Experimental studies on an indigenous coconut shell based activated carbon suitable for natural gas storage

Experimental studies are carried out to characterize an indigenous, coconut shell based, activated carbon suitable for storage of natural gas. Properties such as BET surface area, micropore volume, average pore diameter and pore size distribution are obtained by using suitable instruments and techniques. An experimental setup is developed to estimate the equilibrium methane adsorption capacity and adsorption/desorption kinetics. The experimental isothermal uptake data is used to fit four different isotherm models. Using the constants obtained for the D-A isotherm model the variation of heat of adsorption and adsorbed phase specific heat with equilibrium pressure and temperature are obtained. Similarly Henry's Law coefficients, important at low pressure and low uptake regime are also obtained. Finally using the kinetic data and a linear driving force model, constants in the kinetic equation are obtained. Results show that the indigenous material used in this study offers reasonably high natural gas storage capacity and fast kinetics and is suitable for adsorbed natural gas (ANG) applications. It is expected that this study will be useful in the design and development of ANG systems based on this indigenous material.