Natural gas conversion using plasma technology

With a massive expansion in natural gas deposits, methane conversion has been attracting increasing attention. However, due to the robust C–H bond (434 kJ/mol) in CH4, elevated temperatures (>1000 °C) are typically required to activate CH4 in the conventional thermal chemical process, resulting in a reduced energy efficiency and high capital costs. Nonthermal plasma (NTP) technology has recently emerged as an attractive process for CH4 conversion at low temperatures and atmospheric pressure. In NTP, the inert CH4 molecules can be activated into the corresponding radicals, excited species, and ions by colliding with high-energy electrons under mild conditions. Besides, plasma can be easily switched on and off, allowing for flexible integration with renewable electricity. Through this chapter, we will introduce the fundamentals of plasma-assisted CH4 conversion and highlight the recent advances in this field, including the effects of plasma reactors, operating parameters, and catalysts on two typical CH4 conversion processes: nonoxidative coupling of methane and methane pyrolysis. The current challenges and future perspectives in this emerging area will also be discussed.