Chemically regenerated ion exchange has been the conventional method of purifying boiler feedwater at power plants for over half a century.  Recent improvements in continuous deionization (CEDI) technology has caused a shift towards chemical-free deionization systems.  An RO/CEDI process has become cost competitive with traditional options and offers additional benefits such as reduced downtime, more consistent water quality and a smaller footprint. With careful planning and system design, CEDI can deliver a long service life and reliable production of feedwater without the use of chemicals.