Development of new materials for desalination

One of the most pressing problems of our times is the supply of adequate quantities of drinking water in areas not bestowed with abundant natural resources. Studies have shown the desalting of seawater to be economically sound for certain localities. Of all the available methods, the multi‐stage flash distillation is a proven method. The MSF type desalination plants may be operated independently (single purpose) or linked to power stations (dual purpose). In the MSF type desalination plants, the largest single item of cost is heat exchanger tubes. Design studies have shown that about one‐tenth of a square foot of condensing surface is required to produce one gallon of fresh water per day. For a combined capacity of one billion gallons per day at ¼ sq. ft. of tube, a tube length of 80,000 miles would be required. In MSF type desalination plants, the initial capital cost swallows up to 33% of the money, operating costs about 21% and the remaining 26% goes on power. The colossal amount of heat exchanger surface required in MSF type plants makes it mandatory to investigate new condenser tube materials which may provide ease of fabrication, maximise economy and be abundantly available.