[en] Due to environmental disadvantages and energetic limitations that involves the use of fossilized combustibles, it is necessary to support and to research the new sources of renewable energy. The basis of this End of Degree Project is the development of different catalysts of energy in order to support the process known as Power to Gas. Methane is obtained from carbon dioxide and hydrogen. This technique is divided in two steps: the first one consists on getting hydrogen and oxygen from water hydrolysis, and the second one is based on the methanation process. The experimental study that consists on the comparison of different catalysts to get the greatest methane efficiency as possible is exposed in this document. In order to carry out this study, different catalysts have been prepared, all of them based on 13% of nickel. This metal has been chosen due to its high degree of reactivity in the methanation systems. Opposite to common production techniques, this one shows several advantages regarding the cost and the environmental impact, since the fundamental elements used for the catalysts' base are residues from industrial processes and plentiful minerals. After preparing the catalysts, activity trials have been carried out using a fixed bed conventional reactor. The aim is to set some operational conditions that ensure an appropriate comparison between catalysts acquiring those that show the greatest activity and stability. Moreover, the characterization of each catalyst has been made through the TPR approach, from which the results are connected with the physical-chemical features of each of them, as well as the interaction between the base and the metal and their optimal reduction temperature. Finally, the conversions of H2 and CO2, the selectivity of CH4 and CO, the efficiency of CH4 and the ratio of CH4/H2O all the prepared catalytic formulations are compared. This way, the methane obtained through the renewable energy using the catalysts produced from plentiful minerals and residues of industrial processes, has been proved to be a perfect candidate to replace those combustibles coming from fossil sources.

[eu] Erregai fosilak mugatuak izateak eta ingurumenean sortzen dituzten arazo larriei irtenbidea aurkitu nahiak, jatorri berriztagarriko energia-iturriak garatzea ekarri du. Gradu amaierako lan honen helburu nagusia Power to Gas deritzon teknologia garatzeko katalizatzaile berritzaileak aurkitzeko ikerketa esperimentala egitea da. Metanoa lortzeko karbono dioxidoa eta hidrogenoa behar dira. Prozesu horretan bi pausu ezberdintzen dira, lehenengoa uraren hidrolisia da hidrogenoa eta oxigenoa banantzeko, eta bigarrena berriz, metanazio prozesuari dagokiona da. Proiektu hau, aipatutako azken pausuan oinarrituko da eta beraz, konbertsio altuko katalizatzaileak lortzea da helburua. Ikerketa aurrera eramateko % 13 nikela oinarritzat duen katalizatzaileak prestatu dira. Izan ere, metal honen erreaktibitate maila altua da metanizazio sistemetan. Baina katalizatzaileen kostuak merkatzeko eta horiek ingurumenaren gain ekar ditzaketen eragin negatiboak ekiditeko helburuarekin, euskarritzat mineral natural oparoak zein industria prozesuetako hondakinak erabili dira. Behin katalizatzaileak prestatu ondoren, ohantze finkodun erreaktore batean egin dira aktibitate-entseguak. Hauen xedea, operazio-baldintza zehatzak ezarriz katalizatzaile ezberdinen arteko alderaketa egitea da aukera guztietatik katalizatzaile egonkorrena eta aktiboena lortzeko. Ikerketaren ildotik jarraituz, katalizatzaileak TPR metodoaren bitartez karakterizatuz lortutako emaitzak ezaugarri fisiko-kimikoekin erlazionatu eta metalaren eta euskarriaren arteko interakzioa ondorioztatzeaz gain, hauen erredukzio tenperatura optimoa lortu da. Azkenik, aztertutako formula katalitiko guztiekin CO2 eta H2-ren konbertsioa, CH4 eta CO-aren selektibitatea, CH4-ren errendimendua eta CH4/H2O ratioa erdietsi eta alderatu dira. Horrela, metanoa energia berriztagarrietatik eta ez erregai fosiletik lor daitekeela probatu da metanazio prozesuan mineral natural eta hondakinetan oinarritutako katalizatzaileak erabilita.