NOVELTY - Removal of methane from gaseous non-condensable emissions of a plant further comprising sulfur compounds, involves: (i) mixing inlet gaseous emissions with air and heating the mixture up to a temperature which allows the ignition of the combustion reaction of the hydrocarbons in the mixture; (ii) catalytic oxidation of the mixture coming from step (i) by introducing the same mixture in a reactor comprising a catalyst for the oxidation of methane; and (iii) introduction of the gas exiting the reactor in step (ii) in a main heating exchanger.    USE - For removal of methane from gaseous non-condensable emissions of plant comprising sulfur compounds (claimed).    ADVANTAGE - The catalyst works at high temperatures and in the presence of high amounts of sulfur compounds, is able to efficiently carry out the oxidation process, has high thermal stability and resistance to sulfur poisoning. The method treats gaseous emissions from geothermal plants and reduces emissions of greenhouse gas in the atmosphere.    DETAILED DESCRIPTION - A process of the removal of methane from gaseous non-condensable emissions of a plant further comprising greater than or equal to 100 parts per million (ppm) of sulfur compounds, involves: (i) mixing the inlet gaseous emissions with air and heating the mixture up to a temperature which allows the ignition of the combustion reaction of the hydrocarbons in the mixture; (ii) catalytic oxidation of the mixture coming from step (i) by introducing the same mixture in a reactor comprising a catalyst for the oxidation of methane, having high thermal stability and resistance to sulfur poisoning; and (iii) introduction of the gas exiting the reactor in step (ii) in a main heating exchanger for transferring the heat necessary to warm the mixture of step (i), and sending to cooling towers for the emission from the plant; where in the process, the temperature of the inlet gaseous emissions in step (i) are heated to a temperature of 400-500 degrees C for the inlet into the reactor in step (ii) while the temperature of the gas exiting the reactor of 700-800 degrees C, and the catalyst essentially consists of Platinum dispersed on a previously sintered, inert support of Zirconia. INDEPENDENT CLAIMS are included for the following:    (1) a reactor for the catalytic oxidation at high temperature of methane from non-condensable gaseous emissions of a plant further comprising greater than or equal to 100 ppm of sulfur compounds, comprising: a packed bed reactor with the catalyst in granular form, having a high diameter/height ratio, with a vacuum degree of 0.35-0.6 (preferably 0.45-0.55), for the treatment of a gaseous stream having a mass flow rate of 5000 and 15000 Kg per hour; and    (2) a catalyst for the catalytic oxidation, at high temperature, of methane from non-condensable gaseous emissions of a plant further comprising greater than or equal to 100 ppm of sulfur compounds, having high thermal stability and resistance to sulfur poisoning, comprising Platinum dispersed on a previously sintered, inert support of Zirconia.