Dry Reforming of CH₄ With CO₂ to Generate Syngas by Combined Plasma Catalysis

Abstract

The hybrid plasma catalysis system was investigated for dry reforming of methane (DRM) with CO 2 to form syngas. First, dielectric barrier discharge (DBD) alone was evaluated for the effectiveness in conversion of CO 2 and CH 4 , and with the applied voltage of 15.0-19.5 kV, and frequency of 200 Hz. The ratio of feeding gas (CH 4 /CO 2 ) and total gas flow rate were controlled at 1 and 40 mL/min, respectively. The results indicate that conversions of CO 2 and CH 4 significantly increase with increasing applied voltage. The conversion of both greenhouse gases (CO 2 and CH 4 ) achieved the maximum value of 18.9% and 24.0%, respectively, at applied voltage of 19.5 kV. Selectivity of CO decreases from 53.6% to 42.4% as applied voltage is increased from 15.0 to 19.5 kV, while selectivity of H 2 increases from 30.1% to 35.8%. In addition, the influences of gas flow rate and ratio of feeding gas were also explored for DBD-alone system, and the results indicate that energy efficiency of syngas generation can be significantly increased as the flow rate is increased. As a catalyst with a high dielectric constant is placed into the discharge zone, the conversions of two gases (CO 2 and CH 4 ) reach 27.3% and 31.2%, respectively, at applied voltage of 19.5 kV. Selectivity of CO decreases from 59.4% to 49.6% as applied voltage is increased from 15 to 19.5 kV, while selectivity of H 2 increases from 32.0% to 38.3%. In the meantime, energy efficiency of syngas generation is increased by 0.3%. Overall, this paper indicates that combining DBD with a catalyst of high dielectric constant is a viable process for DRM.Index Terms-Dry reforming of methane (DRM), greenhouse gases (GHGs), nonthermal plasma, plasma catalysis, syngas.

Plasma-Catalytic Ammonia Synthesis beyond the Equilibrium Limit

“…Product yields are typically observed to increase with increasing plasma power [33,36,[38][39][40][41][42][43]46], but are insensitive to [32,36] or even decrease with increasing bulk gas temperatures [37]. Similarly, the introduction of catalyst packing into the reactor is reported sometimes to enhance [38,40,43,[46][47][48] and sometimes to diminish overall yields [33,36,38,39,44,45,47,49] relative to plasma alone. Additionally, apparent beyond-equilibrium effects on product yields for endothermic reactions like dry reforming are difficult to disentangle from local heating (hot spots) of the catalyst surface or reactor walls by the plasma [21,50].…”

Dry reforming of methane by combined spark discharge with a ferroelectric

“…Many catalysts have been used in hybrid systems including PPC and IPC and possible synergistic effects have been identified. However, such hybrid system for DRM faces several challenges, such as insufficient operating time, limited lifetime of the catalyst and low energy utilization [7], [31].…”

“…The polarization of a ferroelectric generates surface charge which can interact with free electrons in plasma, increasing the energy density in the plasma reactor [33]- [34]. Previous studies have demonstrated that syngas generation efficiency can be enhanced by introducing a ferroelectric into plasma reactor [7], [35]. In this work, ferroelectric powder (BaZr0.05Ti0.95O3) that is prepared by the sol-gel method and utilized in a spark discharge reactor to determine the DRM efficiency.…”

CuOx/CeO2 catalyst derived from metal organic framework for reverse water-gas shift reaction

“…CO2 is one of the most dominating greenhouse gases, which mainly comes from fossil fuels (coal, natural gas and oil) combustion for energy generation, transportation and chemical industry. [1] The utilization of CO2 for the production of chemicals is one of the proposed ways to mitigate the global warming, by which CO2 is used as a cheap, nontoxic and abundant C1 source. Conversion of CO2 to CO through the Reverse Water-Gas Shift (RWGS) reaction (Equeation.…”