当前位置: X-MOL 学术J. CO2 Util. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Isotherm characteristics and impact of the governing factors on supercritical CO2 adsorption properties of coals
Journal of CO2 Utilization ( IF 7.7 ) Pub Date : 2020-03-13 , DOI: 10.1016/j.jcou.2020.02.020
Pratik Dutta , Atanu Chatterjee , Santanu Bhowmik

Ten moist and powdered, high- to low-volatile bituminous Indian coal samples were analyzed for their supercritical CO2 (ScCO2) adsorption properties by volumetric method at 40 °C and up to a pressure of ∼12 MPa. The experimental “excess” adsorption capacities were found to increase steadily up to 6.5 MPa. But after that, a sharp fall in ∼7.5 MPa range were observed. The errors and/or uncertainties associated with the nature of CO2 and variation of void volume during ScCO2 adsorption could affect the gas adsorbed significantly. The changes in temperature and moisture along with the free gas density, compressibility factor of CO2 were also analyzed. It was observed that the free gas density varied differently in low to high pressure at 40⁰C, whereas, the compressibility factor decreased linearly in sub-critical range but almost constant or mildly increased in supercritical range. To reduce the uncertainty, a correction for void volume estimation was provided by considering the “mean value” of the void volumes calculated by two “blind runs” to consider the changes in the void volume with pressure. It was found that most of the “negative” excess adsorptions could be improved upto ∼2 mmol/g for an average of 20 % correction in void volume. Sorbed phase density and swelling effect can significantly reduce the excess adsorption by 15 %–30 % and ∼20 % respectively. Whereas, for temperature more than 40⁰C, no such “fall” occurs in the excess ScCO2 adsorption. Finally, the reproducibility tests were performed to show the accuracy of the method adopted for the void volume calibration.



中文翻译:

等温特性及影响因素对煤超临界CO 2吸附性能的影响

在40°C和最高约12 MPa的压力下,通过体积法分析了十个湿性和粉末状,高挥发性至低挥发性的印度煤样品的超临界CO 2(ScCO 2)吸附性能。发现实验“过剩”的吸附容量稳定增加至6.5 MPa。但此后,观察到在7.5 MPa范围内急剧下降。与CO 2的性质以及ScCO 2吸附过程中空隙体积的变化有关的误差和/或不确定性可能会显着影响吸附的气体。温度和湿度的变化以及自由气体密度,CO 2的压缩系数还进行了分析。可以看出,在40⁰C的低压至高压下,自由气体密度变化不同,而可压缩系数在亚临界范围内线性下降,而在超临界范围内几乎恒定或适度增加。为了减少不确定性,通过考虑两个“盲运行”计算的空隙体积的“平均值”来考虑空隙体积随压力的变化,从而对空隙体积的估算值进行了校正。已发现,对于平均20%的空隙体积校正,大多数“负”过量吸附都可以提高到约2 mmol / g。吸附相密度和溶胀作用可以分别将过量的吸附量分别减少15%–30%和〜20%。而对于温度超过40°C的情况,过量的ScCO 2中不会发生这种“下降”吸附。最后,进行了重现性测试,以显示用于空隙体积校准的方法的准确性。

更新日期:2020-03-13
down
wechat
bug