The present disclosure is directed ion-exchange systems and devices that include composite ion-exchange membranes having 3D printed spacers on them. These 3D printed spacers can drastically reduce the total intermembrane spacing within the system/device while maintaining a reliable sealing surface around the exterior border of the membrane. By adding the spacers directly to the membrane using additive manufacturing, the amount of material used can be reduced without adversely impacting the manufacturability of the composite membrane as well as allow for complex spacer geometries that can reduce the restrictions to flow resulting in less pressure drop associated with the flow in the active area of the membranes.

A method and a system for recovering nitrogen, and optionally phosphorus and/or potassium, from a liquid waste stream, such as a stream of urine or manure, or human urine is described. The method comprises passing the waste stream through a multi-compartment electrodialysis bipolar membrane (EDBM) system.

A method of generating electrical power or hydrogen from thermal energy is disclosed. The method includes separating, by a selectively permeable membrane, a first saline solution from a second saline solution, receiving, by the first saline solution and/or the second saline solution, thermal energy from a heat source, and mixing the first saline solution and the second saline solution in a controlled manner, capturing at least some salinity-gradient energy as electrical power as the salinity difference between the first saline solution and the second saline solution decreases. The method further includes transferring, by a heat pump, thermal energy from the first saline solution to the second saline solution, causing the salinity difference between the first saline solution and the second saline solution to increase.

The present invention provides a process for recovering glycol from a process stream comprising glycol, water, dissolved salts, and hydrocarbons. The process comprises subjecting the process stream to a salt-enrichment process to obtain a salt-enriched stream having a salt concentration higher than salt concentration of the process stream, and a salt-reduced stream; subjecting the salt-enriched stream to a glycol reclaiming process to separate the salts and at least a portion of the hydrocarbons from the salt enriched stream to obtain a substantially salt-free water-glycol stream; and blending the salt reduced stream from the salt-enrichment process with the substantially salt-free stream to produce a reclaimed water-glycol stream

An electrochlorination system includes an electrolyzer fluidically connectable between a source of feed fluid and a product fluid outlet, and a sub-system configured to one of increase a pH of the feed fluid, or increase a ratio of monovalent to divalent ions in the feed fluid, upstream of the electrolyzer.

A stack of ion exchange membranes suitable for water purification comprising a plurality of anion exchange membranes (AEMs) and a plurality of cation exchange membranes (CEMs), wherein the colour properties of the AEMs are visibly different to the colour properties of the CEMs. The invention also provides a process for making membrane stacks in which the likelihood of there being two consecutive membranes of like charge is reduced. Furthermore, it is easy to identify whether there are two consecutive membranes of like charge present in the stacks.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

The present invention includes a method including providing an anode and a cathode; providing a desalination device operably coupled to establish an electrical potential between the anode and the cathode when the desalination device is operating; providing water containing dissolved solids; thereby establishing the electrical potential; reducing a salinity of the water by supplying the water to the desalination device; and generating electrical power by reducing the salinity of the water.

A method for desalination is provided. An electric potential difference is applied across a saline solution, where a salinity of the saline solution is in a range of 2.5 to 7.8 parts per thousand. The saline solution is separated, using electrodialysis, into a concentrated saline solution and a first diluate. The concentrated saline solution is transferred to a reverse osmosis chamber. The concentrated saline solution is pumped through a partially permeable membrane, thereby removing salt ions from the concentrated saline solution, and creating a second diluate and a brine solution. A pressure of the solution is then increased, using a pressure exchanger, by transferring water pressure from the brine solution to the concentrated saline solution. The first diluate and the second diluate are combined, where a first recovery ratio of the first diluate is greater than a second recovery ratio of the second diluate.

An ion-exchange apparatus has a raw-water tank 1, a treatment tank 2, an ion exchanger 3 and a voltage applying device E. The raw-water tank 1 contains a to be treated liquid that has impurity ions. The treatment tank 2 contains a treatment material with exchange ions exchangeable with the impurity ions. The ion exchanger 3 enables the passage of the impurity ions from the raw-water tank 1 to the treatment tank 2 and the passage of the exchange ions from the treatment tank 2 to the raw-water tank 1. The voltage-applying device E applies a voltage to the ion exchanger 3.