A Study of Throat Size Effect on Downdraft Biomass Gasifier Efficiency

The present research article aims to study the throat size effect on downdraft biomass gasifier efficiency. Two type of biomass; eucalyptus and leucaena were used as fuel for producing producer gas by gasification process. The downdraft gasifier has a 30 cm diameter and 250 cm high. For combustion zone, the throat size was varied to 10, 15, 20 and 25 cm respectively. The consumption of biomass was 10 kg with the size of biomass was 5-10 mm thick and moisture content less than 15%. The air flow rate into the combustion chamber was set at 1 - 5 m(3)/hr. to determine the gasifier efficiency and composition of producer gas. The experimental results showed that the gasifier efficiency increase with the air flow rate increase. The throat size 20 cm and air flow rate at 5 m(3)/hr showed the highest efficiency. The gasifier efficiency of the downdraft biomass gasifier was calculated as 35.30 % for leucaena and 43.36 % for eucalyptus. A heating value was calculated as 3.84 MJ/Nm(3) and 4.87 MJ/Nm(3) for eucalyptus and leucaena respectively. (C) 2017 The Authors. Published by Elsevier Ltd.