Design and Preliminary Testing of a Small-Scale Throatless Fixed-Bed Downdraft Gasifier Fueled With Sengon Wood Block

Abstract

The aims of this study are to design and to find out the performance of a throatless fixed bed downdraft gasifier. This gasifier was used to convert sengon wood block from furniture waste into gas fuel called producer gas that is beneficial for green energy production to substitute the fossil fuel. The gasifier was designed to have a thermal power of 30 Kwth with double wall/tube and air as the gasifying medium. Sengon wood block with a size of about 5-8 m3 and moisture content of 10 % was used as the feedstock. The gasifier was tested at various equivalence ratio ranging from 0.18 to 0.28. In this work, the performance of the gasifier was evaluated by observing the temperature profile, flame condition, fuel consumption rate, specific gasification rate, and the amount of solid residue. The results showed that the designed gasifier had a diameter of 22 cm for the inner tube and 32 cm for the outer tube with a gasifier height of 100 cm. It was found that the equivalence ratio highly influenced the gasifier performance. Fuel consumption rate and specific gasification rate increased with the increase of equivalence ratio. In the meantime, the amount of solid residue appeared to be reduced because of high gasification rate. Under the condition investigated, the best gasifier performance was obtained at an equivalence ratio of 0.28 indicated by the stability of the flame during gasification process that is in accordance to the gasifier design parameters.