The goal is to investigate the feasibility to use a local biomass (Posidonia Oceanica and Wood chips), as a raw precursor, to the production of activated carbons (AC) with a high surface area and remarkable hydrogen (H-2) adsorption properties. Biomasses (particle size of 0.3-0.4 mm) were pyrolyzed at 600 degrees C with a heating rate of 5 degrees C/min under an argon atmosphere. The biochar obtained from the carbonization step was chemically activated with KOH. The activation methodology induces a considerable improvement of the properties of the porous carbon in terms of carbon content (from 58 to 69 wt% to 93-96 wt%), surface area (from 41 to 425 m(2)/g to 2810-2835 m(2)/g) and H-2 adsorption in cryogenic condition (from 0,1 wt% to over 5 wt%). All porous carbons were characterized in terms of elemental analysis (CHNS-O), textural properties and H-2 adsorption measurements. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.