Devices, methods, and systems for producing a concentrated feed stream and a diluted feed stream using a solute stream provided to the low pressure side of the semi-permeable membrane during a reverse osmosis process. The process includes providing a semipermeable membrane having a first side and a second side and introducing a first feed solution stream on the first side of the membrane and a second feed solution stream on the second side, wherein the osmotic pressure of the of the first feed solution stream is greater than or equal to the osmotic pressure of the second feed solution stream. The process further includes exerting hydrostatic pressure on the first side of the membrane such that solvent passes from the first side to the second side thereby producing a concentrated first feed solution stream and a diluted second feed solution stream. Devices and systems for performing the processes are provided.

The invention provides an improvement in terms of control and process technology for a method of continuous removal of a component from a liquid mixture using a membrane unit comprising at least one membrane stage. The improvement is that at least some of the overall permeate stream obtained is recycled to the feed vessel and/or beyond the feed vessel but upstream of the conveying device. The presently disclosed method can especially be used for separation of a homogeneously dissolved catalyst from a liquid reaction mixture.

Disclosed is a process for enriching silicate content in drinking water that includes separating raw water via reverse osmosis into a permeate comprising demineralised raw water and a retentate comprising mineral enriched raw water. The permeate is mixed with a water glass solution comprising sodium silicate and/or potassium silicate. An ion exchange process is used to reduce the concentration of sodium and/or potassium ions in at least part of the mixture. At least part of the retentate is supplied to the mixture after reducing the concentration of sodium and/or potassium ions to provide a silicate-enriched drinking water. Also disclosed is an apparatus for producing a drinking water enriched with silicate. The apparatus includes a reverse osmosis unit, a mixing unit, an ion exchanger, and a feed unit for feeding at least part of the retentate to the mixture after reducing the concentration of sodium and/or potassium ions.

A gas separation system for controlling a concentration of a first gas species and a second gas species in an outlet gas comprises a splitter unit. The splitter unit comprises a gas membrane system having a gas inlet port. The gas inlet port is in fluid connection with an air intake. A membrane is a selective barrier and allows some things to pass through but stops others.

A membrane gas separator with a built-in valve along with a method of open and closing the membrane gas separator are disclosed herein. The membrane separator contains an an inlet chamber, hollow selective fibres, an outlet chamber, a central core element and a flushing space. The membrane separator contains a built-in combined valve in the outlet chamber and a the central space and a check valve at an inlet manifold. The built-in valve contains a throttling section to ensure a reduced backflow of a final product from the outlet manifold to the inner space of hollow fibres, and the sealing section to stop the flow of the flushing medium from the outlet chamber to the flushing space when no inlet medium flows through the separator. The method of opening of the membrane separator includes opening of the sealing section and subsequent opening and deactivation of the throttling section. The method of closing of the membrane separator includes closing and activation of the throttling section and closing of the sealing section.

Examples disclosed herein relate to methods and systems for controllably removing one or more solutes from a solution. Examples disclosed herein relate to methods and systems for removing water from alcoholic beverages.

The present invention relates to a dialysate regeneration method that reduces a urea concentration of a urea-containing aqueous solution, the method including a reverse osmosis process of obtaining, from the urea-containing aqueous solution, a concentrate having a higher urea concentration and a permeate having a lower urea concentration by using a reverse osmosis membrane element at an operating pressure of 0.5 MPa or more and 2.0 MPa or less, in which the urea concentration of the urea-containing aqueous solution is 0.5 g/L or more, the reverse osmosis membrane element includes a reverse osmosis membrane, and the reverse osmosis membrane has a pore diameter of 7.0 Å or less as measured by a positron annihilation lifetime measurement method.

A precipitation system for precipitating the target component is provided. The precipitation system includes: a reverse osmosis module; a precipitation device; a membrane separation device that includes a semipermeable membrane module including a first chamber and a second chamber separated by a semipermeable membrane, and that makes the feed solution after precipitation of the target component in the precipitation device flow to each of the first chamber and the second chamber and pressurizes the feed solution in the first chamber to transfer water into the second chamber via the semipermeable membrane and thereby concentrate the feed solution in the first chamber and dilute the feed solution in the second chamber; first return means for returning the feed solution concentrated in the membrane separation device to the precipitation device; and second return means for returning the feed solution diluted in the membrane separation device to the reverse osmosis module.

A gas separation system for controlling a concentration of a first gas species and a second gas species in an outlet gas comprises a splitter unit. The splitter unit comprises a gas membrane system having a gas inlet port. The gas inlet port is in fluid connection with an air intake. A membrane is a selective barrier and allows some things to pass through but stops others.

A multi-stage polymeric membrane module system separates a gas, such as air, into components of high purity. In at least two of the stages, a portion of the retentate gas is directed into the low-pressure side of the module, to act as a sweep gas. The use of the sweep gas reduces the partial pressure of permeate gas on the low-pressure side of the membrane, and therefore improves the flow of permeate through the membrane. In a preferred embodiment, there are three modules. The output streams are taken from the retentate outlet of one module, and from the permeate outlet of another module. The output streams have very high purity, relative to the number of modules required, as compared with systems of the prior art.