Simulation of Methane Adsorption in ANG Storage System

P.K. Sahoo[1], K.G. Ayappa[1], M. John[2], B.L. Newalkar[2], and N.V. Choudary[2]
[1]Department of Chemical Engineering, Indian Institute of Science, Bangalore, Karnataka
[2]Corporate R&D Centre, Bharat Petroleum Corporation Ltd. Greater Noida, India
Published in 2010

Recently adsorptive storage has been identified as the most promising low-pressure (3.5 - 4.0 MPa) alternative for storing natural gas for vehicular use. However in order to successfully implement this technology, the filling and discharge characteristics of the adsorbent bed must be well understood. Significant temperature changes that occur during adsorption and desorption retard the system performance. In this work thermal effects associated with dynamic charge of methane in a 1.82 l adsorbed natural gas (ANG) cylinder filled with activated carbon, has been studied both theoretically and experimentally. COMSOL Multiphysics simulation of such a natural gas storage cylinder, based on a 2D model where hydrodynamics, heat transfer and adsorption phenomena are coupled, is presented. The temperature profiles obtained from experiments are in good agreement with the model prediction. Although a higher charging rate of methane reduces filling time, a large bed temperature rise retards the storage capacity of the ANG cylinder.