82results about "Crystallisation purification/separation" patented technology

The invention provides a method for synthesizing 1, 2-bis (4-vinyl phenyl) ethane, which comprises the following steps: adding a first solvent, methyl triphenyl phosphine halide and strong alkali into a reaction flask, and uniformly stirring to obtain a first mixed solution; heating the first mixed solution and carrying out reflux reaction for 1 hour; dropwise adding a 1, 2-bis (p-formaldehyde phenyl) ethane solution until the reflux reaction is finished to obtain a second mixed solution; reducing the temperature of the second mixed solution to room temperature, and adjusting the pH value of the second mixed solution to obtain a first solution; layering the first solution, and taking an organic layer; adding a polymerization inhibitor into the organic layer to obtain a second solution; concentrating the second solution to obtain a 1, 2-bis (4-vinyl phenyl) ethane crude product; adding a poor solvent into the crude product, stirring and crystallizing; filtering the crystal to obtain a filter cake, adding a second solvent into the filter cake, and washing and drying the filter cake to obtain 1, 2-bis (4-vinyl phenyl) ethane; the method for synthesizing the BVPE is simple and low in raw material cost, and the synthesized BVPE is high in purity and free of product isomeride.

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.

This invention discloses a method for controlling photon spin-orbit coupling in an organic alloy microcavity, belonging to the field of optical microcavity technology. This invention prepares β-type Pe by doping different amounts of DCA into Pe using a volatilization method. 1‑x DCA x An organic alloy, wherein x ≤ 20 wt%, allows for the controllability of crystal color from yellow-green to orange-red. Furthermore, this organic alloy exhibits birefringence, and its application in the fabrication of optical microcavities allows for the observation of TE-TM spin-orbit coupling and Rashba-Dresselhaus spin-orbit coupling within the microcavities. This provides a novel type of microcavity for studying the interaction between light and matter in organic alloy microcavities, and the controllability of photon spin-orbit coupling within these microcavities can be achieved by adjusting the value of x.

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 application provides a crystallization method of refined fluorene, which comprises the following steps: adding a raw material fluorene fraction into a mixed solution, carrying out a first beating and washing at normal temperature, and obtaining crude fluorene through centrifugal separation; mixing the crude fluorene with a solvent A, stirring and heating to 65-85 DEG C, cooling to 5-30 DEG C after the solid part is dissolved, keeping the temperature for 1 h, and obtaining industrial fluorene through centrifugal separation, and the mother liquor is used as a washing agent to participate in the first beating and washing. The method has simple and easy-to-control operation conditions and low cost. Through reducing the high-temperature operation time, using a high-boiling and low-volatility solvent to reduce the solvent loss in the crystallization process, using a single solvent to facilitate solvent recovery, using the mother liquor in the process to increase the yield and reduce the solvent consumption, using the beating and washing mode in the first step operation to operate at normal temperature, reducing the energy consumption and shortening the process cycle, and cooling and crystallizing in the second step operation, the crystal part is dissolved, the remaining solid is used as a crystal seed, so that the crystallization process is controllable, the primary burst nucleation is avoided, and the walling condition is reduced.

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 application belongs to the field of photodynamic therapy, and specifically discloses a vitamin K co-crystal material for photodynamic therapy and a preparation method thereof. The vitamin K co-crystal material takes vitamin K as an electron acceptor, and the two carbonyl groups at the para positions of the vitamin K quinoid six-membered ring make the vitamin K exhibit electron deficiency, form an organic charge transfer complex with the electron acceptor, and self-assemble to form a co-crystal, so that the absorption spectrum of the system is widened, a wider wave band of light is more effectively utilized, the photodynamic therapy response wavelength of the vitamin K is adjusted from the ultraviolet region to the visible region and the near infrared region, the problem of low penetration depth and light damage caused by photodynamic therapy using light in the ultraviolet region is avoided, and the vitamin K has excellent photodynamic performance and good application prospects in surface sterilization and disinfection, treatment of body surface infection, and directional cancer treatment based on visible light or near infrared light.

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 relates to a high-efficiency energy-saving p-xylene production device, and relates to the technical field of chemical equipment, a bottom plate mechanism of the high-efficiency energy-saving p-xylene production device comprises an inner concave bottom plate capable of moving up and down in a round tank, crystals adhered to the inner wall of the round tank are scraped off by utilizing the rising inner concave bottom, and most reaction liquid can also be pressed into a distillation tank; the liquid pump has the advantages that the later use time of the liquid pump is shortened, the liquid discharge energy consumption is reduced, crystals on the concave bottom plate can be easily scraped, the crystal cleaning efficiency is improved, meanwhile, the bottom of the concave bottom plate is concave, the scraped crystals gather together at the center of the concave bottom plate through gravity, workers can conveniently take out the crystals, and after all the crystals in the tank are scraped, the crystal cleaning efficiency is improved. And the filtering mechanism is used for filtering the scraped crystals and screening the scraped crystals according to the size, so that linkage scraping and screening among a plurality of mechanisms are realized while all the crystals in the tank can be taken out, the collection effect of the device is improved, and waste of small crystals is also avoided.

The invention discloses a crystallization purification method of indene in C9 petroleum resin, which comprises the following steps: S1, pretreating the C9 petroleum resin to obtain concentrated indene; s2, mixing the concentrated indene with a solvent I, performing primary cooling crystallization, and filtering after heat preservation to obtain crystals and filtrate; s3, mixing the crystals with a solvent II, carrying out secondary cooling crystallization, carrying out heat preservation, and filtering to obtain a filter cake; and S4, dissolving the filter cake, and carrying out negative pressure distillation to remove the solvent so as to obtain indene. According to the method, low-temperature crystallization is adopted, target substances can be selectively separated out, impurities are effectively removed, and a C9 petroleum resin mixture with large solubility difference is separated. And moreover, the crystals cannot be caked or caked during precipitation, the dispersion difficulty is low, filtration is easy, and the process difficulty is reduced.

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 discloses a kind of ultrasonic reinforced C8 aromatic hydrocarbon crystallization separation method and system, belong to C8 aromatic hydrocarbon separation technical field.The system of the present application mainly includes primary crystallizer, centrifugal filter, melting tank, ultrasonic generator and the like device.According to the different separation requirements of raw material, different process flow and process system are used in the present application, two-stage filtration process and the combination process of fine filtration are first proposed in C8 aromatic hydrocarbon separation, and the separation of ethylbenzene and xylene can be realized through primary crystallization and filtration, with high separation purity;At the same time, the present application can select coarse separation or fine separation according to the purity requirement of process product, and the raw material has wide adaptability and flexible process.

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 present invention relates to a novel method for isolating capsanthin and several other carotenoids from paprika oleoresin, a concentrated extract of paprika fruit (Capsicum annuum). In another aspect, the invention relates to the use of mild non-aqueous and aqueous saponification methods for isolating highly pure capsanthin and other carotenoids from paprika oleoresin at temperatures of about 20-50°C. In another aspect, the invention relates to a saponification method that results in a crystalline mixture of capsanthin, β-carotene, β-cryptoxanthin, and zeaxanthin, which can be separated by solvent extraction and crystallization to obtain highly pure capsanthin and other carotenoids.

The invention provides a method capable of producing a monocyclic aromatic hydrocarbon such as benzene or xylene effective as a base raw material, with a naphtha raw material containing renewable naphtha. The method for producing at least one monocyclic aromatic hydrocarbon of benzene or xylene with a naphtha raw material containing renewable naphtha includes step (A-1) of pyrolyzing the naphtha raw material in the presence of water vapor, to produce and separate toluene, and step (A-2) of subjecting toluene to disproportionation reaction or transalkylation reaction, to produce and separate at least one monocyclic aromatic hydrocarbon of benzene or xylene.

The invention discloses a crystallizer based on a high-pressure crystallization method, and belongs to the technical field of 2-methylnaphthalene preparation, the crystallizer comprises a tank body, two sides of the top of the tank body are respectively provided with a raw material inlet and a nitrogen inlet pipe, the outer side of the tank body is sleeved with a jacket for temperature control, and the bottom end of the tank body is connected with a three-way valve for discharging materials and impurities. Through a rotary lifting mechanism composed of a main gear, a first sleeve, a driven gear, an outer spline, a guide groove, a fixing ring and a guide column in the nitrogen transfer box, a motor is matched with a shaft rod to serve as a unified driving source, a nitrogen discharge pipe can be driven to synchronously achieve rotation and lifting actions, and a propeller and a crystallization pipe are linked to form relative movement; according to the design, the limitation that bubbles are only locally diffused in traditional equipment is broken through, materials in the crystallizer can be actively driven to form global circulating flow, local temperature difference is effectively avoided, uniform temperature distribution in the tank is ensured, a stable thermodynamic environment is created for preferential crystallization of 2-methylnaphthalene, and the purity of a crystallized product and the consistency of crystal morphology are remarkably improved.

The present disclosure relates to a process for producing high purity aromatic compounds from a mixed aromatic feed stream. The present disclosure provides systems and methods for producing aromatic compounds in high yields from a mixed aromatic feed stream. Also disclosed are systems and methods for producing aromatic compounds in high yields from oxygen-containing hydrocarbons, such as carbohydrates, sugars, sugar alcohols, sugar degradation products, and the like.

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 relates to a C8 aromatic hydrocarbon complexing extraction-crystallization integrated efficient separation method, which comprises the following steps: carrying out complexing extraction reaction on a C8 aromatic hydrocarbon raw material and an extraction agent to obtain an extraction phase and a raffinate phase; heating and decomposing the extraction phase to obtain a high-purity MX product and an extraction agent; and taking the raffinate phase, stirring and cooling to 2.3 DEG C to obtain a solid-liquid mixture of PX-rich crystals, OX and ethylbenzene, continuously cooling to-34.9 DEG C to obtain a solid-liquid mixture of PX-OX eutectic and ethylbenzene, and then carrying out centrifugal separation to obtain a PX-OX-rich eutectic product and a high-purity ethylbenzene product. A C8 aromatic hydrocarbon complex extraction-crystallization integrated efficient separation system comprises a reactor, a separator, a crystallizer and a centrifugal machine. According to the separation method, through integration of a complexing extraction method and a crystallization method, the purity and yield of products such as m-xylene and ethylbenzene are improved, the energy consumption of a traditional crystallizer is reduced, and the treatment capacity and efficiency of equipment are improved.

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.