meanwhile, the strength of the catalyst is greatly improved by introducing the modified graphene. The invention discloses a preparation method of the catalyst and application of the catalyst in synthesis of polyether amine gasoline detergents. The catalyst disclosed by the invention can show high activity and high primary amine selectivity in application, and the catalyst is low in cost.

Description

Technical Field

[0001] The invention relates to the technical field of catalysis, and in particular to a catalyst for amination of polyether polyols and a preparation method thereof. Background Art

[0002] The main agent of gasoline detergent dispersant is a surfactant, which consists of two parts: non-polar group and polar group. Its polar group can adsorb carbon deposits, dust, sediments, etc., making them loose and small particles to be washed out, which has a cleaning effect on the engine. At the same time, due to the double electron layer effect, the detergent dispersant prevents small particles from aggregating to form large particles and avoids deposition on the metal surface, achieving a cleaning effect. In addition, the detergent dispersant can also improve the atomization state of gasoline, making gasoline burn more fully, and playing a role in energy saving and environmental protection.

[0003] Polyetheramine is a general term for a class of chemical substances, whose molecular structure contains ether bonds and terminal amine structures. Polyetheramine gasoline detergents effectively control the formation of fuel and intake system deposits, while also significantly reducing the formation of combustion chamber carbon deposits (CCD).

[0004] The main methods for synthesizing polyetheramines include high-pressure catalytic amination, leaving group method, aminobutyric acid ester method, polyether nitrile alkylation method, etc. The catalytic amination method for synthesizing polyetheramines is the most advanced method in the world with stable product quality and better compliance with environmental protection requirements. It is also the main method for industrial production of polyetheramines abroad.

[0005] The prior art discloses various processes for the production of polyetheramines.

[0006] US5696293A uses a catalyst with precious metal Ru as the main active component to prepare polyetheramines, and investigates the effects of the loading amount and the distribution ratio of other active components on the catalyst performance.

[0007] US3654370A studies the synthesis process of T series (trifunctional) and D series (difunctional) amino-terminated polyoxypropylene ethers.

[0008] CN102336903A discloses a polyether polyol amination process with a molecular weight of more than 100, which uses a skeleton nickel catalyst with a Ni content of 85-95% and an Al content of 5-15%. The process is a batch production process.

[0009] CN104119239B discloses a continuous preparation process for polyetheramines with a molecular weight of 100-5000. The process uses 2-6 fixed bed or tubular reactors connected in series, and by loading Raney metal catalysts and supported metal catalysts, or loading catalysts with different nickel and cobalt contents, the toxicity of generated water to the catalyst is reduced, the water resistance of the entire catalytic system is enhanced, and the reaction conversion rate is improved.

[0010] In the process of using polyetheramine gasoline detergent to remove carbon deposits in the engine combustion chamber, the additive needs to maintain a high carbon removal activity and be able to decompose in the engine combustion chamber. The combustion chamber temperature is 300-400°C. If the content of heavy components such as secondary amines and tertiary amines in polyetheramines is too high, the decomposition temperature of the heavy components is higher than the combustion chamber temperature. After long-term use, the heavy components will accumulate on the inner wall of the engine combustion chamber, greatly reducing the effect of carbon removal. The existing technology cannot control the secondary tertiary amine value to less than 1% when preparing polyetheramines. At the same time, the lateral pressure strength of the tablet molding of the existing catalyst without the addition of a binder is often no more than 50N / cm. Summary of the invention

[0011] In order to solve the problems existing in the prior art, the present invention provides a catalyst for amination of polyether polyols and a preparation method thereof, and by preparing the corresponding catalyst, high-selective conversion of polyether is achieved, and secondary and tertiary amine by-products are greatly reduced. The method has the advantages of high product purity, simple process flow, and low three waste emissions.

[0012] In order to achieve the above invention object, the present invention adopts the following technical solutions:

[0013] A catalyst for amination of polyether polyols, the catalyst comprising an active component and an auxiliary agent, the active component comprising Co oxide, Cu oxide and Al oxide; the auxiliary agent is one or more selected from Zn, Zr, Cr, Mo, Ce, La, Cr, Sb and Mg metal oxides, preferably one or more selected from Zr, Ce, La and Cr metal oxides, more preferably La and / or Ce oxides.

[0014] The composition of the catalyst of the present invention is as follows:

[0015] The oxide content of Co is 20-90wt%, preferably 30-85wt%, more preferably 45-75%, calculated as CoO;

[0016] The Cu oxide content is 1-30wt%, preferably 5-25wt%, more preferably 8-20%, calculated as CuO;

[0017] The Al oxide content is 1-50 wt%, preferably 5-45 wt%, more preferably 10-40%, calculated as Al2O3.

[0018] The content of the auxiliary agent is 1-8wt%, preferably 2-6wt%, more preferably 3-5wt%.

[0019] A method for preparing a catalyst for amination of polyether polyols comprises the following steps:

[0020] a1: co-precipitate the metal salt solution and the precipitant solution to control the pH value of the reaction solution;

[0021] a2: using a precipitant solution to adjust the pH of the product of step a1, allowing it to stand for aging, filtering, and washing;

[0022] a3: preparing an ethanol solution of PDMS, adding graphene and performing low-temperature calcination to obtain modified graphene;

[0023] a4: mixing the product of step a2 and the modified graphene and dopamine of step a3 for reaction, filtering after the reaction, drying the filter cake, and calcining to obtain a catalyst.

[0024] In some specific embodiments, the cobalt salt in the metal salt includes but is not limited to cobalt nitrate and cobalt sulfate, preferably cobalt nitrate.

[0025] In some specific embodiments, the copper salt in the metal salt includes but is not limited to copper nitrate and copper sulfate, preferably copper nitrate.

[0026] In some specific embodiments, the aluminum salt in the metal salt includes but is not limited to aluminum nitrate and aluminum sulfate, preferably aluminum nitrate.

[0027] In some specific embodiments, the precipitant includes but is not limited to sodium hydroxide, potassium hydroxide, ammonia water, sodium carbonate, sodium bicarbonate, etc., preferably sodium carbonate.

[0028] In some specific embodiments, the temperature in step a1 is 60-80°C, preferably 65-75°C; the pH is 5-7, preferably 5.5-6.5.

[0029] In some specific embodiments, the pH of the product of step a1 is adjusted to 7-8, preferably 7.2-7.8, using a precipitant and aged for 1-24 h, preferably 6-12 h.

[0030] In some specific embodiments, step a2 uses deionized water to wash the filter cake for 2-10 times, preferably 6-8 times.

[0031] In some specific implementation schemes, the mass concentration of the PDMS ethanol solution in step a3 is 0.1-2%, the amount of graphene added is 5-20% of the mass of the solution, stirring is carried out in a closed container at 40°C-70°C for 1-24h, and low-temperature calcination is carried out at 100-200°C for 1-10h to obtain modified graphene.

[0032] In some specific embodiments, the number average molecular weight of PDMS in step a3 is 4000-10000.

[0033] In some specific implementation schemes, the mass ratio of modified graphene in step a4: dopamine: product of step a2 is (1-4): (0.1-1): 100, deionized water is added to prepare a 5-50wt% suspension, stirred at 50-90°C for 6-24h, and filtered to obtain a filter cake.

[0034] In some specific embodiments, in step a4, the drying is carried out at 80-140°C, preferably 100-120°C, for 1-24 hours, preferably 6-16 hours, and after drying, the calcination is carried out at 100-800°C, preferably 200-600°C, for 1-24 hours, preferably 8-16 hours.

[0035] The catalyst of the present invention is formed by tabletting, and the shape of the catalyst is cylindrical or spherical. The diameter and height of the cylindrical catalyst are 2-5 mm, the diameter of the spherical catalyst is 2-5 mm, the lateral pressure strength of the cylindrical catalyst is ≥100 N / cm, and the lateral pressure strength of the cylindrical catalyst is ≥150 N / cm.

[0036] The catalyst of the present invention is reduced and activated in an atmosphere containing hydrogen before being used in the amination reaction of polyether polyols. The catalyst activation temperature is 200-450° C., preferably 250-350° C., the absolute pressure is 2-20 MPa, preferably 8-14 MPa; the hydrogen flow rate is 100-400 L / min / kg catalyst, preferably 150-300 L / min / kg catalyst, and the activation time is 12-48 h, preferably 20-40 h.

[0037] A method for preparing polyetheramine by amination of polyether polyol comprises the following steps: in the presence of an aminating agent, hydrogen and the catalyst of the invention, performing a reductive amination reaction on the polyether polyol to prepare the polyetheramine.

[0038] The method for preparing a polyetheramine described in the present invention has a continuous reaction process.

[0039] The polyether polyol of the present invention is obtained by using long-chain alkyl alcohol or long-chain alkyl phenol as an initiator and propylene oxide as a polymerization unit, and has a molecular weight of 500-2000, preferably 600-1600, and particularly preferably 800-1200.

[0040] The long-chain alkyl alcohol or long-chain alkyl phenol initiator of the present invention includes alkanols with 10-20 carbon atoms and alkylphenols with 6-12 carbon atoms, preferably alkanols with 12-16 carbon atoms and alkylphenols with 8-10 carbon atoms, and more preferably dodecanol and nonylphenol.

[0041] The polyether space velocity of the present invention is 0.2-3 g / h / g catalyst, the liquid ammonia space velocity is 1.5-3 g / h / g catalyst, the molar ratio of hydrogen to polyether is (10-40):1, the reaction temperature is 190-210°C, and the absolute reaction pressure is 12-16Mpa.

[0042] The polyether conversion rate of the present invention is greater than 98%, and the primary amine selectivity of the polyetheramine is greater than 99%.

[0043] The beneficial effects of the present invention are as follows: (1) Since the raw material polyether described in the present invention is immiscible with water, by loading modified graphene on the catalyst, and since there are a large number of hydroxyl groups on the surface of graphene, PDMS is used to modify the graphene, and PDMS forms hydrogen bonds with the surface of graphene. By introducing hydrophobic groups into the surface of graphene through modification, the oleophilic and hydrophobic properties of graphene are further enhanced, and the contact efficiency between the raw material and the active sites of the catalyst can be greatly improved, thereby improving the conversion rate of the raw material polyether and the selectivity of the product. At the same time, the water generated by the reaction can be quickly removed from the active sites of the catalyst under the hydrophobic effect of the modified graphene, thereby greatly improving the activity of the catalyst.

[0044] (2) Graphene material itself has very high strength. By introducing dopamine, the ortho-hydroxyl groups on the benzene ring of the dopamine molecule can form a hydrogen bond network structure with the surface of the modified graphene, which greatly strengthens the binding force between the modified graphene and dopamine. At the same time, since the active component of the catalyst Al2O3 is acidic, the terminal amine group of dopamine combines with Al, which can greatly improve the binding force between dopamine and the catalyst. Modification by this method can greatly improve the strength of the catalyst. DETAILED DESCRIPTION

[0045] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are within the spirit scope of the present invention.

[0046] The present invention is further described below in conjunction with embodiments, but the present invention is not limited to the listed embodiments, and should also include equivalent improvements and modifications of the technical solutions defined in the claims attached to the present application.

[0047] Hydroxyl value determination method: see GB / T 12008.3-2009.

[0048] Total amine value determination method: Use 0.5 mol / L hydrochloric acid solution to titrate the product, and the total amine value of the product can be calculated by the mass of hydrochloric acid consumed.

[0049] Secondary / tertiary amine value determination method: After the product is mixed with an equal mass of salicylaldehyde and stirred for 30 minutes, the product is titrated with 0.5 mol / L hydrochloric acid solution. The sum of the secondary and tertiary amine values ​​of the product can be calculated by the mass of hydrochloric acid consumed.

[0050] Primary amine ratio = (total amine value - secondary / tertiary amine value) / total amine value × 100%.

[0051] Polyether polyol conversion rate = total amine value of product / total hydroxyl value of raw materials × 100%.

[0052] Example 1

[0053] 77.7gCo(NO3)2·6H2O, 90.8gCu(NO3)2·3H2O, 360.4gAl(NO3)3·9H2O and 2.6gLa(NO3)3·6H2O were added to 3L deionized water respectively, stirred, and co-precipitated with 20wt% sodium carbonate aqueous solution at 60°C, and the pH value of the solution was controlled to be 5.0. The pH of the mixed solution was adjusted to 7.0 using a precipitant solution, and the precipitate was allowed to stand for 1h. The obtained suspension was filtered, the filter cake was washed with water twice, and the filtrate was filtered to obtain a filter cake.

[0054] Prepare an ethanol solution of PDMS with a molecular weight of 4000, with a mass concentration of 0.1%, add 5% of the solution mass of graphene, stir at 40°C for 1 hour, and calcine the mixture at 100°C for 1 hour to obtain modified graphene. Prepare a mixture of modified graphene: dopamine: catalyst filter cake at a mass ratio of 1:0.1:100, add deionized water to prepare a 5wt% suspension, stir at 50°C for 6 hours, filter the suspension after stirring to obtain a filter cake, dry the filter cake at 80°C for 1 hour, and calcine at 100°C for 1 hour to obtain a coprecipitated catalyst, press the catalyst into a cylindrical shape with a diameter of 2mm, and measure the catalyst side pressure strength to be 110N / cm.

[0055] 200 g of the coprecipitated catalyst precursor prepared above was added to the tubular reactor and activated with hydrogen at an activation temperature of 200° C., an activation pressure of 2 MPa, a hydrogen dosage of 100 L / min / kg catalyst, and an activation time of 12 h to obtain an active catalyst.

[0056] Nonylphenol was used as the initiator, and polypropylene glycol with an average molecular weight of 1000 was used as the polyether raw material, which was mixed with liquid ammonia and hydrogen and then entered into a reactor for reaction. The space velocity of the polyether was 0.2 g / h / g cat, the space velocity of the liquid ammonia was 1.5 g / h / g cat, and the molar ratio of hydrogen to polyether was 10: 1. The reactor temperature was controlled at 190°C and the pressure was controlled at 14 MPa.

[0057] The product liquid extracted from the tubular reactor is stirred at an absolute pressure of 2 kPa and 110°C for 1 hour to remove liquid ammonia, water and light components in the product liquid. The polyetheramine product is obtained and sampled for titration analysis.

[0058] The polyether conversion rate was 98.2%, and the polyetheramine primary amine selectivity was 99.2%.

[0059] Comparative Example 1

[0060] The difference from Example 1 is that the graphene is not modified by PDMS, and other conditions remain unchanged. The coprecipitated catalyst is pressed into a cylindrical shape with a diameter of 2 mm, and the catalyst side pressure strength is measured to be 90 N / cm. After the reaction, the polyether conversion rate is 92.1%, and the polyetheramine primary amine selectivity is 95.6%.

[0061] Comparative Example 2

[0062] The difference from Example 1 is that the catalyst is not loaded with modified graphene, and other conditions remain unchanged. The coprecipitated catalyst is pressed into a cylindrical shape with a diameter of 2 mm, and the catalyst side pressure strength is measured to be 60 N / cm. After the reaction, the polyether conversion rate is 90.4%, and the polyetheramine primary amine selectivity is 93.8%.

[0063] Comparative Example 3

[0064] The difference from Example 1 is that the catalyst is not modified with dopamine, and other conditions remain unchanged. The coprecipitated catalyst is pressed into a cylindrical shape with a diameter of 2 mm, and the catalyst side pressure strength is measured to be 70 N / cm. After the reaction, the polyether conversion rate is 94.1%, and the polyetheramine primary amine selectivity is 96.2%.

[0065] Example 2

[0066] 349.2g Co(NO3)2·6H2O, 3.1g Cu(NO3)2·3H2O, 7.5g Al(NO3)3·9H2O and 17.5g Ce(NO3)3·6H2O were added to 3L deionized water respectively, stirred, and co-precipitated with 20wt% sodium carbonate aqueous solution at 80°C, and the pH value of the solution was controlled to 7.0. The pH of the mixed solution was adjusted to 8.0 using a precipitant solution, and the precipitate was allowed to stand for aging for 24h. The obtained suspension was filtered, the filter cake was washed with water 10 times, and the filtrate was filtered to obtain a filter cake.

[0067] Prepare an ethanol solution of PDMS with a molecular weight of 10,000 and a mass concentration of 2%, add 20% of the solution mass of graphene, stir at 70°C for 24 hours, and calcine the mixture at 200°C for 10 hours to obtain modified graphene. Prepare a mixture of modified graphene: dopamine: catalyst filter cake at a mass ratio of 4:1:100, add deionized water to prepare a 50wt% suspension, stir at 90°C for 24 hours, filter the suspension after stirring to obtain a filter cake, dry the filter cake at 140°C for 24 hours, and calcine at 800°C for 24 hours to obtain a coprecipitated catalyst, press the catalyst into a sphere with a diameter of 5 mm, and measure the catalyst lateral pressure strength to be 190N / cm.

[0068] 200 g of the coprecipitated catalyst precursor prepared above was added to the tubular reactor and activated with hydrogen at an activation temperature of 450° C., an activation pressure of 20 MPa, a hydrogen dosage of 400 L / min / kg catalyst, and an activation time of 48 h to obtain an active catalyst.

[0069] n-dodecanol was used as the initiator, polypropylene glycol with an average molecular weight of 1000 was used as the polyether raw material, and then mixed with liquid ammonia and hydrogen and entered into a reactor for reaction, the space velocity of the polyether was 3.0 g / h / g cat, the space velocity of the liquid ammonia was 3.0 g / h / g cat, and the molar ratio of hydrogen to polyether was 40: 1. The reactor temperature was controlled at 210°C and the pressure was controlled at 16 MPa.

[0070] The product liquid extracted from the tubular reactor is stirred at an absolute pressure of 2 kPa and 110°C for 1 hour to remove liquid ammonia, water and light components in the product liquid. The polyetheramine product is obtained and sampled for titration analysis.

[0071] The polyether conversion rate was 98.8%, and the polyetheramine primary amine selectivity was 99.6%.

[0072] Example 3

[0073] 213.3 g of Co(NO3)2·6H2O, 48.4 g of Cu(NO3)2·3H2O, 183.8 g of Al(NO3)3·9H2O and 19.5 g of Zn(NO3)2·6H2O were added to 3 L of deionized water respectively, stirred, and co-precipitated with 20 wt% sodium carbonate aqueous solution at 70°C, and the pH value of the solution was controlled to be 6.0. The pH of the mixed solution was adjusted to 7.5 using a precipitant solution, and the precipitate was allowed to stand for aging for 12 hours. The obtained suspension was filtered, the filter cake was washed with water 7 times, and the filtrate was filtered to obtain a filter cake.

[0074] Prepare an ethanol solution of PDMS with a molecular weight of 6000, with a mass concentration of 1%, add 10% of the solution mass of graphene, stir at 55°C for 12 hours, and calcine the mixture at 150°C for 5 hours to obtain modified graphene. Prepare a mixture of modified graphene: dopamine: catalyst filter cake at a mass ratio of 2:0.5:100, add deionized water to prepare a 25wt% suspension, stir at 70°C for 15 hours, filter the suspension after stirring to obtain a filter cake, dry the filter cake at 110°C for 12 hours, and calcine at 400°C for 12 hours to obtain a coprecipitated catalyst, press the catalyst into a cylindrical shape with a diameter of 3mm, and measure the catalyst side pressure strength to be 140N / cm.

[0075] 200 g of the coprecipitated catalyst precursor prepared above was added to a tubular reactor and activated with hydrogen at an activation temperature of 300° C., an activation pressure of 10 MPa, a hydrogen dosage of 250 L / min / kg catalyst, and an activation time of 36 h to obtain an active catalyst.

[0076] Nonylphenol was used as the initiator, and polypropylene glycol with an average molecular weight of 1200 was used as the polyether raw material, which was mixed with liquid ammonia and hydrogen and then entered into a reactor for reaction. The space velocity of the polyether was 1.5 g / h / g cat, the space velocity of the liquid ammonia was 2.0 g / h / g cat, and the molar ratio of hydrogen to polyether was 25: 1. The reactor temperature was controlled at 200°C and the pressure was controlled at 15 MPa.

[0077] The product liquid extracted from the tubular reactor is stirred at an absolute pressure of 2 kPa and 110°C for 1 hour to remove liquid ammonia, water and light components in the product liquid. The polyetheramine product is obtained and sampled for titration analysis.

[0078] The polyether conversion rate was 98.6%, and the polyetheramine primary amine selectivity was 99.4%.

[0079] Example 4

[0080] 174.6 g of Co(NO3)2·6H2O, 60.5 g of Cu(NO3)2·3H2O, 235.1 g of Al(NO3)3·9H2O and 15.6 g of Cr(NO3)3·6H2O were added to 3 L of deionized water respectively, stirred, and co-precipitated with 20 wt% sodium carbonate aqueous solution at 65°C, and the pH value of the solution was controlled to be 5.5. The pH of the mixed solution was adjusted to 7.2 using a precipitant solution, and the precipitate was allowed to stand for 6 hours of aging. The obtained suspension was filtered, the filter cake was washed with water 6 times, and the filtrate was filtered to obtain a filter cake.

[0081] Prepare an ethanol solution of PDMS with a molecular weight of 5000 and a mass concentration of 0.5%, add 8% of the solution mass of graphene, stir at 50°C for 8 hours, and calcine the mixture at 120°C for 3 hours to obtain modified graphene. Prepare a mixture of modified graphene: dopamine: catalyst filter cake at a mass ratio of 4:0.1:100, add deionized water to prepare a 15wt% suspension, stir at 60°C for 10 hours, filter the suspension after stirring to obtain a filter cake, dry the filter cake at 100°C for 6 hours, and calcine at 200°C for 8 hours to obtain a coprecipitated catalyst, press the catalyst into a sphere with a diameter of 4mm, and measure the catalyst side pressure strength to be 170N / cm.

[0082] 200 g of the coprecipitated catalyst precursor prepared above was added to a tubular reactor and activated with hydrogen at an activation temperature of 250° C., an activation pressure of 8 MPa, a hydrogen dosage of 150 L / min / kg catalyst, and an activation time of 20 h to obtain an active catalyst.

[0083] Nonylphenol was used as the initiator, and polypropylene glycol with an average molecular weight of 800 was used as the polyether raw material, which was mixed with liquid ammonia and hydrogen and then entered into the reactor for reaction. The space velocity of the polyether was 1.2 g / h / g cat, the space velocity of the liquid ammonia was 1.8 g / h / g cat, and the molar ratio of hydrogen to polyether was 15: 1. The reactor temperature was controlled at 195°C and the pressure was controlled at 14 MPa.

[0084] The product liquid extracted from the tubular reactor is stirred at an absolute pressure of 2 kPa and 110°C for 1 hour to remove liquid ammonia, water and light components in the product liquid. The polyetheramine product is obtained and sampled for titration analysis.

[0085] The polyether conversion rate was 98.4%, and the polyetheramine primary amine selectivity was 99.3%.

[0086] Example 5

[0087] 291.0g Co(NO3)2·6H2O, 24.2g Cu(NO3)2·3H2O, 88.1g Al(NO3)3·9H2O and 13.4g Zr(CH3COO)4 were added to 3L deionized water respectively, stirred, and co-precipitated with 20wt% sodium carbonate aqueous solution at 75°C, and the pH value of the solution was controlled to be 6.5. The pH of the mixed solution was adjusted to 7.8 using a precipitant solution, and the precipitate was allowed to stand for aging for 12h. The obtained suspension was filtered, the filter cake was washed with water 8 times, and the filtrate was filtered to obtain a filter cake.

[0088] Prepare an ethanol solution of PDMS with a molecular weight of 8000 and a mass concentration of 1.5%, add 14% of the solution mass of graphene, stir at 60°C for 16 hours, and calcine the mixture at 180°C for 8 hours to obtain modified graphene. Prepare a mixture of modified graphene: dopamine: catalyst filter cake at a mass ratio of 2:0.5:100, add deionized water to prepare a 40wt% suspension, stir at 80°C for 20 hours, filter the suspension after stirring to obtain a filter cake, dry the filter cake at 120°C for 16 hours, and calcine at 600°C for 16 hours to obtain a coprecipitated catalyst, press the catalyst into a cylindrical shape with a diameter of 5mm, and measure the catalyst side pressure strength to be 150N / cm.

[0089] 200 g of the coprecipitated catalyst precursor prepared above was added to the tubular reactor and activated with hydrogen at an activation temperature of 350° C., an activation pressure of 14 MPa, a hydrogen dosage of 300 L / min / kg catalyst, and an activation time of 40 h to obtain an active catalyst.

[0090] Nonylphenol was used as the initiator, and polypropylene glycol with an average molecular weight of 1000 was used as the polyether raw material, which was mixed with liquid ammonia and hydrogen and then entered into a reactor for reaction. The space velocity of the polyether was 2.0 g / h / g cat, the space velocity of the liquid ammonia was 2.5 g / h / g cat, and the molar ratio of hydrogen to polyether was 30: 1. The reactor temperature was controlled at 205°C and the pressure was controlled at 16 MPa.

[0091] The product liquid extracted from the tubular reactor is stirred at an absolute pressure of 2 kPa and 110°C for 1 hour to remove liquid ammonia, water and light components in the product liquid. The polyetheramine product is obtained and sampled for titration analysis.

[0092] The polyether conversion rate was 98.7%, and the polyetheramine primary amine selectivity was 99.5%.

[0093] Example 6

[0094] 174.6 g Co(NO3)2·6H2O, 33.4 g Cu(NO3)2·3H2O, 294.0 g Al(NO3)3·9H2O and 4.9 g (NH4)6Mo7O were added to 3 L of deionized water. 24 ·4H2O, stirred, co-precipitated with 20wt% sodium carbonate aqueous solution at 60°C, and the pH value of the solution was controlled to be 5.7. The pH of the mixed solution was adjusted to 7.4 using a precipitant solution, and the precipitate was aged for 16 hours. The obtained suspension was filtered, and the filter cake was washed with water 7 times, and the filtrate was filtered to obtain a filter cake.

[0095] Prepare an ethanol solution of PDMS with a molecular weight of 9000 and a mass concentration of 1.2%, add 16% of the solution mass of graphene, stir at 65°C for 14h, and calcine the mixture at 140°C for 6h to obtain modified graphene. Prepare a mixture of modified graphene: dopamine: catalyst filter cake at a mass ratio of 3:0.7:100, add deionized water to prepare a 30wt% suspension, stir at 65°C for 12h, filter the suspension after stirring to obtain a filter cake, dry the filter cake at 90°C for 8h, and calcine at 300°C for 10h to obtain a coprecipitated catalyst, press the catalyst into a spherical shape with a diameter of 2mm, and measure the catalyst side pressure strength to be 180N / cm.

[0096] 200 g of the coprecipitated catalyst precursor prepared above was added to a tubular reactor and activated with hydrogen at an activation temperature of 400° C., an activation pressure of 6 MPa, a hydrogen dosage of 350 L / min / kg catalyst, and an activation time of 16 h to obtain an active catalyst.

[0097] n-dodecanol was used as the initiator, polypropylene glycol with an average molecular weight of 800 was used as the polyether raw material, and then mixed with liquid ammonia and hydrogen and entered into a reactor for reaction, the space velocity of the polyether was 1.0 g / h / g cat, the space velocity of the liquid ammonia was 1.5 g / h / g cat, and the molar ratio of hydrogen to polyether was 20: 1. The reactor temperature was controlled at 200°C and the pressure was controlled at 15 MPa.

[0098] The product liquid extracted from the tubular reactor is stirred at an absolute pressure of 2 kPa and 110°C for 1 hour to remove liquid ammonia, water and light components in the product liquid. The polyetheramine product is obtained and sampled for titration analysis.

[0099] The polyether conversion rate was 98.5%, and the polyetheramine primary amine selectivity was 99.4%.

Claims

1. A catalyst for the amination of polyether polyols, comprising an active component and an auxiliary agent, wherein the active component comprises an oxide of Co, an oxide of Cu and an oxide of Al; the auxiliary agent is one or more selected from metal oxides of Zn, Zr, Cr, Mo, Ce, La, Sb and Mg, preferably one or more metal oxides of Zr, Ce, La and Cr, more preferably an oxide of La and / or Ce.

2. The catalyst according to claim 1, characterized in that Contains the following components: The oxide content of Co is 20-90wt%, preferably 30-85wt%, more preferably 45-75%, calculated as CoO; the oxide content of Cu is 1-30wt%, preferably 5-25wt%, more preferably 8-20%, calculated as CuO; The Al oxide content is 1-50wt%, preferably 5-45wt%, more preferably 10-40%, calculated as Al2O3; The content of the auxiliary agent is 1-8wt%, preferably 2-6wt%, more preferably 3-5wt%.

3. A method for preparing the catalyst according to claim 1 or 2, comprising the steps of: a1: co-precipitate the metal salt solution and the precipitant solution to control the pH value of the reaction solution; a2: using a precipitant solution to adjust the pH of the product of step a1, allowing it to stand for aging, filtering, and washing; a3: preparing an ethanol solution of PDMS, adding graphene and performing low-temperature calcination to obtain modified graphene; a4: mixing the product of step a2 and the modified graphene and dopamine of step a3 for reaction, filtering after the reaction, drying the filter cake, and calcining to obtain a catalyst.

4. The method according to claim 3, characterized in that The cobalt salt in the metal salt includes cobalt nitrate and / or cobalt sulfate; the copper salt in the metal salt includes copper nitrate and / or copper sulfate; the aluminum salt in the metal salt includes aluminum nitrate and / or aluminum sulfate.

5. The method according to claim 3 or 4, characterized in that: In step a1, the temperature is 60-80°C, preferably 65-75°C; the pH is 5-7, preferably 5.5-6.

5.

6. The method according to any one of claims 3 to 5, characterized in that: In step a2, the pH of the product of step a1 is adjusted to 7-8, preferably 7.2-7.8, using a precipitant, and aged for 1-24 hours, preferably 6-12 hours.

7. The method according to any one of claims 3 to 6, characterized in that: In step a3, the mass concentration of the PDMS ethanol solution is 0.1-2%, the amount of graphene added is 5-20% of the mass of the ethanol solution, stirring is carried out in a closed container at 40° C.-70° C. for 1-24 h, and low-temperature calcination is carried out at 100-200° C. for 1-10 h to obtain modified graphene.

8. The method according to any one of claims 3 to 7, characterized in that: In step a3, the number average molecular weight of PDMS is 4000-10000.

9. The method according to any one of claims 3 to 8, characterized in that: In step a4, graphene is modified: The mass ratio of dopamine: product of step a2 is (1-4): (0.1-1):

100.

10. The method according to any one of claims 3 to 9, characterized in that: In step a4, the mixture is dried at 80-140°C, preferably 100-120°C, for 1-24 hours, preferably 6-16 hours. After drying, the mixture is calcined at 100-800°C, preferably 200-600°C, for 1-24 hours, preferably 8-16 hours.