超临界CO_(2)压力与温度对甲苯在活性炭中脱附的影响

Effects of supercritical CO_(2)pressure and temperature on toluene desorption from activated carbon

研究了超临界二氧化碳(SC-CO_(2))压力与温度对甲苯在活性炭中脱附效果的影响,并进行了机理分析。实验结果表明:甲苯脱附率随SC-CO_(2)压力增加而增加;温度对脱附率的影响与压力有关,当SC-CO_(2)压力较低时,脱附率随温度升高而降低;当压力较高时,脱附率随温度升高先增加后减小。机理分析表明,压力对甲苯脱附率的影响由密度效应控制,而温度对甲苯脱附率的影响由密度效应与扩散效应共同控制,当SC-CO_(2)压力较低时,密度效应占优势;当SC-CO_(2)压力较高时,扩散效应占优势。

The effects of supercritical CO_(2)(SC-CO_(2))pressure and temperature on toluene desorption from activated carbon was investigated,and the influence mechanism was analyzed.The experimental results show that:The toluene desorption ratio increases as SC-CO_(2)pressure increases;The effect of temperature on the toluene desorption ratio is related to pressure,and the desorption ratio decreases as temperature increases at lower pressure,while the desorption ratio increases at the beginning but then decreases with the increase of temperature at higher pressure.The mechanism analysis presents that the influence of pressure on the toluene desorption ratio is governed by density effect,while the influence of temperature on the toluene desorption ratio is governed by density effect and diffusion effect together.When SC-CO_(2)pressure is low,density effect dominates;When SC-CO_(2)pressure is high,diffusion effect dominates.