Plasma-Assisted Hydrocarbon Reforming: Effect of Carrier Gas on Product Distribution

This study explores the impact of different carrier gases, such as methane (CH4), propane (C3H8), and argon (Ar), on product distribution in the plasma reforming of liquid fuels (C16H32) in a multiphase medium. Each carrier gas was introduced to the plasma reactor in a 90 to 10 ratio with hydrogen (H2), and the resulting gas and liquid phase products, as well as solid byproducts, were examined. Gas chromatography–mass spectrometry revealed that the use of CH4 and C3H8 produced comparable amounts of lighter hydrocarbon components (C9–C15), and it greatly outperformed the product yields seen with Ar. The enhanced conversion of C16H32 in CH4 and C3H8 environments is associated with the formation of reactive radicals (e.g., CH3•, C2H5•) from the carrier gases that directly participate in larger hydrocarbon fragmentation, a process absent when using Ar. Despite similar hydrogen yields in all cases, gas-phase products revealed that C3H8 produced more ethylene (C2H4), ethane (C2H6), propylene (C3H6), and hydrocarbons in the C4–C9 range than CH4 and Ar. Acetylene (C2H2) generation was significantly lower in the C3H8 case, indicating that plasma reactions involving propane favor the formation of stable hydrocarbons and the growth of secondary products over severe fragmentation. Analysis of solid byproducts shows that C3H8 generated the most amount of carbon soot because of the higher C to H ratio among all three carrier gas conditions. These findings show the critical importance of carrier gas chemistry in controlling the distribution of products in plasma multiphase reforming and offer new insights into enhancing plasma-assisted hydrocarbon reforming processes.