Experiments and numerical simulation of sawdust gasification in an air cyclone gasifier

In this paper the gasification of sawdust in an air cyclone gasifier was investigated to produce a high quality fuel gas with less tar. The effect of air to fuel ratio on the gasification characteristics was studied. The results indicate that as the air to fuel ratio varying from 0.23 to 0.35, the lower heating value of the produced gas is 4.5–5.7 MJ/Nm3, the carbon conversion is 77.0–94.2%, the cold gas efficiency of the gasification system is 53.6–63.0%, while the tar content is 4.4–8.4 g/Nm3. A detailed CFD model of a cyclone gasifier has been developed, based on the Fluent package. Models of sawdust pyrolysis and combustion of volatiles and char have been added to the standard model. The model provides information on the gas temperature in the gasifier and the composition of the outlet gas.

► High-temperature gasification with less oxygen is studied in a cyclone gasifier.
► Biomass fast pyrolysis model is built.
► Particle size, tar combustion and gas temperature effect the yields of CO and CO2.