Abstract: A treatment process for a hydrogen-containing off-gas stream from a refinery, petrochemical plant or the like. The process includes three separation steps: condensation, membrane separation and hydrocarbon fraction separation. The membrane separation step is characterized in that it is carried out using a polymeric separation membrane that is selective in favor of hydrocarbons, including methane, over hydrogen, so that the hydrogen-enriched stream is delivered at high pressure.

Abstract: A membrane separation process for treating a gas stream containing methane and nitrogen, for example, natural gas. The separation process works by preferentially permeating methane and rejecting nitrogen. We have found that the process is able to meet natural gas pipeline specifications for nitrogen, with acceptably small methane loss, so long as the membrane can exhibit a methane/nitrogen selectivity of about 4, 5 or more. This selectivity can be achieved with some rubbery and super-glassy membranes at low temperatures. The process can also be used for separating ethylene from nitrogen.

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least one glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: A process for separating organic compounds, such as solvents, from gases, e.g. waste gases of paint shops. The gases to be treated are conducted in an adsorber over a sorbent which is composed of particulate activated carbon in an oxidic carrier. The charged sorbent is regenerated by passing therethrough, preferably according to the countercurrent principle, a heated regeneration gas, the regeneration gas charged with desorbate is cooled so that organic compounds condense and can then be separated, whereupon the regeneration gas is reheated and reused for the desorption of the charged sorbent. Heating of the regeneration gas as well as cooling of the regeneration gas charged with desorbate are, at least partially, effected by a heat pump. It will be expedient to provide at least two adsorbers which are charged and regenerated alternately. An apparatus for carrying out the process is additionally described.

Abstract: Oxygen is recovered from a hot, compressed oxygen-containing gas, preferably air, by an oxygen-selective ion transport membrane system. Hot, pressurized non-permeate gas from the membrane is cooled and useful work is recovered therefrom by expansion at temperatures below the operating temperature of the membrane. The recovered work is used together with the oxygen permeate product in applications such as oxygen-enriched combustion of liquid fuels, wood pulping processes, steel production from scrap in mini-mills, and metal fabrication operations. Oxygen permeate product can be compressed utilizing a gas booster compressor driven by expansion of cooled, pressurized non-permeate gas.

Abstract: The invention provides a method and apparatus for recovering a target material including using an adsorbent such as activated charcoal, the target material recovered in a continuous manner, as well as a method and an apparatus for recovering a solvent based on such a method and apparatus. The adsorbent for the target material is rotated to move the adsorbed material in direction of centrifugal force while the target material is attracted to the adsorbent. The excess target material is detached from a peripheral edge of the adsorbent by centrifugal force. The detached material is recovered by a recovery device provided in corresponding relation to the adsorbent.

Abstract: A rotary valve at the inlets of a plurality of columns cyclically (1) selects first columns on a cyclic basis to receive compressed air, adsorb nitrogen and other components in the compressed air and pass oxygen and argon to a user (e.g. patient), second columns to desorb the adsorbed components in such columns and (3) third columns to equalize pressures where the first columns change progressively to the second columns and vice versa. A compressor having adjustable characteristics and regulated in an open or closed loop introduces the compressed air through the valve to the first columns to provide an adjustable air flow for obtaining a prescribed oxygen flow to the user. An indication may be provided when the compressor characteristics regulated for obtaining the prescribed oxygen flow rate are outside particular limits. The valve may have a variable speed related to the compressor flow variations to regulate the air pressure in the columns in accordance with the air flow rate into the columns.

Abstract: A hybrid system for producing both low purity oxygen and high purity nitrogen at high product recovery rates wherein desorption effluent from an adsorbent system feeds a cryogenic rectification column and, preferably, bottom fluid from the column provides additional feed for the adsorbent system.

Abstract: A method for the collection and subsequent regeneration of substances exhausted through a vacuum pump. In a first phase, an exhaust stream from the pump to an adsorption bed in which one or more components of the stream are adsorbed. In a second phase, adsorbed component(s) are regenerated from the bed by connecting the bed to the inlet side of the vacuum pump.

Abstract: Novel procedures are described for the production of syngas fuel intermediates from abundantly available natural gas.

Abstract: The invention relates to a process for separating out hydrogen chloride from a gas mixture forming in the chlorination of methane, which gas mixture contains unreacted methane, its chlorination products and hydrogen chloride formed in the reaction, by cooling and compression of the gas mixture and subsequent scrubbing with a scrubbing liquid which comprises at least one liquid chlorination product of methane. The gas mixture is separated into a methane-containing gas phase and a liquid phase containing hydrogen chloride and methane chlorination products, and the hydrogen chloride is then desorbed from the liquid phase by heating.

Abstract: A process and apparatus for the selective recovery of solvents from solvent gas mixtures according to which the solvent gas mixture undergoes a sorption process, individual solvent gas fractions are fractionally desorbed from the sorption agent, condensed at staggered time intervals, measured to determine their composition, and collected separately.

Abstract: A membrane process for separating chlorine from chlorine-containing gas streams is disclosed. The process employs a permselective membrane that is selective to chlorine and is stable in the long-term presence of chlorine. The process can be used to treat tail-gas from chlor-alkali plants, for example.

Abstract: A process is provided for the removal and recovery of chlorine from a chlorine plant offgas stream. A pressure swing adsorption (PSA) process is used to remove from the chlorine plant offgas a vent gas stream comprising hydrogen and a tail gas stream comprising chlorine which is subsequently liquefied. The PSA zone comprises at least 2 adsorption beds, wherein each of the adsorption beds contains a weak adsorbent selective for the adsorption of chlorine and the PSA process is operated with a short cycle having an adsorption time of less than about 6 minutes. The vent gas withdrawn from the process is essentially free of chlorine and a liquefied chlorine product is recovered. The process provides an economic and efficient way of removing chlorine from a chlorine plant offgas stream without requiring a vacuum pump or heat removal equipment.

Abstract: A process is set forth for purifying and liquefying a feed gas mixture with respect to its less strongly adsorbed component of lower volatility which integrates temperature swing adsorption (TSA), pressure swing adsorption (PSA) and cryogenic distillation to optimize overall performance. The TSA portion of the process is used to remove the strongly adsorbed component from the feed; the PSA portion of the process is used to remove the moderately strongly adsorbed component from the feed; and the cryogenic distillation portion of the process is used to remove the less strongly adsorbed component of higher volatility from the feed while also providing for the liquefaction of the product. A key to the present invention is the use of the PSA and distillation waste streams in the regeneration of the TSA and PSA adsorbents. An important application of the present invention is the purification and liquefaction of a natural gas feed stream with respect to its methane/C.sub.2 hydrocarbon component.

Abstract: The present invention provides a process for the recovery of methyl chloride from a mixture thereof with isobutane. The process employs pressure swing adsorption with a size selective adsorbent having a pore opening of between about 3.7.times.3.7 Angstroms and about 4.9.times.5.7 Angstroms, such as zeolite A, clinoptilolite and mixtures thereof to selectively adsorb methyl chloride from vent streams comprising methyl chloride and isobutane and recovering a tail gas stream enriched in methyl chloride. The process may be used in applications such as treating the vent gas streams from the direct synthesis of methyl chlorosilanes. The process provides an economical route to recovering a valuable raw material in the process of making silicones and reduces the volume and methyl chloride content of the vent stream which is typically incinerated to avoid the release of halogenated hydrocarbons to the atmosphere.

Abstract: Waste heat generated within a pressure swing adsorption system is effectively captured and utilized to preheat the feed gas passing to a feed gas blower for compression to the desired adsorption pressure level. The energy efficiency of the system, and overall system performance, are thereby enhanced.

Abstract: A separation of gas by permeation, comprising the steps of and the apparatus for compressing a gaseous mixture to be separated at a first temperature (Ta) in a compressor (2), cooling to a second temperature (To) the compressed mixture to condense condensable impurities in the compressed gaseous mixture, purifying the compressed gaseous mixture of condensable and/or adsorbable impurities at a third temperature (T.sub.1) greater than the second temperature (T.sub.0) and passing the purified gaseous mixture into a gaseous permeation unit comprising at least one membrane module to obtain at least one production gas. The third temperature (T.sub.1) is so regulated that it will not be less than a first predetermined value. The second temperature (To) is greater than the first temperature (Ta) by a value comprised between 1.degree. and 5.degree. C., the first value being not less than 20.degree. C.

Abstract: A process is provided for the removal and recovery of chlorine from a chlorine plant offgas stream. A pressure swing adsorption (PSA) process is used to remove from the chlorine plant offgas a vent gas stream comprising hydrogen and a tail gas stream comprising chlorine which is subsequently liquefied. The PSA zone comprises at least 2 adsorption beds, wherein each of the adsorption beds comprises a first adsorption layer and at least a second adsorption layer. The first adsorption layer contains a weak adsorbent selective for the adsorption of chlorine and has a large pore structure with 12 member rings or more. The second adsorption layer contains a strong adsorbent selective for the adsorption of chlorine and has a small pore structure with 10 member rings, or less. The vent gas withdrawn from the process is essentially free of chlorine.

Abstract: A composite semipermeable membrane comprising microporous adsorbent material supported by a porous substrate is operated in series with a pressure swing adsorption (PSA) system and the PSA reject gas is used as a sweep gas to improve membrane performance. The integrated membrane-PSA system is particularly useful for recovering high-purity hydrogen from a mixture of hydrogen and hydrocarbons, and is well-suited for integration with a steam-methane reformer.

Abstract: In order to separate a mixture of two gaseous components with different boiling temperatures, it is proposed that the mixture be initially compressed and thereupon cooled so that its temperature lies below the boiling temperature of the gas components to be removed. The gas components to be removed undergo condensation and can be led off for reutilization without contaminating the environment. Furthermore, it is proposed to feed the gas mixture through activated carbon filters (4, 5) after the condensation process, in order to bind remaining proportions of the gas components to be removed. It is also intended to partially return the gas mixture for renewed liquefaction after it has passed through said activated carbon filters. At the same time, the invention proposes a suitable installation for the execution of this process.