Abstract: The invention relates to a process for the production of hydrogen by steam reforming of methanol, in which water and methanol are reacted (4), under relatively high pressure, over a suitable catalyst. The gases emitted from the reaction are contacted (10), after condensation (7) under relatively high pressure, with an adsorption agent, such that the byproducts of the reaction are adsorbed and a hydrogen-rich gas is liberated (11). Also, byproducts which are recycled to the steam reforming reactor (4), are periodically desorbed under relatively low pressure at along with a fraction of the hydrogen present in the adsorption zone (10), after being submitted to recompression (13) and removal (14), under relatively high pressure, of at least a portion of carbon the dioxide, the desorbed gas fraction is recycled to the steam reforming reactor.

Abstract: The invention concerns a combined process of catalytically hydroreforming a heavy naphtha in at least one reaction zone (10) and catalytically hydroisomerizing a light naptha in at least one reaction zone (34).The invention is characterized in that the hydrogen produced in the hydroreforming unit (line 27) is used to isomerize the light naphtha, the obtained reformate and isomerate being fractionated preferably together in the same stabilization column (51 in FIG. 1).A better thermal integration, a better recovery of light hydrocarbons and a lowering of the utilities requirements and investments, as compared with units operating separately, are thus achieved.