A method for preparing a bio-based isomeric cetyl

Abstract

The application provides a preparation method of bio-based isomeric hexadecane, and belongs to the technical field of organic chemical industry.The preparation method comprises the following steps: first-order rectification: taking bio-based aviation kerosene with an isomeric alkane content of greater than or equal to 70% as raw material, feeding the bio-based aviation kerosene into a first-order rectification tower, and performing first-order rectification to obtain a first product; second-order rectification: feeding the first product into a second-order rectification tower, and performing second-order rectification to obtain a second product; isomerization catalysis: adding the second product into an isomerization reactor to perform isomerization reaction, and obtaining a third product; and composite adsorption deodorization: adding the third product into an adsorption column with a precision of 50-100 nm to perform adsorption deodorization, so that bio-based isomeric hexadecane is prepared.The preparation method has the advantages of simple and efficient production process, simple operation, energy saving, and the like, can obtain high-quality bio-based isomeric hexadecane meeting the cosmetic indexes, and is applied to the field of cosmetic manufacturing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic chemical industry, and particularly relates to a preparation method of bio-based isohexadecane. BACKGROUND

[0002] Compared with conventional hexadecane, isohexadecane has a more complex molecular structure with multiple different branched structures. Isohexadecane is a highly branched alkane, which is a colorless, odorless and transparent liquid, has high stability and low toxicity, and is widely used in the fields of chemical industry and daily chemical industry, and is often used in high-performance engine oil, industrial lubricating oil and cosmetics. Isohexadecane is mainly used as a solvent and a diluent in cosmetics, which can help to improve the application feeling, absorbency and durability of the cosmetics, and is also widely used in skin care products, perfumes and other products to improve the use feeling and stability.

[0003] The traditional preparation method of isohexadecane mainly includes two ways of petroleum cracking and synthesis. The petroleum cracking method is to decompose long-chain alkanes in petroleum into short-chain alkanes through high temperature and catalyst, and then to obtain petroleum-based isohexadecane through hydrogenation and isomerization. The synthesis method can accurately control the proportion of isomers, so as to produce isohexadecane with higher purity and better performance. However, the traditional preparation method usually uses catalysts with high pressure and high temperature, which has high energy consumption and harsh conditions. In addition, the petroleum cracking method produces petroleum-based isohexadecane, which greatly limits the application field of isohexadecane. Therefore, it is necessary to provide a preparation method of high-quality isohexadecane with simple and efficient production process, simple operation and energy saving. SUMMARY

[0004] The application proposes a preparation method of high-quality isohexadecane with simple and efficient production process, simple operation and energy saving, in order to solve the technical problems of the traditional preparation method of isohexadecane, which needs to crack or synthesize petroleum and rely on catalysts with high temperature and high pressure, and has complicated process, complex operation and high energy consumption. The bio-based isohexadecane prepared by the method meets the cosmetic index and can be applied to the manufacture of cosmetics.

[0005] In order to achieve the above purpose, the technical scheme adopted by the application is as follows: a preparation method of bio-based isohexadecane, comprising the following steps:

[0006] First-order rectification: taking bio-based isohexadecane with an isohexadecane content of greater than or equal to 70% as raw material, feeding the bio-based isohexadecane raw material into a first-order rectification tower, and performing first-order rectification to obtain a first product;

[0007] Second-order rectification: feeding the first product into a second-order rectification tower, and performing second-order rectification to obtain a second product;

[0008] Isomerization catalysis: the second product is added into an isomerization reactor for isomerization reaction to obtain a third product;

[0009] Composite adsorption deodorization: the third product is added into an adsorption column with a precision of 50-100 nm for adsorption deodorization to obtain a bio-based isohexadecane.

[0010] In the technical scheme, the biomass aviation kerosene is used as the raw material, the specific aromatic hydrocarbon residues in the raw material are cut by rectification, the primary separation and impurity rough screening are completed by first-order rectification, the deep purification and narrow fraction cutting are completed by second-order rectification, and the molecular structure directional reconstruction is completed by isomerization, so that the defects that the molecular configuration cannot be changed by traditional rectification are solved; the composite adsorption deodorization step is performed after the isomerization catalysis reaction, so that the odor molecules newly generated in the high-temperature reaction of the isomerization reaction can be captured and the impurities can be removed.

[0011] It can be understood that the precision of the adsorption column can be adjusted by the person skilled in the art within the above range according to the actual situation, for example, the precision of the adsorption column can also be 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm or any point value in the above range.

[0012] In one embodiment, in the first-order rectification step, the design pressure of the first-order rectification column is-0.1-0.6 MPa, the operating pressure is 0.001 MPa, the design temperature is 300 DEG C, and the operating temperature is 80-150 DEG C.

[0013] In the technical scheme, the water, light components such as ethanol and heavy components such as heavy metals and aromatic hydrocarbons in the biomass aviation kerosene are removed by first-order rectification to obtain the first product after rough cutting, wherein the first-order rectification is a primary separation and impurity rough screening step, the dehydration rate is greater than 99%, and the subsequent catalyst poisoning caused by water can be avoided; the light component impurities with a boiling point of less than 100 DEG C under negative pressure conditions are removed to reduce odor precursors; and the heavy components with a boiling point of greater than 150 DEG C under negative pressure conditions are intercepted to protect the downstream reaction catalyst.

[0014] It can be understood that the operating temperature of the first-order rectification can be adjusted by the person skilled in the art within the above range according to the actual situation, for example, the operating temperature can also be 80 DEG C, 85 DEG C, 90 DEG C, 95 DEG C, 100 DEG C, 105 DEG C, 110 DEG C, 115 DEG C, 120 DEG C, 125 DEG C, 130 DEG C, 135 DEG C, 140 DEG C, 145 DEG C, 150 DEG C or any point value in the above range.

[0015] In one embodiment, in the second-order rectification step, the design pressure of the second-order rectification column is-0.1-0.6 MPa, the operating pressure is 0.001 MPa, the design temperature is 300 DEG C, and the operating temperature is 100-180 DEG C.

[0016] In the technical solution, C16 alkanes are enriched in a fraction under the conditions of 100-180 DEG C and negative pressure through second-order rectification, isomers are accurately separated, and aromatics, nitrogen, oxygen and sulfur compounds, and olefins are removed to obtain a second product.

[0017] It can be understood that the operation temperature of the second-order rectification can be adjusted by the person skilled in the art within the above range according to the actual situation, for example, the operation temperature can also be 100 DEG C, 105 DEG C, 110 DEG C, 115 DEG C, 120 DEG C, 125 DEG C, 130 DEG C, 135 DEG C, 140 DEG C, 145 DEG C, 150 DEG C, 155 DEG C, 160 DEG C, 165 DEG C, 170 DEG C, 175 DEG C, 180 DEG C or any point value within the above range.

[0018] In one embodiment, in the isomerization catalysis step, the reaction temperature is 300-380 DEG C, the operation pressure is 2-4 MPa, the volume ratio of hydrogen to raw material is 300-800:1, the liquid hourly space velocity is 0.5-2 h -1 , and the reaction time is 4 h.

[0019] In the technical solution, through isomerization reaction, n-hexadecane is converted from straight chain to branched chain structure of isohexadecane through skeletal isomerization, the isomerization selectivity is greater than or equal to 85 %, the branching rate is greater than or equal to 80 %, and single-methyl branched chain isomers are generated; the low-temperature flowability is improved, and the freezing point is reduced from 18 DEG C of straight chain to-40 DEG C of branched chain; the cracking side reaction can also be inhibited, the cracking rate is controlled to be less than 1 %, and the generation of short-chain alkanes is avoided to affect the purity.

[0020] In one embodiment, in the isomerization catalysis step, the catalyst for the isomerization reaction is a SAPO-11 molecular sieve loaded Pd catalyst.

[0021] In one embodiment, in the composite adsorption odor removal step, a composite adsorbent is filled in the adsorption column, and the composite adsorbent includes molecular sieves, activated carbon and aluminum oxide, and the mass ratio of the molecular sieves, the activated carbon and the aluminum oxide is 1:1:1.

[0022] In the technical solution, trace impurities are targetedly removed through composite adsorption odor removal, and the odor grade is reduced from level 3 that can be perceived to level 0 that has no odor, wherein the molecular sieve layer removes residual moisture, so that the moisture content is less than 100 ppm, and removes methanol, hydrogen sulfide and other nitrogen, oxygen and sulfur compounds; the activated carbon layer removes heavy metals, pigments and mercaptans; and the aluminum oxide layer captures mercaptans, acetic acid and other polar odor molecules.

[0023] In one embodiment, the molecular sieve is 10X molecular sieve.

[0024] Compared with the prior art, the application has the advantages and positive effects that:

[0025] The preparation method of the application takes biomass aviation coal as raw material, and through first-order rectification, second-order rectification, isomerization catalysis and composite adsorption deodorization steps, a continuous and efficient process with low energy consumption and low cost is realized, and bio-based isohexadecane meeting the cosmetic index is prepared. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0027] The application provides a preparation method of bio-based isohexadecane, which takes biomass aviation coal as raw material, and through first-order rectification, second-order rectification, isomerization catalysis and composite adsorption deodorization steps, a continuous and efficient process with low energy consumption and low cost is realized, and bio-based isohexadecane meeting the cosmetic index is prepared. The application efficiently removes organic impurities, moisture and heavy metals through first-order rectification and second-order rectification, and the obtained primary product is catalyzed by an isomerization catalyst and deodorized by a composite adsorbent, so as to realize continuous and efficient production of bio-based isohexadecane. The first-order rectification provides dehydrated and heavy metal-removed feed for the second-order rectification; the second-order rectification obtains narrow fraction C16 enrichment, and ensures that the isomerization catalyst only acts on target molecules; the isomerization catalysis inputs high-purity straight-chain alkanes to generate branched structures, and solves the problem of low-temperature applicability of cosmetics; and through composite adsorption, low-sulfur and low-oxygen intermediates are adsorbed, and the adsorbent can be reused and activated for subsequent reactions.

[0028] The preparation method of bio-based isohexadecane includes the following steps:

[0029] First-order rectification: the biomass aviation kerosene with an isoparaffin content of ≥70% is fed into a first-order rectification tower to remove water, heavy metals, free fatty acids, and acetic acid to obtain a first product after rough cutting; wherein the tower diameter of the first-order rectification tower is DN20, the tower height is 1.2 m, the material is S316, the design pressure is -0.1~0.6 MPa, the operating pressure is 0.001 MPa, the design temperature is 300 ℃, the operating temperature is 80~150 ℃, and the filler specification is 3×3 mm θ ring;

[0030] Second-order rectification: the first product after the first-order rectification treatment is fed into a second-order rectification tower to remove aromatic hydrocarbons, nitrogen, oxygen, and sulfur compounds, and olefins to obtain a second product; wherein the tower diameter of the second-order rectification tower is DN20, the tower height is 1.2 m, the material is S316, the design pressure is -0.1~0.6 MPa, the operating pressure is 0.001 MPa, the design temperature is 300 ℃, the operating temperature is 100~180 ℃, and the filler specification is 3×3 mm θ ring;

[0031] Isomerization catalysis: the second product after the second-order rectification treatment is added into an isomerization reactor for isomerization reaction to obtain a third product; wherein the catalyst for the isomerization reaction is a SAPO-11 molecular sieve loaded Pd catalyst, the reaction temperature is 300~380 ℃, and the operating pressure is 2~4 MPa; the isomerization reaction is carried out in a hydrogen atmosphere, and a continuous hydrogen environment can prevent the oxidation or sintering aggregation of metal components, thereby maintaining their high dispersity and activity; the volume ratio of hydrogen to the second product is 300~800:1, the liquid hourly space velocity is 0.5~2 h -1 , the reaction time is 4 h, n-hexadecane is converted into isohexadecane through skeletal isomerization, the isomerization selectivity is ≥85%, and the isohexadecane content in the third product is ≥80%;

[0032] Composite adsorption odor removal: the third product after the isomerization catalysis treatment is added into an adsorption column for adsorption odor removal to prepare a bio-based isohexadecane; wherein the adsorption column specification is 5 inches, the material is PP, and the precision is 50~100 nm; the adsorption column is filled with a composite adsorbent, the composite adsorbent includes molecular sieves, activated carbon, and alumina, and the molecular sieves, activated carbon, and alumina are mixed and filled in a mass ratio of 1:1:1; preferably, the molecular sieves are 10X molecular sieves, the purity of the bio-based isohexadecane in the obtained product is ≥98%, the colority is +30, the kinematic viscosity is 3~7 mm 2 / s, and the refractive index is 1.4~1.5 nD.

[0033] In the preparation method of the bio-based isomeric hexadecane, biomass aviation kerosene is used as a raw material, organic impurities, water, and heavy metals are efficiently removed through first-order rectification and second-order rectification, the obtained primary product is subjected to isomerization catalysis and odor removal by a composite adsorbent, the above specific step sequence provides pure reaction substrates for subsequent steps, and the subsequent steps repair defects in the previous steps, such as isomerization, which cannot be solved by rectification, to solve the problem of freezing point, so that the bio-based isomeric hexadecane can be continuously and efficiently produced, meet the cosmetic index, and be applied to the manufacture of cosmetics. In the present application, if the isomerization catalytic reaction is performed first and then the rectification treatment is performed, the product yield is greatly reduced, because the boiling points of branched alkanes are close, the rectification separation efficiency is reduced, and the isomerization cracking is intensified at high temperature; if the composite adsorption odor removal is performed first and then the isomerization catalytic reaction is performed, new odor molecules will be generated due to the high isomerization reaction temperature, which will cause odor again, and the adsorbent will be ineffective; if the first-order rectification is omitted, water and metal ions will poison and deactivate the catalyst, and the service life of the catalyst will be greatly shortened; if the second-order rectification range is too wide, C18 unsaturated alkanes will be mixed into the product, and the double impurities will not be removed, and the iodine value will exceed the standard.

[0034] In order to more clearly and detailedly introduce the preparation method of the bio-based isomeric hexadecane provided by the embodiments of the present application, the following will be described in combination with specific embodiments.

[0035] Embodiment 1

[0036] Raw material: biomass aviation kerosene, isomeric alkane content ≥ 70 %;

[0037] The preparation method of the bio-based isomeric hexadecane of the present embodiment specifically comprises the following steps:

[0038] 5 Kg of biomass aviation kerosene is fed at 0.1 Kg / h, the raw material enters the first-order rectification tower, the bottom heating temperature is set to 83 ℃, and the tower internal pressure is set to 0.001 MPa, to obtain the first product after rough cutting;

[0039] The first product after rough cutting in the first-order rectification tower is fed to the second-order rectification tower with a reflux ratio of 5:1 for continuous rectification, the bottom heating temperature is set to 116 ℃, and the tower internal pressure is set to 0.001 MPa, to complete dehydration and removal of organic impurities, and obtain the second product;

[0040] The second product is fed to the isomerization reactor for isomerization reaction, the catalyst for isomerization reaction is SAPO-11 molecular sieve loaded with Pd catalyst, the reaction temperature is set to 320 ℃, the operating pressure is set to 2 MPa, the volume ratio of hydrogen to raw material is 500:1, the liquid hourly space velocity is 1 h -1 , the reaction time is 4 h, and the third product is obtained;

[0041] The third product is passed through an adsorption column filled with 10X molecular sieve, activated carbon and aluminum oxide with a mass ratio of 1:1:1 at normal temperature and pressure, and an adsorption accuracy of 52 nm, to effectively remove most of the odor and nitrogen, oxygen and sulfur compounds, to obtain an odor-free target product which can be directly applied to the preparation process of daily chemical products such as fragrances and spices.

[0042] The obtained target product is analyzed and detected, and the moisture content is 18.21 ppm, the purity is 98.84%, the color is +30, the kinematic viscosity is 5.706 mm 2 / s, and the refractive index is 1.4330 nD.

[0043] Example 2

[0044] Raw material: biomass aviation fuel, isomerized alkane content ≥70%;

[0045] The preparation method of the bio-based isomerized hexadecane of the embodiment specifically includes the following steps:

[0046] 5 Kg of biomass aviation fuel is fed at a rate of 0.1 Kg / h, the raw material enters a first rectifying column, the bottom heating temperature is set to 150 ℃, and the internal pressure is set to 0.001 MPa, to obtain a first product after rough cutting;

[0047] The first product after rough cutting in the first rectifying column is fed to a second rectifying column with a reflux ratio of 5:1 for continuous rectification, the bottom heating temperature is set to 180 ℃, and the internal pressure is set to 0.001 MPa, to complete dehydration and removal of organic impurities, and obtain a second product;

[0048] The second product is fed to an isomerization reactor for isomerization reaction, the catalyst for isomerization reaction is a SAPO-11 molecular sieve loaded with Pd catalyst, the reaction temperature is set to 380 ℃, the operating pressure is set to 4 MPa, the volume ratio of hydrogen to raw material is 500:1, the liquid hourly space velocity is 1 h -1 , and the reaction time is 4 h, to obtain a third product;

[0049] The third product is passed through an adsorption column filled with 10X molecular sieve, activated carbon and aluminum oxide with a mass ratio of 1:1:1 at normal temperature and pressure, and an adsorption accuracy of 100 nm, to effectively remove most of the odor and nitrogen, oxygen and sulfur compounds, to obtain an odor-free target product which can be directly applied to the preparation process of daily chemical products such as fragrances and spices;

[0050] The obtained target product is analyzed and detected, and the moisture content is 34.08 ppm, the purity is 98.45%, the color is +30, the kinematic viscosity is 5.708 mm 2 / s, and the refractive index is 1.4330 nD.

[0051] Example 3

[0052] Raw material: biomass aviation fuel, isomeric alkane content ≥ 70 %;

[0053] The preparation method of the biomass-based isohexadecane of the present example specifically comprises the following steps:

[0054] 5 Kg of biomass aviation fuel was fed at 0.1 Kg / h, the raw material entered the first-stage rectifying tower, the bottom heating temperature was set to 83 ℃, and the tower internal pressure was set to 0.001 MPa, to obtain the first product after rough cutting;

[0055] The first product after rough cutting in the first-stage rectifying tower was fed to the second-stage rectifying tower with a reflux ratio of 5:1 for continuous rectification, the bottom heating temperature was set to 116 ℃, and the tower internal pressure was set to 0.001 MPa, to complete dehydration and removal of organic impurities, and obtain the second product;

[0056] The second product was fed to an isomerization reactor for isomerization reaction, the catalyst for the isomerization reaction was a SAPO-11 molecular sieve loaded Pd catalyst, the reaction temperature was set to 320 ℃, the operating pressure was set to 2 MPa, the volume ratio of hydrogen to raw material was 500:1, the liquid hourly space velocity was 1 h -1 , the reaction time was 4 h, and the third product was obtained;

[0057] The third product was passed through an adsorption column filled with 10X molecular sieve, activated carbon and alumina at a mass ratio of 1:1:1 under normal temperature and pressure conditions, the adsorption accuracy was 50 nm, most of the odor and nitrogen and oxygen and sulfur compounds were removed efficiently, and the target product was obtained, which could be directly applied to the preparation process of daily chemical products such as fragrances and spices;

[0058] The target product was analyzed and detected, the moisture content was 18.21 ppm, the purity was 98.84 %, the colority was +30, the kinematic viscosity was 5.706 mm 2 / s, and the refractive index was 1.4330 nD.

[0059] Comparative Example 1

[0060] Raw material: biomass aviation fuel, isomeric alkane content ≥ 70 %;

[0061] The preparation method of the biomass-based isohexadecane of the present example specifically comprises the following steps:

[0062] 5 Kg of biomass aviation fuel was fed at 0.1 Kg / h, the raw material entered the first-stage rectifying tower, the bottom heating temperature was set to 83 ℃, and the tower internal pressure was set to 0.001 MPa, to obtain the first product after rough cutting;

[0063] The first product after crude cutting by the rectifying tower is fed into an isomerization reactor for isomerization reaction, the catalyst for the isomerization reaction is a SAPO-11 molecular sieve loaded Pd catalyst, the reaction temperature is set to 320 DEG C, the operating pressure is 2 MPa, the volume ratio of hydrogen to raw material is 500:1, the liquid hourly space velocity is 1 h -1 , the reaction time is 4 h, and a second product is obtained;

[0064] The second product is subjected to an adsorption column filled with 10X molecular sieves, activated carbon and alumina at a mass ratio of 1:1:1 under normal temperature and pressure, and an adsorption accuracy of 50 nm, so that most of the odor and nitrogen, oxygen and sulfur compounds are removed efficiently, and a target product is obtained;

[0065] The target product is analyzed and detected, and the moisture content is 73.2 ppm, the purity is 60.20 %, the color is +30, the kinematic viscosity is 5.706 mm 2 / s, and the refractive index is 1.4330 nD.

[0066] Comparative Example 2

[0067] Raw material: biomass aviation coal, isomerized alkane content ≥70 %;

[0068] The preparation method of the biomass-based isohexadecane in the present comparative example specifically includes the following steps:

[0069] 5 Kg of biomass aviation coal is fed at 0.1 Kg / h, the raw material enters the rectifying tower, the bottom heating temperature is set to 116 DEG C, and the tower internal pressure is set to 0.001 MPa, and a first product after crude cutting is obtained;

[0070] The first product after crude cutting by the rectifying tower is fed into an isomerization reactor for isomerization reaction, the catalyst for the isomerization reaction is a SAPO-11 molecular sieve loaded Pd catalyst, the reaction temperature is set to 320 DEG C, the operating pressure is 2 MPa, the volume ratio of hydrogen to raw material is 500:1, the liquid hourly space velocity is 1 h -1 , the reaction time is 4 h, and a third product is obtained;

[0071] The third product is subjected to an adsorption column filled with 10X molecular sieves, activated carbon and alumina at a mass ratio of 1:1:1 under normal temperature and pressure, and an adsorption accuracy of 50 nm, so that most of the odor and nitrogen, oxygen and sulfur compounds are removed efficiently, and a target product is obtained;

[0072] The target product is analyzed and detected, and the moisture content is 53.4 ppm, the purity is 74.61 %, the color is +30, the kinematic viscosity is 5.706 mm 2 / s, and the refractive index is 1.4330 nD.

[0073] Comparative Example 3

[0074] Raw material: biomass aviation fuel, isomeric alkane content ≥ 70 %;

[0075] The preparation method of the biomass-based isomeric hexadecane of the present comparative example specifically comprises the following steps:

[0076] 5 Kg of biomass aviation fuel was fed at 0.1 Kg / h, the raw material entered the first rectifying column, the bottom heating temperature was set to 83 ℃, and the internal pressure of the column was set to 0.001 MPa, to obtain the first product after rough cutting;

[0077] The first product after rough cutting in the first rectifying column was fed to the second rectifying column with a reflux ratio of 5:1 for continuous rectification, the bottom heating temperature was set to 116 ℃, and the internal pressure of the column was set to 0.001 MPa, to complete dehydration and removal of organic impurities, and obtain the second product;

[0078] The second product was fed to an isomerization reactor for isomerization reaction, the catalyst for the isomerization reaction was a SAPO-11 molecular sieve loaded Pd catalyst, the reaction temperature was set to 320 ℃, the operating pressure was 2 MPa, the volume ratio of hydrogen to raw material was 500:1, the liquid hourly space velocity was 1 h -1 , the reaction time was 4 h, and the third product was obtained;

[0079] The third product was passed through an adsorption column filled with 10X molecular sieves under normal temperature and pressure conditions, the adsorption accuracy was 100 nm, and part of the odor and nitrogen and sulfur compounds could be removed, to obtain the target product containing a weak gasoline smell;

[0080] The obtained target product was analyzed and detected, the moisture content was 29.34 ppm, the purity was 98.20 %, the colority was +30, the kinematic viscosity was 5.708 mm 2 / s, and the refractive index was 1.4330 nD.

[0081] Comparative Example 4

[0082] Raw material: biomass aviation fuel, isomeric alkane content ≥ 70 %;

[0083] The preparation method of the biomass-based isomeric hexadecane of the present comparative example specifically comprises the following steps:

[0084] 5 Kg of biomass aviation fuel was fed at 0.1 Kg / h, the raw material entered the first rectifying column, the bottom heating temperature was set to 83 ℃, and the internal pressure of the column was set to 0.001 MPa, to obtain the first product after rough cutting;

[0085] The first product after the rough cutting of the first-order rectifying tower is fed into the second-order rectifying tower with a reflux ratio of 5:1 for continuous rectification, the bottom heating temperature is set to 116 ℃, the tower internal pressure is set to 0.001 MPa, dehydration and removal of organic impurities are completed, and the second product is obtained;

[0086] The second product is fed into an isomerization reactor for isomerization reaction, the catalyst for the isomerization reaction is a SAPO-11 molecular sieve loaded Pd catalyst, the reaction temperature is set to 320 ℃, the operating pressure is set to 2 MPa, the volume ratio of hydrogen to raw material is 500:1, the liquid hourly space velocity is 1 h -1 , the reaction time is 4 h, and the third product is obtained;

[0087] The third product is passed through an adsorption column filled with activated carbon at normal temperature and pressure, the adsorption accuracy is 100 nm, and part of the odor and nitrogen and sulfur compounds can be removed, and the target product containing a weak gasoline smell is obtained;

[0088] The obtained target product is analyzed and detected, the moisture content is 24.72 ppm, the purity is 98.31%, the color is +30, the kinematic viscosity is 5.706 mm 2 / s, and the refractive index is 1.4330 nD.

[0089] Comparative Example 5

[0090] Raw material: biomass aviation coal, isomeric alkane content ≥70%;

[0091] The preparation method of the biomass-based isohexadecane in the present comparative example specifically includes the following steps:

[0092] 5 Kg of biomass aviation coal is fed at 0.1 Kg / h, the raw material enters the first-order rectifying tower, the bottom heating temperature is set to 83 ℃, and the tower internal pressure is set to 0.001 MPa, and the first product after rough cutting is obtained;

[0093] The first product after the rough cutting of the first-order rectifying tower is fed into the second-order rectifying tower with a reflux ratio of 5:1 for continuous rectification, the bottom heating temperature is set to 116 ℃, the tower internal pressure is set to 0.001 MPa, dehydration and removal of organic impurities are completed, and the second product is obtained;

[0094] The second product is fed into an isomerization reactor for isomerization reaction, the catalyst for the isomerization reaction is a SAPO-11 molecular sieve loaded Pd catalyst, the reaction temperature is set to 320 ℃, the operating pressure is set to 2 MPa, the volume ratio of hydrogen to raw material is 500:1, the liquid hourly space velocity is 1 h -1 , the reaction time is 4 h, and the third product is obtained;

[0095] The third product is passed through an adsorption column filled with alumina at normal temperature and pressure, with an adsorption accuracy of 100 nm, to remove part of the odor and nitrogen, oxygen and sulfur compounds, to obtain the target product containing a weak gasoline odor;

[0096] The target product is analyzed and detected, with a moisture content of 37.34 ppm, a purity of 98.77%, a color of +30, a kinematic viscosity of 5.706 mm 2 / s, and a refractive index of 1.4330 nD.

[0097] As can be seen from the above, the bio-based isohexadecane prepared by the technical scheme of the present application in Example 1 has a moisture content of 18.21 ppm, a purity of 98.84%, a color of +30, a kinematic viscosity of 5.706 mm 2 / s, and a refractive index of 1.4330 nD; the bio-based isohexadecane prepared by the technical scheme of the present application in Example 2 has a moisture content of 34.08 ppm, a purity of 98.45%, a color of +30, a kinematic viscosity of 5.708 mm 2 / s, and a refractive index of 1.4330 nD; the bio-based isohexadecane prepared by the technical scheme of the present application in Example 3 has a moisture content of 18.21 ppm, a purity of 98.84%, a color of +30, a kinematic viscosity of 5.706 mm 2 / s, and a refractive index of 1.4330 nD. It is shown that the product obtained by the first-order rectification-second-order rectification-isomerization catalysis-composite adsorption odor removal of the present application has high purity and no odor, and can be directly applied to the preparation process of fragrances, spices and other daily chemical products.

[0098] The product obtained by only once rectification of the raw material in Comparative Example 1 has a water content of 73.2 ppm and a purity of only 60.20%; the product obtained by only once rectification of the raw material in Comparative Example 2 has a water content of 53.4 ppm and a purity of only 74.61%; it is shown that the two rectification steps in the present application are indispensable, and only once rectification has certain influence on the removal rate of impurities in the raw material, and the purity of the obtained product is lower. The product obtained by adsorption using only the adsorption column filled with 10X molecular sieve in Comparative Example 3 has a water content of 29.34 ppm, a purity of 98.20%, but has a weak gasoline smell; the product obtained by adsorption using only the adsorption column filled with activated carbon in Comparative Example 4 has a water content of 24.72 ppm, a purity of 98.31%, but has a weak gasoline smell; the product obtained by adsorption using only the adsorption column filled with alumina in Comparative Example 5 has a water content of 37.34 ppm, a purity of 98.77%, but has a weak gasoline smell; it is shown that it is necessary to use the composite adsorbent for adsorption in the present application, and only using one kind of adsorbent can only remove part of the odor and nitrogen, oxygen and sulfur compounds, and the obtained product has a weak gasoline smell, and cannot be directly applied to the preparation process of daily chemical products such as fragrances and spices.

[0099] The above-described embodiments are merely preferred embodiments of the present application, and do not limit the scope of the present application, and various modifications, modifications, evolutions, improvements of the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope determined by the claims of the present application.

Claims

1. A method for the production of a bio-based isomeric hexadecane, characterized in that, The method comprises the following steps: First-order rectification: taking biomass aviation kerosene with an isoparaffin content of ≥70% as raw material, feeding the biomass aviation kerosene into a first-order rectification tower, and performing first-order rectification to obtain a first product; Second-order rectification: feeding the first product into a second-order rectification tower, and performing second-order rectification to obtain a second product; Isomerization: adding the second product into an isomerization reactor to perform isomerization to obtain a third product; Composite adsorption deodorization: adding the third product into an adsorption column with a precision of 50-100 nm to perform adsorption deodorization to obtain a bio-based isohexadecane.

2. The method of producing a bio-based isomeric cetyl according to claim 1, characterized in that, In the first-order rectification step, the design pressure of the first-order rectification tower is-0.1-0.6 MPa, the operating pressure is 0.001 MPa, the design temperature is 300 ℃, and the operating temperature is 80-150 ℃.

3. The method of producing a bio-based isomeric cetyl according to claim 1, characterized in that, In the second-order rectification step, the design pressure of the second-order rectification tower is-0.1-0.6 MPa, the operating pressure is 0.001 MPa, the design temperature is 300 ℃, and the operating temperature is 100-180 ℃.

4. The method of producing a bio-based isomeric cetyl according to claim 1, characterized in that, In the isomerization step, the reaction temperature is 300-380 ℃, and the operating pressure is 2-4 MPa.

5. The method of making biobased isomeric cetyl alkanes according to claim 1, wherein, In the isomerization step, the catalyst for the isomerization reaction is a SAPO-11 molecular sieve loaded Pd catalyst.

6. The method of making biobased isomeric cetyl alkanes according to claim 1, wherein, In the composite adsorption deodorization step, the adsorption column is filled with a composite adsorbent, and the composite adsorbent comprises molecular sieves, activated carbon, and alumina, and the mass ratio of the molecular sieves, the activated carbon, and the alumina is 1:1:

1.

7. The method of producing a bio-based isomeric cetyl according to claim 6, characterized in that, The molecular sieves are 10X molecular sieves.