论文部分内容阅读
根据文献中气化速率对总压不敏感、对反应气体分压敏感的实验结论，探索利用常压热重实验得到加压动力学参数的便捷方法。采用NETZSCH STA449F3同步热分析仪进行4种煤焦与水蒸气反应的常压热重实验(水蒸气分压pH2O为0.016~0.053 MPa)，通过实验数据处理，获得反应速率与温度、水蒸气分压的关系式，分别以 n 级速率方程和Langmuir-Hinshelwood (LH)速率方程表示，并对上述关系式在水蒸气分压为0.057~0.063 MPa 的工况下进行了实验验证。随着水蒸气分压增大，计算结果与实验数据的相对误差逐渐减小。LH速率方程比n级速率方程更适合描述水蒸气分压的作用。水蒸气分压对反应速率的影响程度随水蒸气分压升高而减小。温度对煤焦-水蒸气反应速率的影响程度大于水蒸气分压对反应速率的影响。温度范围较窄时，煤种本身引起的煤焦反应活性变化幅度会超过温度对煤焦反应活性的影响。在不同的温度和水蒸气分压下，煤种的化学反应活性强弱次序会发生变化，某一特定工况下的次序不能未加实验而随意扩展到其他工况。“,”According to the conclusions in literatures that the gasification rate is sensitive to reactive gas partial pressure, not total pressure, a convenient method to get pressurized kinetic parameters through atmospheric thermo gravimetric analyzer (TGA) experiments was investigated. NETZSCH STA449F3 simultaneous thermal analyzer was used to carry out char-steam atmospheric TGA experiments (steam partial pressure pH2O was 0.016~0.053 MPa) on four different types of coals. After processing the raw experiment data, relationships between reaction rate, temperature and pH2O were acquired, and expressed in the form of nth rate equation and Langmuir-Hinshelwood (LH) rate equation. The expressions were validated by experiments where pH2O was 0.057~0.063 MPa. The results show that the relative error between theoretical and experiment decreases with the increase of pH2O. LH rate equation can describe the effect of pH2O more accurately than nth rate equation in real applications. The effect of pH2O on reaction rate decreases when pH2O increases. The effect of temperature on reactivity of char-steam reaction is larger than that of pH2O. The effect of coal type will beat that of temperature while the range of temperature is narrow. The orders of chemical reactivity of coals at different temperatures and partial pressures are not completely consistent, and therefore cannot be generalized from a specific condition.