Flow Through Capacitor basics

The Flow Through Capacitor, also known as capacitive deionization, is a recently applied addition to the few known means to remove total dissolved solids from water. A basic theory is offered to explain fundamentals of this technology. An improvement, the Charge Barrier Flow Through Capacitor, purifies ions from water with a Coulombic efficiency approaching unity, high water recovery and low energy usage. The minimum energy used to deionize water, without use of energy recovery, approaches the averaged voltage applied during a charge cycle, plus the Nernst potential. At limiting flow and purification rates, the measured energy on a salt removal basis approaches the thermodynamic minimum for desalination of such concentrated feeds as seawater.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The Charge Barrier Flow Through Capacitor operates at high coulombic efficiency. ► The Charge Barrier allows the Flow Through Capacitor to operate at higher energy efficiencies, salinities and recoveries. ► The limiting energy of deionization approaches thermodynamic minimum energies for desalination of sea water. ► Basic theoretical models predicting Flow Through Capacitor energy usage and purification are verified by data.