Non-Oxidative Reforming of Methane in a Mini-Gliding Arc Discharge Reactor: Effects of Feed Methane Concentration, Feed Flow Rate, Electrode Gap Distance, Residence Time, and Catalyst Distance

Abstract

In this work, a mini-gliding arc discharge reactor was employed for the reforming of methane under ambient temperature and pressure operation. Acetylene and hydrogen were produced dominantly with high selectivities of *70-90 and *75%, respectively. The results showed that both methane conversion and product selectivities depended strongly on various operating parameters, including feed methane concentration, feed flow rate, electrode gap distance, residence time, and the presence of a reforming catalyst (as a function of catalyst distance). The Ni catalyst-loaded porous alumina-silica plate was used to study the catalytic effect on the process performance at various residence times. A considerable enhancement of methane conversion and product yields was achieved in the combined plasma-catalytic system, particularly at a longer residence time. The catalyst distance, or packing position of catalyst plate, was also found to be an important factor affecting the process performance of the combined plasma-catalytic methane reforming. The closer catalyst distance led to the greater methane conversion because of the greater possibility of adsorption-desorption interactions of excited gaseous species on the catalyst surface to enhance subsequent reactions.

Plasma Catalytic Conversion of CH4 to Alkanes, Olefins and H2 in a Packed Bed DBD Reactor

“…However, the gas-phase plasma reactions occur via a free radical mechanism [2] and may not be efficiently selective to desired products. In a plasma-catalyst hybrid system, reactive plasma species (e.g., radicals) can interact with the catalyst, which can influence the reaction pathways and the selectivity of the desired products [3][4][5][6][7][8][9][10][11][12][13]. The plasma provides the required energy for activation of the stable molecule by breaking the bond (e.g., C-H for methane activation) and generates a pool of radicals, which can react with the catalyst, as the medium that is capable of conducting the interaction among radicals, selectively shifting reaction pathways towards more value-added products.…”

Plasma-Catalytic Fischer–Tropsch Synthesis at Very High Pressure

“…The most suitable reactor-catalyst configuration was found to be that of the gliding arc discharge reactor [64,65], where the catalyst material was coated onto a ceramic substrate, which was positioned within close proximity to the discharge (but not in direct contact). This gliding arc catalyst configuration was combined with the catalyst coating technique used for monolithic (ceramic) catalysts [57,[66][67][68][69][70][71][72][73], in order to produce a catalyst consisting of cobalt and γ-Al 2 O 3 , which were separately coated onto a pre-formed mullite substrate.…”

Ethylene epoxidation in a low-temperature parallel plate dielectric barrier discharge system with two frosted glass plates

“…The configuration of electrodes was found to influence the efficiency of EO production in that a cylindrical DBD provided superior ethylene epoxidation performance as compared to a parallel plate DBD [7]. The input power, voltage, and electrode gap distance significantly affected the performance of methane reforming [11,12,[30][31][32], corresponding to the study that the dielectric material and thickness changed the plasma behavior [33].…”