Showing papers on "Gas separation published in 1985"

Gas separation process

Abstract: A process for separating oxygen from gas mixture containing oxygen is disclosed The gas mixtures are contacted with a solution of an organometallic complex oxygen carrier and an electrolyte in an organic solvent During the contact, oxygen is bound to the carrier After the contacting step is completed the solution is electrochemically oxidized with resultant release of oxygen which is recovered The solution is then electrochemically reduced bringing the oxygen carrier to its original condition and ready for reuse

Calculation methods for multicomponent gas separation by permeation

Abstract: Calculation methods for the single-stage permeation of a multicomponent gas mixture are presented for five flow patterns: cocurrent flow, countercurrent flow, cross flow, perfect mixing, and one-side mixing. The derivations are cast in a form suitable for computer calculation. The calculation methods presented are appropriate for systems with any number of components. Calculation results are shown for the separations of a NH3, H2, and N2 gaseous mixture by means of a polyethylene membrane, and for a H2, CH4, CO, N2, and CO2 mixture through a microporous glass membrane.

Gas separation by pressure swing adsorption: A pore‐diffusion model for bulk separation

Abstract: Etude theorique et experimentale. En faisant varier de facon cyclique la pression d'un lit de charbon actif entre 3 et 500 psig (0,021 a 3,445 MPa), a la temperature ambiante, un melange 50/50 H 2 /CH 4 est separe en deux produits de plus de 90% de purete. Toutes les caracteristiques du procede peuvent etre predites par un modele de diffusion dans les pores

Method of making membranes for gas separation and the composite membranes

Abstract: Composite membranes suitable for separating gas mixtures are made by in situ crosslinking of aminoorganofunctional polysiloxane, 1 to 9 mol percent aminosiloxane units, with diisocyanate on the surface of a highly porous polymer substrate, such as polysulfone. Using the crosslinked polysiloxane as a gutter layer, a gas separating entity can be coated on the gutter layer to make a double layer composite membrane which has a higher separation factor than the crosslinked polysiloxane and can be used effectively for flat sheet membranes, as well as, hollow fiber membranes.

Selective-permeation gas-separation process and apparatus

Abstract: A permeant gas is selectively transferred from a feed-gas mixture which comprises the permeant gas and at least one other component to an output fluid by the process of the invention. The process involves introducing a selective-permeation liquid into a permeation-transfer chamber. A gas-depletion channel and a gas-enrichment channel pass through the permeation chamber and are separated from the chamber respectively by porous walls. The selective-permeation liquid contacts the porous walls but does not flow into the gas-depletion or gas-enrichment channels. The feed-gas mixture is introduced into the gas-depletion channel so that permeant gas in the mixture can pass through the pores of the walls of the channel into the selective-permeation liquid and from the selective-permeation liquid through the pores of the walls of the gas-enrichment channel into the gas-enrichment channel. Permeant gas is withdrawn from the gas-enrichment channel and a stream of gas depleted in the permeant gas is withdrawn from the gas-depletion channel. A gas-transfer unit permits the process of the invention to be carried out effectively.

Pillared interlayered clays

Abstract: Pillared, interlayered clay products suitable as gas separation agents or as substrates for catalyst compositions are prepared by methods that provide an increase in surface area and pore volume as compared to similar products made by prior art methods.

Thin film polymer blend membranes

Abstract: Gas separation membranes comprising an inorganic compound-organic polymer blend may be prepared by admixing an organic polymer such as poly(vinyl alcohol) with a phosphoric acid or sulfuric acid in a mutually miscible solvent. After allowing the mixture to proceed for a period of time sufficient to form a blend, the solution may be cast on an appropriate casting surface and, after the solvent has been evaporated, the desired membrane which may have a thickness of from about 0.1 to about 100 microns, is recovered.

Gas separation process and apparatus

Abstract: A pressure swing adsorption process for separating a product gas comprising less and more readily adsorbable constituents employs four adsorption columns. The following sequence of steps is performed repeatedly. 1. A chosen column is pressurised with feed gas. 2. Less readily adsorbable gas is taken from the column and used to pressurise another column. 3. Product gas is collected from the column. 4. The pressure in the column is reduced to atmospheric pressure. 5. The column is evacuated. 6. The column is purged with gas from another column. 7. The column is pressurised with product gas produced by another column. This sequence of steps is followed by each column in appropriate time relationship with the other columns. A pressure equalisation step may for example be performed between steps 3 and 4. The process can operate with a low feed gas pressure. Flue gases can be treated to separate hydrogen and another gas, eg methane, oxygen, nitrogen, carbon monoxide and carbon dioxide.

Method for dehumidifying mixed gas

Abstract: PURPOSE: To miniaturize the apparatus and to control the waste of a dry gas by using a gas separation membrane made of an aromatic polyimide and having more than a specified ratio in the gas permeation velocity of steam to methane and dehumidifying a mixed gas while passing a small amt. of dry gas along the permeated gas side of the membrane. CONSTITUTION: A mixture of an aromatic tetracarboxylic acid component such as biphenyltetracarboxylic dianhydride, and an aromatic diamine component such as a diamino-dimethyl-diphenylen sulfone and 2,6-diaminopyridine are polymerized and iminated to obtain an aromatic polyimide which is formed into a membrane. Consequently, a gas separation membrane having ≥200 ratio in the gas permeation velocity of steam to methane can be obtained. The membrane 2 is housed in a gas separator 1 and a steam-contg. mixed gas is supplied from a mixed gas supply port 3. Less then 10vol% dry gas, based on the mixed gas, is supplied from a dry gas supply port 6, passed along the permeated gas side of the membrane 2 and discharged from a discharge port 5 along with the steam permeated through the membrane 2. The dehumidified nonpermeated gas is discharged from a discharge port 4. COPYRIGHT: (C)1987,JPO&Japio

Gas purification: Fourth edition

Abstract: This fourth edition is a substantial revision incorporating the significant advances in the field of gas purification and dehydration since 1979. It includes expanded coverage of widely used technologies, such as the alkanolamine processes for H/sub 2/S and CO/sub 2/ removal and lime/limestone-based processes for flue gas desulfurization. It also describes new processes that have attained commercial status, such as the use of sterically hindered amines for H/sub 2/S and CO/sub 2/ absorption, the Cosorb process for removing and recovering CO, and the membrane permeation process for a variety of gas separation operations. The book stresses the removal from gas streams of gas-phase impurities present in minor proportions rather than the removal of discrete solids.

Composite gas separation membranes

Abstract: A membrane having an improved separation factor with respect to at least one gas of a gaseous mixture through the incorporation of an in situ formed non-porous intermediate layer (8) between a porous support (4) and an in situ-formed separating layer (2). The intermediate layer (8) is comprised of a polymer material which is highly permeable to the at least one gas relative to the separating layer (2) which has a separation factor for the at least one gas which is greater than the separation factor exhibited by the intermediate layer (8).

Production of thin membrane

Abstract: PURPOSE: To continuously and easily form the titled uniform and thin gas separation membrane by forming a substrate layer consisting of an air-permeable polymer on the surface of a water-impregnated supporting membrane, and then forming the film membrane of a gas separation membrane forming material. CONSTITUTION: A polysulfone porous membrane 4, etc., are laminated on the porous layer 3 of polyester nonwoven fabric, etc., by a wet membrane forming method. The water droplets 5 on the front and rear surfaces of the membrane 1 are removed, and then a soln. 11 consisting essentially of an air-permeable polymer is coated. The inside of the membrane 1 is filled with water, and the infiltration of the soln. 11 can be prevented. the material is instantaneously dried in an oven to vaporize and remove the water in the membrane 1, and the substrate layer 18 is formed. The substrate layer of double structure can also be formed. Then the org. solvent soln. 25 consisting essentially of the gas separation membrane forming material is coated. The material is instantaneously dried in an oven to form the gas separation layer 27 of a thin membrane. The layer of double structure can also be formed. COPYRIGHT: (C)1987,JPO&Japio

Structure with membranes having pores extending throughout, process for producing this structure and its uses

Abstract: A structure which can be used as an ultrafiltration membrane has membranes (20) with penetrating carrier pores, which are bound to or bound into a support (21) which may be porous. These membranes (20) each consist of protein molecules or protein-containing molecules which are arranged in the manner of a two-dimensional crystal lattice and between which penetrating pores of identical size and shape having pore diameters especially between 1 and 8 nm remain free, and are in each case advantageously formed from molecules, which were separated off especially from cell walls of prokaryotes, by a recrystallisation process described as self-organisation and preferably flushed onto or into the carrier (21) and crosslinked intramolecularly or intermolecularly or to the carrier (21) by extraneous molecules. The structure is also suitable as a separation element for a gas separation or for an ion exchange process and also as a carrier structure for other semipermeable membranes such as hyperfiltration membranes. It can also be used with membranes in a vesicular form as a chromatography column or in film form as a wrapping material for the most diverse substances.

Gas separation membrane

Abstract: PURPOSE:To obtain a membrane suitable as a gas separation membrane simple to prepare, excellent in stability and separability and capable of adsorbing and desorbing gas at room temp., by supporting a Schiff base metal complex by a porous polymer support membrane. CONSTITUTION:For example, an org. or inorg. porous membrane having pores with a pore size of 20Angstrom -0.1mum and a thickness of 10-300mum is used as a porous polymer support membrane. A Schiff base metal complex is supported by said porous polymer support membrane by coating or impregnation. A support amount may be within range of about 0.01-5mg/cm . A Schiff base ligand has a structure formed from alpha-diketone, beta-diketone, salicylaldehyde or substituted salicylaldehyde and amine, diamine or triamine by dehydro- condensation. As a core metal, a low valency transition metal such as Co, Fe, Cu, Ni, Mn, Cr or Zn is used. This membrane can be suitably used in the concn. of oxygen.

Gas separation membrane and process for preparing it

Abstract: A gas separation membrane and its preparation is disclosed. The membrane is an aromatic polyamide or amide-like polymer which has been treated with a dilute solution of a cationic surfactant in a volatile non-polar organic solvent.

Gas separation method and apparatus

Abstract: A pressure swing adsorption process employing at least three adsorption beds or columns for separating a gas mixture including hydrogen involves performing seven operating steps. i) Feed gas mixture is passed through bed A and product gas is collected. ii) The pressure in bed A is equalised with the pressure in bed B. iii) The pressure in bed A is further reduced by passing gas to bed C. iv) Bed A is evacuated. v) Bed A is purged with gas from bed B while evacuation is continued. vi) Bed A is repressurised with product gas. vii) The pressure in bed A is equalised with the pressure in bed C. Corresponding steps are performed in appropriate sequence by beds B and C. The process may be performed at a relatively low adsorption pressure.

Integrated gas separation process

Abstract: The present invention involves an efficient process for separating components of a gas stream containing two or more components by the integration of one or more membrane units with a non-membrane type separation unit.

Selective gas separation membrane

Abstract: A selective gas separation membrane comprising a fumaric diester polymer having a repeating unit represented by the following general formula (1): ##STR1## wherein X and Y are each independently an alkyl, cycloalkyl, aryl, trialkylsilylalkyl or siloxane-containing alkyl group.

A shaped body for gas separation

Abstract: The inventive shaped body for gas separation is prepared on the base of a film shaped of a poly(silyl acetylene) such as poly(1-methyl-2-trimethylsilyl acetylene) by subjecting the base film to a treatment of exposure to an atmosphere of low temperature plasma of an inorganic gas, eg nitrogen, hydrogen, argon, etc Contrary to expectation, the base film is stable against the plasma treatment without decrease in the mechanical strengths and imparted with high performance for gas separation, especially, for the enrichment of oxygen in air with a separation factor between oxygen and nitrogen of 25 to 35

Method for concentrating and recovering gas by using psa apparatus

Abstract: PURPOSE: To enhance a produce recovery rate, by adsorbing two adsorbable components among three gaseous components and desorbing said components to separate both components by a separation membrane while supplying a highly adsorbable component as the washing gas of a PSA apparatus. CONSTITUTION: Stock gas containing H 2 O and CO 2 being highly adsorbable components, CO being a medium adsorbable component and N 2 , H 2 and O 2 being low adsorbable components is flowed in either one of the adsorbing towers 3a, 3b of a PSA apparatus and N 2 , H 2 and O 2 are exhausted out of the system from a pipe 7. Adsorbed H 2 O, CO 2 and CO are desorbed by a vacuum pump 9 to be supplied to a gas separation membrane unit 13a through a compressor 10 and a pressure regulating tank 11 to transmit H 2 O and CO 2 while conc. CO is also conc. in the next stage gas separation membrane unit 13b where conc. to be taken out from a recovery pipe 15. H 2 O and CO 2 are guided to the adsorbing towers 3a, 3b and purge N 2 to discard the same from a discharge pipe 8. COPYRIGHT: (C)1986,JPO&Japio

Apparatus for gas separation membrane

Abstract: PURPOSE:To obtain high separation efficiency with a single gas separation operation by providing two membranes for separating a mixed gas by the difference in permeation velocity, and also providing a discharging means for discharging a part of a permeated gas from between said membranes. CONSTITUTION:A mixed gas charging means 1 for charging the mixed gas, two membranes 1A and 1B which are installed so that one surface of each membrane may be kept in contact with the passage of the mixed gas capable of separating the mixed gas by the difference in permeation velocity, a permeated gas discharging means 5 capable of discharging a part of the permeated gas from between the two membranes 1A and 1B, a separated gas discharging means 3 for taking out the separated gas after permeating the two membranes 1A and 1B, and a discharging means 4 for discharging the mixed gas which do not permeate the membranes 1A and 1B are provided to constitute the apparatus.

Structure, permeability, and separation characteristics of porous alumina membranes

Abstract: In this paper a survey is given on ceramic, porous γ-Al2O3 membranes. The information of the membranes can be described with a slibcasting model. This means that the layer thickness of the membranes increases linearly with the square root of the dipping time. The pores of these membranes are slit-shaped and the pore size depends on the temperature/time treatment. It amounts 2.7 nm and 4.8 nm at temperatures of 400°C and 800°C respectively while the porosity remains constant in this temperature range (> 50%). The water permeability is proportional to the pressure drop till at least 50 bar and inversely proportional to the membrane thickness. In ultrafiltration experiments the 'cut off' value of the membrane with 2.7 nm pores is 2000 for polyethylene glycols. The membrane surface can be modified with several types of ions and therefore these types of membranes can be made suitable for gas separation and hyperfiltration applications.

Composite membrane for gas separation

Abstract: PURPOSE:To provide the titled composite membrane for gas separation having high permeability and selectivity and excellent mechanical strength, workability, resistance to chemicals, and durability by forming a thin film consisting of poly (perfluoro chemical) on the surface of a porous supporting membrane. CONSTITUTION:A porous supporting membrane is fixed on a rotary disk 1 of a plasma polymerization device. A monomer of a perfluoro chemical such as perfluorotributylamine is vaporized while evacuating the inside of a chamber 2 to fill the inside of the chamber with the vaporized monomer. Then glow discharge is generated between electrodes 3 while rotating the rotary disk 1, and a thin film of the poly(perfluoro chemical) is formed on the surface of the supporting membrane while plasma-polymerizing the perfluoro chemical to obtain the composite membrane for gas separation.

Separation of volatile impurities from aluminum chloride before electrolysis

Abstract: Separating volatile impurities from AlCl3 by supplying impure AlCl3 into a molten salt bath of a gas separation compartment in an electrolysis cell. The impurities are removed from the compartment and molten salt bath containing dissolved AlCl3 is carried under a partition into a chamber where the AlCl3 is electrolyzed. In a preferred embodiment, desublimation is avoided by supplying AlCl3 to the bath as a gas rather than in solid form.

Evaluation of advanced separation techniques for application to flue gas cleanup processes for the simultaneous removal of sulfur dioxide and nitrogen oxides

Abstract: Thirteen advanced separation techniques were reviewed in detail for application to flue gas cleanup processes. Of these, the three most promising for application to systems for simultaneous removal of sulfur dioxide and nitrogen oxides from flue gas are solvent extraction, electrodialysis, and inverse thermal phase separation. Gas separation membranes would also be promising if a membrane could be developed that would be selective for SO/sub 2/ and NO/sub x/. Specific utility or industrial systems incorporating some of these processes are suggested. Preliminary estimates of annual revenue requirements for three gas-separation-membrane flue gas cleanup systems and an electrodialysis system are compared with an estimate for a limestone system with selective catalytic reduction. In addition, fourteen wet simultaneous SO/sub 2//NO/sub x/ flue gas cleanup processes that have progressed beyond bench scale were reviewed for possible modification to incorporate advanced separation techniques. It appeared that in processes where modifications were possible, either such modification would result in marginal improvement, or the process would no longer be recognizable. 147 refs., 10 figs., 9 tabs.

Asymmetric membranes for gas separations

Abstract: Recent membrane developments for gaseous mixture separations are compared to the development of reverse osmosis membranes for water desalination. The goals of these developments have been the search for ideal permselective polymeric materials, techniques for producing ultrathin membrane layers free of imperfections and transforming gelled reverse osmosis membranes into solid gas permeation membranes. A novel approach to meeting the basic requirements of high permselectivity is attempted by altering the physical polymer structure within the membrane prior to application for gas separation. The influence of these physical interactions on membrane properties is presented. 47 references, 11 figures, 6 tables.

Pore size evaluation for fine porous freeze-dried cellulose acetate membrane by gas separation

Abstract: The pore size for a fine porous freeze-dried cellulose acetate membrane was evaluated by gas separation methods, where the Present–deBethune equation was applied. Separation coefficients were referred to the calculated value for each pore size from this equation. Nuclepore, Millipore VS, and Millipore VC, whose pore sizes were already known by bubble point method, were tested for this method. Pore diameters for this cellulose acetate membrane, thus determined, were about 25 and 40 A from Ar–Kr and N2–Kr separation systems, respectively, which agreed well with the results from electron microscope (50 A) and N2 gas permeability (50 A). However, it is impossible to apply this method to He gas separation, since He gas permeability is higher than the expected value as Knudsen flow, which indicates that some channels are existing in this membrane, where He gas is more permeable than the other gases.