Oxidation Of Methane In The Air Using Cold Plasma With Catalyst

Methane is a major greenhouse gas, which is recognized to contribute 23 times to global atmosphere warming than CO₂ at equivalent emission rate. Besides methane is a harmful contamination in an isolated living space. Hence, the development of a simple and highly efficient process for elimination of methane in the air is of significant commercial interest.Extensive studies have been done on the catalytic oxidation of methane in the air with supported metal catalyst. However, this catalytic route has not yet been industrialized because of the following problems: (1) high temperatures required by the catalytic operations (typically more than 500 oC); (2) water generated can lead to decreasing of catalytic activity. With the development of plasma technology, scientists gradually developed plasma oxidation of methane and found that plasma can be operated with a lower reaction temperature.In this paper, the elimination of methane by plasma method is systematically studied under environmental temperature. The following results have been obtained: (1) the different electrode material has different effect on the catalytic activity of methane oxidation, the order of catalytic activity is: stainless steel (Fe-Ni)> copper (Cu)> brass (Cu-Ni); (2) the methane conversion to CO2 increases with increasing residence time of plasma region, besides the high concentration of methane is favor of increase the selectivity to CO₂; (3) the smaller plasma region leads to higher electron energy, which increases methane conversion; (4) the addition of water is favored for the methane conversion to CO₂.