Methane conversion to syngas via air microwave plasma: towards renewable electricity storage

Abstract

In this study, a 915 MHz atmospheric-pressure microwave plasma system with a maximum power of 100 kW was employed to supply energy to a high-temperature-resistant reactor for methane conversion, targeting the co-production of syngas and carbon nanomaterials. Six experiments were performed at microwave powers of 40 and 60 kW with methane flow rates of 100, 150, and 200 slm. The highest hydrogen yield of 22 % was achieved at 60 kW and 200 slm, corresponding to a methane conversion rate of 80 %. The resulting carbon nanomaterials were characterized using STEM. STEM analysis confirmed the influence of process parameters on the morphology of carbon products: higher methane flow rates led to smaller primary particles, while increased microwave power resulted in larger particles. These trends are attributed to reactor temperature variations, with higher temperatures promoting primary particle growth.