41results about "Crystallisation purification/separation" patented technology

The invention relates to the technical field of chemical separation and purification, and discloses a method for separation and purification of taxadiene from tobacco and GC-MSMS quantitative detection.The method for separation and purification of taxadiene from tobacco comprises the following steps that S1, tobacco leaves are made into powder, an extracting agent is added, ultrasonic extraction is conducted for multiple times, and extract liquor is obtained; s2, evaporating the extract to dryness, adding an organic solvent, and dissolving to form a concentrated solution; s3, the concentrated solution is added into a silica gel column for gradient elution, and an extraction sample is obtained; and S4, evaporating the extracted sample to dryness, adding acetonitrile for dissolving, and carrying out secondary recrystallization to obtain purified taxadiene. According to the method, the efficiency and purity of separating the taxadiene from the tobacco are improved, and the taxadiene is accurately quantified.

The crystallization purification preparation system for 2, 6-dimethylnaphthalene comprises a suspension stirring crystallizer and a crystal filter, the suspension stirring crystallizer is connected to one end of the crystal filter, and the other end of the crystal filter is connected with a residual liquid tank and a static crystallizer; a mother liquid tank and a finished product tank are arranged on the first pipeline between the static crystallizer and the crystal filter; meanwhile, the residual liquid tank, the mother liquid tank and the static crystallizer are also respectively connected with a waste removal and discharge pipeline; wherein the suspension stirring crystallizer is connected with a cooling and heating all-in-one machine through a cooling and heating medium pipeline, and the static crystallizer is also connected with the cooling and heating all-in-one machine through the cooling and heating medium pipeline. According to the method, high-purity 2, 6-dimethylnaphthalene is obtained from low-value petrochemical raw materials by adopting a crystallization purification method.

The utility model relates to recovery device technical field, concretely is a kind of benzene recovery device, including waste oil buffer tank, waste oil buffer tank is connected with the top of crude benzene crystallization tank by pipeline, the bottom of crude benzene crystallization tank is connected with the top of fine benzene rectifying column by pipeline one, and cooling pipe is wound in side portion, and cooling pipe is connected with freezer;Pipeline one is provided with feed pump;The top of fine benzene rectifying column is connected with fine benzene condenser by pipeline, and bottom is connected with heavy residue discharge pipe;Fine benzene condenser is connected with fine benzene buffer tank by pipeline two;The utility model is through being provided with crude benzene crystallization tank and fine benzene rectifying column, first crystallization comes out crude benzene, and then distills crude benzene, and the fine benzene of distillation comes out, to realize the extraction and recovery of benzene, avoid the waste of resources, reduce cost.

The application provides a method for preparing beta-methylnaphthalene from a methylnaphthalene-containing fraction based on solution homogenization crystallization separation, and comprises the following steps: pumping the methylnaphthalene-containing fraction into a fluidized bed reactor, performing primary cooling treatment, and performing ultrasonic treatment through an ultrasonic device arranged on the inner wall of the fluidized bed reactor, and then filtering after the crystallization treatment; re-heating the solid in the fluidized bed reactor, then performing secondary cooling treatment and ultrasonic treatment at the same time, and then filtering after the crystallization treatment; re-heating the solid in the fluidized bed reactor, then performing third cooling treatment, and performing ultrasonic treatment at the same time, and then filtering after the crystallization treatment, collecting the filter residue, and then drying to obtain high-purity beta-methylnaphthalene. The method combines the fluidized bed reactor with the ultrasonic treatment technology, and adopts step-by-step crystallization, so that impurities are effectively removed, high-purity beta-methylnaphthalene is obtained, and the yield of the product is obviously improved.

Disclosed are apparatuses and processes for preparation and conversion comprising / using: a fractionation chain (4-6) that produces a xylene fraction (24); a xylene separation unit (10) that treats the xylene fraction to produce a para-xylene extract (39) and a raffinate (40); an isomerization unit (11) treating the raffinate to produce an isomerization product (42) of xylenes fed to the fractionation chain; the synthesis gas production unit (14; 15) that treats the hydrocarbon feedstock (30) to produce a synthesis gas (34) containing CO and CO2; a methanol synthesis reaction section (50) that treats the synthesis gas (34) to produce methanol (51); a toluene alkylation reaction section (13) treating the toluene-containing fraction (23) with methanol (51) to produce an alkylation effluent (32) containing xylene and fed to the fractionation chain.

The invention belongs to the technical field of photothermal conversion materials, and discloses a preparation method and application of an inorganic-organic hybrid polyoxotungstate photothermal material with wide spectrum absorption. The structural formula of the photo-thermal material is Per4W10O32, the crystal structure belongs to a triclinic system, the space group is P-1, and the photo-thermal material has specific unit cell parameters. The preparation method comprises the following steps: oxidizing perylene molecules through constant current electrolysis in a mixed solvent system containing perylene molecules and a decatungstate precursor in an electrochemical oxidation manner, and assembling the oxidized perylene molecules with decatungstate anions to form bulk crystals; the photo-thermal material has continuous strong absorption in a region from ultraviolet light to short wave infrared, the photo-thermal conversion efficiency is as high as 98.24%, when the photo-thermal material is applied to the fields of solar driven interface photo-thermal evaporation and water treatment, the evaporation rate of a two-dimensional system is 1.89 kg.m <-2 >. H <-1 >, the evaporation rate of a three-dimensional hydrogel system is increased to 3.02 kg.m <-2 >. H <-1 >, salt deposition can be inhibited in long-term seawater desalination operation, and the photo-thermal material has a good application prospect. Fresh water quality meets drinking water standards.

The present application relates to the field of basic organic chemistry synthesis, and particularly to a high-yield preparation method of o-terphenyl based on hydrogen participation; comprising the steps of preparing a catalyst mixed solution, preparing a reaction mixed solution, filling micro-pressure hydrogen, heating and hydrogenation coupling reaction, rough extraction through reduced pressure distillation, and recrystallization and drying; a pre-assembly reaction precursor is formed by a bidentate phosphine bidentate phosphine ligand and a supported palladium catalyst, and a coupling reaction occurs with diphenyl under the cooperation of micro-pressure hydrogen and an acidic cocatalyst; the present application does not need to use traditional halogenated aromatic hydrocarbons and organic metal reagents, solves the problems of isomer mixing and difficult separation and halogen residue affecting the performance of downstream optoelectronic materials, realizes the preparation of o-terphenyl, and simplifies the separation and purification process.

This invention provides a method for purifying mesitylene through suspension melt crystallization, belonging to the field of fine chemical separation technology. By adding a crystallization aid to assist in the suspension melt crystallization of mesitylene, this invention overcomes the limitations of traditional crystallization separation. The addition of the crystallization aid interacts with impurities in the crude product, effectively altering the crystallization behavior of the impurities and inhibiting their entry into the mesitylene lattice during crystal growth. This reduces the amount of impurities trapped during mesitylene crystallization, accelerates the crystallization process, and reduces the number of multi-stage crystallization. Without altering the main molecular configuration of mesitylene, this invention achieves highly efficient separation and purification of mesitylene, significantly improving its purity and yield. It solves the problem of isomer separation and overcomes the technical bottleneck of low efficiency in the existing mesitylene purification and separation process.

The present application relates to a kind of device and method for extracting high-purity chemicals from coal tar wash oil fraction, comprising: naphthalene separation column, methylnaphthalene separation unit, acenaphthene-fluorene-dibenzofuran separation unit;Methylnaphthalene separation unit includes methylnaphthalene separation tower, β-methylnaphthalene subunit and α-methylnaphthalene subunit connected in sequence;Acenaphthene-fluorene-dibenzofuran separation unit includes light removal tower, acenaphthene subunit, dibenzofuran subunit and fluorene subunit connected in sequence;The material outlet of the bottom of naphthalene separation column is connected with methylnaphthalene separation tower;The material outlet of the bottom of methylnaphthalene separation tower is connected with the material inlet of light removal tower.The device provided by the present application can effectively extract target chemicals in coal tar wash oil fraction by reasonable configuration of the device and coupling cooperation between devices, and obtain high-purity products.Compared with existing wash oil extraction chemical technology, it has higher efficiency, wider applicability and better product quality.

The invention relates to the technical field of production of 2, 6-dimethylnaphthalene, and discloses a production method and a production system of 2, 6-dimethylnaphthalene, and the production method comprises the following steps: (1) under a liquid phase condition, in the presence of an alkyl transfer catalyst, contacting reaction raw materials with a transfer alkylating agent to obtain a product mixture; the content of the 2, 6-dimethylnaphthalene is not less than 15wt% on the basis of the total content of the bicyclic aromatic hydrocarbon in the product mixture; (2) rectifying the product mixture to obtain a light component and a heavy component containing the dimethylnaphthalene isomer, and returning the light component to the step (1) to provide at least part of reaction raw materials; (3) mixing the heavy component obtained by rectification with a complexing agent, carrying out complexing crystallization, and then carrying out alkali washing to obtain a 2, 6-dimethylnaphthalene crude product; and (4) mixing the 2, 6-dimethylnaphthalene crude product with a solvent, and recrystallizing. The method has the advantages of high purity and high yield of the 2, 6-dimethylnaphthalene.

The utility model discloses a p-xylene crystallization device which at least comprises a raw material input pipeline, the at least one crystallization unit is connected with the raw material input pipeline; the at least one separation unit is connected with the outlet of the crystallization unit; the mother liquor buffer tank is connected with an outlet of the separation unit; an inlet of the mother liquor pump is connected with an outlet of the mother liquor buffer tank; the subcooler is connected with an outlet of the mother liquor pump; the industrial wind input pipeline is connected with the other inlet of the mother liquor pump; and the industrial wind output pipeline is connected with the other outlet of the mother liquor pump. According to the p-xylene crystallization device provided by the utility model, the operation stability of the crystallization device can be improved.

This invention belongs to the technical field of anthracene oil processing and production, and discloses a production method for increasing the anthracene and carbide content in crude anthracene products using crystal nucleus seeds. The method mainly involves cooling the heated raw anthracene oil to 75°C, then adding high-quality crystal nucleus seeds (70% anthracene content, 17% carbide content, and ≤1% mechanical impurities) to a crystallization tank at a mass ratio of 1:75. At this point, the high-quality crystal nucleus seeds promote the formation of new crystal nuclei in the anthracene oil liquid. As the temperature decreases, the newly formed crystal nuclei gradually grow. Simultaneously, the temperature is naturally lowered to below 65°C through stirring, and the cooling system in the crystallization tank is activated to further cool the temperature to 35-40°C. The mixture is then repeatedly fed and dried in a centrifuge to produce high-quality crude anthracene. This invention utilizes unique high-quality crystal nucleus seeds to achieve an anthracene content of over 40% and a carbide content of over 14% in crude anthracene even when the anthracene and carbide content in the raw anthracene oil is low or unstable, resulting in a superior-grade crude anthracene product.

The invention discloses a crucible descent growth method of a large-size bibenzyl scintillation crystal, and relates to a growth method of a bibenzyl scintillation crystal. The method aims at solving the technical problem that the quality of crystals obtained through an existing bibenzyl single crystal solution growth method is poor, a bibenzyl raw material is sealed in a quartz crucible of a capillary structure, the raw material is melted and a stable solid-liquid interface is formed by precisely controlling the temperature field of a furnace body and the descending rate of the crucible, and the bibenzyl single crystal is obtained. And then enabling the crucible to pass through a temperature gradient region at a constant rate to realize directional solidification growth of the bibenzyl single crystal, and then carrying out cooling annealing treatment. The diameter of the prepared bibenzyl scintillation crystal is 25 mm, the length of an equal-diameter section reaches 80 mm, the light-induced decay time of the bibenzyl scintillation crystal is 2.7 ns, the light yield and the decay time of the bibenzyl scintillation crystal under the excitation of a 137 Cs radioactive source are 21600 ph / Mev and 3.71 ns respectively, and the bibenzyl scintillation crystal can be used in the field of ray detection and imaging devices.

The application provides a preparation method of high-purity naphthalene from ethylene tar, and relates to the technical field of chemical separation, and the preparation method of high-purity naphthalene from ethylene tar, in a three-stage rectification process, the pressure of each tower is maintained below-85KPa, because the relationship between pressure and boiling point is proportional, therefore, under the condition of low pressure, the flash evaporation temperature can be reduced, the operating temperature can be significantly reduced, thereby the energy consumption of the flash evaporation tower can be reduced, the boiling point of the material can be reduced, the residence time of the material under high temperature can be reduced, the heating time of the material can be shortened, the gelation and self-polymerization reaction of unsaturated compounds in the ethylene tar can be effectively inhibited, the plugging phenomenon of the rectification tower filler can be reduced, the flux and separation efficiency in the tower can be improved, the selective separation of naphthalene components can be realized by the stage-by-stage rectification strategy, the naphthalene components can be fully evaporated into the flash evaporation tower top, high-purity naphthalene products can be finally obtained, and the problems of increased equipment maintenance frequency and production interruption caused by gelation can be avoided.

The invention relates to a method for separating and purifying camphene and tricyclene, which comprises the following steps: adding a camphene crude product to be treated into a crystallizer, slowly cooling to a cooling end point when the temperature of a jacket is controlled to reach a supersaturated point temperature, and carrying out suction filtration to obtain crystallization mother liquor; slowly raising the temperature by controlling the temperature of the jacket, melting and sweating, and carrying out solid-liquid separation to obtain high-purity camphene; carrying out reduced pressure rectification on the separated crystallization mother liquor to obtain a tricyclene crude product; the method comprises the following steps: adding a tricyclene crude product into a crystallizer, slowly cooling to a cooling end point when a solution reaches a supersaturated point temperature by controlling the temperature of a jacket, and carrying out suction filtration to obtain crystallization mother liquor; and slowly raising the temperature by controlling the temperature of the jacket, melting and sweating, and carrying out solid-liquid separation to obtain the high-purity tricyclene. Compared with the prior art, the method has the advantages of no solvent influence in the purification process, green and environment-friendly purification process, low energy consumption, high product yield and high product quality.

A crucible-descent growth method for ultrafast scintillation crystals of trans-stilbene is disclosed, relating to melt growth methods for organic single crystals. This method aims to address the technical problems of compositional deviation and difficulty in controlling crystal quality and size in existing solution-grown trans-stilbene single crystals. The method first purifies the raw material using solution recrystallization, then seals the recrystallized trans-stilbene in a crucible. By precisely controlling the furnace temperature field and the crucible descent rate, a stable vertical temperature gradient is formed, achieving directional solidification growth of the crystal. The trans-stilbene scintillation crystals prepared by this method have a diameter of 25 mm and a constant-diameter section length of 60 mm, exhibiting excellent optical quality and a photo-induced decay time of 4.49 ns. 137 The light yield under Cs radiation source excitation reaches 21000 ph / MeV, with a decay time of 3.81 ns, making it suitable for radiation detection.

The invention discloses a mixture purification and separation process and equipment based on melt crystallization, which comprises the following steps: feeding a crude product material into a crystallization purification device through a crude product storage tank to obtain a high-purity target crystal and a low-purity mother solution; the low-purity mother liquor is fed into a mother liquor storage tank to serve as a material to be purified again; the crystals with higher purity are subjected to countercurrent washing in the crystallization purification device, and impurities on the surface layer are melted and taken away to obtain a high-purity target crystal product; and melting the high-purity crystal to obtain a liquid product or granulating to obtain a solid product. A crude product is conveyed to a second crystallization area through a raw material pump and then is in contact with a cold material to be crystallized and separated out, and a solid falls to a third crystallization area; and the crystals passing through the washing area enter the melting area to be melted, and the melted liquid part is extracted, so that a high-purity product can be obtained.

The integrated process for producing paraxylene involves catalytically reforming a naphtha feed stream to form a reformed oil stream; this reformed oil stream is then converted into a C1-C7 hydrocarbon stream and C 8+ Steps to separate into hydrocarbon streams; steps to expose the C1-C7 hydrocarbon streams to a first solvent in a solvent extraction unit to form non-aromatic hydrocarbon streams and C6-C7 aromatic compound streams; steps to separate the C6-C7 aromatic compound streams into at least a toluene feed stream; C 8+ Hydrocarbon flow C 9+ Steps to separate the hydrocarbon stream and the xylene stream; steps to separate the xylene stream in a p-xylene separation unit to form a para-xylene stream and a xylene isomer stream; steps to isomerize the xylene isomer stream to produce a para-xylene-rich stream; and steps to separate the toluene feed stream and C in a hybrid dealkylation / transalkylation unit. 9+ The process may include upgrading the hydrocarbon stream with a hydrogen stream and a hybrid transalkylation / dealkylation catalyst to produce a product stream containing paraxylene.

A method for recovering high-purity naphthalene from a Rerun Column bottom residue is disclosed. The process begins with collecting the residue and dividing it into two portions. One portion is maintained at room temperature, while the second is cooled to approximately 16° C. to initiate the selective solidification of naphthalene. Upon gradual warming of the cooled portion to ambient temperature over 3-4 hours, a clear separation between solid naphthalene and the liquid residue is achieved. The liquid layer is decanted, and the remaining solid fraction is filtered using Whatman-1 filter paper with tissue paper to absorb residual liquids. The recovered crystals are washed 3-4 times with water to eliminate impurities and dried in a hot air oven at 100±2° C. for 2 hours. Final settling at room temperature yields dry, white crystalline naphthalene with a melting point of 80.2° C., a purity of 97.27%, and a recovery efficiency of 77.7%.

A process for converting hydrocarbon feedstocks is disclosed in which a first hydrocarbon feedstock (2) is treated in particular by means of a fractionation chain (4-7), a xylene separation unit (10) and an isomerization unit (11), and in which: a pyrolysis unit (13) or an oxycombustion or gasification unit (14) treats a second hydrocarbon feedstock (30) to produce a synthesis gas (32) comprising CO and CO2; a methanol synthesis reaction section (50) treating the synthesis gas to produce methanol (51); and an aromatization reaction section (56) at least partially treating the methanol to produce a hydrocarbon effluent (57) comprising aromatics and feeding the hydrocarbon feedstock with the hydrocarbon effluent.

The invention relates to the technical field of benzene hydrogenation processes, and discloses a system for recovering cyclohexane in benzene hydrogenation tail gas, which comprises a pressure tank, a gas-liquid separator, a crystallizer, a centrifugal machine and a storage hopper, the pressure tank is used for pressurizing the tail gas, the gas outlet of the pressure tank is communicated with the inlet of the gas-liquid separator, and the gas outlet of the gas-liquid separator is communicated with the crystallizer. A liquid phase port of the gas-liquid separator is communicated with a liquid inlet of the crystallizer, an output port of the crystallizer is communicated with the centrifugal machine, and a discharge port of the centrifugal machine is communicated with the storage hopper. The system for recovering cyclohexane in benzene hydrogenation tail gas disclosed by the invention solves or improves the problem that cyclohexane cannot be recovered.

Disclosed are a production and conversion device and method comprising / using: a fractionation train (4-6) producing a xylene fraction (24); a xylene separation unit (10) treating the xylene fraction to produce a paraxylene extract (39) and a raffinate (40); an isomerization unit (11) treating the raffinate to produce an isomerate (42) of xylenes sent to the fractionation train; a syngas production unit (14; 15) treating a hydrocarbon feedstock (30) to produce a syngas (34) containing CO and CO2; a methanol synthesis reaction section (50) treating the syngas (34) to produce methanol (51); a toluene alkylation reaction section (13) treating a fraction containing toluene (23) with the methanol (51) to produce an alkylation effluent (32) that contains xylenes and is sent to the fractionation train.

The application relates to a method and system for purifying durene, and belongs to the technical field of durene purification. The method comprises the following steps: performing primary suspension crystallization on durene-rich liquid at a set cooling speed to obtain primary suspension crystallization slurry with a first temperature; performing solid-liquid separation on the primary suspension crystallization slurry to obtain primary suspension crystallization mother liquor and primary suspension crystallization crystals; performing secondary suspension crystallization on the primary suspension crystallization mother liquor at a set cooling speed to obtain secondary suspension crystallization slurry with a second temperature; performing solid-liquid separation on the secondary suspension crystallization slurry to obtain secondary suspension crystallization crystals; and performing layer-type melt crystallization on the mixed crystals of the primary suspension crystallization crystals and the secondary suspension crystallization crystals to obtain durene crystallization products. Under the synergistic action of the two-stage suspension crystallization and the layer-type melt crystallization, the application can realize high yield and high purity of durene, and the method does not have a gasification and condensation process, and has low energy consumption.

The invention provides a purification method of high-purity 2, 6-diisopropylnaphthalene, which comprises the following steps: rectifying and separating a naphthalene isopropylation product to remove light component impurities and heavy component impurities in the product to obtain an intermediate component containing 2, 6-diisopropylnaphthalene; carrying out static melt crystallization treatment on the intermediate component containing 2, 6-diisopropylnaphthalene to obtain a crude 2, 6-diisopropylnaphthalene crystal; and pulping and washing the crude 2, 6-diisopropylnaphthalene crystal by using a washing solution to obtain the high-purity 2, 6-diisopropylnaphthalene, wherein the washing liquid is prepared from 2, 6-diisopropyl naphthalene with the mass concentration of 65 percent to 90 percent; according to the invention, through efficient integration of rectification, crystallization and washing processes, one-step melt crystallization is combined with pulping and washing to replace a traditional multi-step crystallization purification mode, so that a high-purity product is obtained, and the problems of complex flow, high energy consumption and cost increase caused by multi-step crystallization are avoided. The prepared high-purity 2, 6-diisopropyl naphthalene can be directly applied to a subsequent PEN synthesis process, and is one of key processes in a PEN industrial production process.

The invention belongs to the technical field of coal chemical industry and petrochemical industry, and discloses a system and a method for increasing the yield of benzene and xylene. The system comprises a first reaction unit, a first pre-fractionation unit, a light hydrocarbon separation unit, a second pre-fractionation unit, a family composition separation unit, an aromatic hydrocarbon separation unit, a second reaction unit and a crystal separation unit. According to the method, the oxygen-containing compound is coupled with light hydrocarbon raw materials such as naphtha, so that the yield of benzene and p-xylene is increased, and the target product yield and the energy efficiency can be greatly improved.

The invention relates to the technical field of chemical industry, and provides a method for preparing 2, 6-diisopropylnaphthalene through transalkylation, which comprises the following steps: S1, after naphthalene and propylene are subjected to alkylation reaction, rectification and crystallization separation are performed to obtain first 2, 6-diisopropylnaphthalene and a mixture A; s2, carrying out transalkylation reaction on the mixture A and naphthalene under the action of a supported catalyst to obtain a monoisopropylnaphthalene mixture, continuously carrying out alkylation reaction on the monoisopropylnaphthalene mixture and propylene under the action of a hydrogen mordenite A catalyst to obtain a mixture B, and rectifying and crystallizing the mixture B to obtain second 2, 6-diisopropylnaphthalene and a mixture C; and S3, the sum of the first 2, 6-diisopropylnaphthalene and the second 2, 6-diisopropylnaphthalene is obtained, and the product 2, 6-diisopropylnaphthalene is the sum of the first 2, 6-diisopropylnaphthalene and the second 2, 6-diisopropylnaphthalene. Through the technical scheme, the problems of harsh process conditions and lower yield in the preparation process of 2, 6-diisopropylnaphthalene are solved.

The present invention relates to a process for recycling polystyrene waste containing at least one organic halogen containing compound by converting polystyrene to styrene comprising the steps of: a) providing a melt of polystyrene waste containing at least one organic halogen containing compound, b) subjecting the melt provided in step a) to at least one devolatilization step so as to obtain a devolatilized composition, c) subjecting the devolatilized composition obtained in step b) to at least one pyrolysis step so as to obtain a pyrolyzed composition, d) subjecting the pyrolyzed composition to at least one distillation step so as to obtain a purified styrene composition.

The present application relates to the field of paraxylene separation, and discloses a paraxylene crystallization separation method and a system for paraxylene crystallization separation. The method comprises mixing a cold agent with mixed aromatic hydrocarbons to obtain a mixture; then crystallizing and separating the mixture; wherein the cold agent is in liquid state and has a solubility in the mixed aromatic hydrocarbons of not more than 1000 ppm; the density of the cold agent at the crystallization terminal temperature is not less than 1180 kg / m 3 The method can ensure the quality of paraxylene and improve the crystallization efficiency of paraxylene.

Disclosed is a process for converting a hydrocarbon feedstock, in which a first hydrocarbon feedstock (2) is treated in particular by means of a fractionation train (4-7), a xylene separation unit (10) and an isomerization unit (11), and in which: a pyrolysis unit (13) or an oxycombustion or gasification unit (14) treats a second hydrocarbon feedstock (30) to produce a syngas (32) comprising CO and CO2; a methanol synthesis reaction section (50) treats the syngas to produce methanol (51); and an aromatization reaction section (56) at least partially treats the methanol to produce a hydrocarbon effluent (57) comprising aromatic compounds, and to feed the hydrocarbon feedstock with the hydrocarbon effluent.

The invention belongs to the field of crystallization separation, and particularly relates to a wall scraping type crystallizer, a crystallization system and a paraxylene crystallization separation method. The wall scraping type crystallizer comprises a crystallizer tank body and a stirring paddle, the crystallizer tank body comprises an upper sealing head, a straight cylinder section and a lower sealing head which are connected in a sealing manner; the stirring paddle comprises a stirring main shaft, stirring blades, a supporting shaft and a scraper assembly; the stirring main shaft is coaxial with the straight barrel section; the stirring blades are vertically connected with the stirring main shaft; the supporting shaft is vertically connected with the stirring main shaft; the supporting shaft is parallel to the stirring blades; one end of the scraper assembly is connected with the supporting shaft, and the other end of the scraper assembly is parallel to and makes contact with the inner wall of the straight barrel section or the inner wall of the lower sealing head. The wall scraping type crystallizer disclosed by the invention is beneficial to improving the mixing effect of materials and improving the crystallization separation efficiency.