Compressed natural gas (CNG) is widely used in the automotive industry, but high pressure increases the costs of vessel design and construction, with this process being dangerous as well. To overcome problems associated with CNG, adsorbed natural gas (ANG) was introduced where adsorbents, such as activated carbon, play a fundamental role in this process. In this method, gas storage is low and non-economical, but it is safer. The present research was conducted to solve this problem using adsorbent nanoparticles, particularly nanotubes, and the modeling of natural gas storage in nanoparticles was studied. First, the governing equations of the process were obtained. Second, coding was done using MATLAB software, and the effects of various factors, such as the diameter of the nanotube, loading pressure, surrounding conditions (water bath temperature), and porosity of the process, were investigated. Next, validation results were compared with experimental data, with the largest relative error reported to be equal to 6%. According to the modeling results, one could say that upon an increase in the diameter of the nanotube and the loading pressure, the adsorption capacity and storage of natural gas increased, but the adsorption capacity decreased with an increase in the temperature. In addition, by doubling the nanotube diameter, the amount of the gas adsorption capacity increased by 45%. For instance, the adsorption capacity is 0.4945 gr/gr at 298 K. As the temperature rises to 320 K by reducing the adsorption capacity by 22%, it is achieved at 0.3826 gr/gr. With an increase in the loading pressure from 5e+5 Pa to 1e+6 Pa, the adsorption capacity is almost three times more, but with an increase in the loading pressure from 2.5e+6 Pa to 5e+6 Pa, the adsorption capacity is almost twice more. The porosity changes have impressive effect on the adsorption capacity. In addition, optimal process conditions were provided using the experimental design. The optimal conditions are the largest nanotube diameter, loading pressure, as well as the minimum possible porosity and surrounding conditions (water bath temperature) in the presence of carbon nanotubes.