2.2 Experimental procedures
TGA was carried out in the presence of nitrogen (N2) at the flowing rate of 150 ml/min. EFB and OPT
samples between 0.5 and 1.0 g was pyrolyzed to a maximum temperature of 700°C. The sample was first
heated to 110°C and kept at that temperature for 30 minutes to remove any moisture. After that, the
samples were individually heated at heating rates of 50°C/min and 80°C/min until 700°C.