An experimental study on permeability, diffusivity, and selectivity of CO2 and CH4 through [bmim][PF6] ionic liquid supported on an alumina membrane: Investigation of temperature fluctuations effects

Solubility and diffusivity of H2 and CO2 in the ionic liquid [bmim][PF6]

“…¼ solubility of CO 2 in IL at equilibrium ¼ 0.0149 mol/kg and the average diffusivity D i ¼ 2.51 Â 10 À6 cm 2 /s. These estimates are consistent with the data reported in the literature [15,18,30,33] (see further discussion below), for CO 2 in [bmim][PF 6 ] and, therefore, confirm the accuracy of our experimental method. Fig.…”

“…For CO 2 , A CO 2 ¼ 0.64 and E CO 2 ¼ 32. Similar functional dependence on temperature has been reported for the diffusivity of carbon dioxide and methane in a number of ILs[14,15,30]. Using a gravimetric method for CO 2 diffusivity in the same IL, Shiflett et al[30] reported E CO 2 ¼ 27.2 (kJ/mol), which is consistent (but 15% less) with the value obtained in our work.The Arrhenius-like dependence of the H 2 and CO 2 diffusivities in [bmim][PF…”

“…Nevertheless, the accuracy of the isochoric and the supported IL-based membrane techniques decrease considerably when one deals with low-solubility gases, such as hydrogen. This is mostly due to the inherent susceptibility of the two methods to gas leaks and temperature fluctuations [14,15].…”

“…The practical importance of separating H 2 from CO 2 has already been discussed. The reasons for selecting this particular IL is because it is a common and widely available material that exhibits high solubility towards CO 2 , which makes it a good candidate for various CO 2 removal applications [15,30] (for example, CO 2 separation and capture from fluegas), including the H 2 /CO 2 separation relevant to hydrogen production under study here. There are, in addition, several papers reporting data for CO 2 solubility and diffusivity in [bmim] [PF 6 ] that could be used to validate our experimental method [15,30e34].…”

Interactions between the Ionic Liquid and the ZrO2 Support in Supported Ionic Liquid Membranes for CO2 Separation

“…It turns out that the permeation was quasi-constant with a pressure increase. This behaviour can be explained by the transport mechanism through the ionic liquid, which is described by solution-diffusion mass transport processes when the maximum driving force is directly related to the CO 2 solubility in the ionic liquid [32][33][34][35][36][37][38][39][40] …”