Effect of CaO on tar production and dew point depression during gasification of fuel cane bagasse in a novel downdraft gasifier

Granular calcium oxide was used in syngas conditioning to investigate its impact on tar composition, concentration, dew point and syngas yield during gasification of fuel cane bagasse (FCB). The results showed that the use of 2, 3 and 6 wt.% in-bed CaO promoted the conversion of Class1, 4 and 5 tars to Class 3 tars to varying degrees. Overall, this resulted in a decrease in tar yield ranging from 16 to 35%, a decrease in the tar concentration in syngas of 44–80%, an increase in syngas yield of 17–37%, and a decrease in tar dew point of 37–60 °C as the CaO concentration was increased from 2 to 6 wt.% .

► Biomass gasification carried out in a pilot scale downdraft gasifier. ► In bed calcium oxide was used to crack tars and enhance syngas calorific value. ► Maximum in bed calcium oxide concentration was 6 wt.%. ► Maximum decrease in tar yield was 35% when syngas tar concentration reduced by 80%. ► Maximum depression of tar dew point was 61 oC and syngas yield increased by 37%.