Preparation of High Efficient Coconut Activated Carbon and Its Adsorption Equilibria and Kinetics of CH₄/N₂

Coconut activated carbon with high specific surface area was prepared through carbonization of raw coconut shell and KOH activation under optimum conditions.The adsorption selectivity of CH₄/N₂ was improved with CO₂ activation in order to prepare the high efficient coconut activated carbon for the separation of CH₄/N₂.The adsorption equilibrium isotherms of CH₄ and N₂ on the high efficient coconut activated carbon were measured at 303-363 K and 0-1 000 kPa in a magnetic suspension balance.The experimental data were fitted with Toth model,and the model parameters and kinetic ones such as adsorption heat were obtained.Both the isothermal bidisperse pore model and the diluted breakthrough curve experiment were used to study the adsorption kinetics of CH₄ and N₂ on the high efficient coconut activated carbon.Furthermore,the fixed-bed adsorption and desorption experiments were carried out to study the separation mechanism of CH₄/N₂ using the coconut activated carbon.The results presented here would be significant for the development and optimization of pressure swing adsorption process for CH₄/N₂ effective separation using the high efficient coconut activated carbon.