Switchable system for high-salinity brine desalination and fractional precipitation

A system for desalination using a switchable volatile organic solvent, the method comprising:

• a liquid-liquid extraction system, including:
• (A) a volatile-organic-solvent inlet into which a volatile organic solvent can be fed;
• (B) a saline-feed inlet into which a saline feed stream is fed, wherein the liquid-liquid extraction system is configured to extract water from a saline feed stream that is fed through the saline-feed inlet into volatile organic solvent that is fed through the volatile-organic-solvent inlet;
• (C) a brine outlet through which a concentrated brine, produced from the saline feed stream after water is extracted from the saline feed stream, leaves the system;
• and
• (D) an organic-rich-mixture outlet through which an organic-rich mixture containing the extracted water leaves the system;
• a mechanical-vapor-compression regenerator, including:
• (A) a main compressor;
• and
• (B) a solvent regenerator selected from (i) a heat exchanger providing vaporization and condensation and (ii) a vaporization device and a condenser, the solvent regenerator including:
• (a) an organic-rich-mixture inlet in fluid communication with the organic-rich-mixture outlet of the liquid-liquid extraction system, wherein the solvent regenerator is configured to vaporize dissolved organic compounds from the organic-rich mixture to produce an organic-rich vapor and to leave liquid-phase desalinated water;
• (b) an organic-rich-vapor outlet in fluid communication with the main compressor to feed the organic-rich vapor as volatile organic solvent into the main compressor;
• (c) a volatile-organic-solvent inlet in fluid communication with the main compressor to feed volatile organic solvent in a vapor form from the main compressor, after compression in the main compressor, into the volatile-organic-solvent inlet to transfer heat to the organic-rich mixture in a liquid form in the solvent regenerator;
• (d) a volatile-organic-solvent outlet in fluid communication with the volatile-organic-solvent inlet of the liquid-liquid extraction system for recycling the volatile organic solvent in the liquid form to the liquid-liquid extraction system;
• and
• (e) a desalinated-water outlet positioned to release the desalinated water from the solvent regenerator.