生物质热裂解气喷淋冷却系统的试验研究

Experimental Study of Quenching System for Bio-oil Production from Biomass Pyrolysis

生物质热裂解气体产物的快速冷却是生物质热裂解液化技术的关键。为此,设计了一种利用生物油喷淋冷却生物质热裂解气的装置,利用空心锥喷嘴产生的雾滴与热裂解气体间的温差实现相间换热,从而快速冷却热裂解气,得到液体生物油。利用粒子图像测速仪(PIV)对喷淋流场进行了冷态试验,试验结果表明,空心锥喷嘴非常适合生物质热裂解气体产物的喷淋冷却。当喷嘴孔径为4.0mm、液体压力为0.2MPa时的雾化效果最佳。在流化床生物质热裂解液化试验台上,利用该喷淋冷却方式对秸秆类生物质热裂解进行了热态试验,试验效果比较理想,生物油的收集率达到43%。

Quenching the pyrolysis vapor quickly is very significant for the bio-oil production from biomass pyrolysis.An equipment of spraying quenching system was designed with bio-oil as cooling media which used the temperature difference between the liquid phase(bio-oil droplets) and gas phase(pyrolysis vapor) to quench the pyrolysis vapor.The Particle Image Velocimetry(PIV) was used to measure the bio-oil spraying velocity fields.The results indicated that the hollow-cone type nozzle is very suitable for quenching the pyrolyzed gaseous products which can atomize well as the nozzle diameter is 4.0mm and the fluid flow pressure is 0.2Mpa.The experiments conducted on a fluidized bed indicated that pyrolyzed bio-oil yield recovering from agricultural residues reaches 43% as this type nozzle is used to quench the condensable vapor.