Characteristics of products from rubber woodchip gasification in a fluidised-bed reactor: Effect of equivalent ratio

Abstract

In this study, rubber woodchip was gasified in an atmospheric bubbling fluidised-bed gasifier to investigate the effect of equivalent ratio (ER) on gasification behaviour and its product characteristics. The suitable range of ER for gasification was found to range from 0.2-0.4. The temperature inside the reactor was affected by ER; the bed temperature increased from 720°C by about 100°C as ER was increased from 0.2 to 0.4. The concentration of CO2continuously increased with ER, while CO and H2found their maxima at ER=0.26. The concentration of CH4was about 4 % and unaffected by ER, while C2hydrocarbon gases were also detected with < 1 % in total. At ER=0.26, the LHV of product gas was the highest at 4.6 MJ/Nm3. Carbon-in-ash was found to be related with ER, the higher the ER the less unburned carbon in ash. Different chemical compositions of tars obtained from various ER were thought to be the influence of temperature as a consequence of changing ER; higher temperature appeared to yield tar with relatively higher proportion of large to small molecular weight fractions.