神木煤焦与CO 2和水蒸气反应后期动力学特性

采用等温热重法对比神木煤焦在900～1 050 ℃分别与CO 2和水蒸气气化的反应活性。为研究气化残炭反应性，分别采用均相模型、缩核模型、混合模型和修正体积模型对煤焦气化后期反应速率与碳转化率的关系进行拟合。结果表明：混合模型和修正体积模型对实验数据有很好的拟合效果；均相模型和缩核模型的拟合效果随气化温度和反应气氛而变化；不同模型预测煤焦分别与CO 2和水蒸气反应后期的活化能范围分别为200.65～231.00 kJ/mol和105.48～169.10 kJ/mol；修正体积模型预测神木煤焦在这两种气氛中反应后期的活化能都比前中期高36 kJ/mol左右；在实验温度范围内，神木煤焦气化后期以化学反应控制为主。

Dynamic characteristics of Shenmu char at the late stage of reaction with CO2 and steam

A comparative study on the reactivity of Shenmu char with CO 2 and steam was conducted at the temperatures from 900 ℃ to 1 050 ℃ using isothermal thermogravimetric analysis method.To better understand the reaction activity of residual carbon，the homogeneous model，the shrinking un reacted core model，the integrated model and the modification volumetric model were applied to correlate the relationship between reaction rate and carbon conversion at the late gasification stage.The results show that both the integrated model and the modification volumetric model have a better fitting accuracy.The fitting accuracies of the homogeneous model and the shrinking un reacted core model change with the gasification temperatures and the agents.At the late stage，the ranges of the apparent activation energy of Shenmu char in the atmosphere of CO 2 and steam are 200.65-231.00 kJ/mol and 105.48-169.10 kJ/mol，respectively.The apparent activation energy calculated with the modification volumetric model is approximately 36 kJ/mol higher at the late stage than that at the early and middle stages.Shenmu coal char gasification was under chemical reaction control at the late stage within the experimental temperature range.