Adsorption and diffusion of CO2 in CPO-27-Ni beads
Adsorption and diffusion of CO2 in CPO-27-Ni beads
复制标题
CPO-27-Ni 珠中 CO2 的吸附和扩散
DOI：
10.1007/s10450-019-00162-x
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发表时间：
2019
期刊：
影响因子：
3.3
通讯作者：
Krishnamurthy S
中科院分区：
文献类型：
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作者：
Krishnamurthy S
目前的工作涉及的CPO-27-Ni金属有机框架的放大和表征，使用一系列的实验技术，旨在确定平衡和动力学参数，以评估其潜在的燃烧后碳捕获。以CPO-27-Ni为原料，采用分子烹饪法制备了公斤级CPO-27-Ni。用容量法测定了不同温度下纯CO2和N2在该小球上的吸附等温线，并对吸附等温线进行了双中心Langmuir模型拟合。然后通过定量加入已知体积的CO2在容量装置中进行一系列实验，并随时间监测压力。然后通过将一系列曲线拟合到等温扩散模型来提取扩散时间常数。从时间常数，获得的扩散系数的值，并与从第一原理相关性，其中采用的孔径，并从独立的压汞实验的孔隙率值获得的值进行比较。分析结果表明，CO2在微珠中的传输符合Knudsen扩散机制和粘性扩散机制。实验还使用零长度柱（ZLC）装置通过制备10%CO2-He和10%CO2-N2混合物进行。对ZLC曲线的分析表明，两种不同的载气具有长时间斜率的影响，表明存在大孔控制的扩散机制。
The present work involves the scale-up and characterization of CPO-27–Ni metal organic framework using a range of experimental techniques aimed at determining equilibrium and kinetic parameters to assess its potential for post-combustion carbon capture. CPO-27–Ni was prepared from its precursors by molecular gastronomy methods in kilogram scale. Adsorption of isotherms of pure CO2and N2were obtained for different temperatures on these beads, using a volumetric apparatus and the isotherms were fitted to a dual-site Langmuir model. A series of experiments were then carried out in the volumetric apparatus by dosing a known volume of CO2and the pressure was monitored with time. The diffusional time constants were then extracted by fitting the series of curves to an isothermal diffusion model. From the time constants, the values of the diffusivities were obtained and compared with the values obtained from first principles correlations, which employed the pore size, and the porosity values from independent mercury porosimetry experiments. The results from the analysis showed that the transport of CO2in the beads was well described by a combination of Knudsen and viscous diffusion mechanisms. Experiments were also carried out using a zero-length column (ZLC) apparatus by preparing a 10% CO2–He and 10% CO2–N2mixture. The analysis of the ZLC curves showed that the two different carrier gases had an effect of the long-time slope, indicating the presence of a macropore-controlled diffusion mechanism.