基于镍基载氧体的串行流化床煤化学链燃烧实验

Chemical looping combustion of coal in interconnected fluidized bed with NiO/Al_2O_3 oxygen carrier

以NiO/Al2O3为载氧体,在1 kWth串行流化床反应器上进行了煤化学链燃烧实验,通过四个参数:碳转换效率ηC,coal、煤气化产物的转换效率、碳捕集效率ηC,cap及煤燃烧效率ηcombust对煤燃烧过程进行表征,考察了燃料反应器温度tFR、过量空气系数α、隔离器水煤比SLS/C、燃料反应器水煤比SFR/C和热负荷等参数的影响。结果表明,tFR和SLS/C的增大有利于煤气化产物的转换;tFR、α和SLS/C的增大有助于ηC,coal的提高,随着SFR/C由0.8增加到1.8,ηC,coal呈先增加再减小的趋势,并在SFR/C=1.2达到最大值;ηcombust和ηC,coal变化趋势保持一致,主要受飞灰含碳量中残碳损失的影响;tFR提高有助于提高ηC,cap,而α和SLS/C的增大使得ηC,cap降低。

The chemical looping combustion of coal with NiO/Al2O3 oxygen carrier was experimentally investigated in a 1 kWth interconnected fluidized bed.The carbon conversion ηC,coal,the conversion of gaseous products,the carbon capture efficiency ηC,cap and the coal combustion efficiency ηcombust were calculated and discussed.Several influencing factors including the temperature tFR,excess air coefficy α,the ratio of steam flow rate in the loopseal to the feed coal SLS/C,the ratio of steam flow rate in the fuel reactor to the feed coal SFR/C were examined.The results indicate that the increase in either tFR or SLS/C is favorable for increasing ηC,coal and the conversion of gas products from coal gasification.A larger α can also give a higher ηC,coal.With the SFR/C increasing from 0.8 to 1.6,ηC,coal first increases and then decreases with the maximum at SFR/C=1.2.ηcombust has the same trends as ηC,coal;it is mainly affected by the loss of carbon in the fly ash.Contrary to α or SLS/C,increasing TFR can give a higher ηC,cap.