Synthesis Gas from Methane by Using a Plasma-Assisted Gliding Arc Catalytic Partial Oxidation Reactor

Abstract

In this work, the potential for the catalytic partial oxidation (CPOX) of methane (CH4) to produce synthesis gas (H2 and CO) was studied both experimentally and thermodynamically at a fixed pressure (1 bar) and electric power (0.3 kW). The investigations were performed in a partially adiabatic plasma-assisted (nonthermal) Gliding Arc (GlidArc) reactor, using a Ni-based catalyst. Two cases were studied: in the first, normal air (molar ratio of O2/N2 = 21/79) was used, whereas enriched air (O2/N2 = 40/60) was utilized in the second. The individual effect of the O2/CH4 molar ratio, gas hour space velocity (GHSV), and bed exiting temperature (T exit) was studied for both cases. The main trends of the CH4 conversion, the synthesis gas yield, and the thermal efficiency of the reactor based on the LHV (lower heating value) were analyzed and compared, and any deviations from equilibrium could be explained by temperature gradients and an irregular gas flow. In the findings from the studies, the results revealed that an H2/CO ratio of 2 could be obtained. For the normal air case, an optimal value of the O2/CH4 molar ratio of 0.7, a GHSV of 1.8 NL/(gcat.h), and a maximum temperature (T max) of 1065 °C were good reforming choices, whereas for enriched air, these values were 0.7, 1.8, and 1105 °C, respectively.

Experimental Investigation of Biogas Reforming in Gliding Arc Plasma Reactors

“…Figure 4(d) shows that less energy was consumed at high CH 4 /CO 2 ratios. This was contributed to the fact that greater amount of air was available for an exothermic partial oxidation reaction, in line with the published literature [16,24,25]. viewed to have longer residence time for reforming reaction.…”

Plasma‐Assisted Reforming of Methane

“…Producing syngas through simultaneous exothermic and endothermic reactions is attractive because it significantly reduces the energy requirements. [ 96 ] Noncatalytic POM occurs only at extremely high temperatures. [ 97 ] Many studies have focused on the POM reaction over different catalysts.…”

“…The POM reaction is an exothermic process expressed as reaction R2.10. [ 94 , 95 , 96 ] In the POM reaction, the molar ratio of H 2 and CO in the product (syngas) is 2, which is different from that of the SMR reaction (H 2 /CO = 3) and the DRM reaction (H 2 /CO = 1). The POM process's coupled exothermic oxidation reaction, and endothermic reforming reactions can be carried out simultaneously in the catalyst bed.…”

Review on Innovative Catalytic Reforming of Natural Gas to Syngas

“…It occurs when a sub-stoichiometric fuel-air mixture is partially combusted in a high temperature reformer [8], and it produces hydrogen rich syngas. Partial oxidation is an exothermic reaction and, thus, considered more economic than the processes of steam reforming or dry reforming, because it requires a smaller amount of thermal energy.…”