Theoretical Modeling and Simulation for Adsorbed Natural Gas Storage System Using Activated Carbon

Numerous studies have been conducted for the theoretical modeling and simulation of adsorbed natural gas (ANG) storage where the cylinders are packed with the adsorbents. However, a gas storage system with internal thermal control, based on fin and tube type heat exchangers, is yet to be studied. In this study, the transient distributed-parameter model is employed for the adsorption bed and the heat exchanger. The heat and fluid flow inside the porous adsorbent bed are modeled taking the inertial and viscous effects. The models used for adsorption isotherms and kinetics fit the experimentally measured data for methane adsorption on pitch-based activated carbon (type Maxsorb III) at temperatures ranging from 15 °C to 75 °C and the pressures varying up to 2.5 MPa. Transient pressure and temperature profiles are obtained for the adsorption bed during charge and discharge cycle. The stored amount of methane in charge cycle and the time of gas delivered during discharge cycle are compared for both with and without heat exchanger arrangement.