Brackish and sea water desalination using a hybrid ion exchange-nanofiltration process
US7901577B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 2008 |
| Grant date | Mar 8, 2011 |
| Priority date | — |
| Expiry date | Mar 6, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A20/131
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Desalination is carried out by a hybrid ion exchange-nanofiltration process in which ion exchange is followed by pressure-driven nanofiltration. Monovalent ions of sodium and chloride of saline water are exchanged for equivalent concentrations of poly-valent ions (for example, sodium ions for magnesium ions or chloride ions for sulfate ions) when passed through ion exchangers in the form of those poly-valent ions. The resultant solution has a lower osmotic pressure than the initial solution containing monovalent sodium and chloride ions, and requires less transmembrane pressure for membrane desalination compared to traditional reverse osmosis. The concentrated reject stream from the membrane process is used as regenerant for the exhausted ion exchanger, which has been converted to monovalent anionic or cationic form.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.