Dry Reforming of Methane Using Microwave Irradiated Metal Oxide/Coal Char Catalysts

Abstract

This research focuses on the synthesis of both shaped and amorphous powder materials, the combination of these materials with dried Powder River Basin (PRB) coal char, and their reactionary properties with methane and carbon dioxide gasses with conventional and microwave (MW) heating. The first goal of this project was to synthesize shaped micro and nano sized particles with ideal dielectric properties for converting electromagnetic energy into heat and proven capabilities of activating methane. These particles were synthesized via solvothermal, hydrothermal, and co-preceptory treatments alone and onto the surface of dried PRB coal char. PRB is a sub-bituminous, low-ranking coal (LRC) containing impurities processing ideal properties for heating using microwave radiation. MW irradiation of metal oxides and char improved conversion of reforming gasses (CH4 and CO2), reacting at lower temperatures than typically used with conventional heating methods. Lower DRM temperature parameters translate into diminished energy requirements, optimizing cost minimalization for a manufacturer. Outlet stream gases were monitored to examine effects of altering a particle’s morphology, size, and shape, and the products that evolve from these reactor experiments. Additionally, varying the wt% of the catalysts on the dried PRB coal char were tested. Characterizations were completed using scanning electron microscopy (SEM), X-ray diffraction (XRD), temperature-controlled desorption (TPD), thermogravimetric analysis (TGA), gas chromatography (GC), and transmission line and free space method dielectric testing on all the materials synthesized. The purpose of this research was to improve understandings and the development of low-rank coal char to fuel synthesis, evaluate solid/gas interactions between Mo-based metal oxides, PRB coal char, and reforming gases, analyze the effects of MW irradiation use in these reactions compared to conventional heating methods, observe the effects of metal oxide particle sizes/morphologies and their effects on reforming reactions, and increase future viability and applicability of these processes.