2.2. Characterisation of rice hull ash
BET isotherm method was used to determine the surface area,
pore size and pore volume of the ash samples. Mass of sample
weighed was 0.2 g and the samples were degassed under nitrogen
atmosphere condition and analysed using liquid nitrogen. The
chemical compositions of the ashes were determined by scanning
electron microscopy (Tescan HRSEM) coupled with an electron dispersive
spectroscopy (EDS).