Co-gasification of coal and biomass blends using dolomite and olivine as catalysts

Abstract

Abstract Natural catalysts (dolomite and olivine) not only reduce the tar content, they also have a high potential to enhance hydrogen production during gasification process. In this study, a bubbling fluidized bed (BFB) was used to evaluate the effect of the operating parameters on co-gasification of pine sawdust and brown coal namely gasification temperature (Tg) in the range of 700–1000 °C, fuel particle size (dp) in the range of 2.0–3.5 mm, steam/fuel ratio (S/F) in the range of 0.5–0.8, equivalence ratio (ER) in the range of 0.1–0.4, biomass ratio (BR) in the range of 0.0–100%, and catalyst loading in the range of 3.0–12.0 wt%. With increase in catalyst loading from 3.0 to 12.0 (wt %), the hydrogen yield was increased from 52.9 to 55.5 (g/kg-fuel) for dolomite and from 47.5 to 52.1 (g/kg-fuel) for olivine, while the tar yield sharply decreased from 5.4 to 0.4 (g/Nm3) and from 7.0 to 0.8 (g/Nm3), respectively. Fuel particle size showed a negligible influence on the upgrading of hydrogen production and tar yield.