In this process, the carbonization temperature has the most
significant effect, followed by heating rate, nitrogen flow rate, and
finally residence time [3,21]. Normally, higher carbonization
temperatures (600–700 8C) result in reduced yield of char while
increasingthe liquid and gases release rate [3]. Higher temperature
will also increaseash and fixed carbon content and lower amount
of volatile matter [3,21,31]. Thus, high temperatures result in
better quality char but also decrease yield. This is due to the
primary decomposition of biomass at higher temperatures and
also secondary decomposition of char residue [3]. Thus, as the
temperature of primary degradation increased or the residence
times of primary vapors inside the cracked particle is shorter, the
char yields decrease [31]. According to Ioannidoue and Zabaniotou
[3], higher carbonization temperatures also increase ash and fixed
carbon content due to the decrease in volatile matter. As a result, a
higher temperature yields char with improved quality.