模型辅助的合成气化学链燃烧操作优化

Model-Assisted Operation Optimization of Syngas-Chemical Looping Combustion

基于Abad等的模型,模拟了Cu14Al-I氧载体与合成气(CO+H_2)在500,Wth流化床的燃料反应器中的反应过程,并根据模拟结果对该系统中合成气的燃烧过程进行优化.对于反应动力学,使用合成气中CO和H2叠加的反应速率代替整体反应速率能够较好地预测实验结果.经过与实验的对比,证实了该反应器模型能够准确模拟Cu14Al-I氧载体与合成气的反应过程.模拟结果显示,合成气成分、反应温度、氧载体循环流率等参数对流化床的运行均有一定的影响.合成气中2CO Hn/n由1∶1升高至3∶1时,燃料的燃烧性能有所降低.较高的操作温度有利于合成气的燃烧,当温度为900,℃时,?=1.5即可实现合成气的完全燃烧.较高的固体循环流率下,不利于合成气的充分燃烧.最后,基于模拟结果对流化床进行了优化:当温度为850,℃时,各运行参数应调整为Fs=6.7,kg/h、?=1.8、氧载体转化率Xs=0.73,才能使500,Wth流化床的燃料反应器中合成气达到最佳的燃烧效果.

Based on the fluidized bed model developed by Abad et al,the combustion of syngas（CO＋H2）with Cu14 Al-I oxygen carrier was simulated,and the simulation results were then used for optimization.For reaction kinetics in the reactor model,it was found that the summation of the rates for reactive components（CO and H2）can be used for better prediction of TGA data.Afterwards,the reactor model was validated against the experimental data obtained from the 500,Wth pilot plant.The modeling results show that the syngas composition,temperature,oxygen carrier circulation rate have impacts on the combustion performance of syngas.For2 CO Hn/n from 1∶1 to 3∶1,higher 2 CO Hn/n ratio is disadvantageous for combustion.Higher temperature can assist the combustion,thus ф=1.5 is sufficient for complete combustion at 900,℃.Higher circulation rate of oxygen carrier is disadvantageous for syngas combustion.Finally,the optimization shows that at 850,℃ the operation parameters should be adjusted to Fs=6.7,kg/h,ф=1.8,Xs=0.73 to achieve the best performance of syngas combustion in the 500,Wth plant.