Method for reducing monovalent ions in concentrate of nanofiltration system and the nanofiltration system
US11406940B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 2018 |
| Grant date | Aug 9, 2022 |
| Priority date | — |
| Expiry date | Apr 11, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2301/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
This specification describes a method for lowering the content of monovalent ions in a final concentrate of a nanofiltration system relative to a brine and a corresponding nanofiltration system. The nanofiltration system comprises at least three stages of nanofiltration, wherein the concentrate from each segment flows into the next segment. A feed stream is sent into one stage to generate a concentrate stream, and a first portion of the concentrate stream is recirculated to the one stage. The pH of the feed stream is controlled in a range of 2-7. The temperature of the feed stream is in a range of 20-60° C. The feed stream includes the recirculated concentrate stream and at least part of a concentrate generated from an upstream stage. The method and the system described herein can reduce the concentration of monovalent ions in the final concentrate during a nanofiltration separation process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.