Abstract
Vehicles that use natural gas exhibit lower costs and emissions, when compared to the gasoline-fuelled vehicle. The present challenge of natural gas is how to improve its energy density. This research solves the problem of energy density by studying the natural gas storage technologies with improved adsorbent. Comparisons between the two storage systems, thus; with adsorbent and with conventional method are made technically based on associated amount of moles. We also compare gas storage in different cylinder types (Kusmiyati et al., 2004, Wei et al., 2015 and Torregrosa et al., 2013) based on weight factor and storage capacity. For the storage tank system, we discussed the concept of carbon adsorbents, when used in CNG tanks, offer a means of increasing onboard fuel storage and, thereby, increase the driving range of the vehicle. It confirms that the density of the stored gas in ANG is higher than that of compressed natural gas (CNG) operated at the same pressure. The obtained experimental data were correlated using 1st order kinetics, 2nd order kinetics, and isotherms (Sips and Toth) models with linear regression analysis. The best fitness obtained using 2nd order kinetics with a correlation coefficient of 9945 at 35 bar. Regression coefficient (R2) of Sips with value of 0.9982 gives better fitness and with the lowest RSMD value of 0.0148. The findings revealed the potential of adsorbent in natural gas storage applications.

Key words: Natural Gas, Adsorbent, compressed natural gas, Adsorption