Cheng Yuesheng, Huang Qinglin, Eić Mladen, Balcom Bruce J
Department of Chemistry, MRI Center, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick E3B 5A3, Canada.
Langmuir. 2005 May 10;21(10):4376-81. doi: 10.1021/la047302p.
We present the first 13C magnetic resonance imaging study of CO2 transient adsorption/desorption processes in a zeolite 5A column. CO2 transient concentration profiles were measured with a centric scan spin-echo single point imaging technique. The adsorption wave profiles were determined under flow conditions, with the results analyzed by the Bohart-Adams model. The model adequately accounts for the spatial and the temporal behavior of CO2 in the column. CO2 adsorption rate constants were calculated from the fit. Desorption profiles were acquired by blowing a helium stream through a zeolite 5A column saturated with CO2. An asymmetry between the adsorption and desorption profiles is readily apparent. A linear relationship between the CO2 condensed phase concentration and square root of time was observed.
我们展示了首个关于5A分子筛柱中二氧化碳瞬态吸附/解吸过程的13C磁共振成像研究。采用中心扫描自旋回波单点成像技术测量了二氧化碳瞬态浓度分布。在流动条件下测定了吸附波分布,并通过博哈特-亚当斯模型对结果进行分析。该模型充分说明了柱中二氧化碳的空间和时间行为。通过拟合计算出二氧化碳吸附速率常数。通过向充满二氧化碳的5A分子筛柱中吹入氦气流来获取解吸分布。吸附和解吸分布之间的不对称性很明显。观察到二氧化碳凝聚相浓度与时间平方根之间存在线性关系。