Experimental Study on the Effects of Beeswax as Absorber for Solar Still

An experimental study on the effects of beeswax incorporated in the construction of the absorber for a solar still was conducted. As part of the study, two solar stills of the same geometry were constructed with the same water depth and volume. The one without a phase change material (PCM) was used as the control still, while the other with beeswax as a phase change material laid at the bottom of its basin to serve as an absorber was used as the experimental still. The experiments were conducted in the thermodynamic laboratory of JS Tarka University, Makurdi, Nigeria, between 10.00 am and 5.00 pm for two weeks. 16 litres of water were used for each still, corresponding to 100 mm depth. The stills were kept side by side and exposed to sunshine from 10.00 am to 5.00 pm for three days. Temperatures of the water at inlet and in the still were measured. HT-9815 digital thermocouple was used to determine the temperature of water in the basin and that of the inner glass cover. SM206 solar power meter was used to measure the amount of solar energy incident on the still’s collector. The results showed that the still with beeswax as phase change material (experimental still) has an improved thermal efficiency enhancement of 109.30% as compared to the still without a phase change material with a thermal efficiency enhancement of 86.1%. This implies that beeswax is a good phase change material for solar stills, and the use of beeswax should be encouraged as it is non-toxic and organic.