Transport properties of methane, ethane, propane, and n-butane in water

Abstract

In this work, we have estimated self diffusion coefficients along with the binary diffusion coefficients of mixtures of alkane (methane, ethane, propane and n-butane) in SPC/E water(H 2 O). Molecular dynamics study of a binary mixture of alkane gas and SPC/E water, with alkane as solute and water as solvent, have been carried out at different temperatures ranging from 283.15 K to 333.15 K. We have taken a dilute solution of 3 alkane (methane, ethane, propane and n-butane) molecules and 971 water molecules in a system. The role of interaction in the structure of the constituents of the system as a function of temperature is studied with the help of the radial distribution function (RDF) and the coordination numbers. The self-diffusion coefficient of the constituents of the mixture was calculated by using mean square displacement (MSD) and the binary diffusion coefficients of alkane in water have been calculated by using Darken's relation. The results are then compared with the available experimental values. The values of self-diffusion coefficients of water from the present work come in good agreement with the experimental values within 9% error. The binary diffusion coefficients of ethane, methane, propane and n-butane lie in between the previous experimental values performed by Wise and Houghton, and Witherspoon and D. N. Saraf. The estimated values lie within 30% error to each of the previously reported experimental values. The dependence of the diffusion coefficients on temperature is approximated by Arrhenius-type exponential relationship. 4 2 6 3 8 , and C H 4 10 respectively. Some of the common uses of them are are heating, electricity generation, cooking, production of polymers, serves as intermediate in the synthesis of drugs, pesticides and other chemicals. They are also used as propellants OPEN ACCESS RECEIVED

Temporal Patterns of Methane Emissions From Two Streams With Different Riparian Connectivity

“… and d propane were calculated from the in situ stream water temperature (in K ) using the following equations from Pokharel et al. (2018): for propane, parameter d 0 = 18.67 × 10 7 m 2 s −1 , E a = 17.81 kJ mol −1 ; for CH 4 , parameter d 0 = 7.00 × 10 7 m 2 s −1 , E a = 15.13 kJ mol −1 , molar gas constant R = 8.31 J mol −1 K −1 . Gas transfer velocity k (m d −1 ) was then calculated using Halbedel and Koschorreck (2013): where Q is the discharge (L s −1 ), is the stream reach surface area (m 2 ), which was calculated from the reach width and length.…”

“…The value for was -0.5 according to Hope et al (2001). 4 and were calculated from the in-situ stream water temperature (in K) using the following equations from Pokharel et al (2018):…”

“…were calculated from the in situ stream water temperature (in K) using the following equations fromPokharel et al (2018): …”

Diffusion of fructose in water: a molecular dynamics study

“…Di↵usion is a transport phenomenon which occurs due to the presence of concentration gradient [19]. The transport of mass takes place from higher chemical potential region to the lower chemical potential region till the steady state is achieved [20]. Di↵usion is a response property of the system to a concentration inhomogeneity [21].…”

“…shows sharp peaks and troughs up to infinity where the separations and heights are the characteristics of the lattice structure [20]. RDF oscillates up to certain orders and then attains constant value as unity [29].…”