Methane and Natural Gases Kinetic and Equilibrium Adsorption Comparison on Synthesised Porous Coconut Shell Kernel Activated Carbon

Abstract

Instability of diesel and gasoline market price with the generation of environmental pollution attracted world attention in looking towards natural gas (NG) as a means of alternative fuel. This research work presents an investigation of experimental adsorption uptake of pure methane (CH₄) and NG onto a hybrid of coconut shell and polyetheretherketone (PEEK) porous carbon. The hybrid porous carbon was prepared by KOH microwave-assisted activation of a coconut shell with PEEK. The Porous carbon (M33P15) was used as a potential sorbent to investigate the adsorption characteristics of the two gasses. The adsorption is applied at an ambient and 5 °C adsorption temperatures and at a pressure of 3.5 MPa. The comparison is based on measuring adsorption uptake differences between the two gases onto porous carbon. The ideal CH₄ and NG adsorption uptake on porous carbon are investigated using volumetric adsorption method. The CH₄ adsorption capacity of 9.7045 and 9.9958 mmol CH₄ adsorbed/g adsorbent was achieved at an ambient and 5 °C adsorption temperature. While NG adsorption capacity of 9.9432 and 10.0901 mmol NG adsorbed/g was achieved at an ambient and 5 °C adsorption temperatures. In conclusion, the results show that NG adsorption uptake is slightly higher than CH₄ adsorption uptake. This is due to the ability of the adsorbent to adsorb other components of the NG other than CH₄. It is also suggested that applying heat management strategies, by lowering the temperature of adsorbent during the adsorption process, can significantly improve the storage capacity of CH₄ and NG.