Reforming of Tar in Producer Gas from Woody Biomass : Application of the Inverse Diffusion Flame in the Partial Combustion(Thermal Engineering)

Experimental study for clarifying the effect of combustion mechanism on reforming of producer gas was carried out. The inverse diffusion flame was formed in the actual gas reformer by partial combustion of producer gas. Direct observation and laser diagnostics were applied to the inverse diffusion flame formed in the modeled gas reformer. Experimental parameters are steam concentration in supplied model producer gas (X_) corresponding to moisture content of wood, and the flame configuration (flame at the nozzle and lifted flame). The main results are as follows. In the condition of 20% concentration of oxygen, flames at the nozzle and lifted flames were formed in the same supply condition. One might identify a type of hysteresis in flame formation that determines its configuration. When the flames at the nozzle were formed, the exergy yield was increased with the increase of X_ because soot formation was suppressed and steam reforming of model tar can be promoted. In contrast, when the lifted flames were formed, the exergy yield was decreased with the increase of X_ because of formation of the particulate matter such as the soluble organic fraction and the young soot.