TECHNICAL AND ECONOMIC-EVALUATION OF DISTILLATION AND REVERSE-OSMOSISDESALINATION PROCESSES

This study shows that distillation in large dual plant is still compet itive with seawater reverse osmosis, for Middle East conditions. Howev er, if energy costs are high, such as in Europe, and the USA, reverse osmosis becomes increasingly attractive. A distillation plant is gener ally more tolerant of difficult seawater conditions and severe operati ng conditions than RO when membrane performance and life can be advers ely affected by silt or contamination of the feedwater. Multiple effec t distillation is well established for the small to medium size range. The lower capital cost and auxiliary power consumption make MED compe titive with MSF, even though a larger number of units are needed. MED plants is now a major contender for all but the very largest installat ions. MED has greater potential than MSF for high performance ratio de signs. An RO plant has considerable scope for future development in te rms of membrane performance and cost reduction. RO is likely to be the main contender in high energy cost areas.