Adsorbed Natural Gas Technology (ANG) is a natural gas storage method based on the principle of adsorption which utilizes a highly porous material as adsorbents. This technology facilitates a natural gas with high methane contents storage method which may be done with simple compression. One of the porous materials that is commonly applied to adsorb methane in ANG tank is activated carbon which is a material that has large surface area because of its high porosity. Activated carbon can be produced from banana peel waste and water hyacinth because of its high carbon contents. The production of activated carbon from banana peel waste and water hyacinth is carried out by variation of two different chemical activator, ZnCl2, concentrations (0.25 N and 1 N). Activated carbon with the best characterization from each source will be adopted as adsorbents on the designed ANG tank system in order to discover their storage capacity and delivery capacity based on their adsorption isotherm properties. They are compared with the commercially available activated carbon EnerG2 which has a surface area of 1750 m2/g. The best activated carbon produced from banana peel waste and water hyacinth has a surface area of 797.04 m2/g and 540.77 m2/g, respectively. The increase of pressure in an ANG system causes an increase of storage capacity for each activated carbon where at 35 bar, EnerG2, banana peel waste, and water hyacinth activated carbons adsorb 0.454 kg/kg, 0.278 kg/kg, and 0.269 kg/kg gas, respectively.