CN114058400A

CN114058400A - Multistage extraction device and method for aromatic hydrocarbons from waste tire pyrolysis oil by using ionic liquid

Info

Publication number: CN114058400A
Application number: CN202111409083.6A
Authority: CN
Inventors: 陈标华; 张明鑫; 于刚强; 代成娜; 徐瑞年; 刘宁; 王宁
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2021-11-24
Filing date: 2021-11-24
Publication date: 2022-02-18

Abstract

A multistage extraction device and method for aromatic hydrocarbon from waste tire pyrolysis oil by using ionic liquid belong to the technical field of chemical separation and purification. The adopted device comprises a first extraction tower (C1), a second extraction tower (C2), a raffinate flash tank (S1) and an extract flash tank (S2); by adopting the extraction agent based on the ionic liquid, the multistage countercurrent-cross flow combined extraction method of the extraction agent realizes the high-efficiency separation of the aromatic hydrocarbon mixture of the tire pyrolysis oil, reduces the energy consumption of the device and simultaneously reduces the equipment cost.

Description

Multistage extraction device and method for aromatic hydrocarbons from waste tire pyrolysis oil by using ionic liquid

Technical Field

The invention relates to a multistage combined extraction device and method for waste tire pyrolysis oil aromatic hydrocarbons by using ionic liquid. The ionic liquid extractant can be single ionic liquid, mixed ionic liquid or a mixture of the ionic liquid and a traditional organic solvent; belongs to the technical field of chemical separation and purification.

Background

With the development of the transportation industry and the prosperity of the automobile industry, the demand for tires is increasing, and as a result, the accumulation and disposal of waste tires are brought about. The automobile industry in China develops rapidly, the production capacity and the consumption of tires are huge, and the problem of waste tires is increasingly obvious. The waste tires are treated by mainly stacking and burying, original shape utilization, heat utilization and recycling. The pile-up occupies a large amount of land resources and is liable to cause a fire. The original shape utilization means that the waste tires are transformed into articles with use value, the articles can be used as wave-proof equipment, amusement tools and the like, the rubber can be used as the best as possible, but the utilization rate of the waste tires is low in part. The heat utilization means that the waste tires can be used as fuel, and the heat value of the waste tires is higher than that of wood and coal. The recycling and reusing mainly comprises tire land retreading, reclaimed rubber utilization and waste tire land thermal cracking treatment. The tires are difficult to degrade in a natural state, and the thermal cracking is a way for efficiently converting organic solid wastes so as to realize a method approach for recycling the waste tires. The main chemical components of the waste tire are natural rubber, styrene butadiene rubber, butadiene rubber and carbon black, the contained combustible element C, H is high in content, the heat productivity is large, and the potential of energy utilization is achieved. Under the condition of oxygen deficiency or the existence of inert gas, the tyre cracks rubber macromolecules into cracking gas, cracking oil and cracking carbon black at a proper temperature by a thermal cracking technology. The pyrolysis oil is a mixture of paraffin, olefin and aromatic hydrocarbon, has more complex components and higher heat value, is a complex mixture with wide boiling point, and has larger proportion of aromatic hydrocarbon in the pyrolysis oil. The cracked oil can be separated into different fractions according to the distillation product, namely a light fraction (<200 ℃), a medium fraction (200-350 ℃) and a heavy fraction (>350 ℃). The light fraction is also called naphtha fraction, which contains more aromatic compounds and has higher octane number, can be used as an additive of gasoline for vehicles, and can separate various organic raw materials such as BTX (benzene, toluene and xylene), gasoline, kerosene, asphalt and the like. The medium fraction is very complex in composition, and its use is limited by the high content of aromatics and sulfur elements, which must be further refined. The medium fraction can be used as a blending component of low freezing point diesel oil after hydrofining. The heavy fraction can be used as fuel oil for diesel generators, engines, heavy equipment and the like, can also be used as a raw material for producing coke, or can be used as a modifier of asphalt. Aromatic hydrocarbons are abbreviated as aromatic hydrocarbons, which are the general names of benzene and derivatives thereof, and refer to hydrocarbon compounds containing one or more benzene rings in the molecular structure. The source of its name is due to the fact that in the early stages of development of organic chemistry, this class of compounds is almost all found in volatile, odoriferous substances; and later generally refers to hydrocarbons containing a benzene ring structure in the molecule. Aromatic hydrocarbons are mainly derived from coal, tar and petroleum. The aromatic hydrocarbon is insoluble in water and soluble in an organic solvent; generally lighter than water, the boiling point increases with increasing molecular weight; aromatic hydrocarbon is easy to generate substitution reaction and can also generate addition reaction under certain conditions. The aromatic hydrocarbon is mainly used in pharmaceutical industry, dye industry and the like. The aromatics in pyrolysis oil are gasoline blending components with higher octane and calorific values, but they can cause the formation of carcinogens upon combustion, especially benzene, as a major component in toxic emissions. Aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene are important basic raw materials in the chemical industry, and they can be used for producing rubber, nylon and the like. Therefore, the extraction of aromatic hydrocarbons from pyrolysis oil is of great significance.

The separation of aromatic and aliphatic hydrocarbons is very complex because their boiling points are very close and they can form azeotropes. The concentration of aromatic hydrocarbons in the feed determines the separation technique to be selected. Liquid-liquid extraction is used when the aromatic content is between 20 and 65 wt.%, and extractive distillation is selected when the aromatic content is between 65 and 90 wt.%. The traditional organic solvent for industrial aromatic extraction, such as sulfolane, N-formyl morpholine, dimethyl sulfoxide and the like, is generally toxic, volatile and flammable, and for diesel oil fractions with high aromatic content, the phenomenon of solvent and raw material mixing can occur, and the defect of high energy consumption exists in the solvent recovery process, so that the pollution to the environment is increased more and more, and therefore, an environment-friendly green solvent needs to be found to replace the traditional organic solvent. In recent years, ionic liquid has attracted great attention as a substitute solvent in various separation processes, and the ionic liquid is a very clean liquid-liquid extraction medium, is applied to dearomatization and has advantages compared with the traditional molecular solvent. The ionic liquid is an ionic system which is composed of organic cations and organic or inorganic anions and is in a liquid state at room temperature or above, and part of the ionic system is solid. The ionic liquid generally has the advantages of high boiling point, low vapor pressure, high thermochemical stability, electrochemical stability and the like, and can be used in the fields of catalysis, synthesis, separation, electrochemistry and the like. And the ionic liquid is used as a green solvent, so that the defects of toxicity, easy volatilization, difficult biodegradation and the like of the traditional extracting agent can be avoided. Due to its specific non-volatility, the ionic liquid will simplify the aromatics extraction unit, the extraction process of the ionic liquid will require fewer process steps than conventional solvents, and the energy consumption will be lower because the hydrocarbons extracted from the ionic liquid based solvent can be separated by simple flashing or stripping. At present, a plurality of ionic liquids are used for separating and extracting aromatic hydrocarbon and have good separation effect. At present, the aromatic hydrocarbon separation is mainly realized by adopting hydrofining and aromatic hydrocarbon extraction technologies in industry, and the research of the ionic liquid on the aromatic hydrocarbon separation is mainly focused on the two aspects. The aromatic extraction technology is divided into two types of extraction distillation and liquid-liquid extraction, wherein the extraction distillation is to add a solvent or an extracting agent with a boiling point higher than that of a separation component after the solvent is added, so as to change the relative volatility of the original components to separate the components; the liquid-liquid extraction is to form an aromatic hydrocarbon and non-aromatic hydrocarbon two-phase system after adding a solvent, and to separate the aromatic hydrocarbon and the non-aromatic hydrocarbon by utilizing the difference of solubility and selectivity of the aromatic hydrocarbon and the non-aromatic hydrocarbon. The present document describes a technology for extracting aromatic hydrocarbons from waste tire pyrolysis oil by using different ionic liquids.

Chinese patent CN102021024A discloses a system and method for preparing high quality diesel oil, the system includes an extraction device, a part of aromatic hydrocarbons in diesel oil are removed by solvent extraction, high quality diesel oil is obtained by hydrogenation treatment of raffinate oil, and the extracted aromatic hydrocarbons are discharged from the system. The raw materials processed by the method are diversified, can be various diesel oil, and the aromatic hydrocarbon is separated from the diesel oil, so that the cetane number of the diesel oil is greatly improved, and the condensation point of the diesel oil is reduced.

Chinese patent CN102443436A discloses a combined method of hydrotreatment, catalytic cracking and extraction of cracked oil from tires of residual oil. In the method, residual oil is hydrotreated in the presence of hydrogen and a hydrogenation catalyst, effluent is separated to obtain a gas-phase product and a liquid-phase product, the liquid-phase product directly enters a catalytic cracking device for reaction without fractionation, reaction effluent is separated to obtain dry gas, liquefied gas, catalytic cracking gasoline, catalytic cracking diesel and heavy distillate oil, the catalytic diesel is extracted by aromatic hydrocarbon, extract oil and catalytic cracking heavy distillate oil are recycled to the hydrotreating device after being filtered, and raffinate oil is discharged from the device to obtain the diesel with high cetane number. In the method, the hydrocracking reaction effluent directly enters the catalytic cracking device without fractionation, so that the load of the catalytic cracking device is increased undoubtedly, and the processing capacity of the device is influenced; secondly, the effluent of the hydrocracking reaction contains a certain amount of light components, and the light components enter a catalytic cracking device and then undergo secondary reaction, so that light distillate oil is reduced, the gas yield is increased, and certain economic loss is caused.

TABLE 1 Main physical Properties of conventional extractants

The invention realizes the high-efficiency separation of the aromatic hydrocarbon mixture of the tire pyrolysis oil by the extraction agent multi-stage countercurrent-cross flow combined extraction method and the extraction agent based on the ionic liquid, reduces the energy consumption of the device and simultaneously reduces the equipment cost.

Disclosure of Invention

The invention aims to provide a multistage combined extraction device and method for waste tire pyrolysis oil aromatic hydrocarbons by using ionic liquid. The device can reduce the solvent ratio, can overcome the problem of mixing and dissolving of the solvent and the mixture to be separated, can improve the separation efficiency of the cracked oil of the tire and the quality of the diesel oil product of the cracked oil of the tire, and can improve the quality of the diesel oil and expand the aromatic hydrocarbon resources.

The invention is realized by the following technical scheme.

The multistage combined extraction device for the waste tire pyrolysis oil by using the ionic liquid is characterized by mainly comprising the following parts:

a first extraction column (C1), a second extraction column (C2), a raffinate flash drum (S1), and an extract flash drum (S2);

sending aromatic hydrocarbons of the waste tire cracked oil to be separated into a first extraction tower (C1) from the lower part, sending a first ionic liquid extraction solvent (A1) into the first extraction tower (C1) from an upper feeding hole, extracting through a liquid phase, discharging raffinate oil rich in olefin from the top of the first extraction tower (C1), arranging a pipeline at the top of the first extraction tower (C1) to be connected with the lower part of a second extraction tower (C2), and sending a second ionic liquid extraction solvent (A2) into the second extraction tower (C2) from an extraction agent feeding hole at the top of the second extraction tower (C2); the upper part of the second extraction tower (C2) is provided with a pipeline which is connected with the raffinate flash tank (S1), and the oil extracted from the second extraction tower (C2) enters the raffinate flash tank (S1) from the upper part of the second extraction tower (C2);

a pipeline is arranged at the top of the second extraction tower (C2) and is connected with the middle part of the flash tank (S1), raffinate oil discharged from the top of the second extraction tower (C2) is subjected to flash separation in the flash tank (S1), and non-aromatic hydrocarbon components (comprising alkane, olefin and the like) are discharged from the top of the raffinate flash tank (S1); the bottoms of the first extraction tower (C1) and the second extraction tower (C2) are respectively provided with a pipeline connected with the middle part of the extraction liquid flash tank (S2), the extracted oil discharged from the bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the extraction liquid flash tank (S2), flash separation is carried out in the extraction liquid flash tank (S2), and aromatic hydrocarbon components (including polycyclic aromatic hydrocarbon) are discharged from the top of the extraction liquid flash tank (S2).

Further, if necessary, the non-aromatic hydrocarbon component flowing out of the raffinate flash drum (S1) is provided with a partial reflux line for refluxing to the middle lower part of the second extraction tower (C2), and the reflux pipeline of the raffinate flash drum (S1) is connected with the middle lower part of the second extraction tower (C2) for partial reflux; the aromatic hydrocarbon components (including polycyclic aromatic hydrocarbon) flowing out of the top of the extract liquid flash tank (S2) are also provided with a part of reflux pipelines to reflux to the middle lower part of the first extraction tower (C1), and a pipeline refluxing from the extract liquid flash tank (S2) is connected with the middle lower part of the first extraction tower (C1) to carry out part of reflux.

Meanwhile, the bottom of the raffinate flash tank (S1) and the bottom of the extract flash tank (S2) are combined by pipelines and are respectively connected with the upper feed inlet of the first extraction tower (C1) and the upper feed inlet of the second extraction tower (C2) and used for providing an extracting agent for the first extraction tower (C1) and the second extraction tower (C2).

The method for extracting and separating the tire pyrolysis oil by utilizing the device to perform the multistage combination of the solvent based on the ionic liquid mainly comprises the following steps:

(1) the first ionic liquid extraction solvent (A1) enters a first extraction tower (C1) from the top of the first extraction tower (C1), and the tire cracking oil enters from the lower part of the first extraction tower (C1); after high-efficiency separation, raffinate oil is discharged from the top of a first extraction tower (C1) and enters the lower part of a second extraction tower (C2), and extract oil rich in ionic liquid enters the middle part of an extract liquid flash tank (S2) from the bottom of the first extraction tower (C1);

(2) a second ionic liquid extraction solvent (A2) enters a second extraction tower (C2) from the top of the second extraction tower (C2), extract oil enters the middle part (S2) of an extract liquid flash tank from the bottom of the second extraction tower (C2), after high-efficiency separation is carried out in the extract liquid flash tank (S2), aromatic hydrocarbon (including polycyclic aromatic hydrocarbon) is obtained at the top of the extract liquid flash tank (S2), and an ionic liquid extraction agent is obtained at the bottom of the extract liquid flash tank (S2);

(3) a pipeline is arranged at the top of the second extraction tower (C2) and is connected with the middle part of the raffinate flash tank (S1), raffinate oil discharged from the top of the second extraction tower (C2) is subjected to flash separation, non-aromatic hydrocarbons (alkane, olefin and the like) are obtained at the top of the raffinate flash tank (S1) after the raffinate oil is efficiently separated by the raffinate flash tank (S1), and an ionic liquid extraction solvent is obtained at the bottom of the raffinate flash tank (S1);

(4) the ionic liquid extraction solvent obtained from the bottoms of the raffinate flash tank (S1) and the extract flash tank (S2) are mixed into a whole at a material flow outlet, and then are respectively connected with the top extraction agent feed inlets of the first extraction tower (C1) and the second extraction tower (C2) for recycling the ionic liquid extraction agent.

(5) Aromatic hydrocarbon components (including polycyclic aromatic hydrocarbons) and non-aromatic hydrocarbon components flowing out of the tops of the raffinate flash tank (S1) and the extract flash tank (S2) are also provided with partial reflux lines, and a pipeline (D1) refluxing from the extract flash tank (S2) is connected with the middle lower part of the first extraction tower (C1) for partial reflux; a conduit (D2) returning from the raffinate flash drum (S1) was connected to the lower middle portion of the second stripping column (C2) and partially returned.

And if the non-aromatic hydrocarbon components and the aromatic hydrocarbon components (including polycyclic aromatic hydrocarbon) flowing out of the tops of the raffinate flash tank (S1) and the extract flash tank (S2) partially reflux, the mass ratio of the reflux amount to the system output amount is 0.1-0.5.

According to another preferred embodiment of the invention, the operating pressure of the first extraction tower (C1) is 1-5 atm, the theoretical plate number (N) is 3-12, preferably 5-10, the operating temperature is 20-100 ℃, the feeding position of the extracting agent is 1-2, the feeding position of the tire cracking oil in the first extraction tower (C1) is (N-1) -N, and N is the last feeding plate;

the operating pressure of the second extraction tower (C2) is 1-5 atm, the theoretical plate number (N) is 3-12, preferably 5-10, the operating temperature is 20-100 ℃, the feeding position of the extracting agent is 1-2, the produced liquid at the top of the first extraction tower (C1) enters the second extraction tower (C2) from the bottom of the second extraction tower (C2), the feeding position of the tire cracking oil in the first extraction tower (C1) is (N-1) -N, and N is the last feeding plate.

According to another preferred embodiment of the present invention, it is characterized in that the operating pressure of the raffinate flash tank (S1) and the extract flash tank (S2) is 0.1 to 0.5atm, and the operating temperature is 60 to 150 ℃.

According to another preferred embodiment of the present invention, it is characterized in that the first ionic liquid extraction solvent and the second ionic liquid extraction solvent are the same and are each a single ionic liquid, a mixed ionic liquid or a mixture of an ionic liquid and a conventional organic solvent.

According to another preferred embodiment of the invention, the volume ratio of the ionic liquid of each mixing tower of the first extraction tower (C1) and the second extraction tower (C2) to the tire cracking oil is 0.5-3: 1.

According to another preferred embodiment of the present invention, the recovery rate of the solvent obtained after the separation of the tire cracking oil to be separated (with 60 wt% aromatic hydrocarbons +40 wt% olefins as the simulated component) is 99.00% to 99.99%, the recovery rate of the aromatic hydrocarbons in the extract is 99.00% to 99.99%, and the recovery rate of the olefins in the raffinate is 98.50% to 99.99%. Not only can improve the recovery rate of aromatic hydrocarbon and olefin, but also can improve the quality of diesel oil and expand aromatic hydrocarbon resources.

Compared with the prior art, the invention mainly has the following beneficial effects:

(1) the method has the advantages of simple process, convenient operation, stable operation and high aromatic hydrocarbon extraction efficiency, successfully separates the aromatic hydrocarbon mixture of the tire pyrolysis oil, and reduces the content of polycyclic aromatic hydrocarbon in oil products.

(2) The method adopts the extraction agent based on the ionic liquid, strengthens the separation effect of the extraction process, has simple recovery process of the extraction agent, reduces the energy consumption of the process and further reduces the cost of the process.

(3) The invention not only improves the recovery rate of the aromatic hydrocarbon, but also improves the recovery rate of the olefin.

Drawings

FIG. 1 is a flow chart of a process unit for multi-stage combined extraction.

In the figure, C1 — first extraction column; c2-second extraction column; s1-raffinate flash tank; s2-extract liquid flash tank; a1-a first ionic liquid extraction solvent, A2-a second ionic liquid extraction solvent, L1-a produced liquid at the top of a first extraction tower, L2-a produced liquid at the top of a second extraction tower, R1-a produced liquid at the bottom of the first extraction tower, R2-a produced liquid at the bottom of the second extraction tower, D1-a top return pipe of a raffinate flash tank, D2-a top return pipe of an extract flash tank, IL 1-a bottom of a raffinate flash tank to obtain an ionic liquid extraction agent, and IL 2-an extract flash tank to obtain the ionic liquid extraction agent.

Detailed Description

The present invention will be further described with reference to examples, but the present invention is not limited to the following examples, and various examples are included in the technical scope of the present invention without departing from the spirit of the invention described above.

The operating conditions of the first extraction column (C1) and the second extraction column (C2) in the following examples are both normal temperature and normal pressure. The raffinate flash drum (S1) and extract flash drum (S2) were operated at 0.3atm pressure and 100 deg.C.

The mass ratio of the top reflux amount of the raffinate flash tank (S1) and the extract flash tank (S2) to the system output amount of the following examples is 0.2.

Example 1:

common ionic liquid (specifically [ BMPY ] [ TF2N ]) is adopted as an extraction solvent.

The feed flow was 100kg/h and the tire cracked oil to be separated (60 wt% aromatics +40 wt% olefins as simulated components, see Table 1 for specific composition) was fed from the lower part of the first extraction column (C1). The theoretical plate number of the first extraction tower (C1) is 6, the feeding position of the tire pyrolysis oil is 6, the feeding position of the single ionic liquid is 1, the top raffinate oil of the first extraction tower (C1) enters the second extraction tower (C2) from the tower bottom, the single ionic liquid enters the second extraction tower (C2) from the tower top, the raffinate oil at the tower top of the second extraction tower (C2) is provided with a pipeline connected to the middle part of a raffinate flash tank (S1) for flash separation, the extract oil from the tower bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle part of an extract flash tank (S2) for flash separation, the volume ratio of the single ionic liquid to the feed to be separated of the tire pyrolysis oil in each stage of extraction is 1:1, and after multistage high-efficiency separation, the recovery rate of the solvent is 99.30 percent (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.23 percent, and the recovery rate of the olefin is 98.62 percent; the olefin content in the extract liquor is less than 2 percent, and the olefin content in the raffinate is 98.71 percent (mass fraction).

Example 2:

common ionic liquid (specifically [ BMIM ] [ TF2N ]) is used as an extraction solvent.

The feed flow was 100kg/h and the tire cracked oil to be separated (60 wt% aromatics +40 wt% olefins as simulated components, see Table 1 for specific composition) was fed from the lower part of the first extraction column (C1). The theoretical plate number of the first extraction tower (C1) is 6, the feeding position of the tire pyrolysis oil is 6, the feeding position of the single ionic liquid is 1, the top raffinate oil of the first extraction tower (C1) enters the second extraction tower (C2) from the tower bottom, the single ionic liquid enters the second extraction tower (C2) from the tower top, the raffinate oil at the tower top of the second extraction tower (C2) is provided with a pipeline connected to the middle part of a raffinate flash tank (S1) for flash separation, the extract oil from the tower bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle part of an extract flash tank (S2) for flash separation, the volume ratio of the single ionic liquid to the feed to be separated of the tire pyrolysis oil in each stage of extraction is 1:1, and after multistage high-efficiency separation, the recovery rate of the solvent is 99.37 percent (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.26 percent, and the recovery rate of the olefin is 98.77 percent; the olefin content in the extract was less than 2% and the olefin content in the raffinate was 98.66% (mass fraction).

Example 3:

common ionic liquid (specifically [ EMIM ] [ DCA ]) is adopted as an extraction solvent.

The feed flow was 100kg/h and the tire cracked oil to be separated (60 wt% aromatics +40 wt% olefins as simulated components, see Table 1 for specific composition) was fed from the lower part of the first extraction column (C1). The theoretical plate number of the first extraction tower (C1) is 6, the feeding position of the tire pyrolysis oil is 6, the feeding position of the single ionic liquid is 1, the top raffinate oil of the first extraction tower (C1) enters the second extraction tower (C2) from the tower bottom, the single ionic liquid enters the second extraction tower (C2) from the tower top, the raffinate oil at the tower top of the second extraction tower (C2) is provided with a pipeline connected to the middle part of a raffinate flash tank (S1) for flash separation, the extract oil from the tower bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle part of an extract flash tank (S2) for flash separation, the volume ratio of the single ionic liquid to the feed to be separated of the tire pyrolysis oil in each stage of extraction is 1:1, and after multistage high-efficiency separation, the recovery rate of the solvent is 99.54 percent (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.08 percent, and the recovery rate of the olefin is 98.90 percent; the olefin content in the extract was less than 2%, and the olefin content in the raffinate was 98.83% (mass fraction).

Example 4:

mixed ionic liquid (specifically [ BMPY ] [ TF2N ] and [ BMIM ] [ TF2N ] in a volume ratio of 1:1) is adopted as an extraction solvent.

The feed rate was 100kg/h, and the tire cracking oil to be separated (60 wt% aromatics +40 wt% olefins as the simulated components, see Table 1 for specific composition) was fed from the first extraction column (C1) from the lower part of the first extraction column (C1). The theoretical plate number of the first extraction tower (C1) is 6, the feeding position of the tire pyrolysis oil mixture is 6, the feeding position of the mixed ionic liquid is 2, the top raffinate oil of the first extraction tower (C1) enters the second extraction tower (C2) from the tower bottom, the mixed ionic liquid enters the second extraction tower (C2) from the tower top, the raffinate oil at the tower top of the second extraction tower (C2) is provided with a pipeline connected to the middle part of a raffinate flash tank (S1) for flash separation, the extract oil from the tower bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle part of an extract flash tank (S2) for flash separation, the volume ratio of the mixed ionic liquid to the tire pyrolysis oil feed to be separated in the process of each stage is 1:1, and after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.42 percent (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.11 percent, and the recovery rate of the olefin is 98.94 percent; the olefin content in the extract was less than 2%, and the olefin content in the raffinate was 98.88% (mass fraction).

Example 5:

mixed ionic liquid (specifically [ BMPY ] [ TF2N ] and [ EMIM ] [ DCA ] in a volume ratio of 1:1) is adopted as an extraction solvent.

The feed rate was 100kg/h, and the tire cracking oil to be separated (60 wt% aromatics +40 wt% olefins as the simulated components, see Table 1 for specific composition) was fed from the first extraction column (C1) from the lower part of the first extraction column (C1). The theoretical plate number of the first extraction tower (C1) is 6, the feeding position of the tire pyrolysis oil mixture is 6, the feeding position of the mixed ionic liquid is 2, the top raffinate oil of the first extraction tower (C1) enters the second extraction tower (C2) from the tower bottom, the mixed ionic liquid enters the second extraction tower (C2) from the tower top, the raffinate oil at the tower top of the second extraction tower (C2) is provided with a pipeline connected to the middle part of a raffinate flash tank (S1) for flash separation, the extract oil from the tower bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle part of an extract flash tank (S2) for flash separation, the volume ratio of the mixed ionic liquid to the tire pyrolysis oil feed to be separated in the process of each stage is 1:1, and after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.49 percent (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.24 percent, and the recovery rate of the olefin is 98.96 percent; the olefin content in the extract liquid is less than 2 percent, and the olefin content in the raffinate liquid is 98.98 percent (mass fraction).

Example 6:

the mixed ionic liquid (specifically [ BMIM ] [ TF2N ] and [ EMIM ] [ DCA ] with the volume ratio of 1:1) is adopted as the extraction solvent.

The feed rate was 100kg/h, and the tire cracking oil to be separated (60 wt% aromatics +40 wt% olefins as the simulated components, see Table 1 for specific composition) was fed from the first extraction column (C1) from the lower part of the first extraction column (C1). The theoretical plate number of the first extraction tower (C1) is 6, the feeding position of the tire pyrolysis oil mixture is 6, the feeding position of the mixed ionic liquid is 2, the top raffinate oil of the first extraction tower (C1) enters the second extraction tower (C2) from the tower bottom, the mixed ionic liquid enters the second extraction tower (C2) from the tower top, the raffinate oil at the tower top of the second extraction tower (C2) is provided with a pipeline connected to the middle part of a raffinate flash tank (S1) for flash separation, the extract oil from the tower bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle part of an extract flash tank (S2) for flash separation, the volume ratio of the mixed ionic liquid to the tire pyrolysis oil feed to be separated in the process of each stage is 1:1, and after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.66 percent (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.34 percent, and the recovery rate of the olefin is 98.88 percent; the olefin content in the extract was less than 2%, and the olefin content in the raffinate was 98.93% (mass fraction).

Example 7:

common ionic liquid (in particular [ EMIM ] [ SCN ] + [ EMIM ] [ DCA ] with the volume ratio of 1:1) is adopted as an extraction solvent.

The feed rate was 100kg/h, and the tire cracking oil to be separated (60 wt% aromatics +40 wt% olefins as the simulated components, see Table 1 for specific composition) was fed from the first extraction column (C1) from the lower part of the first extraction column (C1). The theoretical plate number of the first extraction tower (C1) is 6, the feeding position of the tire pyrolysis oil mixture is 6, the feeding position of the mixed extractant is 2, the top raffinate oil of the first extraction tower (C1) enters the second extraction tower (C2) from the tower bottom, the mixed extractant enters the second extraction tower (C2) from the tower top, the raffinate oil at the tower top of the second extraction tower (C2) is provided with a pipeline connected to the middle part of a raffinate flash tank (S1) for flash separation, the extract oil from the tower bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle part of an extract flash tank (S2) for flash separation, the volume ratio of the mixed extractant to the tire pyrolysis oil to-be-separated material feeding is 1:1 in each stage, after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.67 percent (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.11 percent, and the recovery rate of the olefin is 99.03 percent; the olefin content in the extract was less than 2% and the olefin content in the raffinate was 98.67% (mass fraction).

Example 8:

common ionic liquid (specifically [ BMPY ] [ TF2N ]) is used as an extraction solvent with reflux.

The feed flow was 100kg/h and the tire cracked oil to be separated (60 wt% aromatics +40 wt% olefins as simulated components, see Table 1 for specific composition) was fed from the lower part of the first extraction column (C1). The theoretical plate number of a first extraction tower (C1) is 6, the feeding position of tire pyrolysis oil is 6, the feeding position of single ionic liquid is 1, raffinate oil at the top of the first extraction tower (C1) enters a second extraction tower (C2) from the bottom of the tower, single ionic liquid enters the second extraction tower (C2) from the top of the tower, raffinate oil at the top of the second extraction tower (C2) is connected to the middle of a raffinate flash tank (S1) through a pipeline for flash separation, extract oil from the bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle of an extract flash tank (S2) for flash separation, a pipeline (D2) returning from the extract flash tank is connected with the middle lower part of the first extraction tower (C1) for partial reflux, and the mass ratio of reflux amount to system extract amount is 0.2; and a reflux pipeline (D1) from the raffinate flash tank is connected with the middle lower part of the second extraction tower (C2) for carrying out partial reflux, and the mass ratio of the reflux amount to the system extraction amount is 0.2. The volume ratio of the single ionic liquid to the tire cracked oil to-be-separated material in each stage of extraction process is 1:1, after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.80% (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.91%, and the recovery rate of the olefin is 99.72%; the olefin content in the extract liquor is less than 2 percent, and the olefin content in the raffinate is 99.51 percent (mass fraction).

Example 9:

common ionic liquid (specifically [ BMIM ] [ TF2N ]) is used as an extraction solvent with reflux.

The feed flow was 100kg/h and the tire cracked oil to be separated (60 wt% aromatics +40 wt% olefins as simulated components, see Table 1 for specific composition) was fed from the lower part of the first extraction column (C1). The theoretical plate number of a first extraction tower (C1) is 6, the feeding position of tire pyrolysis oil is 6, the feeding position of single ionic liquid is 1, raffinate oil at the top of the first extraction tower (C1) enters a second extraction tower (C2) from the bottom of the tower, single ionic liquid enters the second extraction tower (C2) from the top of the tower, raffinate oil at the top of the second extraction tower (C2) is connected to the middle of a raffinate flash tank (S1) through a pipeline for flash separation, extract oil from the bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle of an extract flash tank (S2) for flash separation, a pipeline (D2) returning from the extract flash tank is connected with the middle lower part of the first extraction tower (C1) for partial reflux, and the mass ratio of reflux amount to system extract amount is 0.2; and a reflux pipeline (D1) from the raffinate flash tank is connected with the middle lower part of the second extraction tower (C2) for carrying out partial reflux, and the mass ratio of the reflux amount to the system extraction amount is 0.2. The volume ratio of the single ionic liquid to the tire cracked oil to-be-separated material in each stage of extraction process is 1:1, after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.84% (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.88%, and the recovery rate of the olefin is 99.73%; the olefin content in the extract liquor is less than 2 percent, and the olefin content in the raffinate is 99.66 percent (mass fraction).

Example 10:

common ionic liquid (specifically [ EMIM ] [ DCA ]) is used as an extraction solvent, and reflux is carried out.

The feed flow was 100kg/h and the tire cracked oil to be separated (60 wt% aromatics +40 wt% olefins as simulated components, see Table 1 for specific composition) was fed from the lower part of the first extraction column (C1). The theoretical plate number of a first extraction tower (C1) is 6, the feeding position of tire pyrolysis oil is 6, the feeding position of single ionic liquid is 1, raffinate oil at the top of the first extraction tower (C1) enters a second extraction tower (C2) from the bottom of the tower, single ionic liquid enters the second extraction tower (C2) from the top of the tower, raffinate oil at the top of the second extraction tower (C2) is connected to the middle of a raffinate flash tank (S1) through a pipeline for flash separation, extract oil from the bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle of an extract flash tank (S2) for flash separation, a pipeline (D2) returning from the extract flash tank is connected with the middle lower part of the first extraction tower (C1) for partial reflux, and the mass ratio of reflux amount to system extract amount is 0.2; and a reflux pipeline (D1) from the raffinate flash tank is connected with the middle lower part of the second extraction tower (C2) for carrying out partial reflux, and the mass ratio of the reflux amount to the system extraction amount is 0.2. The volume ratio of the single ionic liquid to the tire cracked oil to-be-separated material in each stage of extraction process is 1:1, after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.74% (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.85%, and the recovery rate of the olefin is 99.47%; the olefin content in the extract was less than 2%, and the olefin content in the raffinate was 99.38% (mass fraction).

Example 11:

mixed ionic liquid (specifically [ BMPY ] [ TF2N ] and [ BMIM ] [ TF2N ] in a volume ratio of 1:1) is used as an extraction solvent with reflux.

The feed rate was 100kg/h, and the tire cracking oil to be separated (60 wt% aromatics +40 wt% olefins as the simulated components, see Table 1 for specific composition) was fed from the first extraction column (C1) from the lower part of the first extraction column (C1). The theoretical plate number of a first extraction tower (C1) is 6, the feeding position of a tire cracking oil mixture is 6, the feeding position of mixed ionic liquid is 2, raffinate oil at the top of the first extraction tower (C1) enters a second extraction tower (C2) from the bottom of the tower, the mixed ionic liquid enters the second extraction tower (C2) from the top of the tower, raffinate oil at the top of the second extraction tower (C2) is connected to the middle of a raffinate flash tank (S1) through a pipeline for flash separation, extract oil from the bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle of an extract flash tank (S2) for flash separation, a pipeline (D2) returning from the extract flash tank is connected with the middle lower part of the first extraction tower (C1) for partial reflux, and the mass ratio of the reflux amount to the system is 0.2; and a reflux pipeline (D1) from the raffinate flash tank is connected with the middle lower part of the second extraction tower (C2) for carrying out partial reflux, and the mass ratio of the reflux amount to the system extraction amount is 0.2. The volume ratio of the mixed ionic liquid to the tire cracked oil to-be-separated material in each stage of extraction process is 1:1, after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.90% (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.89%, and the recovery rate of the olefin is 99.51%; the olefin content in the extract liquid is less than 2 percent, and the olefin content in the raffinate liquid is 99.55 percent (mass fraction).

Example 12:

mixed ionic liquid (specifically [ BMPY ] [ TF2N ] and [ EMIM ] [ DCA ] in a volume ratio of 1:1) is used as an extraction solvent, and reflux is carried out.

The feed rate was 100kg/h, and the tire cracking oil to be separated (60 wt% aromatics +40 wt% olefins as the simulated components, see Table 1 for specific composition) was fed from the first extraction column (C1) from the lower part of the first extraction column (C1). The theoretical plate number of a first extraction tower (C1) is 6, the feeding position of a tire cracking oil mixture is 6, the feeding position of mixed ionic liquid is 2, raffinate oil at the top of the first extraction tower (C1) enters a second extraction tower (C2) from the bottom of the tower, the mixed ionic liquid enters the second extraction tower (C2) from the top of the tower, raffinate oil at the top of the second extraction tower (C2) is connected to the middle of a raffinate flash tank (S1) through a pipeline for flash separation, extract oil from the bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle of an extract flash tank (S2) for flash separation, a pipeline (D2) returning from the extract flash tank is connected with the middle lower part of the first extraction tower (C1) for partial reflux, and the mass ratio of the reflux amount to the system is 0.2; and a reflux pipeline (D1) from the raffinate flash tank is connected with the middle lower part of the second extraction tower (C2) for carrying out partial reflux, and the mass ratio of the reflux amount to the system extraction amount is 0.2. The volume ratio of the mixed ionic liquid to the tire cracked oil to-be-separated material in each stage of extraction process is 1:1, after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.91% (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.80%, and the recovery rate of the olefin is 99.43%; the olefin content in the extract was less than 2%, and the olefin content in the raffinate was 99.71% (mass fraction).

Example 13:

mixed ionic liquid (specifically [ BMIM ] [ TF2N ] and [ EMIM ] [ DCA ] in a volume ratio of 1:1) is used as an extraction solvent, and reflux is carried out.

The feed rate was 100kg/h, and the tire cracking oil to be separated (60 wt% aromatics +40 wt% olefins as the simulated components, see Table 1 for specific composition) was fed from the first extraction column (C1) from the lower part of the first extraction column (C1). The theoretical plate number of a first extraction tower (C1) is 6, the feeding position of a tire cracking oil mixture is 6, the feeding position of mixed ionic liquid is 2, raffinate oil at the top of the first extraction tower (C1) enters a second extraction tower (C2) from the bottom of the tower, the mixed ionic liquid enters the second extraction tower (C2) from the top of the tower, raffinate oil at the top of the second extraction tower (C2) is connected to the middle of a raffinate flash tank (S1) through a pipeline for flash separation, extract oil from the bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle of an extract flash tank (S2) for flash separation, a pipeline (D2) returning from the extract flash tank is connected with the middle lower part of the first extraction tower (C1) for partial reflux, and the mass ratio of the reflux amount to the system is 0.2; and a reflux pipeline (D1) from the raffinate flash tank is connected with the middle lower part of the second extraction tower (C2) for carrying out partial reflux, and the mass ratio of the reflux amount to the system extraction amount is 0.2. The volume ratio of the mixed ionic liquid to the tire cracked oil to-be-separated material in each stage of extraction process is 1:1, after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.91% (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.82%, and the recovery rate of the olefin is 99.63%; the olefin content in the extract was less than 2% and the olefin content in the raffinate was 99.69% (mass fraction).

Example 14:

common ionic liquid (in particular [ EMIM ] [ SCN ] + [ EMIM ] [ DCA ] with the volume ratio of 1:1) is adopted as an extraction solvent, and reflux is carried out.

The feed rate was 100kg/h, and the tire cracking oil to be separated (60 wt% aromatics +40 wt% olefins as the simulated components, see Table 1 for specific composition) was fed from the first extraction column (C1) from the lower part of the first extraction column (C1). The theoretical plate number of a first extraction tower (C1) is 6, the feeding position of a tire cracking oil mixture is 6, the feeding position of a mixed extracting agent is 2, raffinate oil at the top of the first extraction tower (C1) enters a second extraction tower (C2) from the bottom of the tower, the mixed extracting agent enters the second extraction tower (C2) from the top of the tower, raffinate oil at the top of the second extraction tower (C2) is connected to the middle of a raffinate flash tank (S1) through a pipeline for flash separation, extract oil from the bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the middle of an extract flash tank (S2) for flash separation, a pipeline (D2) returning from the extract flash tank is connected with the middle lower part of the first extraction tower (C1) for partial reflux, and the mass ratio of the extracted reflux to the system quantity is 0.2; and a reflux pipeline (D1) from the raffinate flash tank is connected with the middle lower part of the second extraction tower (C2) for carrying out partial reflux, and the mass ratio of the reflux amount to the system extraction amount is 0.2. The volume ratio of the mixed extractant to the tire cracked oil to-be-separated substance feed in each stage of extraction process is 1:1, after multi-stage high-efficiency separation, the recovery rate of the solvent is 99.93 percent (mass fraction), the recovery rate of the aromatic hydrocarbon is 99.94 percent, and the recovery rate of the olefin is 99.79 percent; the olefin content in the extract was less than 2%, and the olefin content in the raffinate was 99.37% (mass fraction).

The data show that the product separated by the method has high purity and high recovery rate, the recovery rate of the aromatic hydrocarbon and the olefin can be improved, the quality of the diesel oil can be improved, the aromatic hydrocarbon resource can be expanded, and the obtained high-purity aromatic hydrocarbon can be used for downstream production.

TABLE 1 pyrolysis oil feed composition

Claims

1. The multistage combined extraction device for the waste tire pyrolysis oil by using the ionic liquid is characterized by mainly comprising the following parts:

a pipeline is arranged at the top of the second extraction tower (C2) and is connected with the middle part of the flash tank (S1), raffinate oil discharged from the top of the second extraction tower (C2) is subjected to flash separation in the flash tank (S1), and non-aromatic hydrocarbon components (comprising alkane, olefin and the like) are discharged from the top of the raffinate flash tank (S1); the bottoms of the first extraction tower (C1) and the second extraction tower (C2) are respectively provided with a pipeline connected with the middle part of the extract liquid flash tank (S2), extract oil discharged from the bottoms of the first extraction tower (C1) and the second extraction tower (C2) enters the extract liquid flash tank (S2), flash separation is carried out in the extract liquid flash tank (S2), and aromatic hydrocarbon components (including polycyclic aromatic hydrocarbon) are discharged from the top of the extract liquid flash tank (S2);

the bottom of the raffinate flash tank (S1) and the bottom of the extract flash tank (S2) are combined by pipelines and are respectively connected with an upper feed inlet of the first extraction tower (C1) and an upper feed inlet of the second extraction tower (C2) and used for providing an extracting agent for the first extraction tower (C1) and the second extraction tower (C2).

2. The multistage combined extraction apparatus for pyrolysis oil of waste tires using ionic liquid as claimed in claim 1, wherein, if necessary, the non-aromatic hydrocarbon component discharged from the raffinate flash tank (S1) is provided with a partial reflux line to the middle lower part of the second extraction column (C2), and the reflux pipe from the raffinate flash tank (S1) is connected to the middle lower part of the second extraction column (C2) to perform a partial reflux; the aromatic hydrocarbon components (including polycyclic aromatic hydrocarbon) flowing out of the top of the extract liquid flash tank (S2) are also provided with a part of reflux pipelines to reflux to the middle lower part of the first extraction tower (C1), and a pipeline refluxing from the extract liquid flash tank (S2) is connected with the middle lower part of the first extraction tower (C1) to carry out part of reflux.

3. The method for extracting and separating the tire pyrolysis oil by the ionic liquid-based solvent multistage combination by using the device of claim 1 or 2 is characterized by mainly comprising the following steps of:

4. The method of claim 3, wherein if the non-aromatic components and the aromatic components flowing out of the top of the raffinate flash tank (S1) and the extract flash tank (S2) are partially refluxed, the mass ratio of the amount of reflux to the amount of system output is 0.1 to 0.5.

5. The process according to claim 3, wherein the first extraction column (C1) is operated at a pressure of 1 to 5atm, a theoretical plate number (N) of 3 to 12, preferably 5 to 10, an operating temperature of 20 to 100 ℃, an extractant feed position of 1 to 2, a tire cracking oil feed position in the first extraction column (C1) of (N-1) to N, and N is the last feed plate.

6. The process according to claim 3, wherein the second extraction column (C2) is operated at 1 to 5atm, the number of theoretical plates (N) is 3 to 12, preferably 5 to 10, the operating temperature is 20 to 100 ℃, the feeding position of the extractant is 1 to 2, the produced liquid at the top of the first extraction column (C1) enters the second extraction column (C2) from the bottom of the second extraction column (C2), the feeding position of the tire cracking oil in the first extraction column (C1) is (N-1) to N, and N is the last feeding plate.

7. The process according to claim 3, wherein the raffinate flash drum (S1) and the extract flash drum (S2) are operated at an operating pressure of 0.1 to 0.5atm and an operating temperature of 60 to 150 ℃.

8. The method according to claim 3, wherein the first ionic liquid extraction solvent and the second ionic liquid extraction solvent are the same and are each a single ionic liquid, a mixed ionic liquid or a mixture of an ionic liquid and a conventional organic solvent.

9. The process according to claim 3, wherein the volume ratio of the ionic liquid of each of the first extraction column (C1) and the second extraction column (C2) to the tire cracking oil is 0.5 to 3: 1.

10. The method according to claim 3, wherein the recovery of the solvent from the separated tire pyrolysis oil is 99.00% to 99.99%, the recovery of the aromatic hydrocarbons from the extract is 99.00% to 99.99%, and the recovery of the olefins from the raffinate is 98.50% to 99.99%.