Abstract Pyrolysis involving gaseous carbon dioxide has been analyzed previously; however, pyrolysis behaviors of coal–liquid carbon dioxide (LCO2) slurries have not been examined yet. In this study, the effect of wet LCO2–coal feeding on pyrolysis and gasification behavior was examined and compared with that of dry coal feeding. The first wet feeding method comprised simultaneous mixing and supply of coal with LCO2. However, the second feeding supplied coal via liquid or gaseous CO2 introduction, which could simulate conventional dry feeding for coal transport applications. The product gas yield and kinetic rate were determined from pyrolysis experiments at two subcritical pressure conditions of CO2. The wet LCO2–coal feeding produced more CO gas yield than that of dry coal feeding, which is observed at low-pressure condition. The result for high-pressure condition further supports better pyrolysis behavior of wet feeding. This may be attributed to easy CO2 diffusion or change in coal structure resulting from LCO2 flash/evaporation process. The highest conversion of coal to product gases was observed with water–coal slurry, particularly for the high-pressure fixed-bed condition.

中文翻译：

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液态二氧化碳对亚临界压力条件下煤热解气化行为的影响

摘要 先前已经分析了涉及气态二氧化碳的热解；然而，煤-液态二氧化碳 (LCO2) 浆液的热解行为尚未得到研究。在本研究中，研究了湿式 LCO2-煤进料对热解和气化行为的影响，并与干煤进料进行了比较。第一种湿式进料方法包括同时混合和供应煤与 LCO2。然而，第二次进料通过液态或气态 CO2 引入来供应煤，这可以模拟用于煤炭运输应用的传统干式进料。产物气体产率和动力学速率由在 CO2 的两个亚临界压力条件下的热解实验确定。在低压条件下观察到，湿式 LCO2 加煤比干加煤产生更多的 CO 气体产量。高压条件的结果进一步支持湿喂料更好的热解行为。这可能是由于 LCO2 闪蒸/蒸发过程导致 CO2 容易扩散或煤结构发生变化。在水-煤浆中观察到煤转化为产品气体的最高转化率，特别是在高压固定床条件下。