The burner tube had six radial fins attached to it to provide large heat transfer surface. Two tangential air ports were connected to the bottom end of the gas burner. There was a fixed grate near the bottom with other two air ports connected underneath the combustion chamber. The samples were cut into size range of 30 – 50mm in diameter and about 1 m long. Prior to the test, pre-weighed batches of biomass materials were loaded into the reactor. About 5 kg of biomass in small pieces was loaded first to be utilized as combustion bed. Long sticks biomass materials were then loaded. The cover was put in place, checking that the reactor was air tight. Figure 2 shows schematically operation step of the carbonization system. Initially, air was supplied and regulated such that oxidation zone at the bottom of the reactor can be established and the chamber got heated. Exhaust gas from combustion and released moisture from biomass was vented through a twin temporary exhaust pipe (Figure 2a). When the pyrolysis temperature of biomass was reached (about 250oC), gaseous products produced from the biomass became combustible. The twin pipe was shut, hence the combustible gas was forced to enter the pyrolysis gas burner through perforated wall. Meanwhile, the bottom air was shut down to stop the combustion at the bottom and the burner air ports were opened. Air was drafted into the burner tube. Mixture of pyrolysis gases and air was ignited to establish a flaming combustion inside the burner tube (Figure 2b). This way, pyrolysis gases was oxidized and process heat was continually supplied to the carbonization chamber