Forced and Diffusive Mass Transfer between Pentane and Athabasca Bitumen Fractions

2011 ◽  
Vol 25 (2) ◽  
pp. 782-790 ◽  
Author(s):  
Ardalan Sadighian ◽  
Mildred Becerra ◽  
Ala Bazyleva ◽  
John M. Shaw
Keyword(s):  
Mass Transfer ◽  
Athabasca Bitumen ◽  
Diffusive Mass Transfer

Diffusive mass transfer in island films

1978 ◽  
Vol 125 (7) ◽  
pp. 489-525 ◽  
Author(s):  
Ya.E. Geguzin ◽  
Yu.S. Kaganovskii
Keyword(s):  
Mass Transfer ◽  
Diffusive Mass Transfer ◽  
Island Films

Microfluidics to determine the diffusive mass transfer of a low viscosity solvent into a high viscosity hydrocarbon

Fuel ◽  
2019 ◽  
Vol 235 ◽  
pp. 1327-1336 ◽  
Author(s):  
Kiarash Keshmiri ◽  
Mohammad Pourmohammadbagher ◽  
Haibo Huang ◽  
Neda Nazemifard
Keyword(s):  
Mass Transfer ◽  
High Viscosity ◽  
Low Viscosity ◽  
Diffusive Mass Transfer

Diffusive mass transfer in island films

1978 ◽  
Vol 21 (7) ◽  
pp. 611-629 ◽  
Author(s):  
Ya E Geguzin ◽  
Yu S Kaganovskiĭ
Keyword(s):  
Mass Transfer ◽  
Diffusive Mass Transfer ◽  
Island Films

An Experimental Study of Transport Properties of Ceramic Membranes for Use in Hemodialysis

2008 ◽  
Author(s):  
Zhonping Huang ◽  
Anil C. Attaluri ◽  
Amit Belwalkar ◽  
William Van Geertruyden ◽  
Dayong Gao ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Molecular Weight ◽  
Pore Size ◽  
Pore Distribution ◽  
Hydraulic Permeability ◽  
High Flux ◽  
Convective Mass Transfer ◽  
Diffusive Mass Transfer ◽  
Solute Clearance ◽  
Uniform Pore Size

Hemodialysis (HD) remains the primary treatment modality for the management of renal failure patients. Hemodialysis membranes play an important role in renal replacement therapy (RRT). HD is an extracorporeal blood clean process where the major mass transfer mechanism is diffusion. This therapy is mainly effectual for low molecular weight (LMW) solutes (such as urea and creatinine) removal or clearance for which diffusive mass transfer is a swift process. There is an increase in the removal of middle molecular weight (MMW) solutes (such as β2-microglobulin) when high flux membranes are available. Hemodiafiltration (HDF) is a treatment where the convective mass transfer accolades with diffusive mass transfer to increase the solute clearance efficacy, specifically for MMW solutes. The convective mass transfer is reliant on the amount of fluid exchanged. Toxin removal efficiency of HDF significantly depends on the porosity, pore size, pore distribution and surface area of the membrane [1, 2]. Although newly developed high flux polysulfone membranes have high MMW solute clearance, the non-uniform pore size and pore distribution is the main contributors to the albumin loss. Previous studies by Huang et al.[3], showed that nanoporous alumina sheet membranes have uniform pore size (∼ 10nm), high hydraulic permeability, uniform pore distribution and excellent pore structure with uniform channels. It was predicted that these membranes would have high molecular removal capacity. Therefore, in this study, experiments were performed to generate the data of intrinsic membrane properties such as hydraulic permeability, sieving coefficient and solute diffusive permeability for the alumina tubular membranes. Results were also compared to current polyethersulfone (PES) dialysis membranes.

scholarly journals Transition to convection in single bubble diffusive growth

2019 ◽  
Vol 871 ◽  
pp. 332-349 ◽  
Author(s):  
Álvaro Moreno Soto ◽  
Oscar R. Enríquez ◽  
Andrea Prosperetti ◽  
Detlef Lohse ◽  
Devaraj van der Meer
Keyword(s):  
Mass Transfer ◽  
Water Solution ◽  
Mass Transfer Rate ◽  
Absolute Pressure ◽  
Onset Of Convection ◽  
Gas Concentration ◽  
Diffusive Growth ◽  
Drag Forces ◽  
Diffusive Regime ◽  
Diffusive Mass Transfer

We investigate the growth of gas bubbles in a water solution at rest with a supersaturation level that is generally associated with diffusive mass transfer. For $\text{CO}_{2}$ bubbles, it has been previously observed that, after some time of growing in a diffusive regime, a density-driven convective flow enhances the mass transfer rate into the bubble. This is due to the lower density of the gas-depleted liquid which surrounds the bubble. In this work, we report on experiments with different supersaturation values, measuring the time $t_{conv}$ it takes for convection to dominate over the diffusion-driven growth. We demonstrate that by considering buoyancy and drag forces on the depleted liquid around the bubble, we can satisfactorily predict the transition time. In fact, our analysis shows that this onset does not only depend on the supersaturation, but also on the absolute pressure, which we corroborate in experiments. Subsequently, we study how the depletion caused by the growth of successive single bubbles influences the onset of convection. Finally, we study the convection onset around diffusively growing nitrogen $\text{N}_{2}$ bubbles. As $\text{N}_{2}$ is much less soluble in water, the growth takes much longer. However, after waiting long enough and consistent with our theory, convection still occurs as for any gas–liquid combination, provided that the density of the solution sufficiently changes with the gas concentration.

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