E-Cell Electrodeionization (EDI) Stacks

Modules for ultrapure and high purity water systems

E-Cell electrodeionization (EDI) stacks are the core component of a fully engineered system to produce ultrapure and high purity water. 91��offers several models with differing capabilities for use in many industries including power generation, semiconductor fabrication, solar panel production, pharmaceutical manufacturing, and at many other heavy industrial sites. E-Cell stacks purchased from 91��are commonly used by original equipment manufacturers (OEMs) building EDI systems in various applications and capacities with Veolia��s technical guidance. 91��also offers stacks to the market through other channels, including direct to end-users for replacement of the EDI stacks in their existing systems.

Product offering & applications
Technology overview
Winflows

Product offering & applications

E-Cell EDI is an established 91��technology with time-tested manufacturing practices and a reputation for providing premium performance including both the highest levels of product water quality and the lowest energy consumption.

91��offers the following E-Cell EDI stacks with recommendations on the typical new-build application for each model.

E-Cell EDI Stack	Nominal Stack Flow Rate	Typical New-Build Applications
	8.0 m3/h (35.2 gpm)	Ultrapure water for solar photovoltaic and green hydrogen Boiler feedwater in power plants and other heavy industrial sites
	7.0 m³/h (31?gpm)	Boiler feedwater for power steam generation Other general industrial use like chemical, petrochemical, pulp & paper and steel
	5.0 m³/h (22?gpm)	Ultrapure water for semiconductor, flat panel display, solar photovoltaic and other microelectronics Boiler feedwater in power plants and other heavy industrial sites
	3.4 m³/h (15?gpm)	Ultrapure water for semiconductor, flat panel display, solar photovoltaic and other microelectronics Boiler feedwater in power plants and other heavy industrial sites
	3.4 m³/h (15?gpm)	USP, EP required quality for pharmaceutical and laboratory purified water injection
	1.0 m³/h (5?gpm)	USP, EP required quality for pharmaceutical and laboratory purified water injection

Technology overview

E-Cell EDI Benefits Versus Ion Exchange

Electrodeionization is a critical part of the evolution of demineralization systems from several sequential ion exchange vessels and toward membrane-based systems. In such a flow sheet with reverse osmosis, EDI systems can replace mixed-bed ion exchange systems and provide reliable production of ultrapure or high purity water. Additionally:

EDI requires no regeneration chemicals which simplifies environmental, health and safety concerns and reduces chemical costs
EDI operates continuously which minimizes risk of breakthrough from exhausted resin and simplifies operations by eliminating the need to take a system offline for regeneration
EDI reduces facility requirements by having a smaller footprint and lower height requirement than ion exchange, particularly when including supporting equipment such as chemical dosing systems
EDI has no hazardous wastewater discharge and wastes can be easily recycled without the neutralization systems needed for ion exchange

For many customers and in addition to the above benefits, choosing to use E-Cell EDI technology provided lower capital costs and reduced operating expenses when compared to mixed bed ion exchange.

Winflows

Winflows is one of the most advanced reverse osmosis (RO) and EDI projection tools on the market. It can model both RO and EDI as stand-alone operations but is unique in its ability to model RO+EDI systems as a combined process in a single tool. This improves ease of use given the requirement that most EDI systems have upstream RO to ensure adequate feed water quality to the EDI system. With one tool, making EDI projections is easier than ever.

Winflows includes functionality for all E-Cell stacks and can be used for projections of any size. The Winflows software can be downloaded here.

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