E-Cell® MK-3 Electrodeionization (EDI) System

Electrodeionization, also known as EDI, is an electrolytic process that removes ions from water. GE’s EDI system removes residual salts as well as ionizable aqueous species. These systems cover many applications including power generation, microelectronics, food and beverage production, and chemical and pharmaceutical manufacturing.

The environmental challenge

The handling of acid and caustic chemicals and the neutralization of regeneration wastewater is becoming an important regulatory issue. Within the pharmaceutical, power and microelectronics industries, there is a move to remove or at least minimize the amount of chemicals handled, and which need to be neutralized.

GE's innovative solution

E-Cell® MK-3 stacks have been designed to allow a simpler system configuration requiring less power than the E-Cell® MK-2E system.

The E-Cell® MK-3 design, compared to GE's previous system, contains fewer components that make it simpler to operate. The E-Cell® MK-3 design also consumes dramatically less power and goes longer between cleanings to remove hardness, a common component of water.

Environmental impact

Based on total 2007 GE EDI system and component (stack) sales, E-Cell® MK-3 systems could save over 10,000 MWh of electricity per year compared to systems using GE's previous EDI technology, avoiding the emission of over 6,000 metric tons of CO2 from traditional U.S. grid sources. This amount is equivalent to the annual impact of removing 1,200 passenger cars from U.S. roads.

Cutting costs

GE E-Cell® MK-3 EDI systems require only a fraction of the acid and base used by mixed-bed purification systems. A 200 gpm (gallons per minute) E-Cell® MK-3 system under typical conditions for the power industry is estimated to use 98 percent less cleaning chemicals than a mixed-bed system with equivalent output. This reduces chemical consumption by almost 70,000 kg per year, which is worth over $50,000 based on 2007 commodity pricing.