(56q) Technology Development for High Surface Area By Cooling Brine.

Abstract:

Salt (NaCl) is mainly produced by supersaturating salt-water by heating. During heating when salt-concentration overshoots the saturation limit, salt crystals begin to separate out. The process is used in tropical countries to convert sea-water into salt. Salt can also be produced from mined solutions of rock-salt. The salt produced by this method has grains that are fairly cubical and coarse. The method of producing salt by heating salt-water is energy intensive as latent heat of evaporation of water is quite high. Much of the input energy is lost a waste heat to surroundings. An alternate way is by salt crystallizing salt as the dihydrate (NaCl·2H2O) and then warming it to produce salt that has high surface area owing to its much finer grain size. This process requires less energy and is best suited to colder regions. The technology under development uses a stirred vertical crystallizer to precipitate dihydrate crystals which are then rewarmed to yield salt. This salt has potential in wellness and food industry owing to its adsorption properties and high dissolution rate compared to normal salt. An alternate crystallizer design under development increases compactness and energy efficiency even further by incorporating features of a heat exchanger as an essential part of its design.