188results about "Membrane purification/separation" patented technology

A device for separating a gas stream which has a compressor and three membrane separation units in series, connected to pass the retentate stream of each of the first two units to the subsequent membrane separation unit, comprises conduits for recycling the permeate streams of the second and the third membrane separation unit to upstream of the compressor and a control device controlling the fraction of the second permeate stream which is recycled. Adjusting which fraction of the second permeate is recycled can be used to maintain a target composition of the retentate obtained in the third membrane separation unit when the flow rate or the composition of the gas stream changes.

The invention provides a methane recovery and purification system in intelligent cleaning equipment, which relates to the technical field of environmental protection, and is characterized in that methane-containing gas is collected from the cleaning equipment, moisture and small particles in the gas are removed to obtain preliminarily purified gas, and then methane is separated and recovered by using a separation technology to obtain purified gas. And the purified methanol is obtained through multi-stage purification treatment. According to the methane recovery technology, a time sequence of gas components, a time sequence of physical properties and a time sequence of process parameters need to be obtained, and local time sequence coding and causal context time sequence aggregation are carried out, so that a separation technology recommendation result is recommended, and operation parameters are dynamically adjusted. Therefore, subjective experience can be abandoned, gas characteristics and process requirements are monitored in real time and accurately matched, the accuracy and objectivity of separation technology selection are improved, and it is ensured that the separation process is always in the optimal state.

A system for separating a gas mixture is provided. The system includes a source of a gas mixture and a membrane separation stage including a gas separation membrane module. The membrane separation stage is in fluid communication with the source of the gas mixture, and the gas separation membrane module is configured to separate the gas mixture into a retentate stream and a permeate stream. The gas separation membrane module also includes a membrane having a permeate side and a retentate side. A sweep stream is provided to the permeate side of the membrane, the sweep stream comprising a portion of the retentate stream.

The invention discloses an MOF-808-CA-Me mixed matrix gas separation membrane as well as a preparation method and application of the MOF-808-CA-Me mixed matrix gas separation membrane. The preparation method comprises the following steps: preparing MOF-808 (Zr) by utilizing a solvothermal method, reacting with citric acid to graft carboxyl to obtain MOF-808-CA, reacting with melamine to obtain MOF-808-CA-Me, uniformly mixing with a Pebax1657 membrane casting solution, pouring on a base membrane, and obtaining a target membrane material by utilizing a solvent evaporation method. According to the method, an amido bond is formed through a reaction between-COOH of citric acid and-NH2 of melamine, and MOF-808-CA-Me is stabilized in the adsorption and desorption processes of carbon dioxide; the preparation process is simple, convenient and efficient, the cost is low, and the prepared MOF-808-CA-Me mixed matrix gas separation membrane has good selectivity to CO2 / CH4.

The invention relates to a lignin-based polymer pervaporation membrane, a preparation method thereof and a method for separating and purifying cyclohexane-KA oil. The invention aims to provide a pervaporation membrane which is high in permselectivity, high in stability and good in mechanical property. The pervaporation membrane is used for cyclohexane-KA oil separation and has the advantages of high separation efficiency, low energy consumption and simple process. The preparation method comprises the following steps: adding the surfactant, the polymer and the solvent into a reactor, and stirring at 50-70 DEG C for 4-6 hours to obtain a mixed solution; the method comprises the following steps: adding lignin and a solvent into a reactor, and stirring at room temperature for 4-6 hours to obtain a lignin solution; dropwise adding the lignin solution into the mixed solution, and continuously stirring at constant temperature for 12-24 hours to obtain a membrane casting solution; transferring the membrane casting solution to a centrifugal tube, performing centrifugal separation, and uniformly coating the membrane casting solution on an ultrafiltration membrane material with the membrane thickness of 100-200mm to form a uniform liquid membrane; and drying the liquid membrane to obtain the lignin-based polymer pervaporation membrane. Belongs to the technical field of membrane separation.

A gas separation system for producing a CH4-enriched gas from a feedstock gas containing CO2 and CH4, including a first gas separation membrane unit and a second gas separation membrane unit, in which the gas separation system includes a feedstock gas supply line connected to a gas inlet of the first gas separation membrane unit; a compression part disposed in the feedstock gas supply line; a first line connecting the retentate gas outlet of the first gas separation membrane unit and the gas inlet of the second gas separation membrane unit; a second line connecting the permeate gas outlet of the second gas separation membrane unit and the feedstock gas supply line; and a cooling part for lowering the operating temperature of the second gas separation membrane unit below the operating temperature of the first gas separation membrane unit.

The invention discloses a preparation method and application of an MFI zeolite membrane.The preparation method comprises the steps that an MFI zeolite nanosheet serves as a seed crystal, a uniformly-distributed and compact seed crystal layer is prepared on a carrier through a vacuum filtration method, namely, a nucleation center crystallized into a membrane is loaded on the surface of the carrier, and directional growth and membrane forming of the zeolite nanosheet can be effectively controlled; the highly b-oriented MFI zeolite membrane can be prepared within several hours, the prepared b-oriented MFI zeolite membrane shows a continuous and compact microstructure and almost has no defects, and compared with a traditional hydrothermal method, the method overcomes the defects that the reaction process is too long in time consumption, uneven in heating is prone to occurring, and the like. And therefore, the time required by crystal growth is greatly shortened. The prepared MFI zeolite membrane can be applied to pervaporation separation of xylene isomers, shows good size screening separation performance, and has important industrial application value.

A gas separation method includes supplying a mixed gas to a zeolite membrane complex and permeating a high permeability gas through the zeolite membrane complex to separate the high permeability gas from other gases. The mixed gas includes a high permeability gas and a trace gas that is lower in concentration than the high permeability gas. The molar concentration of a first gas included in the trace gas in the mixed gas is higher than the molar concentration of a second gas included in the trace gas in the mixed gas. The adsorption equilibrium constant of the first gas on the zeolite membrane is less than 60 times that of the high permeability gas. The adsorption equilibrium constant of the second gas on the zeolite membrane is 400 times or more that of the high permeability gas.

A raw material mixed gas supply line 13 is connected to a gas inlet of the first gas separation membrane unit 11. The non-permeated gas discharge port 11b of the first gas separation membrane unit 11 and the gas inlet of the second gas separation membrane unit 12 are connected by a first non-permeated gas discharge line 14. A second non-permeated gas recovery line 15 is connected to the second non-permeated gas discharge port 12b of the second gas separation membrane unit 12. The first permeated gas discharge port 11c of the first gas separation membrane unit 11 and the second permeated gas discharge port 12c of the second gas separation membrane unit 12 are connected to the raw material mixed gas supply line 13 by a first permeated gas recycle line 16 and a second permeated gas recycle line 17, respectively. The line 16 includes a permeated gas discharge line 18 for at least partially discharging the permeated gas of the first gas separation membrane unit to the outside of the system.

To provide an apparatus capable of efficiently producing concentrated gas of biogas and an efficient production method of concentrated gas of biogas.SOLUTION: An apparatus for producing concentrated gas obtained by concentrating methane gas in biogas comprising methane gas, carbon dioxide gas, and moisture, comprises: a compressor for compressing the biogas; a cooling device for removing part of the moisture as condensed water by cooling the biogas compressed by the compressor; a heating device for heating the biogas cooled by the cooling device; and a separation device for separating at least part of the carbon dioxide gas and at least part of the residual moisture from the biogas heated by the heating device.SELECTED DRAWING: Figure 1

The invention provides an active mediated bimetal MOFs interface assembled gas purification nano-fiber membrane as well as a preparation method and application thereof. The method comprises the following steps: step S1, preparing a nano-fiber membrane with a three-dimensional network structure from polylactic acid through a spinning technology; s2, dipping the nano-fiber membrane obtained in the step S1 in a mixed solution of a buffer solution and dopamine hydrochloride to prepare a polydopamine modified nano-fiber membrane; step S3, putting the polydopamine modified nano-fiber membrane obtained in the step S2 into a zinc-cobalt source co-precursor solution to prepare a zinc-cobalt co-loaded nano-fiber membrane; and step S4, dipping the zinc-cobalt co-loaded nanofiber membrane obtained in the step S3 in a ligand solution, and inducing MOFs nanocrystals rich in micropores to grow in situ on the surface of nanofibers through a coordination reaction, so as to prepare the gas purification nanofiber membrane. The prepared nano-fiber membrane has the remarkable advantages of double-metal adsorption sites, a graded porous structure, a three-dimensional network channel, efficient gas adsorption, separation and screening capacity and the like, and is a nano-fiber membrane material for deep purification of gas.

The invention discloses a double-ligand doped and modified zirconium-based metal organic framework membrane as well as a preparation method and application thereof. According to the membrane material, a central metal node is used, carboxylic acid ligands containing amino and nitryl are used as ligands, the ligands are doped in zirconium-based metal organic framework polycrystal UiO-66 membrane pore channels to construct preferential aromatic hydrocarbon adsorption sites and defects in a membrane framework beneficial to aromatic hydrocarbon separation, and then efficient separation of aromatic hydrocarbon / aliphatic hydrocarbon mixed components is achieved through the membrane. The preparation method comprises the following steps: by adopting a strategy of inducing secondary solvothermal growth by using a nanocrystalline seed and performing double-ligand doping modification, modifying and attaching the nanocrystalline seed to the surface of a support body by using a dip-coating method, and performing self-assembly on two polar carboxylic acid ligands and a metal source in a synthetic solution to form a compact and defect-free ligand-doped modified metal organic framework polycrystalline film. When the membrane is used for toluene / n-heptane mixed components, the selectivity reaches 5.3, and the permeation flux is greater than or equal to 400g / m < 2 > h.

A porous cylindrical support for use in supporting a zeolite membrane has a generally cylindrical inside surface having a central axis extending in the longitudinal direction and a generally cylindrical outside surface that surrounds the inside surface. A zeolite membrane is formed on the outside surface. A maximum value A and a minimum value B of a support thickness in a circumferential direction satisfy (A−B) / (A+B)≤0.3 in at least part of the support in the longitudinal direction, the support thickness being a radial distance between the inside surface and the outside surface. By reducing a variation in support thickness, it is possible to improve uniformity in the thickness of the zeolite membrane formed on the support.

The present invention belongs to the technical field of membrane separation, and specifically relates to a CPOS-based mixed matrix membrane and its preparation method and application. In the present invention, polyethylene glycol is used as the polymer matrix, and crystalline porous organic salt is used as the filler. The crystalline porous organic salt is introduced into the polymer matrix to construct a CPOS-based mixed matrix membrane; the mass of the crystalline porous organic salt is 14% - 34% of the total mass of the CPOS-based mixed matrix membrane. For the CPOS-based mixed matrix membrane of the present invention, at a pressure of 1 bar, when the mass of the crystalline porous organic salt is 33.33% of the total mass of the CPOS-based mixed matrix membrane, the separation factor for 1,3-butadiene and n-butane can reach 4.21, and the separation factor for 1,3-butadiene and isobutene can reach 4.78, showing good separation performance.

The invention belongs to the technical field of membrane preparation and application, and discloses a high-performance ethylene-ethane separation carbon molecular sieve hollow fiber membrane and a preparation method thereof. The preparation method comprises the following steps: firstly, synthesizing a CF3-containing polyimide precursor material by adopting a chemical imidization method, applying the polyimide precursor to hollow fiber membrane spinning, and carbonizing the prepared hollow fiber membrane under a certain heating procedure to obtain the high-performance ethylene-ethane separation carbon molecular sieve hollow fiber membrane. Compared with the existing ethylene and ethane separation carbon molecular sieve hollow fiber membrane, the carbon molecular sieve hollow fiber membrane prepared by the invention has the advantages that the C2H4 / C2H6 separation performance is obviously improved, and the industrial application prospect is better.

The present invention provides systems and methods for preventing the accumulation of light fractions such as methane, ethylene, and ethane in an olefin / paraffin separation system that uses a combination of a membrane and a distillation column for the separation. In one embodiment, a small stripper column is provided downstream of a selective hydrogenation reactor. In another embodiment, a pressure regulating vessel with a receiver is added to the retentate stream of the membrane unit.

The invention provides a method for recovering tail gas generated in production of carbon nanotubes. The method comprises the following steps: compression: introducing tail gas containing methane and hydrogen into a compressor for pressurization; first-stage separation: the pressurized tail gas is introduced into a first-stage membrane separator for separation, methane and first-stage tail gas are obtained, and the main component of the first-stage tail gas is hydrogen; and second-stage separation: introducing the first-stage tail gas into a second-stage membrane separator for separation to obtain hydrogen and second-stage tail gas containing hydrogen. Through two-stage membrane separation, methane and hydrogen are recovered, the methane separated in the first stage can return to the continuous furnace to be continuously used as a raw material for producing carbon nanotubes, and the hydrogen separated in the second stage can be used for producing trichlorosilane, so that the recovery and utilization of resources can be realized.

The present invention relates to field of separation processes, particularly to processes for separation of light hydrocarbons utilizing microporous molecular sieving membranes. The inventive process relies on a membrane system comprising at least two membrane units in sequential order, each membrane unit comprising a membrane where molecular sieves are tightly embedded in channels perpendicular to the membrane surface and the membrane comprises a polymer matrix and allows separating a target compound from a mixture of at least 3 compounds. The invention further provides for new membrane systems.

The invention relates to a method and system for preparing isobutene from tert-butyl alcohol, and the method comprises the following steps: S1, hydrolyzing initial tert-butyl alcohol to obtain a first product containing water, isobutene and unreacted tert-butyl alcohol; s2, performing membrane permeation separation on the first product to obtain a water permeate and a retentate containing isobutene and unreacted tert-butyl alcohol; s3, performing flash evaporation separation on the retentate to obtain gas-phase isobutene and liquid-phase tert-butyl alcohol; circulating the liquid-phase tert-butyl alcohol and repeating the steps S1 to S3 until the total conversion rate of the initial tert-butyl alcohol reaches a preset value; rectifying the liquid-phase tert-butyl alcohol, all water permeates and all gas-phase isobutene obtained in the last-stage circulation to obtain high-purity isobutene, water-tert-butyl alcohol azeotrope and wastewater; the water-tert-butyl alcohol azeotrope is extracted from the side line of the rectifying stripping section and returns to S2 for recycling. Through cyclic coupling of hydrolysis, membrane permeation separation, flash separation and rectification, high-purity isobutene is obtained, the conversion rate of tert-butyl alcohol is high, and the discharge amount of wastewater is low.

The invention relates to the technical field of aromatic hydrocarbon separation and purification, in particular to a system and process flow for removing C8 non-aromatic hydrocarbon in xylene through membrane separation, and the system comprises a membrane separation unit, a feeding unit, a permeation side system, an interception side system, an adsorption tower feeding buffer tank outlet line and a crossover line; the membrane separation unit is provided with a membrane feeding pipeline, one end of the membrane separation unit is connected to an outlet of the membrane separation feeding buffer tank, and the other end of the membrane separation unit is connected to an inlet side pipe orifice of the separation pipeline; a membrane feeding booster pump is arranged on the membrane feeding pipeline; a spiral-wound membrane assembly is arranged in the separation pipeline; the feeding unit is provided with a xylene redistillation tower top outlet line which is connected to an inlet of the membrane separation feeding buffer tank from the xylene redistillation tower top. According to the membrane separation process adopted by the method, the non-aromatic hydrocarbon removal rate can be more than 98% under the operation conditions that the feeding pressure is 1.68 MPa, the permeation side is 20 kPa and the interception side is 1.6 MPa, and the method has definite industrial feasibility and technical advantages.

Example gas recovery systems include a source gas conditioning assembly configured to condition and compress the inlet source gas to provide a conditioned source gas, a first membrane assembly configured to separate the conditioned source gas into a hydrocarbon enriched stream and a recovery stream, a second membrane assembly fluidly coupled to the hydrocarbon enriched stream, and configured to separate the hydrocarbon enriched stream into a hydrocarbon product stream and a recycle stream, a carbon dioxide (CO2) plant assembly fluidly coupled to the recovery stream configured to provide a carbon dioxide product stream and an enriched recycle stream, a standalone membrane assembly configured to separate the enriched recycle stream into a hydrocarbon enriched recycle stream and an effluent stream, and wherein the source gas conditioning assembly is fluidly coupled to the recycle stream and the hydrocarbon enriched recycle stream.

The invention provides a carbon molecular sieve gas separation membrane prepared based on Joule heating and a preparation method and application thereof. According to the preparation method, 6FDA-DAM polyimide is used as a precursor material, an aprotic polar solvent is used as a solvent, a compact precursor film is prepared through a solvent evaporation method, and carbonization treatment is carried out in a vacuum environment in a Joule heating mode. By controlling the carbonization duration, the microporous structure in the membrane, the formation of an ordered carbon skeleton and the removal degree of functional groups can be adjusted, the conversion from surface diffusion to a molecular sieve screening mechanism is realized, and the gas separation capacity is remarkably improved.

Provided is a method for upgrading a bio-based material, the method including the steps of pre-treating bio-renewable oil(s) and / or fat(s) to provide a bio-based fresh feed material, hydrotreating the bio-based fresh feed material, followed by separation, to provide a bio-propane composition.

This invention relates to a sealing structure and its preparation method for a high-pressure, corrosion-resistant acetylene purification membrane module, belonging to the field of gas separation technology. The sealing structure includes: a membrane element support cylinder; an end clamping assembly comprising a limiting step and a pressure equalizing gasket; a double-layer sealing ring consisting of a main sealing ring and an isolation sealing ring, forming an annular isolation cavity between them; and a leakage guide channel connecting the isolation cavity to an external safety collection port. When a micro-leakage occurs in the main seal, the medium enters the isolation cavity and is discharged to the safety collection end through the guide channel, preventing external leakage. The main sealing ring is made of a pressure-resistant, low-permeability material, and the isolation sealing ring is made of a chemically corrosion-resistant material. The preparation method includes precision machining of the sealing groove, sealing ring forming and secondary vulcanization, staged clamping assembly, and leakage testing. This invention transforms micro-leakage into a controllable state, employs a modular design to adapt to different membrane area configurations, and provides a safe and reliable sealing solution for acetylene membrane separation and purification.

The invention relates to the field of chemical engineering, in particular to a catalytic distillation method for removing impurities in isooctane reaction raw materials, which comprises the following steps: S1, separating a C4 raw material and butadiene: treating the C4 raw material with desalted water to obtain a washed C4 raw material; carrying out coalescence dehydration treatment on the washed C4 raw material to obtain a dehydrated C4 raw material; the dehydrated C4 raw material is subjected to catalytic rectification treatment, a rectified C4 raw material is obtained, a catalyst for catalytic rectification treatment is a La-Ce / ZSM-5 catalyst, and the rectified C4 raw material is subjected to membrane separation, so that the C4 raw material and butadiene are obtained; and S2, pumping the C4 raw material into an alkylation reactor, and carrying out an alkylation reaction on the C4 raw material and isobutane under the action of a solid superacid catalyst to prepare isooctane. Compared with the prior art, the method has the advantages that impurities in the C4 raw material are removed, the byproduct butadiene and the C4 raw material are extracted, the service life of a catalyst in the isooctane preparation process can be prolonged by using the C4 raw material, the solid superacid catalyst is improved at the same time, and the C4 conversion rate and the isooctane yield are improved.

The present application relates to the technical field of gas separation, in particular to a preparation method of CoPc-Mo composite hollow fiber membrane. The preparation method comprises the following steps: preparing a hollow fiber ceramic membrane; preparing a PDMS-Mo hollow fiber membrane; preparing CoPc-TFPN-COF and post-modifying carboxyl; and preparing a CoPc-Mo composite hollow fiber membrane. The present application prepares CoPc-TFPN-COF and modifies CoPc-TFPN-COF to obtain CoPc-TFPN-COOH. Compared with CoPc-TFPN-COF, the pore size of CoPc-TFPN-COOH is not much different, but CoPc-TFPN-COOH has a higher specific surface area, which makes CoPc-TFPN-COOH have the temperature resistance of CoPc-TFPN-COF while the maximum flux of helium reaches 288 GPU, so it performs more excellent in gas adsorption.

The application provides a preferentially oriented zeolite imidazolate framework-8 self-supporting gas separation membrane and a preparation method thereof. The method comprises the following steps: dissolving zinc acetate dihydrate, 2-methyl imidazole and cetyl trimethyl ammonium bromide in deionized water, and finally forming a self-supporting gas separation membrane with preferential orientation and cubic morphology through stirring, centrifugal treatment, filtration, standing of the growth solution and drying. In the preparation process, the proportion of each component, stirring conditions, temperature and humidity of the constant temperature and humidity box and other parameters are strictly controlled to ensure uniform growth and good mechanical strength of the membrane. The preparation method is simple and efficient, and the obtained membrane has excellent gas separation performance and long-term stability.

The present disclosure provides compositions and methods for producing a high-purity isoprenoid from an isoprenoid composition, wherein the method includes using chromatography to reduce the impurities in the isoprenoid composition to below parts per million levels. Further provided herein are compositions containing high-purity isoprenoids.

A method for producing para-xylene (PX) includes introducing a C8 aromatic-containing composition to a xylene rerun column to separate the C8 aromatic-containing composition into a xylene-containing effluent and a heavy effluent and passing the xylene-containing effluent to a PX processing loop that includes a PX recovery unit operable to separate PX from the xylene-containing effluent, a membrane isomerization unit operable to convert a portion of the MX, OX, or both to PX, an EB dealkylation unit operable to dealkylate EB to produce benzene, toluene, and other C7- compounds, and a membrane separation unit operable to produce a permeate that is PX-rich and a retentate that is PX-lean. The permeate is passed to the PX recovery unit for recovery of PX, which the retentate is bypassed around the PX recovery unit circulated through the xylene processing loop.

The invention relates to the technical field of aromatic hydrocarbon production, and particularly discloses a low-carbon-emission aromatic hydrocarbon production device and method.The device comprises an aromatic hydrocarbon production unit, a carbon dioxide capture unit, a hydrogen purification unit, a carbon-1 recovery unit and a carbon-based compound synthesis unit, the aromatic hydrocarbon production unit is respectively connected with the carbon dioxide capture unit and the hydrogen purification unit; the hydrogen recovery unit is connected with the carbon I recovery unit; the carbon-based compound synthesis unit is respectively connected with the carbon dioxide capture unit and the carbon-I recovery unit. According to the low-carbon-emission aromatic hydrocarbon production device, hydrogen-containing gas and waste gas generated by the aromatic hydrocarbon production unit are effectively separated, separated products are fully utilized, and near-zero emission of carbon dioxide is achieved.