Experimental validation of a wireless monitored solar still for efficient olive pomace drying and distilled water production

This work presents the prototype of a solar still that can be used as a complement to the traditional fossil fuel-based drying process of olive pomace, a thick sludge with a high moisture content that is massively by-produced in the olive oil industry. In addition, the system allows to recover distilled water, which can be used to irrigate the adjacent fields. The feasibility of the system for the target application was experimentally validated by designing a wireless data acquisition circuit for data collection, remote storage, visualization and analysis in real-time, with access possible from multiple devices. The results from a test campaign revealed that the moisture content of the olive pomace was effectively reduced from 67.17% to 39.90% in a 10-day period. A maximum drying efficiency of 16.64% was achieved, with potential for higher values under favorable weather conditions. The simplicity of the design and the low-cost solution can facilitate the future large-scale implementation of a similar system.