Experimental optimization of a solar still: application to alcohol distillation

This paper presents an experimental study of two solar stills, a single-compartment model and a two compartment type. The single compartment still is optimized under local climatic conditions. An experimental study of the cover slope shows that a cover angle of 16degrees ensures a very good transmission of solar radiation within the still while preventing the drops of the distillate to fall into the basin. In the prototype using two compartments, the glass of the illuminated compartment is a transparent cover with a part of the condensation happening on it, while the other compartment, also made of glass, is covered with a non-transparent material, which shades the sun; it is used only as a condenser. It has been observed that the distillation of a 38% alcohol initial solution yields a product containing 48% of alcohol when using the single-cover model, while under the same climatic conditions the two compartments still gives a 71% alcohol distillate. (C) 2004 Published by Elsevier B.V.