Method for preparing secondary alcohol by using Fischer-Tropsch olefin and C5 + secondary alcohol

Abstract

The invention provides a method for preparing secondary alcohol by using Fischer-Tropsch olefin and C < 5 + > secondary alcohol. The method comprises the following steps: S1, mixing a Fischer-Tropsch olefin raw material and formic acid according to a molar ratio of 1: (0.5-5.0) to obtain a mixed product; s2, introducing the mixed product into a resin catalyst, and carrying out esterification reaction to obtain an ester product; and S3, mixing the ester product with water according to a molar ratio of 1: (1.0-5.0), and carrying out a hydrolysis reaction to obtain the secondary alcohol. According to the method, Fischer-Tropsch olefin is taken as a raw material, formic acid which is easy to recover is introduced as an intermediate substance of reaction, limitation of chemical equilibrium of olefin hydration is broken through, an esterification product is obtained, then hydrolysis reaction is carried out, and a secondary alcohol product is finally prepared with high olefin conversion rate and secondary alcohol selectivity.

Description

Technical Field

[0001] The present invention relates to the field of Fischer-Tropsch synthesis, and in particular to a method for preparing secondary alcohols by utilizing Fischer-Tropsch olefins and C5+ secondary alcohols. Background Art

[0002] Secondary alcohols have a "-CHOH" group in their structure, that is, alcohols with a hydroxyl group directly connected to a secondary carbon atom. They are not only important chemical products, but also important chemical raw materials. They are widely used in many industries. For example, 2-hexanol can be used as a solvent and emulsifier, and can also be used as a raw material for the production of chemical products such as adipic acid; 2-octanol can be used to make plasticizers, synthetic fiber oils, defoamers, etc., and can also be used as a solvent for oils and waxes. In addition, secondary alcohol polyoxyethylene ethers obtained by the reaction of secondary alcohols and ethylene oxide are a high-end non-ionic surfactant that is very popular in the downstream market because of their low pour point, low odor, strong penetration and wetting power, strong emulsification ability, and good biodegradability.

[0003] At present, the main methods for preparing secondary alcohols are paraffin oxidation and olefin hydration. Among them, paraffin oxidation is a mature process for preparing secondary alcohols. It uses normal liquid paraffin as raw material and generates boric acid esters under the catalytic oxidation of boron oxide compounds such as boric acid, metaboric acid, and boric oxide. The oxidation conversion rate is 10% to 30%. The oxidation product is then purified by multi-step purification processes such as vacuum distillation, hydrolysis, saponification, and water washing to obtain secondary alcohol products. The entire process is long, with many steps and complex reactions. The product purity is relatively low, and it also contains a small amount of alkanes, diols, ketones, acids, and impurities. Olefin hydration is another common process for secondary alcohols. It is generally prepared by hydration reaction using olefins as raw materials and inorganic or organic acids as catalysts. The hydration process is divided into direct hydration and indirect hydration. Direct hydration is to obtain alcohol products in one step, and indirect hydration is to first generate esters and then hydrolyze to obtain alcohol products.

[0004] Regarding the olefin hydration method, taking the product of sec-butyl alcohol as an example, the indirect hydration process uses n-butylene as raw material, and an esterification reaction occurs under the action of concentrated H2SO4, first generating sec-butyl sulfate, and then hydrolyzing to obtain sec-butyl alcohol. Because this process uses concentrated H2SO4 for esterification reaction, there are problems such as serious corrosion of pipeline equipment, so it is gradually replaced by the direct hydration process. The direct hydration process uses heteropolyacid or strong acid ion exchange resin as a catalyst, and n-butylene and water directly react to produce sec-butyl alcohol. The representative processes are the solid H2SO4 sulfonated resin synthesis process developed by Texaco and the water-soluble tungstosilicate synthesis process adopted by Idemitsu Chemical Co., Ltd. of Japan. Although this process does not need to add concentrated H2SO4, it can avoid equipment corrosion problems, but it has strict requirements on raw materials. Only when the n-butylene content in the C4 raw material is greater than 90%, the selectivity of sec-butyl alcohol is high, and increasing the number of raw material cycles will lead to increased operating costs.

[0005] Meanwhile, Chinese patent CN117567244A adopts biodiesel (saturated fatty acid methyl ester with carbon number of 8-30) to be first oxidized in liquid phase under the action of catalyst, then reacts with secondary alcohol to generate crude secondary alcohol borate, and hydrolyzes to obtain secondary alcohol product. Chinese patent CN117550954A uses normal C12-14 alkane liquid and normal pressure air at high temperature, selects boric acid as catalyst, and adds auxiliary agent for catalytic oxidation, after generating secondary alcohol, then esterifies with boric acid, washes and purifies with caustic soda saponification, and then purifies by flash distillation and rectification to obtain intermediate product secondary alcohol and by-product high carbon aldehyde, acid, ester, etc. Chinese patent CN116621723A adds olefin, hydrogen donor PhSiH3 and catalyst Fe(acac)3 to polar solvent, combines with oxygen in air through free radical reaction, and converts olefin into secondary alcohol in one step.

[0006] However, the above-mentioned prior art methods for preparing secondary alcohols using olefins as raw materials cannot be industrialized due to the high requirements for raw material purity, which leads to limited raw material sources; or because only low-carbon alcohol products can be obtained; or because the reaction rate and conversion rate are low and are far from meeting the market demand for high-carbon alcohol products.

[0007] Based on this, how to provide a preparation method using Fischer-Tropsch olefins as raw materials to prepare C5+ secondary alcohol products with high olefin conversion rate and secondary alcohol selectivity is one of the important technical problems that need to be solved in this field. Summary of the invention

[0008] The main purpose of the present invention is to provide a method for preparing secondary alcohols using Fischer-Tropsch olefins and C5+ secondary alcohols, so as to solve the problem in the prior art that Fischer-Tropsch olefins cannot be used as raw materials to prepare C5+ secondary alcohol products with high olefin conversion rate and secondary alcohol selectivity.

[0009] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a method for preparing secondary alcohols using Fischer-Tropsch olefins, comprising: step S1, mixing a Fischer-Tropsch olefin raw material with formic acid in a molar ratio of 1: (0.5-5.0) to obtain a mixed product; step S2, passing the mixed product into a resin catalyst to carry out an esterification reaction to obtain an ester product; step S3, mixing the ester product with water in a molar ratio of 1: (1.0-5.0), and obtaining a secondary alcohol after a hydrolysis reaction.

[0010] Furthermore, the Fischer-Tropsch olefin feedstock includes olefins and alkanes, and based on the total weight of the Fischer-Tropsch olefin feedstock being 100%, the content of olefins is 30% to 100%.

[0011] Furthermore, in step S1, the molar ratio of the Fischer-Tropsch olefin feedstock to formic acid is 1:(0.8-1.2).

[0012] Furthermore, in step S1, the reaction temperature of the esterification reaction is 30°C to 150°C, the reaction pressure is 0.3 bar to 0.8 bar, and the reaction time is 2h to 6h; preferably, the reaction temperature of the esterification reaction is 40°C to 80°C, the reaction pressure is 0.4 bar to 0.5 bar, and the reaction time is 3h to 4h.

[0013] Furthermore, in step S3, the molar ratio of the ester product to water is 1:(1.0-1.2).

[0014] Furthermore, in step S3, the reaction temperature of the hydrolysis reaction is 20°C to 120°C, the reaction pressure is 0.1 bar to 0.4 bar, and the reaction time is 2h to 6h; preferably, the reaction temperature of the hydrolysis reaction is 30°C to 40°C, the reaction pressure is 0.2 bar to 0.3 bar, and the reaction time is 3h to 4h.

[0015] Further, in step S2, the resin catalyst is an acidic cation exchange resin, and the acidic cation exchange resin contains a benzenesulfonic acid group; preferably, the acidic cation exchange resin is 15; More preferably, the space velocity of the mixed product in the resin catalyst is 0.9h -1 ~1.0h -1 .

[0016] Further, the Fischer-Tropsch olefin raw material is a C5+ Fischer-Tropsch olefin raw material, preferably a C6-C14 Fischer-Tropsch olefin raw material; more preferably, the Fischer-Tropsch olefin raw material is a C6-C10 Fischer-Tropsch olefin raw material, and the C6-C10 Fischer-Tropsch olefin raw material includes, by weight, 4.5 to 5.0 parts of 1-hexene, 10 to 11 parts of 1-heptene, 18.5 to 20.0 parts of 1-octene, 14.5 to 16.0 parts of 1-nonene, 4.5 to 5.0 parts of 1- Decene, 42.0 to 45.0 parts of C6 to C10 alkanes and 2.0 to 4.0 parts of non-hydrocarbon impurities; or, the Fischer-Tropsch olefin raw material is a C13 to C14 Fischer-Tropsch olefin raw material, and the C13 to C14 Fischer-Tropsch olefin raw material includes, by weight, 14.5 to 16.0 parts of 13-ene, 16.5 to 18.0 parts of 14-ene, 61.0 to 63.5 parts of C13 to C14 alkanes and 5.0 to 6.0 parts of non-hydrocarbon impurities.

[0017] Furthermore, the Fischer-Tropsch olefin raw material is a C6-C10 Fischer-Tropsch olefin raw material, and the molar ratio of the C6-C10 Fischer-Tropsch olefin raw material to formic acid is 1:(0.75-0.80), the conditions for the esterification reaction are: (40±2)°C, (0.4±0.02)bar, the molar ratio of the esterification product to water is 1:(0.9-1.0), and the conditions for the hydrolysis reaction are (40±2)°C, (0.2±0.02)bar. r; or, the Fischer-Tropsch olefin raw material is a C13-C14 Fischer-Tropsch olefin raw material, and the molar ratio of the C13-C14 Fischer-Tropsch olefin raw material to formic acid is 1:(1.1-1.2), the conditions for the esterification reaction are: (80±5)°C, (0.4±0.02)bar, the molar ratio of the esterification product to water is 1:(1.1-1.2), and the conditions for the hydrolysis reaction are (40±2)°C, (0.2±0.02)bar.

[0018] The second aspect of the present invention provides a C5+ secondary alcohol, which is prepared by the above-mentioned method for preparing secondary alcohols using Fischer-Tropsch olefins.

[0019] By applying the technical scheme of the present invention, Fischer-Tropsch olefins are used as raw materials, and easily recyclable formic acid is introduced as an intermediate substance for the reaction, thereby breaking through the limitation of the chemical equilibrium of olefin hydration to obtain an esterification product, and then a hydrolysis reaction is carried out to finally prepare a secondary alcohol product with a high olefin conversion rate and secondary alcohol selectivity. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0021] As described in the background art, there is a problem in the prior art that Fischer-Tropsch olefins cannot be used as raw materials to prepare C5+ secondary alcohol products with high olefin conversion rate and secondary alcohol selectivity. In order to solve the above technical problems, the first aspect of the present invention provides a method for preparing secondary alcohols using Fischer-Tropsch olefins, comprising: step S1, mixing the Fischer-Tropsch olefin raw material with formic acid in a molar ratio of 1: (0.5-5.0) to obtain a mixed product; step S2, passing the mixed product into a resin catalyst to perform an esterification reaction to obtain an ester product; step S3, mixing the ester product with water in a molar ratio of 1: (1.0-5.0), and obtaining a secondary alcohol after a hydrolysis reaction.

[0022] The method provided by the present invention effectively improves the yield and selectivity of secondary alcohol by accurately controlling the molar ratio of Fischer-Tropsch olefin raw material and formic acid and the conditions of esterification reaction and hydrolysis reaction. Specifically, Fischer-Tropsch olefin raw material and formic acid undergo esterification reaction under the action of resin catalyst to generate intermediate ester, and ester undergoes hydrolysis reaction with water to generate secondary alcohol and acid (reaction equation is as follows). The use of resin catalyst can be coordinated with formic acid to achieve efficient promotion of esterification reaction, and at the same time, in the subsequent hydrolysis reaction, the occurrence of side reactions is avoided to the greatest extent, significantly improving the conversion rate of olefin raw material, and also ensuring the purity of the product.

[0023]

[0024] In particular, the raw material of Fischer-Tropsch olefins (mainly α-olefins and β-olefins, specifically α-ethylene, β-ethylene, α-propylene, β-propylene, and so on; including mixtures of the above olefins) is cleaner and more widely available than other olefin raw materials, and the preparation cost is also lower. In particular, the sulfur and aromatic hydrocarbon contents in the components of Fischer-Tropsch olefins are extremely low, which can avoid side reactions to a greater extent and improve the selectivity of secondary alcohol products. The above-mentioned method of preparing secondary alcohols using Fischer-Tropsch olefins not only optimizes the purity and yield of secondary alcohol products by adjusting the specific conditions of the reactions at each stage, but also can effectively utilize Fischer-Tropsch olefins, which is suitable for large-scale industrial production and provides a new synthesis path for the petrochemical industry.

[0025] And, in the preparation method provided by the present invention, the raw material of formic acid has a smaller spatial structure compared to the acids such as chloroformic acid, acetic acid, trifluoroacetic acid, trichloroacetic acid and tribromoacetic acid commonly used in the synthesis of secondary alcohols in the art, so it is easier to break through the steric hindrance of the Fischer-Tropsch olefin molecules, and ultimately more significantly improve the reaction rate and the conversion rate of the raw material olefins. Of course, another point that cannot be ignored is that formic acid is easier to recycle and has low cost, so that it can be recycled multiple times, reduce operation and reaction-related costs, and avoid the generation of a large amount of acidic wastewater. More importantly, compared to other types of acids, formic acid has a small steric hindrance and can better diffuse in the pores of resin catalysts, thereby exerting a good synergistic effect in the entire reaction, so as to further improve the reaction selectivity of the final secondary alcohol product.

[0026] In addition, the method is simple to operate, has mild conditions, produces few by-products, and is easy to industrialize and mass-produce. It opens up a new path for the efficient synthesis of secondary alcohol products and the high-value utilization of Fischer-Tropsch olefins, and has significant economic and environmental benefits.

[0027] Furthermore, in practical applications, the acid is evaporated by heating, cooled and recovered, and can continue to participate in the esterification reaction. After obtaining the secondary alcohol, the obtained crude secondary alcohol is also subjected to alkali washing and drying to obtain a pure secondary alcohol product.

[0028] In several typical embodiments, in order to better balance the reaction rate and product distribution, so as to prepare secondary alcohol products of different chain lengths with a higher conversion rate, the Fischer-Tropsch olefin raw material includes olefins and alkanes, and the total weight of the Fischer-Tropsch olefin raw material is 100%, and the olefin content is 30% to 100%, preferably 30% to 70%. It can also be seen from this that compared with the existing methods of synthesizing secondary alcohols based on olefin raw materials in the art, the above-mentioned preparation method provided by the present invention has lower restrictions on raw materials, and the requirements for its olefin content, that is, purity, are also lower, while reducing the amount of acidic wastewater generated. As for the defects such as many by-products, low conversion rate, and great separation difficulty caused by low olefin content, they can be well compensated by the above-mentioned control of the molar ratio of reactants in each reaction stage and the subsequent reaction conditions, so as to prepare secondary alcohol products with higher selectivity with a wider range of raw materials, thereby improving its product added value.

[0029] For the esterification reaction, the inventors have optimized the molar ratio of the Fischer-Tropsch olefin raw material to formic acid in step S1 through a large number of experiments to be 1: (0.8-1.2), and under this condition, the reaction efficiency of the esterification reaction is improved to obtain an intermediate ester with higher purity.

[0030] In the above-mentioned esterification reaction process, in order to more effectively balance the reaction efficiency of the esterification reaction and the selectivity of the esterification product, and also reduce energy consumption, the reaction temperature is preferably 30°C to 150°C, the reaction pressure is 0.3bar to 0.8bar, and the reaction time is 2h to 6h. On the basis of the above, for the special raw material of Fischer-Tropsch olefins, it is further preferred that the reaction temperature of the esterification reaction is 40°C to 80°C, the reaction pressure is 0.4bar to 0.5bar, and the reaction time is 3h to 4h. This more preferred reaction condition can be better adapted to Fischer-Tropsch olefin raw materials and formic acid raw materials, and can also better activate resin catalysts, thereby obtaining esterification products with higher yields and higher purity, and ultimately improving the conversion rate of Fischer-Tropsch olefin raw materials.

[0031] As for the hydrolysis reaction, in order to further improve the selectivity of the obtained secondary alcohol product, the molar ratio of the ester product to water in step S3 is preferably 1: (1.0-1.2), and the reaction conditions are preferably: the reaction temperature is 20°C-120°C, the reaction pressure is 0.1 bar-0.4 bar, and the reaction time is 2h-6h.

[0032] On the basis of the above-mentioned hydrolysis reaction conditions, it is further preferred that the reaction temperature is 30°C to 40°C, the reaction pressure is 0.2 bar to 0.3 bar, and the reaction time is 3h to 4h, so as to more effectively hydrolyze the ester product while also inhibiting its excessive hydrolysis, so as to improve the selectivity and purity of the secondary alcohol product.

[0033] Furthermore, in step S2, the resin catalyst is an acidic cation exchange resin, and the acidic cation exchange resin contains benzenesulfonic acid groups. Compared with solid heteropolyacid catalysts and acidic molecular sieve catalysts commonly used in esterification reactions and hydrolysis reactions in the art, this catalyst containing benzenesulfonic acid groups has a more suitable electronic structure, exhibits higher activity and stability in the above-mentioned esterification reaction system, and ultimately significantly improves the reaction rate. The inventors have found through a large number of experiments that when the acidic cation exchange resin is 15, it can not only improve the efficiency of the esterification reaction, but also is more suitable for the esterification reaction system formed by Fischer-Tropsch olefins and formic acid provided by the present invention, thereby improving the selectivity of the obtained ester products and the final secondary alcohol products. As for the amount of resin catalyst used, it is more preferred that the space velocity of the mixed product in the resin catalyst is 0.9h / min in order to more effectively suppress the side reactions and cost increase caused by excessive catalyst while improving the reaction efficiency. -1 ~1.0h -1 .

[0034] In several typical embodiments, in order to better adapt to the above-mentioned reaction route and the preferred reaction conditions, secondary alcohols that can better meet the needs of industrial applications are prepared with higher selectivity and conversion rate, and the preferred Fischer-Tropsch olefin raw material is a C5+ Fischer-Tropsch olefin raw material, and especially more preferably a C6-C14 Fischer-Tropsch olefin raw material.

[0035] And, preferably, the Fischer-Tropsch olefin raw material is a C6-C10 Fischer-Tropsch olefin raw material, and the C6-C10 Fischer-Tropsch olefin raw material includes, by weight, 4.5 to 5.0 parts of 1-hexene, 10 to 11 parts of 1-heptene, 18.5 to 20.0 parts of 1-octene, 14.5 to 16.0 parts of 1-nonene, 4.5 to 5.0 parts of 1-decene, 42.0 to 45.0 parts of C6 to C10. 0 parts of alkanes and 2.0 to 4.0 parts of non-hydrocarbon impurities; or, the Fischer-Tropsch olefin raw material is a C13-C14 Fischer-Tropsch olefin raw material, and the C13-C14 Fischer-Tropsch olefin raw material includes, by weight, 14.5 to 16.0 parts of 13-ene, 16.5 to 18.0 parts of 14-ene, 61.0 to 63.5 parts of C13-C14 alkanes and 5.0 to 6.0 parts of non-hydrocarbon impurities. The above-mentioned component ratios preferably obtained for C6 to C10 Fischer-Tropsch olefin raw materials and C13 to C14 Fischer-Tropsch olefin raw materials, respectively, can rely on the above-mentioned preparation method provided by the present invention to more accurately control the distribution of the products, thereby more significantly improving the selectivity of the obtained secondary alcohol product in the entire reaction process.

[0036] When the preferred Fischer-Tropsch olefin raw material is a C6-C10 Fischer-Tropsch olefin raw material, in several more typical embodiments, the molar ratio of the C6-C10 Fischer-Tropsch olefin raw material to formic acid is 1:(0.75-0.80), the conditions for the esterification reaction are: (40±2)°C, (0.4±0.02)bar, the molar ratio of the esterification product to water is 1:(0.9-1.0), and the conditions for the hydrolysis reaction are (40±2)°C, (0.2±0.02)bar. For the C6-C10 Fischer-Tropsch olefin raw material, the above-mentioned optimized reaction conditions can further improve the yield and selectivity of the secondary alcohol product, and also enable the olefin raw material to be converted into esters to a greater extent, thereby obtaining the secondary alcohol product.

[0037] Alternatively, when the preferred Fischer-Tropsch olefin raw material is a C13-C14 Fischer-Tropsch olefin raw material, in several more typical embodiments, and the molar ratio of the C13-C14 Fischer-Tropsch olefin raw material to formic acid is 1:(1.1-1.2), the conditions for the esterification reaction are: (80±5)°C, (0.4±0.02)bar, the molar ratio of the esterification product to water is 1:(1.1-1.2), and the conditions for the hydrolysis reaction are (40±2)°C, (0.2±0.02)bar. For the C13-C14 Fischer-Tropsch olefin raw material, similarly, the inventors have optimized the specific raw material molar ratio and experimental parameters involved in the esterification reaction and the hydrolysis reaction through a large number of experiments, and obtained a higher olefin conversion rate and secondary alcohol selectivity under the above range conditions.

[0038] The second aspect of the present invention provides a C5+ secondary alcohol, which is prepared by the above-mentioned method for preparing secondary alcohol using Fischer-Tropsch olefins. The C5+ secondary alcohol prepared by the method provided by the present invention has high purity and is suitable for a variety of industrial applications. It shows high selectivity during the reaction process, and also has a higher product added value because the raw material is Fischer-Tropsch olefins, and has significant application value.

[0039] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0040] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0041] Tables 1-1 to 1-6 list the specific component contents of each Fischer-Tropsch olefin raw material used in the present invention.

[0042] Table 1-1

[0043]

[0044] Table 1-2

[0045]

[0046] Table 1-3

[0047]

[0048] Table 1-4

[0049]

[0050] Table 1-5

[0051]

[0052] Table 1-6

[0053]

[0054] Example 1

[0055] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0056] C13~C14 Fischer-Tropsch olefin raw material is used as the Fischer-Tropsch olefin raw material to be reacted, and its composition is shown in Table 1-1.

[0057] Formic acid and C13-C14 Fischer-Tropsch olefin raw materials were mixed in a molar ratio of raw material: formic acid = 1:1.2, and the acidic cation exchange resin Amberlyst15 was used as a catalyst. The above-mentioned mixed product was introduced into the mixture for reaction at a space velocity of 0.95h -1 The esterification reaction occurred at 80°C and 0.4 bar for 4 h to obtain ester products.

[0058] Water and the obtained ester product were mixed in a molar ratio of ester: water = 1:1.2, and a hydrolysis reaction was carried out at 40°C and 0.2 bar for 4 hours to obtain C13-C14 secondary alcohol products.

[0059] Example 2

[0060] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0061] The only difference between this embodiment and embodiment 1 is that the molar ratio of C13-C14 Fischer-Tropsch olefin raw material to formic acid is changed to 1:1.05.

[0062] Example 3

[0063] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0064] The only difference between this embodiment and embodiment 1 is that the molar ratio of C13-C14 Fischer-Tropsch olefin raw material to formic acid is changed to 1:0.8.

[0065] Example 4

[0066] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0067] The only difference between this embodiment and embodiment 1 is that the molar ratio of the ester product to water is changed to 1:1.0.

[0068] Example 5

[0069] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0070] The only difference between this embodiment and embodiment 1 is that the conditions of the esterification reaction are changed to 60° C. and 0.05 bar; and the conditions of the hydrolysis reaction are changed to 20° C. and 0.4 bar.

[0071] Example 6

[0072] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0073] The only difference between this embodiment and embodiment 1 is that the conditions of the esterification reaction are changed to 100° C. and 0.5 bar; and the conditions of the hydrolysis reaction are changed to 50° C. and 0.1 bar.

[0074] Example 7

[0075] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0076] C6-C10 Fischer-Tropsch olefin raw materials are used as the Fischer-Tropsch olefin raw materials to be reacted, and their components are shown in Table 1-2.

[0077] Formic acid and C6-C10 Fischer-Tropsch olefin raw materials were mixed in a molar ratio of raw material: formic acid = 1:0.8, and the acidic cation exchange resin Amberlyst15 was used as a catalyst. The above-mentioned mixed product was introduced into the mixture for reaction at a space velocity of 1h -1 The esterification reaction occurred at 40°C and 0.4 bar for 4 h to obtain ester products.

[0078] Water and the obtained ester product were mixed in a molar ratio of ester: water = 1: 1.0, and a hydrolysis reaction was carried out at 40°C and 0.2 bar for 4 hours to obtain a C6-C10 secondary alcohol product.

[0079] Example 8

[0080] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0081] C6-C10 Fischer-Tropsch olefin raw materials are used as the Fischer-Tropsch olefin raw materials to be reacted, and their components are shown in Table 1-2.

[0082] Formic acid and C6-C10 Fischer-Tropsch olefin raw materials were mixed in a molar ratio of raw material: formic acid = 1:0.5, and the acidic cation exchange resin Amberlyst15 was used as a catalyst. The above mixed product was introduced into the mixture for reaction at a space velocity of 1h -1 The esterification reaction occurred at 20°C and 0.5 bar for 4 h to obtain ester products.

[0083] Water and the obtained ester product were mixed in a molar ratio of ester: water = 1:1.5, and a hydrolysis reaction was carried out at 30°C and 0.1 bar for 4 hours to obtain a C6-C10 secondary alcohol product.

[0084] Example 9

[0085] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0086] C5 Fischer-Tropsch olefin raw material is used as the Fischer-Tropsch olefin raw material to be reacted, and its composition is shown in Table 1-3.

[0087] Formic acid and C5 Fischer-Tropsch olefin raw material were mixed in a molar ratio of raw material: formic acid = 1:0.8, and the acidic cation exchange resin Amberlyst15 was used as a catalyst. The above mixed product was introduced into the mixture for reaction at a space velocity of 1h -1 The esterification reaction occurred at 20°C and 0.4 bar for 4 h to obtain ester products.

[0088] Water and the obtained ester product were mixed in a molar ratio of ester: water = 1: 1.0, and a hydrolysis reaction was carried out at 40°C and 0.2 bar for 4 hours to obtain a C5 secondary alcohol product.

[0089] Example 10

[0090] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0091] The only difference between this embodiment and embodiment 9 is that the molar ratio of C5 Fischer-Tropsch olefin raw material to formic acid is changed to 1:1.05, and the conditions of the esterification reaction are changed to 60°C and 0.4 bar.

[0092] Embodiment 11

[0093] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0094] C6 Fischer-Tropsch olefin raw material is used as the Fischer-Tropsch olefin raw material to be reacted, and its composition is shown in Table 1-4.

[0095] Formic acid and C6 Fischer-Tropsch olefin raw material were mixed in a molar ratio of raw material: formic acid = 1:0.8, and the acidic cation exchange resin Amberlyst15 was used as a catalyst. The above mixed product was introduced into the mixture for reaction at a space velocity of 1h -1 The esterification reaction occurred at 40°C and 0.4 bar for 4 h to obtain ester products.

[0096] Water and the obtained ester product were mixed in a molar ratio of ester: water = 1: 1.0, and a hydrolysis reaction was carried out at 40°C and 0.2 bar for 4 hours to obtain a C6 secondary alcohol product.

[0097] Example 12

[0098] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0099] The only difference between this embodiment and embodiment 11 is that the molar ratio of C6 Fischer-Tropsch olefin raw material to formic acid is changed to 1:1.2, and the conditions of the esterification reaction are changed to 80°C and 0.4 bar.

[0100] Embodiment 13

[0101] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0102] C7 Fischer-Tropsch olefin raw material is used as the Fischer-Tropsch olefin raw material to be reacted, and its composition is shown in Table 1-5.

[0103] Formic acid and C7 Fischer-Tropsch olefin raw material were mixed in a molar ratio of raw material: formic acid = 1:1.2, and the acidic cation exchange resin Amberlyst15 was used as a catalyst. The above mixed product was introduced into the mixture for reaction at a space velocity of 1h -1 The esterification reaction occurred at 80°C and 0.4 bar for 4 h to obtain ester products.

[0104] Water and the obtained ester product were mixed in a molar ratio of ester: water = 1:1.2, and a hydrolysis reaction was carried out at 40°C and 0.2 bar for 4 hours to obtain a C7 secondary alcohol product.

[0105] Embodiment 14

[0106] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0107] C9 Fischer-Tropsch olefin raw material is used as the Fischer-Tropsch olefin raw material to be reacted, and its composition is shown in Table 1-6.

[0108] Formic acid and C9 Fischer-Tropsch olefin raw material were mixed in a molar ratio of raw material: formic acid = 1:0.8, and the acidic cation exchange resin Amberlyst15 was used as a catalyst. The above mixed product was introduced into the mixture for reaction at a space velocity of 1h -1 The esterification reaction occurred at 40°C and 0.4 bar for 4 h to obtain ester products.

[0109] Water and the obtained ester product were mixed in a molar ratio of ester: water = 1: 1.0, and a hydrolysis reaction was carried out at 40°C and 0.2 bar for 4 hours to obtain a C9 secondary alcohol product.

[0110] Embodiment 15

[0111] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0112] The only difference between this embodiment and embodiment 14 is that the molar ratio of C9 Fischer-Tropsch olefin raw material to formic acid is changed to 1:1.05, and the conditions of the esterification reaction are changed to 60°C and 0.4 bar.

[0113] Example 16

[0114] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0115] The only difference between this embodiment and embodiment 14 is that the molar ratio of the ester product to water is changed to 1:1.0.

[0116] Embodiment 17

[0117] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0118] The only difference between this embodiment and embodiment 14 is that the molar ratio of C9 Fischer-Tropsch olefin raw material to formic acid is changed to 1:1.2, and the conditions of the esterification reaction are changed to 80°C and 0.4 bar.

[0119] Comparative Example 1

[0120] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0121] The only difference between this comparative example and Example 1 is that the molar ratio of the C13-C14 Fischer-Tropsch olefin raw material to formic acid is changed to 1:0.4; and the molar ratio of the ester product to water is changed to 1:0.5.

[0122] Comparative Example 2

[0123] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0124] The only difference between this comparative example and Example 1 is that the molar ratio of the C13-C14 Fischer-Tropsch olefin raw material to formic acid is changed to 1:6.0; and the molar ratio of the ester product to water is changed to 1:6.0.

[0125] Comparative Example 3

[0126] A method for preparing secondary alcohols using Fischer-Tropsch olefins:

[0127] The only difference between this comparative example and Example 1 is that an equal amount of acidic molecular sieve ZSM-35 is used as a catalyst instead of the acidic cation exchange resin Amberlyst 15 in Example 1.

[0128] The products obtained from each embodiment and comparative example were sampled and analyzed by gas chromatography, and the conversion rate of Fischer-Tropsch olefins and the selectivity of secondary alcohol products corresponding to each embodiment and comparative example were obtained, as shown in Table 2.

[0129] Table 2

[0130]

[0131]

[0132] From the above description, it can be seen that the above embodiments of the present invention achieve the preparation of secondary alcohol products using Fischer-Tropsch synthesis olefins as raw materials.

[0133] In particular, by comparing Examples 1 to 6 with Comparative Examples 1 to 3, it can be seen that selecting a resin compound as a catalyst and strictly controlling the molar ratio of the olefin raw material and formic acid, as well as the molar ratio of the esterification product and water, can ensure high olefin conversion and high secondary alcohol selectivity. By comparing Example 1 with Examples 2 to 6, it can be explained that the molar ratio of the raw materials and the specific experimental conditions in the esterification reaction and the hydrolysis reaction are respectively optimized to be: the molar ratio of the C13-C14 Fischer-Tropsch olefin raw material and formic acid is 1: (1.1-1.2), the conditions of the esterification reaction are: (80±5)°C, (0.4±0.02) bar, the molar ratio of the esterification product and water is 1: (1.1-1.2), and the conditions of the hydrolysis reaction are (40±2)°C, (0.2±0.02) bar (ie, Example 1), which can further improve the olefin conversion and secondary alcohol selectivity.

[0134] Correspondingly, by comparing Examples 7 and 8, it is also shown that for C6-C10 Fischer-Tropsch olefin raw materials, when the preferred reaction conditions are: the molar ratio of C6-C10 Fischer-Tropsch olefin raw materials to formic acid is 1:(0.75-0.80), the conditions for the esterification reaction are: (40±2)°C, (0.4±0.02) bar, the molar ratio of the esterification product to water is 1:(0.9-1.0), and the conditions for the hydrolysis reaction are (40±2)°C, (0.2±0.02) bar, the conversion rate of C6-C10 Fischer-Tropsch olefin raw materials is higher, and C6-C10 secondary alcohol products can be obtained with higher selectivity.

[0135] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0136] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing secondary alcohols using Fischer-Tropsch olefins, characterized in that: The method comprises: Step S1, mixing a Fischer-Tropsch olefin raw material and formic acid at a molar ratio of 1: (0.5-5.0) to obtain a mixed product; Step S2, introducing the mixed product into a resin catalyst to carry out an esterification reaction to obtain an ester product; Step S3, mixing the ester product with water at a molar ratio of 1: (1.0-5.0), and obtaining the secondary alcohol after hydrolysis reaction.

2. The method for preparing secondary alcohols using Fischer-Tropsch olefins according to claim 1, characterized in that: The Fischer-Tropsch olefin feedstock includes olefins and alkanes, and based on the total weight of the Fischer-Tropsch olefin feedstock being 100%, the content of the olefins is 30% to 100%.

3. The method for preparing secondary alcohols using Fischer-Tropsch olefins according to claim 1 or 2, characterized in that: In step S1, the molar ratio of the Fischer-Tropsch olefin raw material to the formic acid is 1:(0.8-1.2).

4. The method for preparing secondary alcohols using Fischer-Tropsch olefins according to any one of claims 1 to 3, characterized in that: In step S1, the reaction temperature of the esterification reaction is 30°C to 150°C, the reaction pressure is 0.3 bar to 0.8 bar, and the reaction time is 2h to 6h; Preferably, the reaction temperature of the esterification reaction is 40° C. to 80° C., the reaction pressure is 0.4 bar to 0.5 bar, and the reaction time is 3 h to 4 h.

5. The method for preparing secondary alcohols using Fischer-Tropsch olefins according to any one of claims 1 to 4, characterized in that: In step S3, the molar ratio of the ester product to the water is 1:(1.0-1.2).

6. The method for preparing secondary alcohols using Fischer-Tropsch olefins according to any one of claims 1 to 5, characterized in that: In step S3, the reaction temperature of the hydrolysis reaction is 20°C to 120°C, the reaction pressure is 0.1 bar to 0.4 bar, and the reaction time is 2h to 6h; Preferably, the reaction temperature of the hydrolysis reaction is 30° C. to 40° C., the reaction pressure is 0.2 bar to 0.3 bar, and the reaction time is 3 h to 4 h.

7. The method for preparing secondary alcohols using Fischer-Tropsch olefins according to any one of claims 1 to 6, characterized in that: In step S2, the resin catalyst is an acidic cation exchange resin, and the acidic cation exchange resin contains a benzenesulfonic acid group; Preferably, the acidic cation exchange resin is 15; More preferably, the space velocity of the mixed product in the resin catalyst is 0.9h -1 ~1.0h -1 .

8. The method for preparing secondary alcohols by using Fischer-Tropsch olefins according to any one of claims 1 to 7, characterized in that: The Fischer-Tropsch olefin raw material is a C5+ Fischer-Tropsch olefin raw material, preferably a C6-C14 Fischer-Tropsch olefin raw material; More preferably, the Fischer-Tropsch olefin raw material is a C6-C10 Fischer-Tropsch olefin raw material, and the C6-C10 Fischer-Tropsch olefin raw material includes, by weight, 4.5 to 5.0 parts of 1-hexene, 10 to 11 parts of 1-heptene, 18.5 to 20.0 parts of 1-octene, 14.5 to 16.0 parts of 1-nonene, 4.5 to 5.0 parts of 1-decene, 42.0 to 45.0 parts of C6 to C10 alkanes, and 2.0 to 4.0 parts of non-hydrocarbon impurities; Or, the Fischer-Tropsch olefin raw material is a C13-C14 Fischer-Tropsch olefin raw material, and in parts by weight, the C13-C14 Fischer-Tropsch olefin raw material includes 14.5 to 16.0 parts of 13-ene, 16.5 to 18.0 parts of 14-ene, 61.0 to 63.5 parts of C13-C14 alkanes and 5.0 to 6.0 parts of non-hydrocarbon impurities.

9. The method for preparing secondary alcohols using Fischer-Tropsch olefins according to claim 8, characterized in that: The Fischer-Tropsch olefin raw material is the C6-C10 Fischer-Tropsch olefin raw material, and the molar ratio of the C6-C10 Fischer-Tropsch olefin raw material to the formic acid is 1:(0.75-0.80), the conditions of the esterification reaction are: (40±2)°C, (0.4±0.02)bar, the molar ratio of the esterification product to the water is 1:(0.9-1.0), and the conditions of the hydrolysis reaction are (40±2)°C, (0.2±0.02)bar; or, The Fischer-Tropsch olefin raw material is the C13-C14 Fischer-Tropsch olefin raw material, and the molar ratio of the C13-C14 Fischer-Tropsch olefin raw material to the formic acid is 1:(1.1-1.2), the conditions of the esterification reaction are: (80±5)°C, (0.4±0.02)bar, the molar ratio of the esterification product to the water is 1:(1.1-1.2), and the conditions of the hydrolysis reaction are (40±2)°C, (0.2±0.02)bar.

10. A C5+ secondary alcohol, characterized in that The C5+ secondary alcohol is prepared by the method for preparing secondary alcohol using Fischer-Tropsch olefins as described in any one of claims 1 to 9.

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