Nexus approach: ZSM-12 derived from industrial waste into microencapsulated in organic wax for solar energy storage system
Maha A. Tony
Abstract
Solar energy storage is gaining scientists interest since it could overcome the key issues affecting the solar energy efficiency. However, the lack of low-cost storage tools still signifies a formidable technological barrier. Zeolite is an answer for such requirements since it could be synthesized via the thermal decomposition of alum sludge waste. The attained ZSM-12, zeolite, was systematically characterized via X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Analysis (EDX). Due to its structure, ZSM-12 is able to store solar energy for matching solar energy availability and demand. A composite of ZSM-12 integrated in paraffin wax in different mass segments subjected into a vertical-type heat exchanger (VHE) and applied as the thermal energy storage material that connected to parabolic trough solar collector (PTC). Water is the heat transfer carrier (HTC) flowing through the solar collector and the VHE in a mass flow rate of 1.83 g/s. The thermal analysis of the PTC is managed and its maximum energy achieved around the solar noon in the summer season. The new composite material displays excellent thermal performance in terms of its chemical stability and durability for melting-solidification cycles. Increasing the ZSM-12 inserted into the system up to 0.6 (wt. %) dispersion is leading to consistently good thermal properties. In addition, experimental charging/discharging data verified a minimum weight loss and simplicity of handling and operation that enhances heat transfer rate. Finally, a numerical optimization is conducted and the overall system efficiency is reached to 93%.