DESIGN AND PERFORMANCE EVALUATION OF RISER-FITTED UPDRAFT GASIFIER USING CORNCOBS AND WOODSHAVINGS AS FEEDSTOCK

The study was focused on the performance of the designed updraft gasifier by using corncobs and wood shavings as feedstock. The gasifier was evaluated at the Agricultural and Biosystems Engineering Machinery Shed, Mindanao State University, Fatima, General Santos City on January 2019. The gasifier was modified by removing all the filtration systems and adding an inner cylinder that acts as a reactor of the gasifier and will create an inner space between the outer and inner cylinder where air can circulate for a better air mixture. Also, a riser was added to reduce the unburned smoke that the previous gasifier produces. The riser converts the unburned smoke into the fire because it allows a better smoke and air mixture and act as a fire concentrator that makes the fire more concentrated and lessens energy loss. The performance of the gasifier using 1 kg of corncobs as fuel was 68.6 seconds on start-up time, 15.85 minutes on operating time, 16.99 minutes on total operating time, 3. 55 kg/hr on the fuel consumption rate, 5.55 minutes on boiling time,17.06 KW/kg on power input, 100.19 kg/hr-㎡ on its specific gasification rate, 65.83 kCal/kg on sensible heat, 143.42 kCal/kg on latent heat, the thermal efficiency of 5.23% and a power output of 0.89 KW/kg that determines that corncobs were a better feedstock than wood shavings. The performance of the gasifier using 0.5 kg of wood shavings as fuel was 7.5 seconds on start-up time, 11.15 minutes on operating time, 12.19 minutes on total operating time,4.95 kg/hr on the fuel consumption rate, 8.54 minutes on boiling time,47.47 KW/kg on power input, 142.25 kg/hr-m2 on its specific gasification rate,133.42 kCal/kg on sensible heat, 126.47 kCal/kg on latent heat, the thermal efficiency of 3.25% and a power output of 1.54 KW/kg that determines that wood shavings perform lesser than corncobs. Furthermore, the size, shape, and weight of the feedstock greatly affect the performance of the gasifier.