**Abstract**

Carbon nanotubes (CNTs) have gained considerable attention over the past decade as up-to-date materials for storing renewable energy. The properties of CNTs, e.g., exceptionally high surface area, thermal conductivity, and electron mobility can be advantageous for applications toward energy storage. Conventional methods in natural gas storage include liquefaction (LNG) and compression (CNG) in the compression range of 2 <sup>10</sup><sup>4</sup> – <sup>3</sup> <sup>10</sup><sup>4</sup> kPa in steel cylinders. But nanotubes carbon (CNT), which includes two models, is used for higher pressures (about 4 10<sup>4</sup> kPa). Single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) are the two models in which the gas storage mechanism is superficial. Studies have also shown that the capacity of MWCNT to store natural gas can be enhanced by treating the nanotubes with acid. In the case of CO2, however, positive CNT charging always enhances the adsorption while negative CNT charging always suppresses it. By doubling the nanotube diameter, the amount of the gas adsorption capacity increased by 45%.

**Keywords:** multiwalled carbon nanotube, single-walled carbon nanotubes, natural gas, adsorption, nanotechnology
