CN112194553A - Method and device for separating carbon nonaarene mixture - Google Patents

Method and device for separating carbon nonaarene mixture Download PDF

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Publication number
CN112194553A
CN112194553A CN202011218310.2A CN202011218310A CN112194553A CN 112194553 A CN112194553 A CN 112194553A CN 202011218310 A CN202011218310 A CN 202011218310A CN 112194553 A CN112194553 A CN 112194553A
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tower
mesitylene
hemimellitene
extractive distillation
pseudocumene
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CN112194553B (en
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尤学民
曹兵
李佳林
张娅
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Chengdu Hongding Petrochemical Co ltd
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Chengdu Hongding Petrochemical Co ltd
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    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C7/00Purification; Separation; Use of additives
    • C07C7/04Purification; Separation; Use of additives by distillation
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C7/00Purification; Separation; Use of additives
    • C07C7/005Processes comprising at least two steps in series
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C7/00Purification; Separation; Use of additives
    • C07C7/04Purification; Separation; Use of additives by distillation
    • C07C7/05Purification; Separation; Use of additives by distillation with the aid of auxiliary compounds
    • C07C7/08Purification; Separation; Use of additives by distillation with the aid of auxiliary compounds by extractive distillation

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  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Analytical Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
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  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Abstract

The invention belongs to the technical field of separation of multi-methyl aromatic hydrocarbon compounds, and particularly relates to a method and a device for separating a carbon nonaromatic hydrocarbon mixture. The method comprises the following steps: introducing light components containing the hemimellitene and at least one selected from p-cymene and indane into a hemimellitene extractive distillation tower, carrying out extractive distillation in the presence of a second extractant, leading out at least one selected from p-cymene and indane from the top of the hemimellitene extractive distillation tower, and leading out heavy components containing the second extractant and the hemimellitene from the bottom of the tower; the second extractant is a mixed solution containing 3,4, 5-trimethylphenol and n-octanol. The method and the device provided by the invention can separate and purify the effective components in the refinery byproduct resources, have wide product application range and greatly improved additional value, and realize the comprehensive utilization of precious resources.

Description

Method and device for separating carbon nonaarene mixture
Technical Field
The invention belongs to the technical field of separation of multi-methyl aromatic hydrocarbon compounds, and particularly relates to a method and a device for separating a carbon nonaromatic hydrocarbon mixture.
Background
Large refinery aromatics complex units have a large resource of reformed carbon nine heavy aromatics with complex compositions, typically over forty components, with different components having different uses. The components capable of forming economic value are generally not more than three, only one component of the pseudocumene is extracted by the prior art, the rest components are used as raw materials of aromatic hydrocarbon solvents or other purposes, and more components with higher economic value are not well separated and purified due to the limitation of the technique and equipment, so that the resource is greatly wasted.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a method and a device for separating a carbon nonaromatic hydrocarbon mixture, which can separate the components of pseudocumene, mesitylene, hemimellitene and o-methylethylbenzene in a carbon nonaromatic hydrocarbon mixture system, realize the separation, purification and comprehensive utilization of high value-added components in the carbon nonaromatic hydrocarbon as a byproduct of a large refinery aromatic hydrocarbon combination device, save energy, reduce emission and are environment-friendly.
Specifically, the present invention provides the following technical solutions.
A process for separating a mixture of carbon nonaromatic hydrocarbons comprising pseudocumene, hemimellitene and at least one member selected from the group consisting of p-methylisoprene and indane, the process comprising the steps of:
(1) introducing heavy components with the boiling point higher than 165.5 ℃ in the carbon nonaromatic hydrocarbon mixture into a pseudocumene rectifying tower, leading out a pseudocumene product from the side line of the pseudocumene rectifying tower, leading out light components with the boiling point between 165.5 and 169.3 ℃ from the top of the tower, and leading out heavy components with the boiling point higher than 170 ℃ from the bottom of the tower;
(2) introducing the heavy component with the boiling point higher than 170 ℃ in the step (1) into a hemimellitene light component removal tower, extracting the light component with the boiling point of 170-176 ℃ from the top of the hemimellitene light component removal tower, and extracting the heavy component with the boiling point higher than 176 ℃ from the bottom of the light component removal tower;
(3) introducing the heavy component with the boiling point higher than 176 ℃ in the step (2) into a trimethyl benzene removing tower, leading out a light component containing trimethyl benzene and at least one of p-methyl isopropylbenzene and indane from the top of the trimethyl benzene removing tower, and leading out the heavy component with the boiling point higher than 177.2 ℃ from the bottom of the tower;
(4) introducing the light components in the step (3) into a hemimellitene extractive distillation tower, carrying out extractive distillation in the presence of a second extractant, leading out at least one of p-methylisoprene and indane from the top of the hemimellitene extractive distillation tower, and leading out heavy components containing the second extractant and the hemimellitene from the bottom of the tower;
wherein the second extractant is a mixed solution containing 3,4, 5-trimethylphenol and n-octanol.
The invention utilizes the properties of different component molecular structures, selects proper polar solvent of a binary system of 3,4, 5-trimethylphenol and n-octanol as an extracting agent, and skillfully separates hemimellitene which has very close boiling point and is difficult to separate by super rectification from indane and p-methylisoprene.
Preferably, in the method for separating the mixture of the carbon nonaromatic hydrocarbons, the molar ratio of the 3,4, 5-trimethylphenol to the n-octanol is 1.5-2.5: 1, and more preferably 1.8-2.2: 1.
Preferably, the method for separating a mixture of carbon nonaromatic hydrocarbons further comprises the following steps: and (4) introducing the heavy component containing the second extractant and the hemimellitene in the step (4) into a hemimellitene resolving tower, leading out a hemimellitene product from the top of the hemimellitene resolving tower, and leading out the second extractant from the bottom of the tower.
Preferably, in the above method for separating a mixture of carbon nonaromatic hydrocarbons, the mixture of carbon nonaromatic hydrocarbons further contains mesitylene and o-methylethylbenzene, the method further comprises the following steps:
(5) introducing a carbon nonaarene mixture into a first light component removal tower, leading out light components with the boiling point lower than 164.5 ℃ from the top of the first light component removal tower, and leading out heavy components containing mesitylene and o-methyl ethylbenzene from the bottom of the tower;
(6) introducing the heavy component in the step (5) into a mesitylene removal tower, and extracting a light component containing mesitylene and o-methyl-ethyl benzene from the top of the mesitylene removal tower, wherein the heavy component with the boiling point higher than 165.5 ℃ is extracted from the bottom of the tower;
(7) introducing the light component containing mesitylene and o-methyl ethylbenzene in the step (6) into a mesitylene extractive distillation tower, carrying out extractive distillation in the presence of a first extractant, leading out an o-methyl ethylbenzene product from the top of the mesitylene extractive distillation tower, and leading out a heavy component containing the first extractant and mesitylene from the bottom of the tower;
the first extracting agent is a mixed solution containing trimethyl trimesate and n-octanol, more preferably, the molar ratio of the trimethyl trimesate to the n-octanol is 3-5: 1, further preferably 3.5-4.5: 1, and most preferably 3.8-4.2: 1.
Preferably, the method for separating a mixture of carbon nonaromatic hydrocarbons further comprises the following steps: and (4) introducing the heavy component containing the first extractant and mesitylene in the step (7) into a mesitylene desorption tower, leading out a mesitylene product from the top of the mesitylene desorption tower, and leading out the first extractant from the bottom of the tower.
The invention also provides a device for separating the carbon nonaarene mixture, which comprises a pseudocumene rectifying tower, a hemimellitene light-removing tower, a hemimellitene extracting and rectifying tower and a hemimellitene analyzing tower;
a raw material inlet is formed in the side part of the pseudocumene rectifying tower, and the raw material inlet of the pseudocumene rectifying tower is used for inputting heavy components with the boiling point higher than 165.5 ℃ in a carbon nonaromatic hydrocarbon mixture;
the pseudocumene rectifying tower is provided with a side line discharge port, a pseudocumene product is led out from the side line discharge port, and a tower kettle discharge port of the pseudocumene rectifying tower is connected with a raw material feed port of the hemicumene connecting light component removing tower;
a discharge port of a tower kettle of the hemimellitene light-ends removal tower is connected with a raw material feed port of the hemimellitene removal tower;
a discharge hole at the top of the hemitritoluene removing tower is connected with a raw material feed hole of the hemitritoluene extracting and rectifying tower;
the hemimellitene extraction and rectification tower is provided with a second extractant feed inlet, a discharge hole at the top of the hemimellitene extraction and rectification tower is used for leading out methylisoprophenyl and/or indane, and a discharge hole at the bottom of the tower is connected with a raw material feed inlet of the hemimellitene desorption tower;
and a hemimellitene product is led out from a discharge hole at the top of the hemimellitene analysis tower.
Preferably, in the above apparatus for separating a mixture of carbon nonaaromatics, at least eight packing materials or trays corresponding to the height of the theoretical trays are provided between the side discharge port of the pseudocumene rectifying column and the top of the pseudocumene rectifying column.
Preferably, the apparatus for separating a mixture of carbon nonaromatic hydrocarbons further comprises a first light component removal tower, a sym-tritoluene extractive distillation tower and a sym-tritoluene desorption tower;
a carbon nonaarene mixture feeding port is formed in the side part of the first light component removal tower, and a tower kettle discharging port of the first light component removal tower is connected with a raw material feeding port of the sym-tritoluene removal tower;
a discharge hole at the top of the mesitylene removing tower is connected with a raw material feed hole of the mesitylene extractive distillation tower; a discharge hole of a tower kettle of the mesitylene removal tower is connected with a raw material feed hole of the pseudocumene rectifying tower;
the mesitylene extractive distillation tower is provided with a first extractant feed inlet, an o-methylethylbenzene product is led out from a discharge hole at the top of the mesitylene extractive distillation tower, and a discharge hole at a tower kettle is connected with a raw material feed inlet of the mesitylene desorption tower;
and a discharge hole at the top of the mesitylene desorption tower is used for leading out a mesitylene product.
Preferably, in the apparatus for separating a mixture of carbon nonaaromatics, the first light component removal column, the sym-tritoluene removal column, the mesitylene extractive distillation column, the hemimellitene light component removal column, the tritolyl removal column, and the hemimellitene extractive distillation column are filled with the bidirectional curvelet efficient structured packing;
the inside of the mesitylene desorption tower, the unsym-trimethylbenzene rectifying tower and the hemimelene desorption tower is filled with a bidirectional oblique wave efficient regular packing.
The invention also provides a method for separating hemimellitene and at least one selected from p-methylisoprene and indane, which comprises the following steps: performing extractive distillation on a system containing hemimellitene and at least one selected from p-methyl isopropylbenzene and indane in the presence of an extracting agent, wherein the extracting agent is a mixed solution comprising 3,4, 5-trimethylphenol and n-octanol; more preferably, the molar ratio of the 3,4, 5-trimethylphenol to the n-octanol is 1.5-2.5: 1, and further preferably 1.8-2.2: 1.
The invention has the following beneficial effects:
the method and the device provided by the invention can separate and purify the effective components in the refinery byproduct resources, have wide product application range and greatly improved additional value, and realize the comprehensive utilization of precious resources.
Drawings
FIG. 1 is a schematic view of an apparatus according to an embodiment; wherein, 1, a raw material delivery pump, 2, a first light component removal tower, 3, a light component delivery pump, 4, a first light component removal tower kettle delivery pump, 5, a mesitylene removal tower, 6, a mesitylene enrichment delivery pump, 7, a mesitylene removal tower kettle component delivery pump, 8, a mesitylene rectification tower, 9, a mesitylene product delivery pump, 10, a mesitylene rectification tower kettle component delivery pump, 11, a first extractant delivery pump, 12, a mesitylene extraction rectification tower, 13, an enrichment o-methyl ethylbenzene delivery pump, 14, a mesitylene extraction rectification tower kettle component delivery pump, 15, a mesitylene desorption tower, 16, a mesitylene product delivery pump, 17, a mesitylene desorption tower kettle first extractant delivery pump, 18, a boiling point 165.5-169.3 ℃ component delivery pump, 19, a mesitylene light component removal tower, 20, a boiling point 170-176 ℃ component delivery pump, 21, a mesitylene light component removal tower delivery pump, 22. a trimethyl benzene removing tower 23, a trimethyl benzene enriching delivery pump 24, a trimethyl benzene removing tower kettle component delivery pump 25, a second extractant delivery pump 26, a trimethyl benzene extracting and rectifying tower 27, an indane and methylisopropyl benzene delivery pump 28, a trimethyl benzene extracting and rectifying tower kettle component delivery pump 29, a trimethyl benzene resolving tower 30, a trimethyl benzene product delivery pump 31 and a trimethyl benzene resolving tower kettle second extractant delivery pump.
FIG. 2 is a gas chromatogram of the final product, pseudocumene, of example 1.
FIG. 3 is a gas chromatogram of mesitylene, the final product of example 1.
FIG. 4 is a gas chromatogram of hemimellitene, the final product of example 1.
FIG. 5 is a gas chromatogram of the final product, o-methylethylbenzene, of example 1.
Detailed Description
Aiming at the defect that high added value components in carbon nonaromatic hydrocarbon can not be effectively separated and purified in the prior art, the invention provides a method and a device for separating a carbon nonaromatic hydrocarbon mixture, which can be used for separating, purifying and comprehensively utilizing the components of pseudocumene, mesitylene, hemimellitene and o-methylethylbenzene in the carbon nonaromatic hydrocarbon as a byproduct of a large refinery aromatic hydrocarbon combination device, and are energy-saving, emission-reducing and environment-friendly.
The method comprises the steps of firstly, adding a raw material of the carbon nine heavy aromatics reformed in the oil refinery into a rectifying tower provided with internals according to a certain speed, and removing light components with a boiling point lower than that of mesitylene under specific conditions of temperature, pressure and reflux.
The carbon nine-heavy aromatic hydrocarbon without light component enters into rectifying tower with inner parts according to certain speed, under specific temperature, pressure and reflux condition, the mesitylene and o-methyl-ethyl benzene with boiling point close to the mesitylene are evaporated out from the top of the tower and enter into the extraction rectifying tower. In the extractive distillation column, the binary extractant system absorbs mesitylene but not o-methylethylbenzene. The steam rich in o-methyl-ethyl benzene is distilled out from the top of the tower as a byproduct. The rich solution of the extractant absorbing the mesitylene is sent into an analytic tower at a certain speed, and the high-purity mesitylene is analyzed out as a product under specific conditions of temperature, pressure and reflux and escapes from the top of the tower. The lean extract liquid in the tower bottom returns to the extraction and rectification tower for recycling.
The carbon nine-heavy aromatic hydrocarbon without mesitylene and near-methyl ethyl benzene is fed into rectifying tower with internal parts at certain speed, and under the condition of specific temperature, pressure and reflux, high-purity pseudocumene product is extracted from side line near the top of tower, and the gas phase at the top of tower is the component whose boiling point is between that of pseudocumene and mesitylene (containing o-toluene). The tower bottom is a component with a boiling point higher than that of the pseudocumene.
The rest carbon nine-heavy aromatic hydrocarbon without the pseudocumene component enters a rectifying tower with internal parts according to a certain speed, and the component with the boiling point between the pseudocumene and the hemimellitene is removed at the top of the tower under the specific conditions of temperature, pressure and reflux. The bottom of the tower contains hemimellitene and components with higher boiling points than the hemimellitene. Feeding into a rectifying tower with internal parts at a certain speed, and under the condition of specific temp., pressure and reflux, the components distilled out from top of the tower are hemimellitene and indan and p-methylisoprene whose boiling point is close to that of hemimellitene. Feeding into an extractive distillation column with internals at a certain speed. The other components with boiling points heavier than that of the hemimellitene (containing indan and p-methyl isopropylbenzene) are obtained in the tower bottom.
In the extractive distillation column, under specific conditions of temperature, pressure and reflux, the binary extractant system absorbs hemimellitene but not indane and p-methylisoprene. Indan-rich and p-methylisoprene-rich vapor is distilled overhead as a by-product. The extractant rich solution absorbing hemimellitene is sent into a resolving tower at a certain speed, and under the conditions of specific temperature, pressure and reflux, high-purity hemimellitene is resolved and escapes from the top of the tower. The barren solution in the tower bottom returns to the extraction and rectification tower for recycling.
Through the steps, the complete separation of the three trimethylbenzenes in the reformed carbon nine raw material is completed, and the maximum effective utilization of resources is realized. The invention skillfully separates mesitylene from o-methyl-ethylbenzene by selecting a proper binary system polar solvent as an extractant by utilizing the properties of very close boiling points and different molecular structures of components which are difficult to separate in super rectification; hemimellitene is separated from indane and p-methylisoprene.
Meanwhile, the technical scheme provided by the invention is more suitable for industrial production, and a super rectification technology, an extractive rectification technology, a thermal coupling technology and a heat integration technology are used. Specifically, the pseudocumene column is designed to be in positive pressure, and pseudocumene steam at the side line of the column can be led back to a reboiler of the light component removal column to be used as a heat source to form thermal coupling; the o-methyl-ethyl benzene steam at the top of the mesitylene extractive distillation tower is led back to a reboiler heat source of the trimesic tower to form thermal coupling; indan and p-methyl isopropylbenzene steam at the top of the hemimellitene extraction rectification tower are led back to a reboiler heat source of the three towers to form thermal coupling; and respectively collecting the steam condensate according to temperature steps and then using the steam condensate as a multi-section raw material, a semi-finished product feeding preheating heat source and a heat tracing heat source to form energy step effective utilization. The method has the advantages of saving energy consumption, effectively reducing production cost, easily controlling the whole production process, stably and continuously operating, high separation precision, high product purity, reliable product quality and high yield of target products, and can be widely applied to totally separating the pseudocumene, the mesitylene and the hemimellitene with high added values from byproduct reformed carbon nonaheavy aromatics in a large-scale oil refinery so as to realize high-efficiency comprehensive utilization of precious resources.
In a preferred embodiment, as shown in fig. 1, the apparatus for separating a mixture of nona-carbon aromatic hydrocarbons according to the present invention includes a raw material transfer pump 1, a first light component removal column 2, a light component transfer pump 3, a first light component removal column bottom transfer pump 4, a mesitylene removal column 5, a mesitylene enrichment transfer pump 6, a mesitylene removal column bottom component transfer pump 7, a mesitylene rectification column 8, a mesitylene product transfer pump 9, a mesitylene rectification column bottom component transfer pump 10, a first extractant transfer pump 11, a mesitylene extractive rectification column 12, an o-methylethylbenzene enrichment transfer pump 13, a mesitylene extractive rectification column bottom component transfer pump 14, a mesitylene desorption column 15, a mesitylene product transfer pump 16, a mesitylene desorption column bottom first extractant transfer pump 17, a boiling point 165.5-169.3 ℃ component transfer pump 18, a mesitylene light component removal column 19, a boiling point 170-176 ℃ component transfer pump 20-176 ℃, A hemimellitene light component removing tower kettle component delivery pump 21, a hemimellitene removing tower 22, a hemimellitene enriching delivery pump 23, a hemimellitene removing tower kettle component delivery pump 24, a second extractant delivery pump 25, a hemimellitene extracting and rectifying tower 26, an indane and methylisoprene delivery pump 27, a hemimellitene extracting and rectifying tower kettle component delivery pump 28, a hemimellitene resolving tower 29, a hemimellitene product delivery pump 30 and a hemimellitene resolving tower kettle second extractant delivery pump 31.
A carbon nonaarene mixture feed port is formed in the side part of the first lightness-removing tower 2, and a tower kettle discharge port of the first lightness-removing tower 2 is connected with a raw material feed port of the sym-toluene-removing tower 5;
a discharge hole at the top of the mesitylene removing tower 5 is connected with a raw material feed inlet of the mesitylene extractive distillation tower 12;
the mesitylene extractive distillation tower 12 is provided with a first extractant feed inlet, an o-methylethylbenzene product is led out from a discharge hole at the top of the mesitylene extractive distillation tower 12, and a discharge hole at the bottom of the tower is connected with a raw material feed inlet of the mesitylene desorption tower 15;
a discharge hole of a tower kettle of the mesitylene removal tower 5 is connected with a raw material feed hole of the pseudocumene rectifying tower 8;
the pseudocumene rectifying tower 8 is provided with a side line discharge port, a pseudocumene product is led out from the side line discharge port, and a tower kettle discharge port of the pseudocumene rectifying tower 8 is connected with a raw material feed port of the continuous pseudocumene lightness removing tower 19;
a discharge port of a tower kettle of the hemimellitene light-ends removal tower 19 is connected with a raw material feed port of the hemimellitene removal tower 22;
a discharge hole at the top of the hemimellitene removing tower 22 is connected with a raw material feed hole of the hemimellitene extracting and rectifying tower 26;
the hemimellitene extraction and rectification tower 26 is provided with a second extractant feeding hole, a discharge hole at the top of the hemimellitene extraction and rectification tower 26 is used for leading out methylisoprene and indane, and a discharge hole at the bottom of the tower is connected with a raw material feeding hole of the hemimellitene desorption tower 29;
and a hemimellitene product is led out from a discharge hole at the top of the hemimellitene desorption tower 29.
In a preferred embodiment, the parameters of the first light ends removal column 2 include: the inner diameter is 3.8 meters, the CHAOPAK6.0 is structured by 40 meters (divided into nine sections, internal parts such as a distributor, a support ring and the like), the number of theoretical plates is 100, and the tangent height of the tower body is 58.5 meters;
the parameters of the de-sym-tritoluene tower 5 comprise: the inner diameter is 2.6 meters, the CHAOPAK6.0 is highly efficient and regular, the height of the packing is 44 meters (divided into eight sections, internal parts such as a matched distributor, a supporting ring and the like), the number of theoretical plates is 86, and the height of a tangent line of the tower body is 62 meters;
the parameters of the pseudocumene rectifying tower 8 comprise: the inner diameter is 2.2 meters, the height of the ZUPAK5.0 efficient structured packing is 34 meters (divided into nine sections, internal parts such as a matched distributor, a supporting ring and the like), the number of theoretical plates is 76, and the height of a tangent line of the tower body is 44.6 meters; a side line discharge port of the pseudocumene rectifying tower 8 is arranged on a liquid collecting disc at the lower part of the second section of the filler;
the parameters of the mesitylene extractive distillation tower 12 comprise: the inner diameter is 1.6 meters, the CHAOPAK5.0 is structured by 22 meters (divided into five sections, internal parts such as a distributor, a support ring and the like), the number of theoretical plates is 40, and the tangent height of the tower body is 28 meters;
the inside diameter of the mesitylene desorption tower 15 is 1.2 meters, the height of the ZUPAK5.0 efficient structured packing is 18.6 meters (divided into four sections, internal parts such as a distributor, a support ring and the like are matched), the number of theoretical plates is 32, and the height of a tangent line of the tower body is 24.4 meters;
the inner diameter of the hemimellitene light-ends removal tower 19 is 2 meters, the CHAOPAK6.0 efficient structured packing height is 28.5 meters (divided into five sections, internal parts such as a distributor, a support ring and the like are matched), the number of theoretical plates is 60, and the tangent height of the tower body is 33.6 meters;
the internal diameter of the connecting and disconnecting tritoluene tower 22 is 1.0 meter, the CHAOPAK6.0 efficient structured packing height is 26.6 meters (divided into eight sections, internal parts such as a matched distributor, a support ring and the like), the number of theoretical plates is 50, and the tangent height of the tower body is 33.6 meters;
the parameters of the hemimellitene extractive distillation tower 26 comprise: the inner diameter is 1.4 meters, the CHAOPAK5.0 is used for efficiently regulating the height of the packing to be 23.6 meters (divided into five sections, internal parts such as a distributor, a support ring and the like), the number of theoretical plates is 42, and the tangent height of the tower body is 30 meters;
the inner diameter of the hemimellitene resolving tower 29 is 1.0 meter, the height of the ZUPAK5.0 efficient structured packing is 16.8 meters (divided into four sections, internal parts such as a distributor, a support ring and the like are matched), the number of theoretical plates is 30, and the height of a tangent line of the tower body is 22.6 meters.
The CHAOPAK and ZUPAK efficient structured packing is from technology GmbH of Tianjin Tiandaitan.
The various columns described above are accompanied by a reboiler/condenser/reflux drum/reflux pump-metering system, which is the equipment required for a standard (super) rectification unit. And the conveying units are all chemical process pumps.
The method for separating the carbon nonaromatic hydrocarbon mixture by adopting the device comprises the following steps:
(1) the method comprises the steps of feeding nine-heavy aromatics of reformed carbon by-products of an oil refinery into a first light component removal tower 2 at a speed of 80-120 kmol/h, removing components with a boiling point lower than 164.5 ℃ (namely, components lower than mesitylene) from the tower top under the operating conditions that the tower top pressure is 10-20 kPa.A, the temperature is 95-115 ℃ and the reflux ratio is 3-4: 1, and using the components as SA1000# aromatic solvent products, wherein the content of mesitylene carried by the components at the tower top is lower than 2% (wt). The tower kettle is composed of mesitylene and components with boiling points higher than that of mesitylene, the content of light components is lower than 0.5%, the heating heat source of the first light component removal tower 2 in the initial operation is external steam, and after the mesitylene rectifying tower 8 is normal, the mesitylene steam is led to be used as the heating heat source;
(2) and (3) feeding tower kettle components obtained in the first light component removal tower 2 into an sym-tritoluene removal tower 5 at a speed of 60-90 kmol/h. Under the operating conditions that the pressure at the top of the tower is 5-10 kPa.A, the temperature is 105-118 ℃ and the reflux ratio is 4-4.8: 1, mesitylene and an o-methyl-ethyl benzene component with a boiling point close to the mesitylene are removed from the top of the tower to form a mesitylene enriched liquid (the total content of the two components is more than or equal to 99.5 wt%). The tower kettle is a component (namely an aromatic hydrocarbon component with the boiling point higher than that of mesitylene and o-methyl ethylbenzene) with the boiling point higher than 165.5 ℃, the content of the mesitylene is lower than 2 percent (wt), and a heating heat source is low-pressure steam flash-evaporated from medium-pressure condensate to form the first heat integration of the invention;
(3) and (3) feeding the tower kettle components of the mesitylene removal tower 5 into the pseudocumene rectifying tower 8 at a speed of 50-80 kmol/h. Under the operation conditions that the pressure at the top of the tower is 110-150 kPa.A, the temperature is 180-200 ℃, and the reflux ratio is 10-15: 1, the top of the tower is a component mixture with the boiling point of 165.5-169.3 ℃ (namely the component with the boiling point of pseudocumene and mesitylene (containing o-methyl ethyl benzene)), and the content of the pseudocumene is less than 3.5% (wt). The pseudocumene product with the purity of more than 99 percent (wt) is extracted from a side-stream discharge port, namely the lower part of the second section of packing, the yield is more than or equal to 91 percent, the pseudocumene product enters a reboiler of a first light component removal tower 2 to be used as a heat source, the coupling of the maximum heat of the invention is formed, and the pseudocumene product is extracted as a product after all latent heat and part of sensible heat are absorbed. The tower kettle is a component with the boiling point higher than 170 ℃, the content of the pseudocumene is lower than 2 percent (wt), and the heating steam of the tower kettle uses external medium-pressure steam as a heat source;
(4) the tower top components of the mesitylene removal tower 5 are fed into a mesitylene extraction rectifying tower 12 at a speed of 10-15 kmol/h. Under the operation conditions that the pressure at the top of the tower is 110-150 kPa.A, the temperature is 170-180 ℃, and the reflux ratio is 10-15: 1, a binary mixed solvent of trimethyl trimesate and n-octanol is used as an extracting agent, the molar ratio of the trimethyl trimesate to the n-octanol is 3-5: 1, and the molar ratio of the extracting solvent to the mesitylene is 8-12: 1. The top of the extractive distillation tower is an o-methyl-ethylbenzene byproduct which is not absorbed by the solvent, the purity is more than or equal to 98 percent (wt), and the content of mesitylene is less than 2 percent (wt). The tower kettle is a mixture of a binary extraction solvent and mesitylene, and heating steam in the tower kettle uses external medium-pressure steam as a heat source;
(5) the tower bottom components of the mesitylene extractive distillation tower 12 are fed into a mesitylene desorption tower 15 at the speed of 30-40 kmol/h. Under the operating conditions that the pressure at the top of the tower is 20-50 kPa.A, the temperature is 110-125 ℃, and the reflux ratio is 3-4: 1, the top of the tower is a mesitylene product, the purity is more than or equal to 99 percent (wt), the tower bottom is a regenerated binary extraction solvent, the mesitylene product is recycled to the mesitylene extractive distillation tower 12 for use, and the yield of the mesitylene is more than or equal to 85 percent (wt relative to the content in the raw materials);
(6) the tower bottom components of the pseudocumene rectifying tower 8 are sent into a hemimellitene light-ends removal tower 19 at the speed of 20-30 kmol/h. Under the operation conditions that the pressure at the top of the tower is 2-12 kPa.A, the temperature is 120-140 ℃ and the reflux ratio is 5-8: 1, a light component mixture (namely light components between pseudocumene and hemimellitene (containing indan and p-methylisoprene)) with the boiling point between 170 and 176 ℃ is generated at the top of the tower, and the content of the hemimellitene is less than 2 percent (wt). The tower bottom is a component with the boiling point higher than 176 ℃ (namely, the component is enriched with hemimellitene and carbon nonaromatic hydrocarbon with the boiling point higher than that of the hemimellitene), and the content of light components is lower than 0.5 percent (wt);
(7) the tower bottom components of the hemimellitene light component removal tower 19 are sent into a hemimellitene removal tower 22 at a speed of 15-20 kmol/h. Under the operating conditions that the pressure at the top of the tower is 5-10 kPa.A, the temperature is 105-118 ℃ and the reflux ratio is 4-4.8: 1, the top of the tower is a hemimellitene concentrated solution formed by hemimellitene and p-methylisoprene and indane with the boiling points close to the hemimellitene, and the total content of the three components is more than or equal to 99.6 percent (wt). The tower bottom is a component (namely a heavy carbon nonaarene component) with the boiling point higher than 177.2 ℃ as a byproduct, and the content of hemimellitene is lower than 2 percent (wt);
(8) the tower top component of the toluene removing tower 22 is fed into a mesitylene extractive distillation tower 26 at the speed of 8-12 kmol/h. Under the operation conditions that the pressure at the top of the tower is 110-150 kPa.A, the temperature is 170-180 ℃, and the reflux ratio is 10-15: 1, a binary mixed solvent of 3,4, 5-trimethylphenol and n-octanol is used as an extracting agent, the molar ratio of the 3,4, 5-trimethylphenol to the n-octanol is 1.5-2.5: 1, and the molar ratio of the extracting solvent to the mesitylene is 6-8: 1; the top of the tower is the p-methyl isopropylbenzene and indane components which are not absorbed by the solvent, the content of the hemimellitene is less than 2 percent (wt), the bottom of the tower is the mixture of the binary extraction solvent and the hemimellitene, and the heating steam of the bottom of the tower uses the external medium-pressure steam as a heat source;
(9) the tower bottom components of the hemimellitene extraction and rectification tower 26 are sent into a hemimellitene desorption tower 29 at the speed of 30-40 kmol/h. Under the operating conditions that the pressure at the top of the tower is 10-40 kPa.A, the temperature is 115-135 ℃ and the reflux ratio is 4-6: 1, hemimellitene products with the purity of more than or equal to 99 percent (wt) are generated at the top of the tower, the yield of the hemimellitene is more than or equal to 82 percent (relative to the content in the raw materials, wt), and a tower kettle is a regenerated binary extraction solvent and is recycled to the hemimellitene extraction and rectification tower 26 for use.
Through the steps, the complete separation of the pseudocumene, the mesitylene, the hemimellitene and the o-methyl-ethyl benzene in the byproduct carbon nine components of the aromatic hydrocarbon combination unit of the oil refinery is realized, and the single component with high added value can be purified to the maximum extent.
In a preferred embodiment, in the above step, the pseudocumene rectifying column 8 is operated at positive pressure, and the rectified pseudocumene vapor in the column side can be introduced back to the reboiler of the first lightness-removing column 2 as a heat source to form a first thermal coupling, and then returned to the pseudocumene reflux drum.
In a preferred embodiment, in the above step, the mesitylene extractive distillation column 12 is operated at positive pressure, and the o-methylethylbenzene vapor as a byproduct at the top of the column can be introduced back to the reboiler of the mesitylene removing column 5 as a heat source to form a second thermal coupling, and then returned to the o-methylethylbenzene reflux drum.
In a preferred embodiment, during the above steps, the hemimellitene extractive distillation column 26 is operated at positive pressure, and the overhead indane-and methylisoprene-rich vapor is introduced back to the reboiler of the tritoluene stripping column 22 as a heat source to form a third thermal coupling, and then returned to the reflux drum of the hemimellitene extractive distillation column 26.
In a preferred embodiment, in the step (1), the operation pressure of the column reactor of the first lightness-removing column 2 is 20 to 24kPa, and the temperature of the column reactor is controlled within a range of 130 to 135 ℃. The purpose of the control is that components with boiling points lower than 164.5 ℃ must be removed from tower bottom components to ensure that the mesitylene product is qualified; the operation pressure at the top of the tower is 12-16 kPa, the top temperature control range is 98-105 ℃, and the reflux ratio is 3.2-3.7: 1. The purpose of this control was to control the amount of mesitylene removed therefrom to ensure an overall yield of the desired product of not less than 85% (wt). The tower kettle heating heat source of the first light component removal tower 2 uses low-pressure steam of a pipe network when the tower is started, and oil gas at the top of the tower is led to be used as the heat source after the unsym-trimethyl benzene refining tower is normally started, so that heat coupling is formed.
In a preferred embodiment, in the step (2), the operation pressure of the column bottom of the mesitylene removing column 5 is 15 to 20kPa, and the temperature of the column bottom is controlled within a range of 135 to 140 ℃. The aim of the control is to remove mesitylene and o-methyl ethylbenzene components in the tower kettle components as much as possible so as to ensure that the comprehensive yield of the mesitylene target product is more than or equal to 85 percent (wt); the operation pressure at the top of the tower is 6-8 kPa, the control range of the top temperature is 108-112 ℃, and the reflux ratio is 4.2-4.6: 1. The aim of the control is to control the purity of the mesitylene and the o-methyl ethylbenzene in the overhead fraction to be more than or equal to 99.5 percent so as to ensure that the quality of the mesitylene product is qualified. When a heating source of a tower kettle of the 5 th of the mesitylene removal tower is started, low-pressure steam of a pipe network is used, and after the whole plant is normal, the byproduct o-methyl-ethyl benzene steam at the top of the mesitylene extraction rectifying tower 12 is used.
In a preferred embodiment, in the step (3), the operation pressure of the column bottom of the pseudocumene rectifying column 8 is 130 to 150kPa, and the temperature of the column bottom is controlled within a range of 195 to 205 ℃. The aim of the control is to remove the pseudocumene component in the tower bottom component as much as possible so as to ensure that the comprehensive yield of the pseudocumene target product extracted from a liquid collecting disc at the lower part of the second section of the packing of the pseudocumene rectifying tower 8 is more than or equal to 91 percent (wt); the operation pressure at the top of the tower is 120-140 kPa, the control range of the top temperature is 188-195 ℃, and the reflux ratio is 11.5-13.5: 1. The aim of the control is to control the content of the pseudocumene in the overhead distillation component to be less than or equal to 2 percent so as to ensure that the comprehensive yield of the pseudocumene target product is more than or equal to 91 percent (wt).
In a preferred embodiment, in the step (4), the operation pressure of the column bottom of the mesitylene extractive distillation column 12 is 125-140 kPa, and the temperature of the column bottom is controlled within a range of 208-215 ℃. The aim of the control is to remove the o-methyl-ethyl benzene component from the tower kettle component as much as possible so as to ensure that the quality of the mesitylene product is qualified; the operation pressure at the top of the tower is 115-130 kPa, the control range of the top temperature is 172-178 ℃, and the reflux ratio is 14-14.6: 1. The control aims to ensure that the mesitylene content in the o-methyl-ethylbenzene product distilled from the tower top is less than or equal to 2 percent (wt) so as to ensure that the comprehensive yield of the mesitylene target product is more than or equal to 85 percent (wt).
In a preferred embodiment, in the step (5), the operation pressure of the column bottom of the mesitylene desorption column 15 is 33 to 48kpa.a, and the temperature of the column bottom is controlled within a range of 130 to 145 ℃. The control aims to completely decompose the mesitylene in the extraction solvent so as to ensure that the comprehensive yield of the mesitylene product is more than or equal to 85 percent (wt); the operation pressure at the top of the tower is 25-40 kPa.A, the control range of the top temperature is 115-120 ℃, and the reflux ratio is 3.2-3.8: 1. The aim of the control is to ensure that the purity of the mesitylene product distilled from the top of the tower is more than or equal to 99 percent (wt).
In a preferred embodiment, in the step (6), the operation pressure of the column bottom of the hemimellitene lightness-removing column 19 is 10 to 20kPa, and the temperature of the column bottom is controlled within a range of 140 to 155 ℃. The purpose of the control is that the components with the boiling point lower than 176 ℃ must be removed from the tower bottom components to ensure that the hemimellitene product is qualified; the operation pressure at the top of the tower is 5-9 kPa, the control range of the top temperature is 125-135 ℃, and the reflux ratio is 6-7: 1. The purpose of this control is to control the amount of hemimellitene removed therefrom to ensure an overall yield of the desired product of > 82% (wt).
In a preferred embodiment, in the step (7), the operation pressure of the column bottom of the toluene elimination column 22 is 15 to 20kPa, and the temperature of the column bottom is controlled in the range of 130 to 140 ℃. The aim of the control is to remove the hemimellitene and the indane and p-methylisoprene components with the boiling points very close to the hemimellitene as far as possible from the tower bottom components so as to ensure that the comprehensive yield of the hemimellitene target product is more than or equal to 82 percent (wt); the operation pressure at the top of the tower is 6-8 kPa, the control range of the top temperature is 108-116 ℃, and the reflux ratio is 4.2-4.6: 1. The aim of the control is to control the total content of the hemimellitene in the overhead fraction and the indan + p-methylisoprene with the boiling point very close to the hemimellitene in the overhead fraction to be more than or equal to 99.6 percent (wt) so as to ensure that the hemimellitene product is qualified in quality. When the heating source of the tower kettle of the connecting tritoluene removing tower 22 is started, the low-pressure steam of a pipe network is used, and the gas phase at the top of the connecting tritoluene extracting and rectifying tower 26 is used after the whole plant is normal.
In a preferred embodiment, in the step (8), the operating pressure of the bottom of the hemimellitene extractive distillation column 26 is 130 to 150kPa, and the temperature of the bottom is controlled within a range of 185 to 205 ℃. The purpose of the control is to remove the indan + p-methyl isopropylbenzene component in the tower kettle component as much as possible so as to ensure that the quality of the hemimellitene product is qualified; the operation pressure at the top of the tower is 120-140 kPa, the control range of the top temperature is 172-176 ℃, and the reflux ratio is 11-12: 1. The aim of controlling in this way is to ensure that the content of hemimellitene in the overhead distillate is less than or equal to 2 percent (wt) so as to ensure that the comprehensive yield of the hemimellitene target product is more than or equal to 82 percent (wt).
In a preferred embodiment, in the step (9), the operation pressure of the column bottom of the hemimellitene analysis column 29 is 25 to 40kpa.a, and the temperature of the column bottom is controlled within a range of 135 to 150 ℃. The aim of controlling is to completely resolve hemimellitene in the extraction solvent so as to ensure that the comprehensive yield of the hemimellitene product is more than or equal to 82 percent (wt); the operation pressure at the top of the tower is 15-30 kPa.A, the control range of the top temperature is 120-130 ℃, and the reflux ratio is 4.5-5.5: 1. The aim of the control is to ensure that the purity of the hemimellitene product distilled from the tower top is more than or equal to 99 percent (wt).
In specific engineering practice, medium-pressure steam and low-pressure steam condensate are respectively collected according to temperature steps and then are used as a multi-section raw material, a semi-finished product feeding preheating heat source and a heat tracing heat source, so that the energy is fully and effectively utilized.
The method provided by the invention ensures that the whole rectification process is safe, efficient, environment-friendly, energy-saving, high in integration level and good in economical efficiency.
The present invention will be described in further detail with reference to specific examples, but the scope of the present invention is not limited thereto.
Example 1
The method comprises the following steps of separating pseudocumene, mesitylene and hemimellitene from a refinery reformed carbon nine-heavy aromatic hydrocarbon raw material to obtain a byproduct o-methyl-ethylbenzene:
(1) feeding reformed carbon nine heavy aromatics raw material from a refinery into a first light component removal tower 2 according to the feeding speed of 10t/h, wherein the operation conditions of the first light component removal tower 2 are that the kettle temperature is 133 ℃ and the top temperature is 100 ℃; jacking and pressing 15 KPa.A; the reflux ratio is 3.5; the amount of light components output by the light component conveying pump 3 is 1.65t/h, and the amount of light components sent to the sym-tritoluene removing tower 5 by the first light component removing tower kettle conveying pump 4 is 8.35 t/h;
(2) the operating conditions of the mesitylene removal column 5 are as follows: the kettle temperature is 138 ℃, and the top temperature is 111 ℃; jacking and pressing 7 KPa.A; the reflux ratio is 4.5; the amount of the mesitylene-rich component output by the mesitylene-rich delivery pump 6 and sent to the mesitylene extractive distillation tower 12 is 1.62 t/h; the feeding amount of the components in the bottom of the mesitylene removal tower, which are sent to the pseudomesitylene rectifying tower 8 by the delivery pump 7, is 6.73 t/h;
(3) the operating conditions of the pseudocumene rectifying column 8 are as follows: the kettle temperature is 211 ℃, the top temperature is 192 ℃, and the side line extraction outlet temperature is 190 ℃; jacking and pressing 133 KPa.A; reflux ratio 12. The amount of the pseudocumene product pumped out by the side-line pseudocumene product delivery pump 9 is 4.11t/h, the amount of the narrow fraction aromatic hydrocarbon solvent SA1000# -A output by the component delivery pump 18 with the boiling point of 165.5-169.3 ℃ is 0.86t/h, and the feeding amount of the pseudocumene rectifying tower kettle component delivery pump 10 sent to the hemicumene light-ends removal tower 19 is 1.76 t/h. The yield of the pseudocumene product is 92.32 percent (wt) calculated by the pseudocumene content in the feed raw material;
(4) the operating conditions of the mesitylene extractive distillation column 12 are as follows: the kettle temperature is 195 ℃ and the top temperature is 175 ℃; jacking and pressing 122 KPa.A; a reflux ratio of 14; the mol ratio of trimethyl trimesate to n-octanol in the extraction solvent is 4: 1, and the mol ratio of the extraction solvent to mesitylene is 10: 1. The amount of the by-product o-methyl-ethylbenzene product output by the enriched o-methyl-ethylbenzene delivery pump 13 is 0.65t/h, and the feed amount sent to the mesitylene desorption tower 15 by the mesitylene extraction rectification tower kettle component delivery pump 14 is 24.18 t/h;
(5) the operating conditions of the mesitylene stripper 15 are: the kettle temperature is 140 ℃ and the top temperature is 118 ℃; jacking and pressing 30 KPa.A; the reflux ratio was 3.5. The amount of the mesitylene product output by the mesitylene product delivery pump 16 is 0.92t/h, and the amount of the extraction solvent which is sent to the mesitylene extractive distillation tower 12 by the first extractant delivery pump 17 at the bottom of the mesitylene desorption tower for recycling is 23.26 t/h. The yield of the mesitylene product is 86.71% (wt) calculated by the mesitylene content in the feed raw material;
(6) the operational conditions of the hemimellitene lightness-removing tower 19 are that the kettle temperature is 148 ℃ and the top temperature is 130 ℃; jacking and pressing 8 KPa.A; the reflux ratio is 6; the amount of light components output by a component delivery pump 20 with the boiling point of 170-176 ℃ is 0.45t/h, and the amount of light components sent to a trimethyl benzene removing light tower bottom component delivery pump 21 to a trimethyl benzene removing light tower 22 is 1.31 t/h;
(7) the operating conditions of the toluene removal column 22 are: the kettle temperature is 135 ℃, and the top temperature is 110 ℃; jacking and pressing 6 KPa.A; the reflux ratio is 4.6; the amount of hemimellitene-rich components output by the hemimellitene-rich delivery pump 23 and sent to the hemimellitene extraction rectifying tower 26 is 1.05t/h, and the amount of hemimellitene-removal tower kettle component delivery pump 24 and sent to the storage tank area is 0.26 t/h;
(8) the operation conditions of the hemimellitene extractive distillation tower 26 are as follows: the kettle temperature is 200 ℃ and the top temperature is 175 ℃; jacking and pressing 130 KPa.A; the reflux ratio is 11; the mol ratio of 3,4, 5-trimethylphenol to n-octanol in the extraction solvent is 2: 1, and the mol ratio of the extraction solvent to mesitylene is 7: 1. The amount of the stream rich in methyl isopropylbenzene and indane output by the indane and methyl isopropylbenzene transfer pump 27 is 0.32t/h, and the feeding amount of the component transfer pump 28 at the bottom of the hemimellitene extraction rectification tower sent to the hemimellitene resolution tower 29 is 6.44 t/h;
(9) the operating conditions of the hemimellitene desorption tower 29 are as follows: the kettle temperature is 145 ℃, and the top temperature is 126 ℃; jacking and pressing 20 KPa.A; the reflux ratio was 5. The amount of the hemimellitene product output by the hemimellitene product delivery pump 30 is 0.71t/h, and the amount of the extraction solvent which is sent to the hemimellitene extraction rectifying tower 26 by the hemimellitene resolving tower kettle second extraction agent delivery pump 31 for recycling is 5.73 t/h. The yield of hemimellitene product is 82.35% (wt) calculated by the hemimellitene content in the feed raw material.
(10) Thermal coupling
The first thermal coupling is to introduce the steam at the top of the pseudocumene rectifying tower 8 into another reboiler of the first lightness-removing tower 2 as a heat source, completely release latent heat and partial sensible heat, change the steam into a liquid phase and then return the liquid phase to a reflux tank of the pseudocumene rectifying tower 8. And the reboiler of the first lightness-removing tower 2 which uses low-pressure steam as a heat source is completely stopped, and the low-pressure steam is saved by 6.35 t/h.
The second thermal coupling is to introduce the steam at the top of the mesitylene extractive distillation column 12 into another reboiler of the mesitylene removing column 5 as a heat source, completely release latent heat and partial sensible heat, change the steam into a liquid phase and then return the liquid phase to a reflux tank of the mesitylene extractive distillation column 12. And the reboiler of the sym-tritoluene removal tower 5 using low-pressure steam as a heat source is completely stopped, and the low-pressure steam is saved by 3.66 t/h.
The third thermal coupling is to introduce the steam at the top of the hemimellitene extractive distillation tower 26 into another reboiler of the toluene removing tower 22 as a heat source, completely release latent heat and partial sensible heat, change the steam into a liquid phase, and then return the liquid phase to a reflux tank of the hemimellitene extractive distillation tower 26. And the reboiler of the toluene removing tower 22 using low-pressure steam as a heat source is completely stopped, and the low-pressure steam is saved by 2.2 t/h.
(11) Heat integration 1
And (4) completely collecting the medium-pressure condensate, introducing the collected medium-pressure condensate into a low-pressure steam flash tank, and merging the low-pressure steam flashed out into a low-pressure steam pipe network for use.
(12) Heat integration 2
In the industrial device, the heated feeding material and the cooled discharging material exchange heat, so that the consumption of steam can be reduced, and the consumption of circulating water can also be reduced. Materials with various temperature levels are heated or cooled step by step according to the temperature gradient, although the process becomes relatively complex and the primary investment is high, the energy saving in long-term operation is considerable.
The condensate generated by the low-pressure steam can be reasonably utilized in a gradient way according to different temperature levels.
This example further examined the three end products obtained, one by-product. The detection specifically comprises the following steps:
(1) according to the method specified by the HS/T-2016 Customs industry standard of the people's republic of China, an Agilent GC-7890 type gas chromatograph is used for respectively measuring three final products and a byproduct, and the specific parameters comprise: FID detector: 7X 10-6mg/ml, PEG-20M capillary column; column temperature: 40 ℃/4 min to 80 ℃/8 min; the heating rate is as follows: 22 ℃/min; vaporization chamber temperature: 188 ℃; the split ratio is as follows: 120: 1, and the solvent is toluene;
the final product, pseudocumene, was chromatographed as shown in FIG. 2.
The analysis result is as follows: the purity of the pseudocumene in the final product was 99.32% (wt).
The chromatogram of the final product mesitylene is shown in FIG. 3.
The analysis result is as follows: the purity of mesitylene in the final product was 99.09% (wt).
The chromatogram of the hemimellitene final product is shown in FIG. 4.
The analysis result is as follows: the purity of hemimellitene in the final product was 99.16% (wt).
The chromatogram of the by-product o-methyl-ethyl benzene is shown in FIG. 5.
The analysis result is as follows: the purity of the by-product o-methyl-ethylbenzene was 95.56% (wt).
Example 2
Compared with example 1, the difference is that: the mol ratio of trimethyl trimesate to n-octanol in the extraction solvent in the step (4) is 3: 1.
The three final products and one by-product are detected, and the result is as follows:
the purity of the pseudocumene in the final product was 99.29% (wt);
the purity of mesitylene in the final product is 98.63% (wt);
the purity of hemimellitene in the final product is 99.10% (wt);
the purity of the by-product o-methyl-ethyl benzene is 93.28% (wt).
Compared with the example 1, the yield of the mesitylene is reduced (relative to the content of the raw materials) to 80.29 percent, and the reduction range is 6.42 percent; the yield of o-methyl-ethyl benzene is reduced by about 10 percent (relative to the content of the raw material).
Example 3
Compared with example 1, the difference is that: the mol ratio of trimethyl trimesate to n-octanol in the extraction solvent in the step (4) is 5: 1.
The three final products and one by-product are detected, and the result is as follows:
the purity of the pseudocumene in the final product is 99.25 percent (wt);
the purity of mesitylene in the final product is 98.68% (wt);
the purity of hemimellitene in the final product is 99.20% (wt);
the purity of the by-product o-methyl-ethyl benzene is 95.61% (wt).
Compared with the embodiment 1, the yield of the mesitylene is increased (relative to the content of the raw materials) to 86.92 percent, and the increase range is 0.21 percent; the yield of the o-methyl ethyl benzene is increased by about 1 percent (relative to the content of the raw material); however, the energy consumption of the whole device is improved by about 6.5 percent, and the economic performance is relatively large and negative. And the purity of the mesitylene product is reduced to below 99 percent.
Example 4
Compared with example 1, the difference is that: the mol ratio of the 3,4, 5-trimethylphenol to the n-octanol in the extraction solvent in the step (8) is 1.5: 1.
The three final products and one by-product are detected, and the result is as follows:
the purity of the pseudocumene in the final product was 99.18% (wt);
the purity of mesitylene in the final product is 99.12% (wt);
the purity of hemimellitene in the final product is 99.21% (wt);
the purity of the by-product o-methyl-ethylbenzene was 95.37% (wt).
Compared with the example 1, the yield of the hemimellitene is reduced (relative to the content in the raw material) to 76.54 percent, and is reduced by 5.81 percent, and the amplitude is large.
Example 5
Compared with example 1, the difference is that: the mol ratio of the 3,4, 5-trimethylphenol to the n-octanol in the extraction solvent in the step (8) is 2.5: 1.
The three final products and one by-product are detected, and the result is as follows:
the purity of the pseudocumene in the final product was 99.22% (wt);
the purity of mesitylene in the final product is 99.06% (wt);
the purity of hemimellitene in the final product is 98.39% (wt);
the purity of the by-product o-methyl-ethylbenzene was 95.44% (wt).
Compared with the example 1, the yield of the hemimellitene is increased (relative to the content of the raw material) to 83.02 percent, and the increase amplitude is 0.67 percent; however, the energy consumption of the whole device is increased by about 5.35%, and the economic performance is relatively large and negative. And the purity of the product is reduced to below 99 percent.
Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims (10)

1. A method for separating a mixture of carbon nonaromatic hydrocarbons, wherein the mixture of carbon nonaromatic hydrocarbons contains pseudocumene, hemimellitene and at least one selected from the group consisting of p-methylisoprene and indane, the method comprising the steps of:
(1) introducing heavy components with the boiling point higher than 165.5 ℃ in the carbon nonaromatic hydrocarbon mixture into a pseudocumene rectifying tower, leading out a pseudocumene product from the side line of the pseudocumene rectifying tower, leading out light components with the boiling point between 165.5 and 169.3 ℃ from the top of the tower, and leading out heavy components with the boiling point higher than 170 ℃ from the bottom of the tower;
(2) introducing the heavy component with the boiling point higher than 170 ℃ in the step (1) into a hemimellitene light component removal tower, extracting the light component with the boiling point of 170-176 ℃ from the top of the hemimellitene light component removal tower, and extracting the heavy component with the boiling point higher than 176 ℃ from the bottom of the light component removal tower;
(3) introducing the heavy component with the boiling point higher than 176 ℃ in the step (2) into a trimethyl benzene removing tower, leading out a light component containing trimethyl benzene and at least one of p-methyl isopropylbenzene and indane from the top of the trimethyl benzene removing tower, and leading out the heavy component with the boiling point higher than 177.2 ℃ from the bottom of the tower;
(4) introducing the light components in the step (3) into a hemimellitene extractive distillation tower, carrying out extractive distillation in the presence of a second extractant, leading out at least one of p-methylisoprene and indane from the top of the hemimellitene extractive distillation tower, and leading out heavy components containing the second extractant and the hemimellitene from the bottom of the tower;
wherein the second extractant is a mixed solution containing 3,4, 5-trimethylphenol and n-octanol.
2. The method for separating a mixture of nonaromatic hydrocarbons according to claim 1, wherein the molar ratio of 3,4, 5-trimethylphenol to n-octanol is 1.5-2.5: 1, preferably 1.8-2.2: 1.
3. The process for the separation of a mixture of carbon nonaromatic hydrocarbons according to claim 1 or 2, further comprising the steps of: and (4) introducing the heavy component containing the second extractant and the hemimellitene in the step (4) into a hemimellitene resolving tower, leading out a hemimellitene product from the top of the hemimellitene resolving tower, and leading out the second extractant from the bottom of the tower.
4. The method for separating a mixture of carbon nonaromatic hydrocarbons as claimed in any one of claims 1 to 3, wherein the mixture of carbon nonaromatic hydrocarbons further comprises mesitylene and o-methylethylbenzene, and wherein the method further comprises the steps of:
(5) introducing a carbon nonaarene mixture into a first light component removal tower, leading out light components with the boiling point lower than 164.5 ℃ from the top of the first light component removal tower, and leading out heavy components containing mesitylene and o-methyl ethylbenzene from the bottom of the tower;
(6) introducing the heavy component in the step (5) into a mesitylene removal tower, and extracting a light component containing mesitylene and o-methyl-ethyl benzene from the top of the mesitylene removal tower, wherein the heavy component with the boiling point higher than 165.5 ℃ is extracted from the bottom of the tower;
(7) introducing the light component containing mesitylene and o-methyl ethylbenzene in the step (6) into a mesitylene extractive distillation tower, carrying out extractive distillation in the presence of a first extractant, leading out an o-methyl ethylbenzene product from the top of the mesitylene extractive distillation tower, and leading out a heavy component containing the first extractant and mesitylene from the bottom of the tower;
the first extracting agent is a mixed solution containing trimethyl trimesate and n-octanol, preferably, the molar ratio of the trimethyl trimesate to the n-octanol is 3-5: 1, more preferably 3.5-4.5: 1, and most preferably 3.8-4.2: 1.
5. The method for separating a mixture of carbon nonaromatic hydrocarbons according to claim 4, further comprising the steps of: and (4) introducing the heavy component containing the first extractant and mesitylene in the step (7) into a mesitylene desorption tower, leading out a mesitylene product from the top of the mesitylene desorption tower, and leading out the first extractant from the bottom of the tower.
6. A device for separating a carbon nonaarene mixture is characterized by comprising a pseudocumene rectifying tower, a hemimellitene light-removing tower, a hemimellitene extracting and rectifying tower and a hemimellitene analyzing tower;
a raw material inlet is formed in the side part of the pseudocumene rectifying tower, and the raw material inlet of the pseudocumene rectifying tower is used for inputting heavy components with the boiling point higher than 165.5 ℃ in a carbon nonaromatic hydrocarbon mixture;
the pseudocumene rectifying tower is provided with a side line discharge port, a pseudocumene product is led out from the side line discharge port, and a tower kettle discharge port of the pseudocumene rectifying tower is connected with a raw material feed port of the hemicumene connecting light component removing tower;
a discharge port of a tower kettle of the hemimellitene light-ends removal tower is connected with a raw material feed port of the hemimellitene removal tower;
a discharge hole at the top of the hemitritoluene removing tower is connected with a raw material feed hole of the hemitritoluene extracting and rectifying tower;
the hemimellitene extraction and rectification tower is provided with a second extractant feed inlet, a discharge hole at the top of the hemimellitene extraction and rectification tower is used for leading out methylisoprophenyl and/or indane, and a discharge hole at the bottom of the tower is connected with a raw material feed inlet of the hemimellitene desorption tower;
and a hemimellitene product is led out from a discharge hole at the top of the hemimellitene analysis tower.
7. The apparatus for separating a mixture of carbon nonaromatic hydrocarbons as claimed in claim 6, wherein at least eight packing elements or trays corresponding to eight theoretical trays are disposed between the side outlet of the pseudocumene rectifying column and the top of the pseudocumene rectifying column.
8. The apparatus for separating a carbon nonaromatic hydrocarbon mixture according to claim 6 or 7, further comprising a first light component removal column, a mesitylene extractive distillation column and a mesitylene desorption column;
a carbon nonaarene mixture feeding port is formed in the side part of the first light component removal tower, and a tower kettle discharging port of the first light component removal tower is connected with a raw material feeding port of the sym-tritoluene removal tower;
a discharge hole at the top of the mesitylene removing tower is connected with a raw material feed hole of the mesitylene extractive distillation tower; a discharge hole of a tower kettle of the mesitylene removal tower is connected with a raw material feed hole of the pseudocumene rectifying tower;
the mesitylene extractive distillation tower is provided with a first extractant feed inlet, an o-methylethylbenzene product is led out from a discharge hole at the top of the mesitylene extractive distillation tower, and a discharge hole at a tower kettle is connected with a raw material feed inlet of the mesitylene desorption tower;
and a discharge hole at the top of the mesitylene desorption tower is used for leading out a mesitylene product.
9. The apparatus for separating a mixture of carbon nonaromatic hydrocarbons according to claim 8, wherein the first light component removal column, the mesitylene extractive distillation column, the mesitylene light component removal column, the mesitylene xylene removal column, the tritolyl removal column, and the mesitylene extractive distillation column are filled with bidirectional curvelet efficient structured packing;
the inside of the mesitylene desorption tower, the unsym-trimethylbenzene rectifying tower and the hemimelene desorption tower is filled with a bidirectional oblique wave efficient regular packing.
10. A method for separating hemimellitene from at least one of p-methylisoprene and indane, which comprises the following steps: performing extractive distillation on a system containing hemimellitene and at least one selected from p-methyl isopropylbenzene and indane in the presence of an extracting agent, wherein the extracting agent is a mixed solution comprising 3,4, 5-trimethylphenol and n-octanol; preferably, the molar ratio of the 3,4, 5-trimethylphenol to the n-octanol is 1.5-2.5: 1, and more preferably, the molar ratio of the 3,4, 5-trimethylphenol to the n-octanol is 1.8-2.2: 1.
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