Preparation method of heptafluorobutanol

Abstract

The invention discloses a preparation method of heptafluorobutanol, which comprises the following steps: preheating and gasifying perfluorobutyric acid and alkyl alcohol, mixing, cooling, introducing into a coil reaction kettle, carrying out one-step reduction reaction with hydrogen introduced into the coil reaction kettle at 200-300 DEG C to obtain crude heptafluorobutanol, cooling, and rectifying to obtain a heptafluorobutanol product. A metal catalyst is loaded in the coil reaction kettle, and the metal catalyst is one of the combination of Ru-Sn, Ru-Co, Ru-Fe, Ni-Sn, Pd-Sn and Pt-Sn. The content of the product is greater than or equal to 98% through gas chromatography analysis, the conversion rate of the perfluorobutyric acid reaches 97% or above, and unreacted gas can be recycled to continue to participate in the reaction.

Description

Technical Field

[0001] The present invention relates to a method for preparing heptafluorobutanol, belonging to the technical field of fluorochemical industry. Background Art

[0002] As an organofluorine fine chemical, perfluoroalkyl alcohol has an important position in the organofluorine chemical industry chain due to its special chemical structure and wide application value. Due to the presence of perfluorocarbon chains, it has unique chemical stability, corrosion resistance, flame retardancy, hydrophobicity and oleophobicity, and is widely used in fields such as fabric finishing agents, surfactants, fluororesins and pharmaceutical intermediates. Perfluoroalkyl alcohol can also be converted into various fluorine-containing drug intermediates, fluorine-containing fine chemicals and fluorine-containing fabric finishing agent monomers through functional group conversion, and further synthesized into various fluorine-containing surfactants, fluorine-containing fabric finishing agents and various series of fluorine-containing drugs and fluoroethers. In addition, perfluoroalkyl alcohol is also the main component of foam fire extinguishers. This fire extinguisher is a multi-purpose and highly efficient fire extinguisher prepared from raw materials such as polymer bioadhesives, composite foaming agents, fluorosurfactants, solvents, etc. Besides having the characteristics of aqueous film-forming foam fire extinguishers, it can form a layer of colloidal film on the surface of alcohol substances, and quickly and effectively extinguish the fire by the dual action of foam and colloidal film.

[0003] At present, there are the following several methods for preparing perfluoroalkyl alcohol: (1) reduction of perfluoroalkyl carboxylic acid, perfluoroalkyl carboxylic acid ester, perfluoroalkyl aldehyde; (2) reaction of perfluoroaliphatic aldehyde with Grignard reagent; (3) addition and hydrolysis of perfluoropropene, or direct hydrolysis reaction of perfluoroalkyl halide, etc. However, the research on these synthesis methods has not yet entered large-scale production, and the process development of downstream products and further application in the fluorochemical industry also need to be further developed and promoted.

[0004] Heptafluorobutanol is also a perfluoroalkyl alcohol, which is an important chemical intermediate. It is a colorless liquid at room temperature, slightly soluble in water, with a boiling point of 96 - 97 °C at room temperature and a relative density of 1.601. It is an important organic solvent and raw material or auxiliary for synthesizing organic polymer materials, and also a new type of fluorocarbon alcohol material. It can be used to synthesize new medicines, pesticides, fragrances, fabric finishing agents, and has great market prospects and development value. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a new method for preparing heptafluorobutanol. This method uses perfluorobutyric acid and alkyl alcohol as raw materials, and under the action of a catalyst, heptafluorobutanol is prepared by a one-step hydrogen reduction reaction.

[0006] To solve the above technical problems, the present invention discloses a method for preparing heptafluorobutanol. Perfluorobutyric acid and an alkyl alcohol are preheated and vaporized, then mixed, and after cooling, they are introduced into a coil reactor, and react with hydrogen introduced into the coil reactor at 200-300 °C through a one-step reduction reaction to obtain crude heptafluorobutanol, and then through cooling and rectification, a heptafluorobutanol product is prepared; a metal catalyst is loaded in the coil reactor, and the metal catalyst is one of the combinations of Ru-Sn, Ru-Co, Ru-Fe, Ni-Sn, Pd-Sn, Pt-Sn.

[0007] Further, in the combination of the metal catalysts, the molar ratio of the former metal to the latter metal is 1:1-3.

[0008] Further, the metal catalyst is supported on a carrier, and the carrier is one of Al2O3, SiO2, TiO2.

[0009] Further, the molar ratio of the metal catalyst to the carrier is 1:1-3.

[0010] Further, the vaporization temperature of the perfluorobutyric acid is 150-200 °C, the vaporization temperature of the alkyl alcohol is 10 °C higher than the boiling point of the alkyl alcohol, and the cooling temperature is 120-140 °C. It is sufficient to vaporize the alkyl alcohol, and generally 10 °C higher than the boiling point is better.

[0011] Further, the alkyl alcohol is a straight-chain or branched-chain alkyl alcohol with 1-10 carbon atoms.

[0012] Further, the molar feeding ratio of the perfluorobutyric acid to the alkyl alcohol is 1:1-3.

[0013] Further, the molar feeding ratio of the perfluorobutyric acid to hydrogen is 1:1-3.

[0014] Further, the metal catalyst is loaded onto the carrier by the following method: dissolve the corresponding metal salt in deionized water, add it to the carrier, let it stand for 12 hours, after the water evaporates, dry it in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 6 hours, and cool it to room temperature for standby.

[0015] Further, the carrier is activated by the following method before use: crush and grind the carrier, soak it in a 5% nitric acid aqueous solution for 5 hours, filter, dry the filter cake in an oven at 120 °C for 12 hours, and then calcine it at a high temperature of 500 °C for 5 hours.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1) The preparation process of the present invention is simple, requires low equipment requirements, has mild reaction conditions, high product purity, good quality, safe production, high raw material conversion rate, low production cost, is suitable for large-scale production, and the unreacted substances can be recycled. It is a green and environmentally friendly synthetic method with zero emissions.

[0018] 2) The metal catalyst described in the present invention has easily available raw materials, a simple preparation method, a long service life, and can be applied to the production of fluorine-containing fine chemicals industry.

[0019] The product of the present invention has a product content ≥ 98% analyzed by gas chromatography, the conversion rate of perfluorobutyric acid reaches more than 97%, and the unreacted gas can be recycled and reused to continue participating in the reaction. Specific Embodiments

[0020] The present invention will be further explained below in conjunction with embodiments. The following embodiments are only used to illustrate the present invention, but do not limit the scope of implementation of the present invention.

[0021] I. Preparation of Catalyst

[0022] Example 1 Preparation of Catalyst 1

[0023] 1) Grind Al2O3 (204 g, 2 mol) into fine powder, soak it in 5 wt% nitric acid aqueous solution for 5 hours, filter, dry the filter cake in an oven at 120 °C for 12 hours, and then calcine it at a high temperature of 500 °C for 5 hours for standby;

[0024] 2) Dissolve Pt(NO3)2 (319 g, 1 mol) and SnC2O4 (209 g, 1 mol) fully in deionized water, then mix with the activated Al2O3 support in step 1), let it stand for 12 hours, evaporate the water, dry it in an oven at 120 °C for 12 hours, and then calcine it at a high temperature of 500 °C for 6 hours, and cool it to room temperature to obtain Catalyst 1 for standby.

[0025] Example 2 Preparation of Catalyst 2

[0026] 1) Grind Al2O3 (306 g, 3 mol) into fine powder, soak it in 5 wt% nitric acid aqueous solution for 5 hours, filter, dry the filter cake in an oven at 120 °C for 12 hours, and then calcine it at a high temperature of 500 °C for 5 hours to obtain the activated Al2O3 support for standby;

[0027] 2) After fully dissolving Pt(NO3)2 (319 g, 1 mol) and SnC2O4 (209 g, 1 mol) in deionized water, mix them with the Al2O3 support activated in step 1), let it stand for 12 hours, evaporate the water, dry it in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 6 hours, and cool it to room temperature to obtain catalyst 2 for standby.

[0028] Example 3 Preparation of Catalyst 3

[0029] 1) Grind Al2O3 (204 g, 2 mol) into fine powder, soak it in a 5 wt% nitric acid aqueous solution for 5 hours, filter it, dry the filter cake in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 5 hours to obtain the activated Al2O3 support for standby;

[0030] 2) After fully dissolving Ni(NO3)2 (183 g, 1 mol) and SnC2O4 (209 g, 1 mol) in deionized water, mix them with the Al2O3 support activated in step 1), let it stand for 12 hours, evaporate the water, dry it in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 6 hours, and cool it to room temperature to obtain catalyst 3 for standby.

[0031] Example 4 Preparation of Catalyst 4

[0032] 1) Grind SiO2 (240 g, 4 mol) into fine powder, soak it in a 5 wt% nitric acid aqueous solution for 5 hours, filter it, dry the filter cake in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 5 hours to obtain the activated SiO2 support for standby;

[0033] 2) After fully dissolving Pt(NO3)2 (319 g, 1 mol) and SnC2O4 (627 g, 3 mol) in deionized water, mix them with the SiO2 support activated in step 1), let it stand for 12 hours, evaporate the water, dry it in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 6 hours, and cool it to room temperature to obtain catalyst 4 for standby.

[0034] Example 5 Preparation of Catalyst 5

[0035] 1) Grind TiO2 (160 g, 2 mol) into fine powder, soak it in a 5 wt% nitric acid aqueous solution for 5 hours, filter it, dry the filter cake in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 5 hours to obtain the activated TiO2 support for standby;

[0036] 2) After fully dissolving Pd(NO3)2 (230 g, 1 mol) and SnC2O4 (209 g, 1 mol) in deionized water, mix them with the TiO2 support activated in step 1), let it stand for 12 hours, evaporate the water, dry it in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 6 hours, and cool it to room temperature to obtain catalyst 5 for standby.

[0037] Example 6 Preparation of Catalyst 6

[0038] 1) Crush and grind Al2O3 (204 g, 2 mol), soak it in a 5 wt% nitric acid aqueous solution for 5 hours, filter it, dry the filter cake in an oven at 120 °C for 12 hours, and then calcine it at a high temperature of 500 °C for 5 hours to obtain the activated Al2O3 support for standby;

[0039] 2) After fully dissolving Ru(NO3)2 (318 g, 1 mol) and SnC2O4 (209 g, 1 mol) in deionized water, mix them with the Al2O3 support activated in step 1), let it stand for 12 hours, evaporate the water, dry it in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 6 hours, and cool it to room temperature to obtain catalyst 6 for standby.

[0040] Example 7 Preparation of Catalyst 7

[0041] 1) Crush and grind Al2O3 (204 g, 2 mol), soak it in a 5 wt% nitric acid aqueous solution for 5 hours, filter it, dry the filter cake in an oven at 120 °C for 12 hours, and then calcine it at a high temperature of 500 °C for 5 hours to obtain the activated Al2O3 support for standby;

[0042] 2) After fully dissolving Ru(NO3)2 (318 g, 1 mol) and Co(NO3)2 (183 g, 1 mol) in deionized water, mix them with the Al2O3 (204 g, 2 mol) support activated in step 1), let it stand for 12 hours, evaporate the water, dry it in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 6 hours, and cool it to room temperature to obtain catalyst 7 for standby.

[0043] II. Preparation of 2,2,3,3,4,4,4 - heptafluorobutanol

[0044] Example 1

[0045] Put the prepared catalyst 1 into a coil reactor. First, introduce hydrogen at 300 °C. After fully mixing perfluorobutyric acid (213 g, 1 mol) vaporized at 150 °C and methanol (32 g, 1 mol) vaporized at 75 °C in a gas holder, cool them to 120 °C through a cooling device, and then introduce them into the coil reactor together with 3 moles of hydrogen respectively. Obtain the crude product of heptafluorobutanol gas through a one-step reduction reaction at 300 °C, and then obtain the heptafluorobutanol product through cooling and rectification. The content of the product analyzed by gas chromatography is ≥98%, and the conversion rate of perfluorobutyric acid reaches 97%.

[0046] Example 2

[0047] Put the prepared catalyst 2 into a coil reactor. First, introduce hydrogen at 200 °C. After fully mixing perfluorobutyric acid (213 g, 1 mol) vaporized at 150 °C and methanol (96 g, 3 mol) vaporized at 75 °C in a gas holder, cool them to 140 °C through a cooling device, and then introduce them into the coil reactor together with 3 moles of hydrogen respectively. Obtain the crude product of heptafluorobutanol gas through a one-step reduction reaction at 200 °C, and then obtain the heptafluorobutanol product through cooling and rectification. The content of the product analyzed by gas chromatography is ≥98%, and the conversion rate of perfluorobutyric acid reaches 97%.

[0048] Example 3

[0049] Put the prepared catalyst 5 into a coil reactor. First, introduce hydrogen at 250 °C. After fully mixing perfluorobutyric acid (213 g, 1 mol) vaporized at 200 °C and benzyl alcohol (108 g, 1 mol) vaporized at 215 °C in a gas holder, cool them to 150 °C through a cooling device, and then introduce them into the coil reactor together with 1 mole of hydrogen respectively. Obtain the crude product of heptafluorobutanol gas through a one-step reduction reaction at 250 °C, and then obtain the heptafluorobutanol product through cooling and rectification. The content of the product analyzed by gas chromatography is ≥98%, and the conversion rate of perfluorobutyric acid reaches 98%.

[0050] Example 4

[0051] Put the prepared catalyst 7 into a coil reactor. First, introduce hydrogen at 250 °C. After fully mixing perfluorobutyric acid (213 g, 1 mol) vaporized at 150 °C and tert-butanol (74 g, 1 mol) vaporized at 93 °C in a gas holder, cool them to 130 °C through a cooling device, and then introduce them into the coil reactor together with 2 moles of hydrogen respectively. Obtain the crude product of heptafluorobutanol gas through a one-step reduction reaction at 250 °C, and then obtain the heptafluorobutanol product through cooling and rectification. The content of the product analyzed by gas chromatography is ≥98%, and the conversion rate of perfluorobutyric acid reaches 98%.

[0052] Example 5

[0053] The prepared catalyst 4 was placed into a coil reactor. First, hydrogen was introduced at 250°C. Perfluorobutyric acid (213 g, 1 mol) vaporized at 150°C and nonanol (144 g, 1 mol) vaporized at 223°C were fully mixed in a gas holder. After being cooled to 130°C by a cooling device, they were introduced into the coil reactor together with 2 moles of hydrogen respectively. A crude product of heptafluorobutanol gas was prepared through a one-step reduction reaction at 250°C. After cooling and rectification, a heptafluorobutanol product was obtained. The content of the product analyzed by gas chromatography was ≥98%, and the conversion rate of perfluorobutyric acid reached 98%.

Claims

1. A method for preparing heptafluorobutanol, characterized in that: Perfluorobutyric acid and alkyl alcohol are preheated and vaporized, then mixed, and after cooling, they are introduced into a coil reactor, and reacted with hydrogen introduced into the coil reactor through a one-step reduction reaction at 200-300 °C to obtain heptafluorobutanol; a metal catalyst is loaded in the coil reactor, and the metal catalyst is one of the combinations of Ru-Sn, Ru-Co, Ru-Fe, Ni-Sn, Pd-Sn, Pt-Sn.

2. The preparation method of heptafluorobutanol according to claim 1, wherein: In the combination of the metal catalysts, the molar ratio of the former metal to the latter metal is 1:1-3.

3. The method for preparing heptafluorobutanol according to claim 1 or 2, characterized in that: The metal catalyst is supported on a carrier, and the carrier is one of Al2O3, SiO2, TiO2.

4. The preparation method of heptafluorobutanol according to claim 3, characterized in that: The molar ratio of the metal catalyst to the carrier is 1:1-3.

5. The preparation method of heptafluorobutanol according to claim 1, characterized in that: The vaporization temperature of the perfluorobutyric acid is 150-200 °C, the vaporization temperature of the alkyl alcohol is 10 °C higher than the boiling point of the alkyl alcohol, and the cooling temperature is 120-140 °C.

6. The preparation method of heptafluorobutanol according to claim 1, wherein: The alkyl alcohol is a straight-chain or branched-chain alkyl alcohol with 1-10 carbon atoms.

7. The method for preparing heptafluorobutanol according to claim 1, characterized in that: The molar feed ratio of the perfluorobutyric acid to the alkyl alcohol is 1:1-3.

8. The preparation method of heptafluorobutanol according to claim 1, characterized in that: The molar feed ratio of the perfluorobutyric acid to hydrogen is 1:1-3.

9. The preparation method of heptafluorobutanol according to claim 3, characterized in that: The metal catalyst is supported on the carrier by the following method: dissolve the corresponding metal salt in deionized water, add it to the carrier, let it stand for 12 hours, after the water evaporates, dry it in an oven at 120 °C for 12 hours, then calcine it at a high temperature of 500 °C for 6 hours, and cool it to room temperature for standby.

10. The preparation method of heptafluorobutanol according to claim 9, characterized in that: The carrier is activated by the following method before use: crush and grind the carrier, soak it in a 5wt% aqueous nitric acid solution for 5 hours, filter, dry the filter cake in an oven at 120 °C for 12 hours, and then calcine it at a high temperature of 500 °C for 5 hours.