Adsorption Thermodynamics of Natural Gas Storage onto Pitch-Based Activated Carbons

摘要

Adsorbed natural gas (ANG) has recently become competitive to compressed natural gas (CNG) for storage and transportation purposes with high energy density and at much lower pressure than CNG. The adsorption characteristics of adsorbents are important information for uptake capacity and thermal management of the adsorptive gas storage. This article presents the adsorption characteristics of methane, which is the major component of NG, on two types of pitch-based activated carbons namely Maxsorb III and ACF (A-20) in the temperature ranges from 5 to 65 °C and pressures up to 2.5 MPa. The uptakes have been experimentally measured by a volumetric technique. The results are regressed with various popular isotherm models used in the literature for physisorption and are compared with the data of other researchers for similar adsorbent - adsorbate pairs. The heat of adsorption has also been extracted from the measured data. The thermodynamic study has been accomplished on the performance of adsorbed natural gas storage system for charging and discharging along with the thermal effects.