Showing papers on "Gas separation published in 1983"

Gas separation by permeators with high-flux asymmetric membranes

Abstract: The permeation behavior of the high-flux asymmetric membrane differs from that of the conventional symmetric membrane. A calculation method for predicting the gas separation performance of a permeator with asymmetric membrane is presented. The model takes into account the permeate pressure drop and is applicable to both hollow-fiber and spiral-wound modules. The effect of permeate-feed flow pattern on module performance is analyzed. It is shown that for the high-flux asymmetric membrane, the countercurrent flow pattern is not necessarily always the preferred operating mode. The mathematical model is verified by large-scale field pilot-plant experiments for helium recovery from natural gas using large hollow-fiber modules (220 m2/unit).

The developing technology of gas separating membranes.

Abstract: The background of and commercial needs leading to the development of practical membrane systems for the separation of industrial gases are presented. The critical issues and fundamental technical limitations that delayed earlier development of such systems and the solutions of some of the major problems in the field are discussed. Particular attention is given to the methods by which high gas fluxes and high selectivities have been achieved in hollow fibers. The performance characteristics of various practical gas separation methods are compared, and the effects of parameters such as pressure and contaminant levels are illustrated with representative examples.

Reactant/gas separation means for beverage carbonation device

Abstract: A separation means is disclosed which effectively isolates the resultant salts of a carbonation reaction while permitting the transfer of gaseous carbon dioxide in a substantially pure, non-contaminated form to a liquid to be carbonated. The separation means comprises a passageway with a plurality of restricted gas communicating apertures and a one-way valve attached to the end of the passageway which is proximate to the liquid to be carbonated. The gas communicating apertures and one-way valve function to retain the chemical by-products of the reaction from the carbonated beverage.

Asymmetric gas separation membranes

Abstract: Asymmetric gas separation membranes of materials having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture, exhibit significantly improved permeation selectivities for the at least one gas when the asymmetric membrane is contacted on one or both surfaces with an effective amount of a Br nsted-Lowry acid. The improved asymmetric gas separation membranes, process for producing the improved membrane, and processes utilizing such membranes for selectively separating at least one gas from a gaseous mixture by permeation are disclosed.

Single bed pressure swing adsorption gas separation system

Abstract: A single bed PSA system having a high pressure compressor embodiment and a low pressure fan driven embodiment. Numerous features are disclosed, including a pressure response technique wherein the actual times of the steps within the cycle are adjusted in accordance with demand. Sub-atmospheric pressure is utilized to enhance the purging step of the single bed and to enhance efficiency as well.

Permeation modified gas separation membranes

Abstract: Asymmetric gas separation membranes of polymeric materials having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture, exhibit improved permeation selectivities for the at least one gas when the asymmetric membranes have been contacted on one or both surfaces with an effective amount of a permeation modifier. The permeation modified asymmetric gas separation membrane having an effective amount of permeation modifier added in a non-homogeneous mode and without loss of Tg.

Hydrocarbon gas separation

Abstract: A cryogenic process for separating methane from ethane and heavier hydrocarbons in which a high pressure gas feed is divided into two gas streams. The gas is cooled either before or after it is divided and this step may include some condensation in which case the condensate is separated from the gas. One of the divided gas streams is expanded through a work expansion machine down to the pressure of the fractionation column. Any separated condensate is also expanded to the column pressure. The second divided gas stream is further cooled by heat exchange and then expanded down to an intermediate pressure whereby a portion is condensed. This condensate is separated from the remaining gas and then expanded to the column pressure. The remaining gas is further cooled and expanded and fed to the column as the top feed.

Gas chromatographic apparatus

Abstract: A gas chromatographic apparatus having at least two gas separation columns arranged in parallel to each other, the outlet of the first gas separation column being connected to a gas sensor through a column switch valve, and the outlet of the second gas separation column being connected to the column switch valve through a gas detection time-controlling pipe, where when the first gas separation column is communicated with the gas sensor, the outlet of the second gas separation column is made open to the atmosphere by the column switch valve, or when the second gas separation column is communicated with the gas sensor, the outlet of the first gas separation column is made open to the atmosphere by the column switch valve, or the apparatus having a first gas separation column whose inlet is connected to the switch valve and at least two second columns whose inlets are connected to the outlet of the first gas separation column, whose outlets are connected to the gas sensor and which are arranged in parallel to each other through the column switch valve, where the first gas separation column, one of the second columns and the column switch valve are communicated with each other, by the column switch valve. A chromatogram with distinctly separated peaks in a continued state can be obtained in a short time by only one detecting and recording means.

Multicomponent membrane for gas separation

Abstract: A multicomponent membrane for gas separation, tr membrane being in the form of a porous, anisotropic substrat membrane and a coating incontact with the substrate men brane, the coating being the condensation product of a silan terminated poly(dimethylsiloxane) and a cross-linking con pound having the formula

Gas separation kinetics in commercial pellets

Abstract: To improve the column dynamics of commercial pelleted sodium aluminosilicate zeolite adsorbents used in gas separation, the pellets are treated by washing in dilute aqueous mineral acid. The treatment is most effective as applied to sodium mordenite pellets, employing hydrochloric acid of about 0.1 normality.

Amino ketone cross-linked polyphenylene oxide

Abstract: Cross-linked polyphenylene oxide compositions comprise the reaction product of haloacylated polyphenylene oxide and a primary monoamine. The polyphenylene oxide chains are cross-linked by amino ketone bonding. Such cross-linked polymers are useful as membranes, for instance gas separation membranes.

Method for separating gas from gas mixture

Abstract: PURPOSE: To separate CO of high purity from a mixed gas consisting essentially of H 2 and CO at a low cost, by using membrane modules having different separation degrees of H 2 /CO in combination. CONSTITUTION: CO of high purity is separated from a mixed gas, consisting essentially of H 2 , and obtained by decomposing heavy oil or coal, etc. using gas separation membranes. In the method, membrane modules having different separation degrees of H 2 /CO are used in combination. In the stage of a raw gas, i.e. a mixed gas consisting essentially of H 2 and CO in a high H 2 concentration, a membrane having a high separation degree of a rapidly permeating component gas (H 2 ) from a slowly permeating component gas (CO) is used. After using the membrane, a membrane having a low separation degree of H 2 /CO is used in the stage of reduced H 2 concentration. Thus, the aimed CO of high purity can be separated without requiring means of boosting the pressure of the raw gas side, reducing the pressure on the permeation side nor purging with the gas (CO) other than the component gas for permeation, etc. COPYRIGHT: (C)1984,JPO&Japio

Gas separation plate for fuel cell

Abstract: PURPOSE:To suppress the cross leak of a gas and the deterioration in a sealing property, by providing a formed ceramic piece to constitute the end portion of a gas separation plate, which includes at least the outlet sides of air feed grooves of the plate, so as to prevent the corrosion of the reactant air outlet side end portion of the gas separation plate. CONSTITUTION:70% by weight of powder of graphite and 30% by weight of powder of a phenolic resin are mixed together and hotpressed. The phenolic resin is thereafter carbonized at a temperature of 900 to 1,000 deg.C so as to manufacture a gas separation plate body A shaped in such a manner that one end portion having reactant air feed grooves 2 is cut-out. Powder of alumina is press-formed and heat-treated at a temperature of 1,600 deg.C so as to manufacture a formed ceramic piece B shaped in such a manner to make up for the cut-out end portion for the gas separation plate body A. The formed ceramic piece B is conjoined to the (cut-off) end of the gas separation plate body A by an adhesive of (fluororubber) so that a gas separation plate 1 is constituted. Since the reactant air outlet side end portion of the gas separation plate 1, which is very likely to corrode, is made of the ceramic piece, the corrosion resistance of the plate is extremely enhanced so as to prevent the dropping of an electrode and the cross leak of a reactant gas.

Polymeric membranes with ammonium salts

Abstract: Asymmetric polymeric gas separation membranes have ammonium salts bonded to the polymer to provide a membrane with enhanced separation factor.

Preparation of heterogeneous film by melting, stretching

Abstract: PURPOSE: To produce efficiently heterogeneous film excellent in gas separation capability, gas permeability rate and dynamical characteristics by executing a little noncrystal stretching and heat treatment after forming molten film in quenching conditions, and then stretching the film at a comparatively low temperature. CONSTITUTION: A hollow thread or a film obtained by melting and extruding thermoplastic crystal polymer on condition that a melting temperature is equal to TmWTm+200°C (Tm: fusing temperature of crystal) and a draft Df is shown by 50≤Df≤10,000 is stretched by 3W200% at Tg-20WTg+50°C (Tg; transition temperature of glass), heat-treated at TgWTm-10°C, then stretched at a temperature Tg-50WTm-10°C and by a stretching magnification 1.1W5.0 and then set thermally at a temperature TgWTm. In this manner heterogeneous film excellent in gas separation capability, gas permeability rate and dynamic characteristics can be produced efficiently. COPYRIGHT: (C)1984,JPO&Japio

Improved gas separation process.

Abstract: The separation of gas mixtures in commercial sized adsorption systems is carried out with a carefully limited difference in loading of the adsorbed component on the bed between the start and the end of the desorption step. Under such conditions, each succeeding adsorption step will be carried out so that an adsorption/heating front is caused to advance sufficiently ahead of a slower moving cooling front that thus serves to cool only the feed end of the bed to the inlet gas mixture temperature. The heat of adsorption is thereby retained in the bed between these two fronts at a temperature tolerable to the gas mixture and to the adsorption bed and is available for the following desorption step.

Separation and recovery of gas

Abstract: PURPOSE: To separate and recover gas to be recovered, by bringing a gaseous mixture consisting of gas to be recovered such as helium or hydrogen and gas to be removed such as acidic gas, oxygen and nitrogen into contact with an alkaline liquid while separating the gas to be recovered through a gas separation membrane. CONSTITUTION: A gaseous mixture is supplied to a first step A and brought into contact with an alkaline liquid. As a means for bringing the gaseous mixture into contact with the alkaline liquid, a simple bubbling method is most pref. and, after the gaseous mixture is blown into the alkali liquid received in an airtight container, the treated gas is sent to the next step. In this case, moisture and humidity in the gaseous mixture may be removed by an adsorbing means B. In the step C, the gas to be recovered and the gas to be removed in the gaseous mixture sent under pressure by a compressor Cp are separated by the difference of permeation speeds of both gases with respect to a gas separation membrane. By this method, the separated gas is recovered in a gas bomb. COPYRIGHT: (C)1984,JPO&Japio

Composite membrane for gas separation and its manufacture

Abstract: PURPOSE:To obtain a polymeric composite membrane for separating hydrogen from a gaseous mixture by laminating polymeric thin films, having two kinds of intrinsic separation factors for a gaseous mixture of hydrogen and nitrogen, in a specified ratio on a polymer and an inorganic material compounding porous membrane having specified porosity. CONSTITUTION:A polymeric soln. A, consisting of a polysulfonic or a polyetheric resin etc. and having >=20 intrinsic separation factor for a gaseous mixture of hydrogen and nitrogen, and a polymeric soln. B, consisting of a silicone or a phosphazene polymer etc. and having the permeability coefficient of hydrogen at least ten times larger than that of the polymer in said soln. A, are coated on a polymer and an inorganic material compounding porous membrane, contg. 10-80wt% granular inorganic material and having 0.1mum mean pore size and porosity in the 30-80% range, and dried. In addition, the ratio of the layer thickness of the thin film consisting of the soln. B to that of the resistance layer consisting of the soln. A is regulated to >=5, and both films are laminated to manufacture the composite membrane.

Preparation of acrylonitrile separation membrane

Abstract: PURPOSE:To form a membrane from a stock liquid prepared by dissolving acrylonitrile in N-methyl pyrrolidone and an org. swelling agent in order to obtain said membrane excellent in reproducibility of membrane capacity and mechanical strength, in preparing an acrylonitrile separation membrane. CONSTITUTION:An acrylonitrile polymer (or a copolymer) is dissolved in a mixed system of N-methyl pyrrolidone and formamide, ethylene glycol, diethylene glycol, triethylene glycol or polyethylene glycol with M.W. of 1,000 or more and the resulting solution is formed into a membrane. This membrane is passed through an inert medium atmosphere and immersed in aqueous solution at 50 deg.C or less to obtain a solid membrane. When this solid membrane is washed by water, stretched and subjected to heat treatment, a separation membrane with an asymmetric structure capable of being used in ultrafiltration, reverse osmosis and gas separation is obtained.

Preparation of polysulfone hollow fiber membrane for gas separation

Abstract: PURPOSE:To obtain an excellent gas separating membrane having high separation efficiency and high permeation speed, by combining a polysulfone hollow fiber treating condition and a plasma treatin condition. CONSTITUTION:A polysulfone resin having repeating units of the formula is used to prepare a hollow fiber by the steps of dope preparation, dope extrusion from an annular nozzle, solvent evaporation coagulation and stretching according to a wet process. The polysulfone resin is dissolved in an aprotic polar solvent and a non-solvent is added to the resulting solution to prepare a homogeneous dope. As the aprotic polar solvent, N,N-dimethylformamide or dimethylacetamide is used and the amount thereof is 20-80wt%. Plasma treatment is carried out under such a condition that glow discharge is carried out under pressure of 0.01-8Torr with electric power of 50-100W and an inorg. gas such as air or nitrogen is supplied into plasm. A fiber with a high bubble point can be prepared in high resin concn. by using the low-molecular non-solvent.

Preparation of polymide composite separation film

Abstract: PURPOSE:To prepare a composite separation film excellent in gas separation capacity and a permeation speed totally formed only from polyimide, by a method wherein a polyimide dilute solution with a specific composition is coated on an aromatic polyimide microporous film and the resulting coating film is dried. CONSTITUTION:A uniform solution of aromatic polyimide obtained by polymerizing an aromatic tetracarboxylic acid component and an aromatic diamine component in an org. polar solvent at a low temp. is used as a dope liquid and an aromatic polyimide microporous film is prepared from this dope liquid. On this microporous film, a polyimide dilute solution consisting of 100pts.wt. halogenated hydrocarbon, 0.5-15pts.wt. phenol compound and 0.01-5pts.wt. soluble aromatic polyimide is coated in a thickness of 0.1-20.0mu and the obtained coating film is dried at 20-300 deg.C. The film obtained by this method is excellent in heat resistance high in hydrogen permeation speed and high in hydrogen separation capaccity from CO.

Electrolytic chlorine gas generator

Abstract: An open-cell electrolytic chlorine gas generator for use in the chlorination of various water streams, including swimming pools, is designed without using a membrane to separate the electrolyte between the anode and the cathode. Instead, a gas separation plate (15) is used which separates the electrolyte (5) above horizontally projecting electrodes (8, 9), so that the different gases produced at the different electrodes (8, 9) are separated from each other when they rise to the surface of the cell (2). The electrolyte (5) containing chloride is admixed with aqueous buffer means, in order to neutralise the hydroxide anions generated at the cathode (9) and thus to optimise the evolution of chlorine gas by stabilising the pH of the electrolyte (5). The chlorine and hydrogen gases generated can be supplied separately to the solution to be treated, an optionally usable cooling circuit (11) receiving the solution prior to treatment and (in heat exchange tubes) passing it through the cell prior to the treatment with the gases. During most of the time when the cell is operated, only the desired product (chlorine gas) and the hydrogen gas, which is easily drawn off, need be removed from the cell.

Rapid cycle gas separation system

Abstract: RAPID CYCLE GAS SEPARATION SYSTEM A gas ballast enriched in the desired gas component is introduced into an absorbent bed to complete its regeneration. The beds are relatively short and are cycled relatively rapidly.

Wasserstoff‐Erzeugung und Kreislaufgas‐Zerlegung für die Kohleverflüssigung

Abstract: Hydrogen generation and recycle gas separation for coal liquefaction. Just as 40 years ago, low-temperature processes are now again being considered for recycle gas separation in today's large scale coal liquefaction projects. Hydrogen can be generated by gasification of heavy residues and by steam reforming of ethane. Alternatives for recycle gas separation into hydrogen and gas products are butane and methane absorption or low-temperature condensation processes at high or medium pressure. These processes employ several additional absorption and adsorption steps for gas purification. They are proven on a large technical scale, and fulfill the requirements of environmental legislation.