The effect of the recent energy cost increase on the relative water costs from RO and distillation plant

Abstract The cost of water produced by seawater RO plant is shown to be less sensitive to energy cost increases than most dual purpose MSF and power plant combinations. As fuel costs increase above US$ 18 per barrel, only MSF with a co-generation cycle plant comprising a gas turbine, waste heat boiler and back pressure stam turbine, remains competitive with RO plant. However power plants using gas turbines as prime movers are more suitable for firing natural gas than heavy fuel oil, which may place limitations on their use. The cycle efficiency of the reference plant used to generate power for RO plant, and for valuing the power exported by dual purpose MSF, also influences process selection. RO is cheaper than all the MSF dual purpose plants examined, if a high efficiency combined cycle plant is used for this purpose.