An electrochemical system includes a first reservoir comprising a first fluid and a catalyst, wherein the first fluid comprises a reaction mixture that reacts to form first and second products, and a second reservoir comprises a second fluid. A first electrode contacts a redox-active electrolyte material solution and has a reversible redox reaction with the electrolyte material to accept at least one ion. A second electrode contacts a redox-active electrolyte material solution and has a reversible redox reaction with the electrolyte material to drive at least one ion into the second fluid as an electrical potential is supplied. A diluted effluent comprising the second product and the catalyst exits the second reservoir, wherein the second product is removed from the first reservoir via electroosmosis, and optionally concurrently via osmosis, and a product stream comprising the first product exits the first reservoir.

An electrochemical separation device includes a first electrode, a second electrode, a cell stack including alternating depleting compartments and concentrating compartments disposed between the first electrode and the second electrode, an inlet manifold configured to introduce a fluid to one of the depleting compartments or the concentrating compartments an outlet manifold, and one or more of a fluid flow director disposed within the inlet manifold and having a surface configured to alter a flow path of the fluid introduced into the inlet manifold and direct the fluid into the one of the depleting compartments or the concentrating compartments, and a second fluid flow director disposed within the outlet manifold and having a surface configured to alter a flow path of the fluid introduced into the outlet manifold via one of the depleting compartments or the concentrating compartments.

Provided are spacers, ion-exchange devices comprising spacers, and methods of preparing spacers for improved fluid distribution and sealing throughout an ion-exchange device. These spacers can include an internal cavity surrounded by a perimeter of the spacer. The perimeter can have a first opening and a second opening within the perimeter, and the first opening and the second opening can be located on opposite sides of the internal cavity. The spacers can also have a first and second plurality of channels located within the perimeter, wherein each channel of the first and second plurality of channels extends from the internal cavity towards the first opening or the second opening.

Provided are spacers, ion-exchange devices comprising spacers, and methods of preparing spacers for improved fluid distribution and sealing throughout an ion-exchange device. These spacers can include an internal cavity surrounded by a perimeter of the spacer. The perimeter can have a first opening and a second opening within the perimeter, and the first opening and the second opening can be located on opposite sides of the internal cavity. The spacers can also have a first and second plurality of channels located within the perimeter, wherein each channel of the first and second plurality of channels extends from the internal cavity towards the first opening or the second opening.

Provided are electrodialysis systems for removing silica from a desalinated water stream and methods for removing silica from a desalinated water stream. For example, described are bipolar membrane electrodialysis devices for removing silica from water comprising one or more anion exchange membranes; one or more bipolar membranes; and a pair of electrodes comprising a positive electrode and a negative electrode. Also described are electrodialysis systems comprising: one or more electrodialysis devices for the removal of dissolved ions and one or more bipolar membrane electrodialysis devices, wherein a product inlet stream of the one or more bipolar membrane electrodialysis devices comprises the product outlet stream of the one or more electrodialysis devices.

Provided are electrodialysis systems for removing silica from a desalinated water stream and methods for removing silica from a desalinated water stream. For example, described are bipolar membrane electrodialysis devices for removing silica from water comprising one or more anion exchange membranes; one or more bipolar membranes; and a pair of electrodes comprising a positive electrode and a negative electrode. Also described are electrodialysis systems comprising: one or more electrodialysis devices for the removal of dissolved ions and one or more bipolar membrane electrodialysis devices, wherein a product inlet stream of the one or more bipolar membrane electrodialysis devices comprises the product outlet stream of the one or more electrodialysis devices.

A two-stage electrodialysis system and a method for recovering waste CO.sub.2-lean amine solvent are provided. The system includes an amine solution pretreatment filtering system, a C-A homogeneous membrane electrodialysis device, a BP-A bipolar membrane electrodialysis system, and a CO.sub.2 recovery and capture system. The C-A homogeneous membrane electrodialysis system includes a material chamber, a C-A homogeneous membrane electrodialysis device, a concentrated HSSs waste solution chamber, an electrode solution chamber, and corresponding pipelines and peristaltic pumps. The BP-A bipolar membrane electrodialysis system includes a secondary feed chamber, a BP-A bipolar membrane electrodialysis device, an acid liquor chamber, an electrode solution chamber, and corresponding pipelines and peristaltic pumps. The waste CO.sub.2-lean amine solvent enters the material chamber after passing through the amine solution pretreatment filtering system. The concentrated HSSs waste solution chamber is connected to the secondary feed chamber by a buffer tank.

A two-stage electrodialysis system and a method for recovering waste CO.sub.2-lean amine solvent are provided. The system includes an amine solution pretreatment filtering system, a C-A homogeneous membrane electrodialysis device, a BP-A bipolar membrane electrodialysis system, and a CO.sub.2 recovery and capture system. The C-A homogeneous membrane electrodialysis system includes a material chamber, a C-A homogeneous membrane electrodialysis device, a concentrated HSSs waste solution chamber, an electrode solution chamber, and corresponding pipelines and peristaltic pumps. The BP-A bipolar membrane electrodialysis system includes a secondary feed chamber, a BP-A bipolar membrane electrodialysis device, an acid liquor chamber, an electrode solution chamber, and corresponding pipelines and peristaltic pumps. The waste CO.sub.2-lean amine solvent enters the material chamber after passing through the amine solution pretreatment filtering system. The concentrated HSSs waste solution chamber is connected to the secondary feed chamber by a buffer tank.

An electrochemical separation device includes a first electrode, a second electrode, and a cell stack including a plurality of sub-blocks each having alternating depleting compartments and concentrating compartments and each including frame and channel portions disposed between the first electrode and the second electrode. An internal seal formed of a first material is disposed between and in contact with the channel portions between adjacent sub-blocks in the cell stack and configured to prevent leakage between depleting compartments and concentrating compartments in the adjacent sub-blocks. An external seal formed of a second material having at least one material parameter different from the first material is disposed between and in contact with the frames of the adjacent sub-blocks in the cell stack and configured to prevent leakage from an internal volume of the electrochemical separation device to outside of the electrochemical separation device.

An electrochemical separation device includes a first electrode, a second electrode, and a cell stack including a plurality of sub-blocks each having alternating depleting compartments and concentrating compartments and each including frame and channel portions disposed between the first electrode and the second electrode. An internal seal formed of a first material is disposed between and in contact with the channel portions between adjacent sub-blocks in the cell stack and configured to prevent leakage between depleting compartments and concentrating compartments in the adjacent sub-blocks. An external seal formed of a second material having at least one material parameter different from the first material is disposed between and in contact with the frames of the adjacent sub-blocks in the cell stack and configured to prevent leakage from an internal volume of the electrochemical separation device to outside of the electrochemical separation device.