Enhanced Mass Transfer Rates in Nanofluids: Experiments and Modeling

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Ratnesh U. Khanolkar ◽  
A. K. Suresh
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Particle Size ◽  
Capillary Tube ◽  
Carbon Dioxide Absorption ◽  
Transfer Coefficients ◽  
Material Density ◽  
Transfer Rates ◽  
Low Volume ◽  
Wetted Wall Column

Enhancement in carbon dioxide absorption in water has been studied using SiO2 and TiO2 nanoparticles using the capillary tube apparatus for which previous results on Fe3O4 nanoparticles were reported earlier. Enhancements of up to 165% in the mass transfer coefficients were observed at fairly low volume fractions of the particles. A model which accounts for the effect of particles in terms of a superimposed convection has been proposed to explain the observed effects of particle size, hold-up, and material density. The model provides a good fit to the data from wetted wall column and capillary tube experiment for Fe3O4 from the previous literature, as well as for the data from this work.

Carbon Dioxide Absorption in Triethanolamine Aqueous Solutions: Hydrodynamics and Mass Transfer

2014 ◽  
Vol 37 (3) ◽  
pp. 419-426 ◽  
Author(s):  
Ana B. López ◽  
M. Dolores La Rubia ◽  
José M. Navaza ◽  
Rafael Pacheco ◽  
Diego Gómez-Díaz
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Aqueous Solutions ◽  
Carbon Dioxide Absorption

Mass Transfer From Single Carbon Dioxide Bubbles in Contaminated Water

2014 ◽  
Author(s):  
Jiro Aoki ◽  
Kosuke Hayashi ◽  
Shogo Hosoda ◽  
Shigeo Hosokawa ◽  
Akio Tomiyama
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Surfactant Concentration ◽  
Bubble Diameter ◽  
Surfactant Solution ◽  
Contaminated Water ◽  
Tail Region ◽  
Transfer Rates ◽  
Small Bubbles ◽  
Taylor Bubbles

Mass transfer from single carbon dioxide bubbles rising through contaminated water in a vertical pipe of 12.5 mm diameter was measured to investigate effects of surfactant. The bubble diameter was widely varied to cover various bubble shapes such as spheroidal, wobbling, cap and Taylor bubbles. The gas and liquid phases were 99.9 % purity carbon dioxide and a surfactant solution made of purified water and Triton X-100. Comparison of mass transfer rates between contaminated and clean bubbles made clear that the surfactant decreases the mass transfer rates of small bubbles. The Sherwood number of small bubbles in the extreme cases, i.e. zero and the highest surfactant concentrations, is well correlated in terms of the bubble Reynolds number, Schmidt number and the ratio, λ, of the bubble diameter to pipe diameter. The Sherwood numbers at intermediate surfactant concentration, however, are not well correlated using available correlations. The mass transfer rates of Taylor bubbles also decrease with increasing the surfactant concentration. They however increase with the diameter ratio and approaches that of clean Taylor bubbles as λ increases. The main cause of this tendency was revealed by interface tracking simulations, i.e. the surfactant adsorbs only in the bubble tail region and the nose-to-side region is almost clean at high λ.

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