Method for determining diffusion coefficients of slightly soluble gases in liquids
1981; Elsevier BV; Volume: 36; Issue: 10 Linguagem: Inglês
10.1016/0009-2509(81)80014-0
ISSN1873-4405
Autores Tópico(s)Field-Flow Fractionation Techniques
ResumoA method is described, according to which the diffusion coefficient of a slightly soluble gas in a liquid is calculated from the volume of gas absorbed per unit of time from a gas bubble of constant size. The gas bubble is fixed on the top of a needle of a syringe. This top is ground in the shape of a truncated cone. The centre of the gas bubble coincides with the hypothetical top of this cone. Through the needle, the gas is continuously supplied to such an extent that, in spite of the gas absorption, the bubble diameter remains constant. In this paper, this method is mentioned constant bubble size method and is referred to as the CBS-method. It has been investigated what precautions have to be taken during the measurements to prevent convection and other error sources. Further, it has been shown why the decreasing bubble size method, referred to as the DBS-method, which has been described in the literature, generally leads to unreliable results. Experiments have been conducted with the hydrogen—water system, at about 1 bar in the range of 20–60°C. Results are given and compared both with literature data and values calculated from some diffusion coefficient predicting equations.
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