Torrefaction of Nigerian Palm Kernel Shell into Solid Fuel

Abstract

Palm kernel shell (PKS) which is a waste from oil palm tree was torrefied to improve its properties as a solid fuel. The study on Palm kernel shell torrefaction was performed under various temperature and time of 200oC, 220oC, 240oC, 260oC, 280oC, 300oC and 40, 80, 120 minutes respectively using a horizontal tubular type reactor made of stainless steel. The electric furnace surrounding the reactor was used to regulate its temperature. An elemental (CHNS) analyzer was also used to get the carbon, hydrogen, nitrogen & sulphur contents. The calorific value was measured using a bomb calorimeter. The mass yield, energy yield, ash content, moisture content, volatile matter content and fixed carbon content were calculated. The results of the study indicate that increase in torrefaction temperature decreased the mass & energy yield of Palm kernel shell. The carbon content of Palm kernel shell increased while hydrogen and oxygen content decreased after torrefaction which resulted in higher heating value of 5 to 20%. Ash content and fixed carbon content of palm kernel shell were observed to have increased with reduction in the moisture and volatile matter therein. It therefore follows that Palm kernel shell possess valuable potentials to supplement the energy supply of Nigeria through sustainable renewable energy technologies.