Gasification of Eucalyptus Wood Chips in a Downdraft Gasifier for Syngas Production in South Africa

Abstract

ABSTRACT The present research article aims to study the gasification of eucalyptus as wood chips for syngas production and its thermogravimetric analysis (TGA) in a nitrogen atmosphere. The eucalyptus wood chips were sourced from a sawmill industry, cut into desired sizes and subjected to gasification in a downdraft gasifier using air as the oxidizing agent. The compositions of the syngas were measured using non-dispersive infrared gas sensors and a palladium/nickel (Pd/Ni) gas sensor. Thermogravimetric analysis was carried out under 20°C/min heating rate using a Perkin-Elmer thermogravimetric analyzer TGA 7 and the gasification zones temperatures were monitored using thermocouples. An average higher heating value (HHV) of 6.08 MJ/Nm 3 containing predominantly of hydrogen, carbon monoxide and methane was obtained from the eucalyptus syngas. The volumetric compositions of the syngas produced varied from 22.3% - 22.5% for hydrogen, 22.3% – 24.3% for carbon monoxide, 1.9% - 2.1% for methane, 9.8% - 10.7% for carbon dioxide and 41.5% – 42.9% for nitrogen. Nitrogen composition was highest due to the use of air as the oxidizing agent. The study have successfully demonstrated gasification as an alternative technology for conversion of waste to energy.