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采用热重分析方法研究谷壳和木屑及其NiO、MgO和CaO添加物在水蒸气气氛下的气化特性,采用两种常用的气固反应模型——收缩核模型和均相反应模型,计算得出反应动力学参数,同时用Ozawa法计算动力学参数,验证两种模型描述反应机理的适用性。在低温催化热解阶段,收缩核模型和均相模型基本适合此阶段反应机理,但在高温半焦催化气化阶段,不能简单地用收缩核和均相模型描述,此阶段反应机理不适合收缩核和均相模型。通过DTG曲线和Ozawa法计算出的表观活化能综合评价,3种催化剂在低温热解段催化活性大小顺序为:NiO>CaO>MgO,在高温气化段的催化活性大小顺序为NiO>MgO>CaO。
The gasification characteristics of chaff and sawdust and NiO, MgO and CaO additives in water vapor were studied by thermogravimetric analysis. Two commonly used gas-solid reaction models - the contracting nuclear model and the homogeneous reaction model were used to calculate The reaction kinetics parameters were obtained, and the kinetic parameters were calculated by Ozawa method. The applicability of the two models to describe the reaction mechanism was verified. In the low-temperature catalytic pyrolysis stage, the contracting nuclear model and the homogeneous model are basically suitable for this stage reaction mechanism. However, they can not be simply described by the contracting nucleus and the homogeneous model in the high-temperature catalytic gasification stage. The reaction mechanism at this stage is not suitable for shrinkage Nuclear and homogeneous model. According to the comprehensive evaluation of apparent activation energy calculated by DTG curve and Ozawa method, the order of catalytic activity of the three catalysts in the low temperature pyrolysis was NiO> CaO> MgO, and the order of the catalytic activity in the high temperature gasification was NiO> MgO > CaO.