487results about "Crystallisation purification/separation" patented technology

The adsorbent for adsorbing and separating paraxylene includes active adsorbing component in mass fraction 85-95 % and adhesive in mass fraction 5-15 %. The active adsorbing component is selected from BaX zeolite and BaKX zeolite, and the adhesive is selected from kaolin, silica and alumina, with the crystal grain size of X zeolite in the adsorbent being 0.5-1.0 micron. The adsorbent is suitable for adsorption and separation of paraxylene from C8 arene and has high adsorption selectivity.

A method and a system for transporting a flow of fluid hydrocarbons containing wax and/or asphaltenes or any other precipitating solids through a treatment and transportation system including a pipeline are disclosed. The flow of fluid hydrocarbons is introduced into a reactor (4), where it is mixed with another fluid flow having a temperature below a crystallization temperature for the wax and/or asphaltenes or other solids and containing particles or crystals acting as nucleating and/or growth cores for the wax and/or asphaltenes or other solids, the mixing temperature providing precipitation of the wax and/or asphaltenes or other solids from the flow of fluid hydrocarbons, and the effluent flow of hydrocarbons and particles is conveyed from the reactor (4) to a pipeline (6) for transportation.

The invention relates to a method for preparing p-xylene by separating and crystallizing mixed xylenes, and mainly solves the problem of large energy consumption in a crystal separating process in the prior art. To well solve the problem, the invention adopts the following technical scheme of preparing the p-xylene by separating and crystallizing the mixed xylenes that: p-xylene crystal I and crystallization filtered stock I are obtained by crystallizing mixed xylenes in a primary crystallizer and separating crystal mush; the crystal I is melted by heat exchange, is partially returned to a first solid-liquid separator, and partially enters a product tank; the crystallization filtered stock I is separated into two streams, one stream returns to the crystallizer, and the other stream entersa pulping tank; one part of crystal mush in the primary crystallizer is cleared so as to obtain clear crystallization stock I which enters the pulping tank; p-xylene crystal II and crystallization filtered stock II are obtained by separating the crystal mush in a secondary crystallizer by a second solid-liquid separator; the crystal II enters the pulping tank, and separated after mixed heat exchange so as to obtain p-xylene crystal III and crystallization filtered stock III; the crystal III is melted by heat exchange, is partially returned to a third solid-liquid separator to be used as cleaning solution, and partially enters the product tank; the crystallization filtered stock II is separated into two streams, one stream returns to the secondary crystallizer, and the other stream enters the pulping tank; the crystallization filtered stock II and the mixed xylenes are subject to heat exchange and enter a stock tank; and the clear crystallization stock II and the mixed xylenes are subjected to heat exchange and enter the stock tank. The method can be used in p-xylene industrial production.

An adsorbing-crystallizing process for separating p-xylene and ethylbenzene from C8 arylhydrocarbon includes such steps as adsorptive separation to obtain the first material flow containing ethylbenzene and p-xylene and the second material flow containing meta-xylene and o-xylene, crystallizing for separating p-xylene from the first material flow, and adsorbing for separating ethylbenzene from the residual mother liquid.

The invention relates to a crystallization method for p-xylene production, and mainly aims to solve the problem of large energy consumption during crystallization separation in existing technologies. According to the method, a slurrying trough is arranged, and a p-xylene crystal obtained from a secondary crystallization process can be slurried so as to enter a first crystallizer, in which a clear mother solution enters the slurrying trough. The technical method of the invention well solves the above problem, and can be used for the industrial production of p-xylene.

The present invention provides an integrated process for the production of p-xylene, comprising the steps of A) separating a mixed feedstock containing benzene, toluene, C₈ aromatic hydrocarbons, C₉ and higher aromatic hydrocarbons, and non-aromatic hydrocarbons from a reforming unit, to obtain a first benzene stream, a first toluene stream, a first C₈ aromatic hydrocarbon stream, a stream of C₉ and higher aromatic hydrocarbons, and a stream of non-aromatic hydrocarbons; B) feeding the stream of C₉ and higher aromatic hydrocarbons from step A) to a C₉ and higher aromatic hydrocarbon dealkylation unit, where dealkylation reaction occurs in the presence of hydrogen, and separating the reaction effluent to obtain a second benzene stream, a second toluene stream, and a second C₈ aromatic hydrocarbon stream; C) feeding both the first toluene stream and the second toluene stream to a toluene selective disproportionation unit, where toluene selective disproportionation reaction occurs in the presence of hydrogen to produce a stream containing C₈ aromatic hydrocarbons including p-xylene and benzene, which stream is separated to obtain a third C₈ aromatic hydrocarbon stream, a third toluene stream, and a third benzene stream, with the third toluene stream being returned to an inlet of this unit; D) feeding both the first C₈ aromatic hydrocarbon stream and the second C₈ aromatic hydrocarbon stream to an adsorption separation unit, to obtain a first p-xylene product stream and a fifth C₈ aromatic hydrocarbon stream, with the fifth C₈ aromatic hydrocarbon stream being passed to an isomerization unit; E) feeding the third C₈ aromatic hydrocarbon stream to a crystallization separation unit, to obtain a fourth C₈ aromatic hydrocarbon stream and a second p-xylene product stream, with the fourth C₈ aromatic hydrocarbon stream being passed to the adsorption separation unit or the isomerization unit; and F) feeding an effluent of the isomerization unit to an inlet of the adsorption separation unit.

A process for the purification of aromatic feedstream to produce paraxylene is disclosed, including the separation of a C8+ aromatic feedstream into a steam comprising C8 aromatic species and a stream comprising C9+ aromatic species. After separation of PX from the C8 aromatic stream, a PX-depleted stream is separated and processed in a liquid phase isomerization unit and a vapor phase isomerization unit in parallel.

The invention is directed to purification of an aromatic hydrocarbon stream including selective removal of phenol from a process stream comprising aromatic hydrocarbon mixtures, especially aromatic hydrocarbon mixtures that contain higher-than-equilibrium paraxylene, by contact with suitable adsorbents, to provide a product stream having lower concentration of phenol than said process stream.

The present invention discloses a method for jointly preparing a series of products of an aromatic solvent, petronaphthalene and durene from a C10 heavy aromatics material, belonging to the C10 heavy aromatics complex utilization technical field. The method comprises the following steps of: A) separating the C10 heavy aromatics material; B)refrigerating and crystallizing an enrichment solution of durene; C)refrigerating and crystallizing an enrichment solution of naphthalene; D) gas phase catalytically oxidizing durene; and E) preparing technical grade PMA, technical grade PMDA and electronic grade PMDA from a crude product. The method has the advantages that the method can carry out joint production to obtain the series of products of aromatic solvent, petronaphthalene and durene by the C10 heavy aromatics material so that the C10 heavy aromatics material obtains sufficient utilization, thereby contributing to resource economizing.

A filter column apparatus comprising a filtration zone and a reslurry zone. These zones are separated by a barrier wall or are in substantial cooperation with each other. Also disclosed is a process for separating at least a portion of at least one substantially solid component from a solid-liquid stream comprising the substantially solid component and at least one substantially liquid component. Also disclosed is a process for forming a substantially solids containing packed bed. Also disclosed is a process for purifying paraxylene in a filtration zone.

A method of producing a wax composition having a constrained carbon number distribution and/or a narrow melting range is described. Additionally, hydrocarbon waxes and hydrocarbon wax compositions having a constrained carbon number distribution and/or melting point are described.

A device for preparing high-purity organic substance by fusion crystallizing method is a tower structure which is divided into upper cooling-crystallizing segment, middle separating-purifying segment and lower crystal fusing segment. Its tower body is inclined and is composed of casing consisting of intersected two cylinders, heater and parallel engaged two spiral stirrers.

A process for the combined production of para-xylene and benzene comprises:

• • separating a first feed, by adsorption in a simulated moving bed SMB, to produce an extract E rich in para-xylene and at least one raffinate R which is depleted in para-xylene;
  • converting a secondary feed of toluene by selective disproportionation to produce benzene and xylenes;
• a) at the start of the cycle, producing a supplemental quantity of para-xylene in a crystallization unit supplied with the xylenes from the disproportionation;
• b) at the end of the cycle, when the adsorbant has aged:
  • dividing the distilled extract E into a first fraction Ea and a complementary second fraction Eb;
  • replacing the feed to the initial crystallization by the stream Ea;
  • and recycling the xylenes from the disproportionation to the SMB.

The invention enables para-xylene and benzene production to be maintained despite ageing of the SMB absorbent.

The proposed process uses crystallization technology to purify paraxylene simultaneously of large concentrations of C8 aromatics and also small concentrations of oxygenated species.

The invention relates to a novel method for the production of beta-carotene from submerged cultures of mucoral fungi such as Blakeslea, Choanephora or Phycomyces by adding lectin to the culture medium and performing pH control once fermentation has started. The method involves beta-carotene recovery stage that makes it possible to simplify the process, optimize yields and increase purification of the product.

A process for preparing high-purity licopin includes such steps as dissolving the licopin oil resin in organic hydrocarbon solvent to obtain saturated solution at higher temp under protection of inertial gas, hot filtering, low-temp cooling while crystallizing, and filtering.

A process for removing contaminants from an off-gas stream generated by the methylation of toluene and/or benzene by methanol to produce para-xylene. The treated off-gas stream, which contains C₄₋ hydrocarbons, may be further processed in an olefins plant/process to yield valuable light alkanes and olefins.