Graphical estimation of interface mass-transfer coefficient (k) using pressure-decay data

Roman, Francisco Javier Pacheco; Hejazi, S. Hossein

doi:10.1016/j.ces.2016.01.049

Cited by 10 publications

(7 citation statements)

References 18 publications

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“…The error is generally associated with the misrepresentation of mixture properties such as equilibrium mass fraction at the gas/liquid interface and fluid densities . Previous researchers developed analytical, semi‐analytical graphical, numerical, and approximate solutions based on various simplifying assumptions. The success and reliability of each of these proposed solutions are defined by their incorporated boundary conditions and the validity of their simplifying assumptions .…”

Section: Introductionmentioning

confidence: 99%

Concentration‐dependent molecular diffusion coefficient of gaseous ethane in liquid toluene

et al. 2020

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We report new experimental data on concentration-dependent molecular diffusion coefficient of ethane in toluene at temperatures ranging from 21 to 125 C and pressures up to 4.14 MPa. An analytical model has also been developed for estimation of the diffusion coefficient utilizing the experimental data of the interface velocity as a result of swelling and the rate of gas dissolution in the liquid phase. It is shown that the diffusion coefficient of ethane in toluene is dependent on the initial mass fraction of the gaseous component in the liquid. In addition, the effect of concentration dependency of the molecular diffusion coefficient on diffusive mass flux is quantified.The results reveal that the assumption of a constant diffusion coefficient introduces 10-60% error in calculation of diffusional mass transfer flux. The developed methodology finds application in estimation of the concentration-dependent molecular diffusion coefficient of gases in liquids.

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Section: Introductionmentioning

confidence: 99%

Concentration‐dependent molecular diffusion coefficient of gaseous ethane in liquid toluene

et al. 2020

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“…Such multiplex character of the solvent gas–liquid systems is described using a free boundary problem for the diffusion equation with unknown diffusion coefficient. In practical applications, the problem of solvent gas–liquid interaction is often solved using simplified approach that neglects the gas swelling into the liquid phase and corresponding gas–liquid interface movement. ,,,,− ,,,,− However, this simplification is often not supported by the real measurements of absorption of different gases into liquids. ,,,, To solve the problem with gas swelling into liquid with an unknown gas–liquid interface, it is necessary to specify an additional condition for the diffusion equation. Such a condition was formulated based on the mass conservation of the dissolved gas and represented in the form of the Stefan’s type boundary value condition at the moving interface. ,− , An alternative approach for identification of the unknown gas–liquid interface was applied based on the moving grid size refinement .…”

Section: Discussionmentioning

confidence: 99%

“…Note that in the case when the constant diffusion is unknown and one concentration profile is measured at some nonzero time t, then h 1 could be defined from (19) and the diffusion coefficient D 0 could be calculated from (18).…”

Section: Constant Diffusion Casementioning

confidence: 99%

“…Several works for diffusion estimation of dissolved gases in liquids considered only estimation of the diffusion coefficients under the assumption that the changes of liquid volume are very small and negligible. − Olander was one of the first who investigated the effect of the volume change due to gas absorption into liquid on the diffusion coefficient. The Olander’s model included a correction for the flux term with respect to the volume change.…”

Section: Introductionmentioning

confidence: 99%

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Estimation of Gas Absorption and Diffusion Coefficients for Dissolved Gases in Liquids

Babak

Kantzas

2018

Ind. Eng. Chem. Res.

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The multifaceted process of gas absorption and diffusion of dissolved gases has several useful applications in engineering, medicine, pharmaceutics, and science. A new systematic study for modeling of this process using an inverse problem for concentration dependent diffusion with free boundary at the gas−liquid interface is presented in this work. The study includes the model derivation based on the Fick's second law of diffusion, the Henry's absorption law, the Stefan's principles of free boundary problems, and the development of new techniques for estimation of concentration dependent diffusion coefficient and the gas absorption coefficient governing propagation of gas−liquid interface due to absorption. The developed estimation technique utilized the dissolved gas concentration profiles measured and different time moments and is applied to real X-ray CT measurement data for a binary gas liquid mixture containing dimethyl ether and bitumen.

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“…followed an approach similar to Upreti and Mehrotra , to study methane/n-hexadecane and methane/oil systems at temperatures of 25, 50, and 80 °C. The later works in this area are focused on proposing analytical approximate solutions to what were previously developed. − …”

Section: Introductionmentioning

confidence: 99%

Measurements of Molecular Diffusion Coefficient and Solubility of Dimethyl Ether in Bitumen at T = (323.15–383.15 K) and P = (0.69–2.76 MPa)

2019

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We report the first comprehensive data set on the molecular diffusion coefficient of dimethyl ether (DME) in bitumen at a temperature range of 70–110 °C and pressures up to 2.76 MPa. A new experimental setup was introduced that allows accurate and reliable measurements of equilibrium solubility and molecular diffusion coefficient of gases in liquids at high pressures and temperatures. The experimental data on diffusional mass transfer of dimethyl ether (DME) into the bitumen is utilized to estimate the molecular diffusion coefficient while taking the liquid swelling into account. The results show that the molecular diffusion coefficient of DME is in the range of ∼0.2–2 × 10–9 m2/s depending on the operating conditions and viscosity of the mixture. The measured data find applications in the design and optimization of solvent-aided thermal recovery of bitumen and heavy oil.

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Graphical estimation of interface mass-transfer coefficient (k) using pressure-decay data

Cited by 10 publications

References 18 publications

Concentration‐dependent molecular diffusion coefficient of gaseous ethane in liquid toluene

Concentration‐dependent molecular diffusion coefficient of gaseous ethane in liquid toluene

Estimation of Gas Absorption and Diffusion Coefficients for Dissolved Gases in Liquids

Measurements of Molecular Diffusion Coefficient and Solubility of Dimethyl Ether in Bitumen at T = (323.15–383.15 K) and P = (0.69–2.76 MPa)

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