Method for preparing N,N-dimethyl cyclohexylamine

Abstract

The invention discloses a method for preparing N,N-dimethyl cyclohexylamine. The method comprises the following steps: (1) adding cyclohexylamine, a solvent and a supported palladium-based catalyst into a reaction kettle, slowly adding a formaldehyde aqueous solution into the reaction kettle, and carrying out a reaction at a certain reaction temperature under a certain hydrogen pressure; (2) afterthe formaldehyde is dropwise added, raising the reaction temperature to continue the reaction to obtain a N,N-dimethyl cyclohexylamine reaction liquid; and (3) carrying out high-temperature phase splitting on the reaction liquid to obtain an oil-phase crude product, and dehydrating and rectifying the oil-phase crude product to obtain the N,N-dimethylcyclohexylamine product. The method has the advantages of cheap and easily available raw materials, high product yield, high product purity, simple process and low production cost, and is suitable for industrial mass production.

Description

technical field

[0001] The invention relates to a preparation method of N,N-dimethylcyclohexylamine. Background technique

[0002] N,N-Dimethylcyclohexylamine, the English abbreviation name is DMCHA, which is mainly used in the polyurethane foaming industry. Relatively balanced catalytic performance, mainly used as a gel catalyst, widely used in refrigerator materials and board materials.

[0003] There are many preparation routes for N,N-dimethylcyclohexylamine, mainly including: catalytic hydrogenation of N,N-dimethylaniline, hydrogenation of phenol and dimethylamine, hydrogenation of cyclohexylamine and dimethylamine , cyclohexanone (alcohol) and dimethylamine hydrogenation method, etc., of which N,N-dimethylaniline catalytic hydrogenation method, phenol and dimethylamine hydrogenation method, cyclohexylamine and dimethylamine hydrogenation method are only It is limited to laboratory research and has no industrialization. At present, mainstream suppliers at home and ab...

Examples

Embodiment 1

[0046] Preparation of 1# modified carrier:

[0047] Weigh 95g hydrogen type ZSM-5 (silicon-aluminum ratio is 100), use 100ml deionized water to configure magnesium nitrate hexahydrate with an impregnation solution containing 5g magnesium oxide (that is, magnesium nitrate can finally be oxidized to 5g magnesium oxide), and then heat To form a uniform solution at 80°C, add the weighed hydrogen ZSM-5 into the impregnation solution, impregnate at 80°C for 12 hours, and bake in an oven at 110°C for 12 hours; The temperature was increased at 3°C / min to 400°C and calcined for 8h to prepare a modified carrier containing 5% MgO+95% hydrogen ZSM-5.

[0048] Preparation of 1# supported palladium-based catalyst precursor:

[0049] Use 100ml of deionized water to prepare a nitrate dipping solution containing 6g of palladium, 0.5g of cobalt, and 0.2g of zinc, heat it to 80°C to form a homogeneous solution, then add 93.3g of 1# modified carrier, soak it at 80°C for 12h, and then Bake in an...

Embodiment 2

[0051] Preparation of 2# modified carrier:

[0052] Weigh 90g of hydrogen-type ZSM-5 (silicon-aluminum ratio is 400), mix barium nitrate hexahydrate with 150ml of deionized water to prepare an impregnation solution containing 10g of barium oxide, then heat to 75°C to form a uniform solution, and the weighed Add hydrogen ZSM-5 into the impregnation solution, impregnate at 75°C for 12 hours, bake in an oven at 120°C for 12 hours; finally move to a muffle furnace, heat up to 450°C for 8 hours in an air atmosphere, A modified carrier containing 10% BaO+90% hydrogen ZSM-5 was prepared.

[0053] Preparation of 2# supported palladium-based catalyst precursor:

[0054] Use 100ml deionized water to prepare a nitrate impregnation solution containing 4g palladium, 0.5g ruthenium, and 0.05g iron, heat to 80°C to form a uniform solution, then add 95.45g 2# modified carrier, soak at 80°C for 12h, and then Bake in an oven at 120°C for 12 hours; finally move to a muffle furnace, heat up to ...

Embodiment 3

[0056] Preparation of 3# modified carrier:

[0057] Weigh 95g of hydrogen-form ZSM-5 (silicon-aluminum ratio is 200), mix magnesium nitrate hexahydrate and barium nitrate hexahydrate with 100ml deionized water to prepare an impregnation solution containing 3g magnesium oxide and 2g barium oxide, and then heat to 90°C to form For a uniform solution, add the weighed hydrogen ZSM-5 into the impregnation solution, impregnate at 90°C for 24h, and bake in an oven at 110°C for 12h; / min to 500°C for 8 hours to prepare a modified carrier containing 3% MgO+2%BaO+95% hydrogen ZSM-5.

[0058] Preparation of 3# supported palladium-based catalyst precursor:

[0059] Use 200ml of deionized water to prepare a nitrate impregnation solution containing 15g of palladium, 0.1g of ruthenium, 0.1g of cobalt, and 0.4g of cerium, heat to 80°C to form a uniform solution, then add 84.4g of 3# modified carrier, and impregnate at 80°C 24h, then oven-baked at 120°C for 12h; finally moved to a muffle fur...

technical field

[0001] The invention relates to a preparation method of N,N-dimethylcyclohexylamine. Background technique

[0002] N,N-Dimethylcyclohexylamine, the English abbreviation name is DMCHA, which is mainly used in the polyurethane foaming industry. Relatively balanced catalytic performance, mainly used as a gel catalyst, widely used in refrigerator materials and board materials.

[0003] There are many preparation routes for N,N-dimethylcyclohexylamine, mainly including: catalytic hydrogenation of N,N-dimethylaniline, hydrogenation of phenol and dimethylamine, hydrogenation of cyclohexylamine and dimethylamine , cyclohexanone (alcohol) and dimethylamine hydrogenation method, etc., of which N,N-dimethylaniline catalytic hydrogenation method, phenol and dimethylamine hydrogenation method, cyclohexylamine and dimethylamine hydrogenation method are only It is limited to laboratory research and has no industrialization. At present, mainstream suppliers at home and ab...

Examples

Embodiment 1

[0046] Preparation of 1# modified carrier:

[0047] Weigh 95g hydrogen type ZSM-5 (silicon-aluminum ratio is 100), use 100ml deionized water to configure magnesium nitrate hexahydrate with an impregnation solution containing 5g magnesium oxide (that is, magnesium nitrate can finally be oxidized to 5g magnesium oxide), and then heat To form a uniform solution at 80°C, add the weighed hydrogen ZSM-5 into the impregnation solution, impregnate at 80°C for 12 hours, and bake in an oven at 110°C for 12 hours; The temperature was increased at 3°C / min to 400°C and calcined for 8h to prepare a modified carrier containing 5% MgO+95% hydrogen ZSM-5.

[0048] Preparation of 1# supported palladium-based catalyst precursor:

[0049] Use 100ml of deionized water to prepare a nitrate dipping solution containing 6g of palladium, 0.5g of cobalt, and 0.2g of zinc, heat it to 80°C to form a homogeneous solution, then add 93.3g of 1# modified carrier, soak it at 80°C for 12h, and then Bake in an...

Embodiment 2

[0051] Preparation of 2# modified carrier:

[0052] Weigh 90g of hydrogen-type ZSM-5 (silicon-aluminum ratio is 400), mix barium nitrate hexahydrate with 150ml of deionized water to prepare an impregnation solution containing 10g of barium oxide, then heat to 75°C to form a uniform solution, and the weighed Add hydrogen ZSM-5 into the impregnation solution, impregnate at 75°C for 12 hours, bake in an oven at 120°C for 12 hours; finally move to a muffle furnace, heat up to 450°C for 8 hours in an air atmosphere, A modified carrier containing 10% BaO+90% hydrogen ZSM-5 was prepared.

[0053] Preparation of 2# supported palladium-based catalyst precursor:

[0054] Use 100ml deionized water to prepare a nitrate impregnation solution containing 4g palladium, 0.5g ruthenium, and 0.05g iron, heat to 80°C to form a uniform solution, then add 95.45g 2# modified carrier, soak at 80°C for 12h, and then Bake in an oven at 120°C for 12 hours; finally move to a muffle furnace, heat up to ...

Embodiment 3

[0056] Preparation of 3# modified carrier:

[0057] Weigh 95g of hydrogen-form ZSM-5 (silicon-aluminum ratio is 200), mix magnesium nitrate hexahydrate and barium nitrate hexahydrate with 100ml deionized water to prepare an impregnation solution containing 3g magnesium oxide and 2g barium oxide, and then heat to 90°C to form For a uniform solution, add the weighed hydrogen ZSM-5 into the impregnation solution, impregnate at 90°C for 24h, and bake in an oven at 110°C for 12h; / min to 500°C for 8 hours to prepare a modified carrier containing 3% MgO+2%BaO+95% hydrogen ZSM-5.

[0058] Preparation of 3# supported palladium-based catalyst precursor:

[0059] Use 200ml of deionized water to prepare a nitrate impregnation solution containing 15g of palladium, 0.1g of ruthenium, 0.1g of cobalt, and 0.4g of cerium, heat to 80°C to form a uniform solution, then add 84.4g of 3# modified carrier, and impregnate at 80°C 24h, then oven-baked at 120°C for 12h; finally moved to a muffle fur...

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