Distillation utilizing waste heat from a portable electric generator

A still utilizing waste heat from a portable electric generator by means of a heat-pipe was proposed and analyzed theoretically to determine its thermal behavior and distillate productivity. Waste gas from a portable electric generator has not been utilized because of its low thermal energy, but the thermal energy can be used as an additional heat source for solar stills. The proposed still is a multiple-effect diffusion still, consisting of a series of closely spaced parallel partitions in contact with saline-soaked wicks, and a heat-pipe is used to transfer thermal energy from waste gas to the still. In the still, evaporation and condensation processes are repeated to recycle the thermal energy to increase distillate productivity. We found that about a half of the thermal energy from waste gas can be transported to the first partition (or heated partition) of the still, and the proposed still can produce 20 kg of distilled water in several hours of operation. This amount of distillate is equivalent to the maximum daily productivity of the solar stills obtained by outdoor experiments.