Abstract: A pervaporation apparatus and process adapted to handle a diverse range of feed stream compositions and volumes. The apparatus includes a pervaporation unit and condenser, one or more tanks and a control system to direct liquid flows within the apparatus according to the chosen processing scheme. The apparatus and process can achieve separation performance comparable to a one-stage, two-stage, two-step or more complicated pervaporation system, including those in which two-phase permeates are produced.

Abstract: A process for removing inorganic components from water is disclosed. The process involves gas stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out using one or multiple gas strippers and using air or any other gas as stripping gas. The membrane separation step can be carried out using a single-stage membrane unit or a multistage unit. Apparatus for carrying out the process is also disclosed. The process is particularly suited for treatment of contaminated groundwater or industrial wastewater.

Abstract: Improved processes for treating gas streams containing hydrogen sulfide, carbon dioxide, water vapor and methane, particularly natural gas streams. The processes rely on the availability of two membrane types, one of which has a hydrogen sulfide/methane selectivity of at least about 40 when measured with multicomponent gas mixtures at high pressure. Based on the different permeation properties of the two membrane types, optimized separation processes can be designed. The membrane separation is combined with non-membrane treatment of the residue and/or permeate streams.

Abstract: Improved membranes and improved membrane processes for treating gas streams containing hydrogen sulfide, carbon dioxide, water vapor and methane, particularly natural gas streams. The processes rely on the availability of two membrane types, one of which has a hydrogen sulfide/methane selectivity of at least about 40 when measured with multicomponent gas mixtures at high pressure. Based on the different permeation properties of the two membrane types, optimized separation processes can be designed.

Abstract: Improved membranes and improved membrane processes for treating gas streams containing hydrogen sulfide and methane, plus water vapor, carbon dioxide or both. The processes rely on the availability of two membrane types, one of which has a high hydrogen sulfide/methane selectivity and a high water vapor/methane selectivity, when measured with multicomponent gas mixtures at high pressures. Based on the different permeation properties of the two membrane types, optimized separation processes can be designed. In favorable cases, the processes can simultaneously dehydrate the gas stream and remove the hydrogen sulfide to very low levels.

Abstract: A process for removing components from liquid is disclosed. This process involves batchwise gas-stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out by circulating the batch repeatedly around the loop formed by the tank and the stripper for sufficient time until the desired degree of component removal is achieved. An additional tank can also be used to avoid mixing treated and untreated liquid streams. The membrane separation step can be carried out using a single-stage membrane unit or a multistage unit. The process is particularly suited for treatment of industrial streams that are small intermittent streams and vary in composition and concentration.

Abstract: A process for treating a gas stream to remove or recover a condensable component. The process involves a condensation step followed by a membrane concentration step. The process is useful in treating raw gas streams containing low concentrations of the condensable component, in treating small-volume raw gas streams, as an alternative to processes that require multistage membrane separation systems, in treating raw gas streams that have the potential to form explosive mixtures, or in situations where the treated gas stream composition must meet narrow target specifications.

Abstract: Pervaporation processes and apparatus with few moving parts. Ideally, only one pump is used to provide essentially all of the motive power and driving force needed. The process is particularly useful for handling small streams with flow rates less than about 700 gpd. Specifically, the process can be used to treat waste streams from glycol dehydrator regeneration units.

Abstract: A membrane module assembly adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation.

Abstract: A process for separating condensable organic components from gas streams. The process makes use of a membrane made from a polymer material that is glassy and that has an unusually high free volume within the polymer material.

Abstract: A process for removing organic compounds from water is disclosed. The process involves gas stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out using one or multiple gas strippers and using air or any other gas as stripping gas. The membrane separation step can be carried out using a single-stage membrane unit or a multistage unit. Apparatus for carrying out the process is also disclosed. The process is particularly suited for treatment of contaminated groundwater or industrial wastewater.

Abstract: A separation process for recovering organic components from liquid streams. The process is a combination of pervaporation and decantation. In cases where the liquid stream contains the organic to be separated in dissolved form, the pervaporation step is used to concentrate the organic to a point above the solubility limit, so that a two-phase permeate is formed and then decanted. In cases where the liquid stream is a two-phase mixture, the decantation step is performed first, to remove the organic product phase, and the residue from the decanter is then treated by pervaporation. Embodiments using two decanters, particularly suited to handling feed streams containing multiple organic compounds of different properties, are included.

Abstract: A membrane separation process and system for removing a component from a fluid stream. An auxiliary membrane module or set of modules is installed across the pump that drives the main membrane unit, so that the permeate streams from the main and auxiliary membrane units are mixed and pass together through a common driving pump. The concentration of the mixed permeate stream is allowed to build up by circulating the stream through the auxiliary unit. When the concentration has reached a desired level, the mixed stream can be tapped and the product stream drawn off.

Abstract: A membrane separation process and system for removing a component from a fluid stream. An auxiliary membrane module or set of modules is installed across the second stage of a two-stage membrane separation system. The driving force for the auxiliary modules is provided by the pump or other driving unit for the first membrane stage. The auxiliary module or modules provides additional treatment of the residue stream from the second membrane stage, but are driven by the first stage driving unit. The invention is particularly useful in any membrane separation operation involving gas separation, vapor separation or pervaporation in which a two-stage system design is to be used, and where it is desirable to improve the efficiency of the two-stage system.

Abstract: A process for treating a gas stream to remove or recover a condensable component. The process involves a condensation step followed by a membrane concentration step. The process is useful in treating raw gas streams containing low concentrations of the condensable component, in treating small-volume raw gas streams, as an alternative to processes that require multistage membrane separation systems, in treating raw gas streams that have the potential to form explosive mixtures, or in situations where the treated gas stream composition must meet narrow target specifications.

Abstract: A process for treating a gas stream to remove or recover a condensable component. The process involves a condensation step and a membrane concentration step. The condensation step may be followed by the membrane step, or vice versa. The process can be designed to yield only two product streams: one, the condensed liquid, ready for use, reuse or discard, and two, a residue gas stream which im most cases will be clean enough for direct discharge or reuse. This result is achieved by recycling other streams within the process. Recovery of 90% or more of the condensable component can be achieved. The process offers substantial energy savings compared with condensation alone.

Abstract: A separation process for recovering organic components from liquid streams. The process is a combination of pervaporation and decantation. In cases where the liquid stream contains the organic to be separated in dissolved form, the pervaporation step is used to concentrate the organic to a point above the solubility limit, so that a two-phase permeate is formed and then decanted. In cases where the liquid stream is a two-phase mixture, the decantation step is performed first, to remove the organic product phase, and the residue from the decanter is then treated by pervaporation. Embodiments using two decanters, particularly suited to handling feed streams containing multiple organic compounds of different properties, are included.

Abstract: A pervaporation process and system for removing a component from a liquid stream. The process includes a pervaporation separation step and a recovery step. An auxiliary membrane module or set of modules is installed across a condenser and/or recovery unit on the downstream side of the main pervaporation unit. This module takes as its feed a stream from the recovery unit and returns a component-enriched stream to the inlet of the condenser or recovery unit. The module can be sized to produce a discharge stream containing the component in about the same concentration as the feed to be treated. This discharge stream can then be mixed with the feed without adverse effect on the efficiency of the system.

Abstract: A system and process useful for a gas separation operation. The system includes three components: a membrane unit, a pump, blower, ejector or the like to provide gas flow to the membrane unit and a gas holding vessel. The system and process can be used to treat any type of gas flow, but have particular advantages for handling streams where the gas flow varies substantially over time.

Abstract: A process for removing an undesirable vapor from a pump exhaust by a membrane separation process. The process takes advantage of the pressure difference between the inlet and outlet sides of the pump to provide the driving force for membrane permeation. The process of the invention can reduce the emission of pollutants or impurities from pumps to a very low level, such as 10% or less of its previous value, with little extra expenditure of energy.