采用TG-FTIR联用研究烟煤热解及热解动力学参数的确定(英文)

Experiment Research on Bituminous Coal Pyrolysis by TG-FTIR and Determination of Pyrolysis Kinetic Parameters

研究煤热解时的组分析出规律对进一步研究低NO燃烧或煤粉再燃时的均相NOx还原反应来说都是非常重要的。采用TG-FTIR实验装置对两种中国烟煤在不同升温速率(10,20,50和80℃/min)下的失重及气体释放规律进行了研究,并将实验数据与FG-DVC软件的模拟结果进行了对比。通过对比发现,其中一种烟煤的模拟结果与实验数据比较相符,但另一种烟煤的模拟结果与实验数据偏差较大。偏差主要是由于FG-DVC模型中提供的有关动力学参数不准确所导致。基于FG-DVC模型的假设,官能团热解形成的轻气体产物的释放过程可以用一系列平行独立的单方程模型描述,应用FTIR的实验结果对热解气体组分的动力学参数进行了修正。采用修正后的动力学参数,FG-DVC能更准确的模拟该煤的热解过程。

It is significant to study the components and the relevant concentration of volatile matters released during pulverized coal pyrolysis,which is fundamental for the further study of low NOx combustion and NOx reduction during coal reburning process.The devolatilisation experiments of two types of Chinese bituminous coal were performed using TG-FTIR （Thermogravimetry combined with Fourier Transform Infrared Spectroscopy） analysis.Four heating rates （10,20,50 and 80 ℃/min） were adopted to research the weight loss and gases evolution.The numerical simulations were performed by using FG-DVC （Functional Group and Depolymerization,Vaporization,Cross-linking） model on the experimental coals.It was indicated that the simulation results were well fitted for one of the two types of coal but not very well for another.The error was caused by the inaccuracy of the kinetic parameters of the main species provided by FG-DVC model.The kinetic parameters are then corrected by introducing FTIR results to a series of first-order formulation by assuming that the light gases evolution are parallel and independent in FG-DVC model.By adopting the corrected kinetic parameters the simulation results are agreed with experiments data much better.