Surface Physicochemical Modification of Kenaf Adsorbent for Hydrogen Adsorption Study

Abstract

In supporting the industrial kenaf plan developed by Malaysian government, this research has extended the use of kenaf as a sorbent to investigate its reliability for hydrogen adsorption system. In satisfying the objective, the effect of impregnation time and the effect of nickel nitrate concentration on hydrogen adsorption has been studied. In addition, to study the adsorption and desorption capability of the modified kenaf on hydrogen adsorption, the regeneration study was also accounted. The kenaf core with the range of particle size in between 300-500µm has been modified through the physicochemical modification by experiencing the carbonization and activation process prior to be impregnated in nickel nitrate solution (Ni(NO3)2). The morphological and elemental studies on the modified-kenaf sorbent have been done with the helped of Variable Pressure Scanning Electron Microscopy (VPSEM) and Energy Dispersive X-Ray (EDX) analyser, respectively. The hydrogen adsorption using the hydrogen adsorption system was controlled at the pressure of 5 bar. The results show that the modified-kenaf sorbent able to improve the hydrogen adsorption as compared to the unmodified-kenaf sorbent. Based on the morphological analysis, the modified-kenaf sorbent contain more micropores compares to the unmodified-kenaf sorbent which help in the adsorption capacity. Besides, the modified-kenaf sorbent has potential to be reused with minimum pressure drop of only 0.207 and 0.109 bar up to second regeneration cycles. This study has revealed that the modified-kenaf material has high capability to be used as hydrogen adsorbent and can be competitive technology over the existing current hydrogen storage technology.