Liang Minyan, Chen Guangjin, Sun Changyu, Yan Lijun, Liu Jiang, Ma Qinglan
State Key Laboratory of Heveay Oil Processing, Chinese University of Petroleum, Changping County, Beijing 102249, People's Republic of China.
J Phys Chem B. 2005 Oct 13;109(40):19034-41. doi: 10.1021/jp0526851.
The decomposition kinetic behaviors of methane hydrates formed in 5 cm3 porous wet activated carbon were studied experimentally in a closed system in the temperature range of 275.8-264.4 K. The decomposition rates of methane hydrates formed from 5 cm3 of pure free water and an aqueous solution of 650 g x m(-3) sodium dodecyl sulfate (SDS) were also measured for comparison. The decomposition rates of methane hydrates in seven different cases were compared. The results showed that the methane hydrates dissociate more rapidly in porous activated carbon than in free systems. A mathematical model was developed for describing the decomposition kinetic behavior of methane hydrates below ice point based on an ice-shielding mechanism in which a porous ice layer was assumed to be formed during the decomposition of hydrate, and the diffusion of methane molecules through it was assumed to be one of the control steps. The parameters of the model were determined by correlating the decomposition rate data, and the activation energies were further determined with respect to three different media. The model was found to well describe the decomposition kinetic behavior of methane hydrate in different media.
在一个封闭系统中，于275.8 - 264.4 K的温度范围内，对5立方厘米多孔湿活性炭中形成的甲烷水合物的分解动力学行为进行了实验研究。为作比较，还测量了由5立方厘米纯游离水和650克/立方米十二烷基硫酸钠（SDS）水溶液形成的甲烷水合物的分解速率。比较了七种不同情况下甲烷水合物的分解速率。结果表明，甲烷水合物在多孔活性炭中的分解比在游离体系中更快。基于冰屏蔽机制建立了一个数学模型，用于描述冰点以下甲烷水合物的分解动力学行为，该机制假定在水合物分解过程中形成了多孔冰层，且甲烷分子通过该冰层的扩散被假定为控制步骤之一。通过关联分解速率数据确定了模型参数，并针对三种不同介质进一步确定了活化能。发现该模型能很好地描述甲烷水合物在不同介质中的分解动力学行为。
