Energy cost for desalination evaporation versus reverse osmosis

The selection of the appropriate desalination technology between evaporation and reverse osmosis is grounded on several factors, including investment cost, maintenance cost, degree of availability, heaviness of the duty, and the required purity of the desalinated water. The main factor is often the running cost of the plant, and specifically the cost of the consumed energy. This paper intends to demonstrate that the real value of the steam bleed is a function of several factors, mainly of the cost of fuel and of its importance in the total cost of the energy. The lower the cost of fuel, the less is the value of the steam bleed up to the extent that the cost of the energy consumption can be lower for evaporation than for reverse osmosis.