Due to hydrogen storage and transport problem, a concrete and immediate solution is the exploitation of the gas pipelines now used for natural gas. In this regard, this work aims to evaluate two main aspects that must be taken into account to make this approach possible: the separation of hydrogen from natural gas-hydrogen mixture and the odorization of the latter, in order to provide the safety of the pipelines. Therefore, the first part of this study is the evaluation of the efficiency of a purification system in presence of a variable quantity of methane in the inner stream. For these purposes, electrochemical hydrogen compression (EHC) system was selected, due to the great advantage of allowing both purification and compression in a single device. Different methane-hydrogen mixtures were taken into consideration, going to evaluate how an increasing amount of methane affects the efficiency of the system. The second part of this work is focused on a further development of a previous simulation study related to a possible process for natural gas-hydrogen mixtures odorization systems using AVEVA's PRO II software. As odorant, GASODOR S-FREE was taken into consideration, thanks to the fact that this is a common odorant used for methane with the great advantage of not containing sulfur, unlike THT and mercaptans