Study on gasification characteristics of pine sawdust using olivine as in-bed material for combustible gas production

Abstract

In order to reduce the tar content in the producer gas, a small-scale fluidized bed was built to gasify the pine sawdust with olivine as in-bed material. The impact of operating conditions, namely, temperature (700–850 °C), steam/biomass ratio (0.3–1.2), and olivine content (10%, 30% and 50%) was studied on the product gas composition, tar content, gas concentration and H2 yield. The main goal of the experiments was to determine the effect of the addition of olivine on the product gas composition and tar concentration. The results of the experiments confirm that steam-gasification of biomass with olivine can be a promising option for the production of H2-rich syngas with less tar formation as well as low CO2 emission. Under different temperatures, the gas yield and H2 yield are similar, higher at the higher temperatures but lower at the lower temperatures. A temperature rise from 700 °C to 850 °C increased the CO and H2 contents by 15.5% and 11%, respectively. The H2 yield increased from 35.4 to 57.2 g/kg as S/B ratio increased from 0.3 to 1.2. The highest H2 yield of 71.4 g/kg and the lowest tar concentration of 1.3 g/Nm3 were achieved at 800 °C, S/B ratio of 1.2 and olivine content of 50%.