Catalyst-free single-step plasma reforming of CH4 and CO2 to higher value oxygenates under ambient conditions

Methane (CH4) is inexpensive, high in heating value, relatively low in carbon footprint compared to coal, and thus a promising energy resource. However, the locations of natural gas production sites are typically far from industrial areas. Therefore, transportation is needed, which could considerably increase the sale price of natural gas. Thus, the development of distributed, clean, affordable processes for the efficient conversion of CH4 has increasingly attracted people's attention. Among them are plasma technology with the advantages of mild operating conditions, low space need, and quick generation of energetic and chemically active species, which allows the reaction to occur far from the thermodynamic equilibrium and at a reasonable cost. Significant progress in plasma‐assisted reforming of methane (PARM) is achieved and reviewed in this paper from the perspectives of reactor development, thermal and nonthermal PARM routes, and catalysis. The factors affecting the conversion of reactants and the selectivity of products are studied. The findings from the past works and the insight into the existing challenges in this work should benefit the further development of reactors, high‐performance catalysts, and PARM routes.

Plasma‐Assisted Reforming of Methane

Hydrogen Production by Microwave Discharge in Liquid: Study on the Characteristics Effect of Suspended Electrode

Deep learning-assisted pulsed discharge plasma catalysis modeling

The single-step conversion of CH4 to higher alcohols without catalyst or complex processing is the dream solution both in C1 chemistry and the chemical industry. Here, an innovative synthesis of higher alcohols from CH4–CH3OH was driven by a highly flexible nanosecond pulsed plasma. Experimental results showed that the products distribution was strongly correlated with the electric field variation and reactants composition, and the maximum conversion of CH4 (35.9%) and CH3OH (77.4%) were obtained at the CH4/Ar ratio of 1:2. Interestingly, the addition of H2O and H2O2 effectively promoted the C2–C4 alcohols selectivity up to 19.4%. In addition, optical diagnostics were used to obtain active species distribution and integrated insights into the C–C coupling of higher alcohols generation. A possible reaction mechanism of CH4–CH3OH plasma was also discussed. 

Yun Liu

Papers

Numerical modeling and mechanism investigation of nanosecond-pulsed DBD plasma-catalytic CH4 dry reforming