Optimizing Phase Change Materials for Volatility Management in Solar-Driven CO₂ Methane Dry Reforming

College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.

^* Corresponding author: xliu@nuaa.edu.cn; cyaohaichen@nuaa.edu.cn

Abstract

Solar-driven CO₂ methane dry reforming (CRM) is a promising technology for integrating solar energy utilization with greenhouse gas reduction. However, the transient nature of solar radiation leads to significant temperature fluctuations, which can adversely affect reactor performance, catalyst stability, and overall system efficiency. This study proposes a passive thermal management approach by integrating phase change materials (PCMs) with structural optimization to mitigate the effects of solar radiation variability. A comprehensive numerical model was developed to simulate the solar-driven CRM process in a porous foam reactor, incorporating solar radiation transport, heat transfer, and thermochemical kinetics. Experimental validation was conducted using a simulated solar concentration system. The results demonstrate that the integration of PCMs reduces temperature fluctuations by 63% and improves the methane conversion rate by 0.4%, ensuring stable reactor performance under fluctuating solar radiation. Furthermore, the use of composite PCMs with enhanced thermal conductivity significantly improves thermal buffering capacity and reaction stability. This study highlights the potential of PCM-based thermal management in advancing solar- driven thermochemical processes, offering a robust solution for improving energy efficiency and system stability in renewable energy applications.