蒸汽煤比对湍动循环流化床煤气化的影响

Effect of steam/coal ratio on coal gasification in turbulent circulating fluidized bed

以空气和水蒸气为气化剂,在压力为0.3MPa的湍动循环流化床热态实验台上对淮北烟煤进行了煤气化试验,研究了蒸汽煤比(质量比)对气化过程的影响.气化炉提升段具有下宽上窄的特点,床料采用宽筛分石英砂.气化试验过程中,实现了提升段下部湍动流化、上部环核流动.试验结果表明:随着蒸汽煤比的增加,煤气中CH4体积分数基本保持不变,CO体积分数从13.12%下降到11.98%,H2体积分数从初始12.3%增加到14.63%而后下降至14.19%,CO2体积分数从13.84%下降至12.94%后,略微上升至13.06%.蒸汽煤比的变化对干煤气产率、冷煤气效率及碳转化率都有影响,其最大值分别为2.89m3/kg,59%,81%.

The gasification experiment of Huaibei bituminous coal with the agent of air and steam at 0. 3 MPa was carried out on a turbulent circulating fluidized bed gasification equipment. The effects of steam/coal ratio on gasification process were studied. The characteristic of lift is that the lower part is broader than the upper. Wide-screen quartz sand is used as bed material. In the gasification experiment, the lift can achieve turbulent fluidization in the dense-phase zone and core-annulus flow in the dilute-phase zone. Experiment results show that： with the increase of steam/coal ratio, CH4 concentration in gas remains basically unchanged, and CO concentration decreases from 13. 12% to 11.98%. H2 concentration increases initially from 12. 3% to 14. 63%, and then drops to 14. 19%. CO2 concentration first decreases from 13.84% to 12. 94%, and then slightly increases to 13.06%. Steam/coal ratio has a significant impact on the yield of dry gas, cold gas efficiency and carbon conversion. The maximal yield of dry gas, cold gas efficiency and carbon conversion are 2. 89 m^3/kg, 59% , 81% respectively.