A method for treating a natural gas containing carbon dioxide using membrane modules which are assigned to a first treatment stage or a second treatment stage and are fluidically connected to a retentate mode or a permeate mode. When evolution in the operating conditions results in one of the processing levels requiring less membrane surface for gas processing and the other processing level requiring more membrane surface for gas processing, then the method allows for reassignment of needed membrane modules assigned from one processing level requiring less membrane surface to another processing level requiring more membrane surface.

This disclosure provides a method for concentrating a solution of a macromolecule that is retained on at least two semi-permeable membranes that have different molecular weight cutoffs (MWCOs), the method comprising passing the solution through a hybrid configuration of said semi-permeable membranes staged in series in a single pass tangential flow filtration (SPTFF) apparatus. The method is applicable to the efficient concentration of biological macromolecules such as proteins, antibodies and nucleic acids.

Methods and systems are provided herein utilizing a membrane cascade to separate a hydrocarbon feed into boiling point fractions. Also provided herein are methods for selecting membranes for said cascades to achieve the desired boiling point fraction separation.

A turbocharger includes a turbocharger housing having an impeller housing comprising a circular cross-section. A main nozzle is disposed within the turbocharger housing communicating a first portion of a fluid stream to a first volute. A first auxiliary channel and a first auxiliary nozzle communicating a second portion of the fluid stream to the first volute. The first auxiliary nozzle is downstream of the main nozzle. A second auxiliary channel and a second auxiliary nozzle communicate a third portion of the fluid stream to the first volute. The second auxiliary nozzle is downstream of the first auxiliary nozzle. A valve assembly is selectively coupling the first auxiliary channel to the first auxiliary nozzle and the second auxiliary channel to the second auxiliary nozzle.

A system and method for producing from saline source water a product containing an increased ratio of multi-valent ions to mono-valent ions, which includes multiple nanofiltration units arranged to selectively remove mono-valent ions from the water fed into each nanofiltration stage in the nanofiltration permeate stream while retaining multi-valent ions in the nanofiltration reject stream. The rate at which the increase in the multi-valent ion- to mono-valent ion ratio is obtained may be enhanced by introduction of lower salinity water into the nanofiltration reject between stages, and by recirculating a portion of downstream nanofiltration reject flow into an upstream nanofiltration unit. The enhanced multi-valent ion product is suitable for multiple uses, including irrigation of plants and remineralization of desalinated water. The relative concentrations of the multi-valent ions in the product may be adjusted, for example by selection of nanofiltration membrane technologies which have higher or lower rejection for specific multi-valent ions.

A system for reverse osmosis, RO, and for pressure retarded osmosis, PRO, includes: a RO subsystem (10) with a high-pressure RO chamber (11) and a low-pressure RO chamber (12) separated by a RO membrane (13), the high-pressure RO chamber (11) having a RO feed inlet (14) and a brine outlet (15) and the low-pressure RO chamber (12) having a permeate outlet (16); a PRO subsystem (20) with a high-pressure PRO chamber (21) and a low-pressure PRO chamber (22) separated by a PRO membrane (23), the high-pressure PRO chamber (21) having a draw inlet (24) and a draw outlet (25) and the low-pressure PRO chamber (22) having PRO feed inlet (26) and a PRO feed outlet (27); an induction motor (30) having a stator and a rotor, wherein the rotor is mechanically connected to an input shaft of a hydraulic pump (31) configured for providing a feed solution to the RO feed inlet (14) and to an output shaft of a hydraulic motor (32) configured for receiving a draw solution from the draw outlet (25). The invention further discloses a method for operating such system for RO/PRO and to the use of such system.

A system and method for producing from saline source water a product containing an increased ratio of multi-valent ions to mono-valent ions, which includes multiple nanofiltration units arranged to selectively remove mono-valent ions from the water fed into each nanofiltration stage in the nanofiltration permeate stream while retaining multi-valent ions in the nanofiltration reject stream. The rate at which the increase in the multi-valent ion to mono-valent ion ratio is obtained may be enhanced by introduction of lower salinity water into the nanofiltration reject between stages, and by recirculating a portion of downstream nanofiltration reject flow into an upstream nanofiltration unit. The enhanced multi-valent ion product is suitable for multiple uses, including irrigation of plants and remineralization of desalinated water. The relative concentrations of the multi-valent ions in the product may be adjusted, for example by selection of nanofiltration membrane technologies which have higher or lower rejection for specific multi-valent ions.

Processes and systems for filtering a liquid sample are provided. Batches of a liquid sample can be routed to two or more cycling tanks (e.g., first and second cycling tanks). Upon filling a first cycling tank, a first batch of the liquid sample can be routed to a filtration assembly by a continuous diafiltration process that includes routing produced retentate back to the first cycling tank or to a collection vessel. Upon filling a second cycling tank, a second batch of the liquid sample is routed to the filtration assembly by a continuous diafiltration process that includes routing produced retentate back to the second cycling tank or to the collection vessel. The filling and continuous diafiltration of batches of the liquid sample continues to alternate between the two or more cycling tanks until a total product volume is processed.

Liquid solution concentration systems, and related methods, are generally described. In some embodiments, the system is an osmotic system comprising a plurality of osmotic modules. For example, the osmotic system can comprise a feed osmotic module configured to produce an osmotic module retentate outlet stream having a higher concentration of solute than the retentate inlet stream transported to the feed osmotic module. The osmotic system can also comprise an isolation osmotic module fluidically connected to the feed osmotic module. The osmotic system can also optionally comprise a purification osmotic module fluidically connected to the feed osmotic module and/or the isolation osmotic module. Certain embodiments are related to altering the degree to which the feed osmotic module retentate outlet stream is recycled back to the retentate-side inlet of the feed osmotic module during operation. Additional embodiments are related to the manner in which the retentate-side effluent from the isolation osmotic module is distributed among the system modules during operation.

The high water recovery hybrid membrane system for desalination and brine concentration combines nanofiltration, reverse osmosis and forward osmosis to produce pure water from seawater. The reject side of a nanofiltration unit receives a stream of seawater and outputs a brine stream. A permeate side of the nanofiltration unit outputs a permeate stream. A feed side of a reverse osmosis desalination unit receives a first portion of the permeate stream and outputs a reject stream. A permeate side of the reverse osmosis desalination unit outputs pure water. A draw side of at least one forward osmosis desalination unit receives the reject stream and outputs concentrated saline solution. A feed side of the at least one forward osmosis desalination unit receives a second portion of the permeate stream and outputs a dilute saline stream, which mixes with the first portion of the permeate stream fed to the reverse osmosis desalination unit.