阅读说明：本技术 一种异构化油的分离方法 (Method for separating isomerized oil ) 是由 邢华斌 王青菊 崔希利 于 2020-05-08 设计创作，主要内容包括：本发明公开了一种异构化油的分离方法,所述异构化油含有C5-C8的低辛烷值烷烃和高辛烷值烷烃,所述低辛烷值烷烃包括正构烷烃、单支链烷烃中的至少一种,所述高辛烷值烷烃包括多支链烷烃；所述分离方法为以具有柔性功能的含氟阴离子杂化多孔材料为分离吸附剂,将所述分离吸附剂与所述异构化油接触,实现所述低辛烷值烷烃和高辛烷值烷烃的选择性吸附分离；所述含氟阴离子杂化多孔材料的结构通式为M-L1-A或M-L2-A,其中：M为金属离子,选自Cu<Sup>2+</Sup>、Zn<Sup>2+</Sup>、Co<Sup>2+</Sup>或Ni<Sup>2+</Sup>；A为无机含氟阴离子,选自SnF<Sub>6</Sub><Sup>2-</Sup>、ZrF<Sub>6</Sub><Sup>2-</Sup>、GeF<Sub>6</Sub><Sup>2-</Sup>、SiF<Sub>6</Sub><Sup>2-</Sup>或TiF<Sub>6</Sub><Sup>2-</Sup>；L1为有机配体1,2-二吡啶乙炔；L2为有机配体4,4’-联吡啶。(The invention discloses a separation method of an isomerized oil, which contains C5-C8 low-octane alkane and high-octane alkane, wherein the low-octane alkane comprises at least one of normal alkane and single-branch alkane, and the high-octane alkane comprises multi-branch alkane; the separation method is to use a fluoride-containing anion hybrid porous material with a flexible function as a separation adsorbent, and the separation adsorbent is contacted with the isomerized oil to realize selective adsorption separation of the low-octane alkane and the high-octane alkane; the structural general formula of the fluorine-containing anion hybrid porous material is M-L1-A or M-L2-A, wherein: m is a metal ion selected from Cu 2+ 、Zn 2+ 、Co 2+ Or Ni 2+ (ii) a A is an inorganic fluorine-containing anion selected from SnF 6 2‑ 、ZrF 6 2‑ 、GeF 6 2‑ 、SiF 6 2‑ Or TiF 6 2‑ (ii) a L1 is an organic ligand 1, 2-dipyridyl acetylene; l2 is an organic ligand 4, 4' -bipyridine.)

1. A separation method of isomerized oil is characterized in that the isomerized oil contains C5-C8 low-octane alkane and high-octane alkane, the low-octane alkane comprises at least one of normal alkane and single-branch alkane, and the high-octane alkane comprises multi-branch alkane;

the separation method is to use a fluoride-containing anion hybrid porous material with a flexible function as a separation adsorbent, and the separation adsorbent is contacted with the isomerized oil to realize selective adsorption separation of the low-octane alkane and the high-octane alkane;

the structural general formula of the fluorine-containing anion hybrid porous material is M-L1-A or M-L2-A, wherein:

m is a metal ion selected from Cu²⁺、Zn²⁺、Co²⁺Or Ni²⁺；

A is an inorganic fluorine-containing anion selected from SnF₆ ^2-、ZrF₆ ^2-、GeF₆ ^2-、SiF₆ ^2-Or TiF₆ ^2-；

L1 is an organic ligand 1, 2-dipyridyl acetylene;

l2 is an organic ligand 4, 4' -bipyridine.

2. The separation method of claim 1, wherein the normal alkane is at least one of n-pentane, n-hexane, n-heptane, and n-octane;

the single-branched alkane comprises at least one of 2-methylbutane, 2-methylpentane, 3-methylpentane, 2-methylhexane, 3-methylhexane, 2-methylheptane and 3-methylheptane;

the multi-branched alkane includes at least one of 2, 2-dimethylbutane, 2, 3-dimethylbutane, 2-dimethylpentane, 2, 3-dimethylpentane, 2, 3-trimethylbutane, 2-dimethylhexane and 2, 3-dimethylhexane.

3. The separation method according to claim 1, wherein the adsorption temperature is-30 to 100 ℃ and the adsorption pressure is 0 to 10 bar.

4. The separation method according to claim 1, wherein after the selective adsorption separation is finished, the separation adsorbent is subjected to desorption and desorption to regenerate the separation adsorbent;

the temperature of desorption and desorption is 0-160 ℃, and the pressure is 0-1 bar.

5. The separation method of the 2, 2-dimethylbutane and the 2, 3-dimethylbutane is characterized in that a fluoride-containing anion hybrid porous material with a flexible function is used as a separation adsorbent, and the separation adsorbent is contacted with a mixture containing the 2, 2-dimethylbutane and the 2, 3-dimethylbutane to realize selective adsorption separation of the 2, 2-dimethylbutane and the 2, 3-dimethylbutane;

the structural general formula of the fluorine-containing anion hybrid porous material is M-L1-A or M-L2-A, wherein:

m is a metal ion selected from Cu²⁺、Zn²⁺、Co²⁺Or Ni²⁺；

A is an inorganic fluorine-containing anion selected from SnF₆ ^2-、ZrF₆ ^2-、GeF₆ ^2-、SiF₆ ^2-Or TiF₆ ^2-；

L1 is an organic ligand 1, 2-dipyridyl acetylene;

l2 is an organic ligand 4, 4' -bipyridine.

6. The separation method according to claim 5, wherein the adsorption temperature is-30 to 100 ℃ and the adsorption pressure is 0 to 10 bar.

7. The separation method according to claim 5, wherein after the selective adsorption separation is finished, the separation adsorbent is subjected to desorption and desorption to regenerate the separation adsorbent;

the temperature of desorption and desorption is 0-160 ℃, and the pressure is 0-1 bar.

8. The application of the fluorine-containing anion hybrid porous material with the flexible function in selectively adsorbing low-octane alkane of C5-C8 is characterized in that the low-octane alkane is normal alkane and/or single-branch alkane;

the structural general formula of the fluorine-containing anion hybrid porous material is M-L1-A or M-L2-A, wherein:

m is a metal ion selected from Cu²⁺、Zn²⁺、Co²⁺Or Ni²⁺；

A is an inorganic fluorine-containing anion selected from SnF₆ ^2-、ZrF₆ ^2-、GeF₆ ^2-、SiF₆ ^2-Or TiF₆ ^2-；

L1 is an organic ligand 1, 2-dipyridyl acetylene;

l2 is an organic ligand 4, 4' -bipyridine.

9. The application of the fluoride-containing anion hybrid porous material with the flexible function in selective adsorption of 2, 3-dimethylbutane is characterized in that the general structural formula of the fluoride-containing anion hybrid porous material is M-L1-A or M-L2-A, wherein:

m is a metal ion selected from Cu²⁺、Zn²⁺、Co²⁺Or Ni²⁺；

A is an inorganic fluorine-containing anion selected from SnF₆ ^2-、ZrF₆ ^2-、GeF₆ ^2-、SiF₆ ^2-Or TiF₆ ^2-；

L1 is an organic ligand 1, 2-dipyridyl acetylene;

l2 is an organic ligand 4, 4' -bipyridine.

Technical Field

The invention relates to the technical field of chemical engineering, in particular to a method for separating isomerized oil.

Background

Environmental issues are becoming more and more demanding on gasoline quality, and the production of clean gasoline requires blending components that are low in sulfur, low in olefins, and have a high octane number. At present, the isomerized oil is an environment-friendly product with low sulfur, no olefin and no aromatic hydrocarbon, is an excellent clean gasoline blending component, and generally accounts for 5-10% of the isomerized oil in the motor gasoline. The isomerized oil mainly comprises a mixture of normal paraffins, single-chain paraffins and multi-chain paraffins of C5-C8, wherein the multi-chain paraffins not only have higher octane number, but also are completely combusted, and are used as final blending components for upgrading gasoline in the future, and the single-chain paraffins and the normal paraffins have lower octane numbers and need to be separated from mixed oil, so that the octane number of oil products is further improved.

At present, the industry mainly separates the isomerized oil by a cryogenic rectification mode, namely, multi-branched paraffin with high octane number is separated from normal or single-branched paraffin with low octane number by the difference of the boiling points of the paraffin in the composition of the isomerized oil, thereby improving the octane number of gasoline. However, the components of the isomerized oil have relatively low volatility and similar physical properties, so that the traditional separation mode has the defects of high energy consumption, high cost, complex process and the like, and the industrial application of the components is greatly limited. Therefore, it is necessary to develop an efficient and energy-saving separation technique to separate the isomerized oil.

The adsorption separation is an efficient and energy-saving separation technology, has low energy consumption and simple operation, and is gradually replacing the traditional cryogenic rectification technology. The key to this technology is the development of adsorbent materials with both high capacity and high selectivity. The existing adsorbent material for separating isomerized oil is mainly zeolite molecular sieve, and has the defects of low capacity, slow diffusion mass transfer, high regeneration energy consumption and the like, for example, patent CN 105080475A. And it is difficult to realize the selective separation between isomers with extremely small difference in branched chain isomeric size, and it is unable to meet the requirements of new industry and technology, and it seriously affects their industrial application value, for example, patent US4709116A, 5A molecular sieve can selectively adsorb the smaller molecular size normal paraffin in the isomerized oil, and can improve the octane number of oil to a certain extent, but 5A molecular sieve can not separate the multi-branched paraffin and single-branched paraffin isomers, and can not obtain the high-purity multi-branched paraffin with highest octane number, which is urgently needed by the industry at present, so the further improvement of the octane number of oil is limited.

In recent years, more researchers have investigated the separation performance of metal organic framework materials on isomerized oil alkanes. For example, a metal organic framework material having a triangular pore structure Fe (BDP)₃The separation of C6 alkane isomers in the isomerized oil can be realized, and the separation of single and double branched isomers is realized based on the difference of single and double branched alkane and frame force, but the separation selectivity is only 1.2(Science,2013,340(6135): 960-. As another example, the metal-organic framework material Ca (H)₂tcpb) separation of mono-and di-branched alkanes from C6 alkanes in isomerate was achieved by temperature induced configuration change, but with high adsorption temperature (120 ℃) and low capacity (1.2mmol/g) (Energy)&Environment Science,2018,234,6135)。

Therefore, the development of an adsorbent material with high capacity and high selectivity and low regeneration energy consumption to realize efficient separation of the isomerized oil still has great challenges.

Disclosure of Invention

Aiming at the defects in the field, the invention provides a method for separating isomerized oil, aiming at improving the octane number of gasoline. Specifically, the invention can adsorb and separate low-octane alkane from the C5-C8 isomerized oil containing normal paraffin, single-branch paraffin and multi-branch paraffin (the number of branches is not less than 2) so as to obtain high-purity high-octane multi-branch paraffin, thereby efficiently improving the octane number of gasoline. The invention can also adsorb and separate the 2, 3-dimethylbutane with high octane value from the isomerized oil containing the 2, 2-dimethylbutane and the 2, 3-dimethylbutane, and desorb to obtain the highly pure double-branched alkane 2, 3-dimethylbutane with the highest octane value, thereby further improving the octane value of gasoline.

A separation method of isomerized oil, the isomerized oil contains C5-C8 low octane alkane and high octane alkane, the low octane alkane comprises at least one of normal alkane and single branch alkane, the high octane alkane comprises multi-branch alkane;

the separation method is to use a fluoride-containing anion hybrid porous material with a flexible function as a separation adsorbent, and the separation adsorbent is contacted with the isomerized oil to realize selective adsorption separation of the low-octane alkane and the high-octane alkane;

the structural general formula of the fluorine-containing anion hybrid porous material is M-L1-A or M-L2-A, wherein:

m is a metal ion selected from Cu²⁺、Zn²⁺、Co²⁺Or Ni²⁺；

A is an inorganic fluorine-containing anion selected from SnF₆ ^2-、ZrF₆ ^2-、GeF₆ ^2-、SiF₆ ^2-Or TiF₆ ^2-；

L1 is an organic ligand 1, 2-dipyridyl acetylene (C)₁₂H₈N₂) Structural formula is

L2 is an organic ligand 4, 4' -bipyridine (C)₁₀H₈N₂) Structural formula is

The invention uses the fluoride-containing anion hybrid porous material with the flexible function as an adsorbent, and the fluoride-containing anion hybrid porous material is contacted with C5-C8 isomerized oil containing normal paraffin, single-branch paraffin and multi-branch paraffin, so that the single-branch paraffin and the normal paraffin with low octane number are selectively identified and captured, the multi-branch paraffin with high octane number is excluded, and the high-efficiency separation of the isomerized oil is realized.

The normal alkane is at least one of n-pentane, n-hexane, n-heptane and n-octane;

the single-branched alkane comprises at least one of 2-methylbutane, 2-methylpentane, 3-methylpentane, 2-methylhexane, 3-methylhexane, 2-methylheptane and 3-methylheptane;

the multi-branched alkane includes at least one of 2, 2-dimethylbutane, 2, 3-dimethylbutane, 2-dimethylpentane, 2, 3-dimethylpentane, 2, 3-trimethylbutane, 2-dimethylhexane and 2, 3-dimethylhexane.

The fluorine-containing anion hybrid porous material with the flexible function can be synthesized by any one of a solid phase grinding method, an interface slow diffusion method, a solvothermal method and a room temperature coprecipitation method. The preparation method itself is prior art.

The fluorine-containing anion hybrid porous material with the flexible function has certain flexibility due to the ligand, shows response to low-octane normal paraffin and single-branch paraffin, and can accurately identify and adsorb gas molecules of the normal paraffin and the single-branch paraffin. And the proper pore size can effectively exclude the large-size multi-branched alkane, thereby realizing gas separation.

The three-dimensional structure of the fluorine-containing anion hybrid porous material with the flexible function is shown as the following formula (I) or (II):

the pyridine rings in L1 and L2 have certain flexibility and can rotate.

The invention realizes the precise regulation and control of the pore diameter of the flexible functional fluorine-containing anion hybrid porous material by regulating the types of inorganic fluorine-containing anions and metal ions. According to the research of the invention, the anion action site can selectively react with different C5-C8 alkane molecules to form hydrogen bonds, so that the efficient separation of C5-C8 alkane isomer molecules is realized. The pyridine ring on the organic ligand has certain flexibility and shows induced rotation in response to the normal paraffin and the single-branch paraffin with low octane number, so that the normal paraffin and the single-branch paraffin gas molecules can be accurately identified and adsorbed. And because the high-density fluorine-containing anions are distributed on the surface of the pore channel, strong interaction is shown on the adsorbed molecules, and the adsorption capacity of the alkane molecules with low octane number is ensured. And the proper pore diameter enables the multi-branched alkane molecules with larger sizes to be blocked outside the pore channels, so that the high-purity multi-branched alkane with the highest octane number can be obtained. Therefore, the porous material has very high adsorption capacity and adsorption separation selectivity of low-octane alkane, is low in regeneration energy consumption, and has a very good application prospect when being used as an adsorbent in the field of oil isomerate separation.

From the inorganic fluorine-containing anion A, a metal ion M and an organic ligand 1, 2-dipyridyl acetylene (C)₁₂H₈N₂) The structural unit of the fluorine-containing anion hybrid porous material with the flexible function constructed by coordinate bonds is shown in figure 1 and has a one-dimensional pipeline type pore structure, whereinIs an inorganic anion, and the anion is an inorganic anion,is a metal ion, and is a metal ion,is an organic ligand 1, 2-dipyridyl acetylene (C)₁₂H₈N₂)。

From the inorganic fluorine-containing anion A, a metal ion M and an organic ligand 4, 4' -bipyridine (C)₁₀H₈N₂) The structural unit of the fluorine-containing anion hybrid porous material with the flexible function constructed by the coordination bond is shown in FIG. 2.

In a preferred embodiment, the inorganic fluorine-containing anion is SnF₆ ^2-Organic ligand is 1, 2-dipyridyl acetylene, metal ion is Cu²⁺The composite fluorine-containing anion hybrid porous material with the flexible function is SnFSIX-2-Cu-i. SnFSIX-2-Cu-i has adsorption capacities of up to 2.2mmol/g and 1.0mmol/g respectively for n-hexane and 2-methylpentane/3-methylpentane under the conditions of 16kPa and 298K, hardly adsorbs double-branched butane, and can separate oil products with octane numbers of up to 94-105 from C6 mixed alkane.

The mole percentage of each component in the C6 mixed alkane can be 1-99%. The oil with octane number up to 105 can be separated under the gas composition.

According to the separation method of the isomerized oil, the adsorption temperature is preferably-30-100 ℃, the further preferred temperature is 15-45 ℃, and the adsorption pressure is preferably 0-10 bar, the further preferred pressure is 0.5-2 bar.

Preferably, after the selective adsorption separation is finished, the separation adsorbent is subjected to desorption and desorption, so that the separation adsorbent is regenerated, and a high-purity adsorbed component is obtained;

the temperature of desorption and desorption is preferably 0-160 ℃, further preferably 25-50 ℃, and the pressure is preferably 0-1 bar, further preferably 0-0.2 bar.

The separation method of the isomerized oil can be a fixed bed adsorption separation process. Specifically, mixed steam or mixed liquid of C5-C8 oil isomerate is introduced into an adsorption column filled with an adsorbent, low-octane alkane is adsorbed by the adsorbent, high-octane alkane penetrates through the adsorption column, and high-octane oil can be obtained at an outlet of the adsorption column. The desorption can be realized by desorbing the adsorbed component from the adsorbent by methods such as inert gas purging, temperature rising desorption, vacuum desorption, alkane replacement and the like, so that the adsorption column is regenerated, and the adsorbent is the flexible fluorine-containing anion hybrid porous material.

The invention also provides a separation method of 2, 2-dimethylbutane and 2, 3-dimethylbutane, which comprises the step of contacting the separation adsorbent with a mixture containing 2, 2-dimethylbutane and 2, 3-dimethylbutane by taking the fluoride-containing anion hybrid porous material with the flexible function as a separation adsorbent to realize selective adsorption separation of the 2, 2-dimethylbutane and the 2, 3-dimethylbutane.

And (3) contacting the fluoride-containing anion hybrid porous material with the flexible function with the isomerized oil containing 2, 2-dimethylbutane and 2, 3-dimethylbutane, selectively recognizing and capturing the 2, 3-dimethylbutane, and excluding the 2, 2-dimethylbutane, so that the isomerized oil is efficiently separated.

The molar percentage of each component in the mixture containing 2, 2-dimethylbutane and 2, 3-dimethylbutane can be between 1% and 99%. The oil with octane number up to 105 can be separated under the mixed composition.

According to the separation method of the 2, 2-dimethylbutane and the 2, 3-dimethylbutane, the adsorption temperature is preferably-30-100 ℃, the adsorption pressure is preferably 0-10 bar, and the adsorption pressure is preferably 0.5-2 bar.

Preferably, the separation method of 2, 2-dimethylbutane and 2, 3-dimethylbutane is characterized in that after the selective adsorption separation is finished, the separation adsorbent is subjected to desorption, so that the regeneration of the separation adsorbent is realized, and simultaneously, high-purity adsorbed components are obtained;

the temperature of desorption and desorption is preferably 0-160 ℃, further preferably 25-50 ℃, and the pressure is preferably 0-1 bar, further preferably 0-0.2 bar.

In a preferred embodiment, the inorganic fluorine-containing anion is SiF₆ ^2-Organic ligand is 4, 4' -bipyridine, and metal ion is Cu²⁺The composite fluorine-containing anion hybrid porous material with the flexible function is SiFSIX-1-Cu. SiFSIX-1-Cu has an adsorption capacity of up to 4.2mmol/g for 2, 3-dimethylbutane under 16kPa and 298K, and hardly adsorbs 2, 2-dimethylbutane, so that an oil product with an octane number of up to 105 can be separated from C6 double-branched mixed alkane.

The invention also provides application of the fluorine-containing anion hybrid porous material with the flexible function in selective adsorption of low-octane alkane of C5-C8, wherein the low-octane alkane is normal alkane and/or mono-branched alkane.

The invention also provides application of the fluorine-containing anion hybrid porous material with the flexible function in selective adsorption of 2, 3-dimethylbutane.

Compared with the prior art, the invention has the main advantages that:

(1) the method for adsorbing and separating the isomerized oil by the fluoride-containing anion hybrid porous material with the flexible function is provided, normal paraffin and single-branch paraffin with low octane number in the isomerized oil can be separated by accurately regulating and controlling the pore diameter of the anion hybrid porous material, and double-branch paraffin with high octane number is subjected to exclusion, so that the octane number of gasoline is improved.

(2) The method for adsorbing and separating the isomerized oil by the fluoride-containing anion hybrid porous material with the flexible function can separate the 2, 3-dimethylbutane with the high octane number from the isomerized oil containing the 2, 2-dimethylbutane and the 2, 3-dimethylbutane, and the high octane number of the 2, 3-dimethylbutane can be obtained by desorption, so that the octane number of the gasoline can be further improved.

(3) Compared with the conventional adsorbent, the fluorine-containing anion hybrid porous material with the flexible function has the advantages of adjustable pore structure, flexible structure, adjustable acting force with adsorbate molecules and the like, and simultaneously has high adsorption capacity and high separation selectivity.

(4) The anion hybrid porous material adsorbent has simple preparation method and low regeneration energy consumption, can be regenerated and recycled at 25 ℃, and the regeneration temperature of the conventional adsorbent 5A molecular sieve is up to 200 ℃ under the same condition.

(5) The method can obtain oil products with high octane number, and the highest octane number can reach 105.

(6) Compared with the extraction rectification and precision rectification technologies, the separation method provided by the invention has the outstanding advantages of low energy consumption, small equipment investment and the like, and is suitable for industrialization.

Drawings

FIG. 1 shows a reaction mixture of an inorganic fluorine-containing anion A, a metal ion M and an organic ligand 1, 2-dipyridyl acetylene (C)₁₂H₈N₂) A schematic structural unit diagram of the fluorine-containing anion hybrid porous material with the flexible function constructed by coordinate bonds;

FIG. 2 shows a reaction mixture of an inorganic fluorine-containing anion A, a metal ion M and an organic ligand 4, 4' -bipyridine (C)₁₀H₈N₂) A schematic structural unit diagram of the fluorine-containing anion hybrid porous material with the flexible function constructed by coordinate bonds;

FIG. 3 is an adsorption isotherm of the anion hybrid porous material SnFSIX-2-Cu-i obtained in example 1 at 298K for n-hexane, 2-methylpentane, 3-methylpentane, 2-dimethylbutane and 2, 3-dimethylbutane;

FIG. 4 is the adsorption isotherm of the anion hybrid porous material SiFSIX-2-Cu-i obtained in example 1 at 298K on n-hexane, 2-methylpentane, 3-methylpentane, 2-dimethylbutane and 2, 3-dimethylbutane;

FIG. 5 is a penetration curve of the anion hybrid porous material SnFSIX-2-Cu-i obtained in example 1 at 298K for a mixed gas of n-hexane, 2-methylpentane, 3-methylpentane, 2-dimethylbutane and 2, 3-dimethylbutane;

FIG. 6 is the adsorption isotherm of 2, 2-dimethylbutane and 2, 3-dimethylbutane at 298K for the anion-hybrid porous material SiFSIX-1-Cu obtained in example 7;

FIG. 7 is a graph of the penetration curve of the anion hybrid porous material SiFSIX-1-Cu obtained in example 7 at 298K for a mixture of 2, 2-dimethylbutane and 2, 3-dimethylbutane.

Detailed Description

The invention is further described with reference to the following drawings and specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The following examples are conducted under conditions not specified, usually according to conventional conditions, or according to conditions recommended by the manufacturer.