Deionization and desalination using electrostatic ion pumping

US7981268B2 · kind B2 · utility

Assignee

• Lawrence Livermore National Security, LLC · US

Inventors

• William L. Bourcier · Livermore, US
• Roger D. Aines · Livermore, US
• Jeffery J. Haslam · Livermore, US
• Charlene M. Schaldach · Pleasanton, US
• Kevin C. O'Brien · San Ramon, US
• Edward L. Cussler · Minneapolis, US

Key dates

• Filing date: Jan 19, 2007
• Grant date: Jul 19, 2011
• Expiry date: May 4, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02A20/131
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The present invention provides a new method and apparatus/system for purifying ionic solutions, such as, for example, desalinating water, using engineered charged surfaces to sorb ions from such solutions. Surface charge is applied externally, and is synchronized with oscillatory fluid movements between substantially parallel charged plates. Ions are held in place during fluid movement in one direction (because they are held in the electrical double layer), and released for transport during fluid movement in the opposite direction by removing the applied electric field. In this way the ions, such as salt, are “ratcheted” across the charged surface from the feed side to the concentrate side. The process itself is very simple and involves only pumps, charged surfaces, and manifolds for fluid collection.