TECHNICAL AND ECONOMIC-EVALUATION OF DISTILLATION AND REVERSE-OSMOSIS DESALINATION PROCESSES

This study shows that distillation in large dual plant is still competitive with seawater reverse osmosis, for Middle East conditions. However, if energy costs are high, such as in Europe, and the USA, reverse osmosis becomes increasingly attractive. A distillation plant is generally more tolerant of difficult seawater conditions and severe operating conditions than RO when membrane performance and life can be adversely affected by silt or contamination of the feedwater. Multiple effect distillation is well established for the small to medium size range. The lower capital cost and auxiliary power consumption make MED competitive with MSF, even though a larger number of units are needed. MED plants is now a major contender for all but the very largest installations. MED has greater potential than MSF for high performance ratio designs. An RO plant has considerable scope for future development in terms of membrane performance and cost reduction. RO is likely to be the main contender in high energy cost areas.