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.

The present disclosure is directed to methods and systems of purifying solvents. The purified solvents can be used for cleaning a semiconductor substrate in a multistep semiconductor manufacturing process.

A method of removing chemical contaminants from a composition comprising an active, a solvent, and a contaminant can include providing an initial feed supply, wherein the initial feed supply comprises the active, the solvent, and the contaminant, wherein the contaminant can include 1,4 dioxane, dimethyl dioxane, or a combination thereof; including filtering the initial feed stock through a nanofilter.

A reverse osmosis system includes a first conductivity sensor for measuring electrical conductivity of water supplied to the reverse osmosis system, and a second conductivity sensor for measuring electrical conductivity of a permeate produced by the reverse osmosis system. The system also includes an AI unit designed to use a statistical model for calculating and accordingly setting a proportion of a concentrate produced by the reverse osmosis system that is to be recirculated according to the measured electrical conductivity of the water supplied to the reverse osmosis system, and according to the measured electrical conductivity of the permeate produced by the reverse osmosis system. The statistical model can be trained with training data.

Lithium recovery processes are described using concentration and conversion techniques. A vaporizer or membrane can be used to concentrate lithium and precipitate impurities. A conversion process can be used to replace anions in lithium bearing streams by adding a second anion and precipitating lithium in a salt with the second anion. Rotary separation can be used to separate the precipitated lithium salt.

Disclosed herein are membrane-based gas separation methods and systems. The methods and systems may, in particular, be used for separating a feed stream comprising methane and carbon dioxide (such as for example a biogas feed stream) in order to provide a methane product stream (such as for example a biomethane stream).

Systems and methods for desalinating a liquid feed using a membrane-based fluid filtration system are disclosed herein. The desalination system of the present embodiments can include a first osmotically assisted reverse osmosis (OARO) unit in fluid communication with a second OARO unit for desalination and brine concentration of a liquid feed into the first OARO unit. The concentrate product from the first OARO unit can be split into a first stream and a second stream, with the first stream entering the concentrate side of the second OARO unit and the second stream entering the diluate side of the second OARO unit. Additionally, or alternatively, the diluate product of the second OARO unit can be further split between inlets of the first and second OARO units. In some embodiments, the OARO units can be in fluid communication with a reverse osmosis (RO) unit to receive a RO concentrate feed therethrough.

A water purification apparatus receives raw water, which sequentially passes through a pre-filter, a pump, an RO filter, and a post-filter and is stored in the post-filter as drinking water. A recirculating water loop is in fluid communication with the post-filter and the pump to facilitate flow of the drinking water. A water quality detector generates a water quality signal corresponding to a quality value of the drinking water. A control valve is in fluid communication with the recirculating water loop. A controller receives the water quality signal and is stored with a water quality standard and a recirculation period. When a water discharging member stops discharge of the drinking water and the quality value exceeds the water quality standard, the controller activates the pump and the control valve, such that the drinking water in the post-filter recirculates through the recirculating water loop and is re-purified.

The present disclosure relates to a carbon dioxide capture apparatus and process combined with biogas upgrading, and there is provided the carbon dioxide capture apparatus combined with biogas upgrading for simultaneously obtaining high purity methane and carbon dioxide, and improving separation efficiency without an additional process by making use of gas streams after a liquefaction process, and recovering cold heat in the process.

Provided herein are systems and methods for removing radon from a natural gas stream. The system includes a radon permeable membrane. The radon permeable membrane is configured to separate a natural gas stream into a radon rich permeate stream and a radon reduced retentate stream. The radon rich stream can be stored for a period of time to yield a decayed permeate stream or reinjected into the source formation. The system can include a second radon permeable membrane configured to separate the radon reduced retentate stream into a second permeable stream and a second retentate stream. The decayed permeate stream and second retentate stream can be combined to form a sales gas.