Measurement of local specific interfacial area in bubble columns via a non-isokinetic withdrawal method coupled to electro-optical detector

García-Salas, Sergio; Alfaro, M.E. Rosales Peña; Porter, R. Michael; Thalasso, F.

doi:10.1016/j.ces.2007.11.003

Cited by 8 publications

(6 citation statements)

References 30 publications

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“…In this study, the five parameters used to correlate the separation performance of froth flotation are: average air bubble size diameter, Sauter mean diameter, air bubble surface area flux, air bubble number flux, and the specific surface area of air bubbles [19,[52][53][54][55][56][57]. All of these air bubble parameters need to be taken into consideration for the scale up of a froth flotation column, apart from basic process parameters such as surfactant concentration, air flow rate, and hydraulic retention time (HRT).…”

Section: Effect Of Surfactant On Air Bubble Characteristicsmentioning

confidence: 99%

“…where d i is the equivalent spherical diameter (m) of air bubble i, and n is the number of bubbles [54,55].…”

Section: Effect Of Surfactant On Air Bubble Characteristicsmentioning

confidence: 99%

“…Small air bubbles, with a homogeneous size distribution throughout the column, are desired to maximize the mass-transfer interfacial area of the system [17,18]. The bubble size distribution in the froth flotation column is used to determine the mass-transfer interfacial area [19].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Motor oil removal from water by continuous froth flotation using extended surfactant: Effects of air bubble parameters and surfactant concentration

Watcharasing

Kongkowit

Chavadej

2009

Separation and Purification Technology

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Section: Effect Of Surfactant On Air Bubble Characteristicsmentioning

confidence: 99%

“…where d i is the equivalent spherical diameter (m) of air bubble i, and n is the number of bubbles [54,55].…”

Section: Effect Of Surfactant On Air Bubble Characteristicsmentioning

confidence: 99%

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Motor oil removal from water by continuous froth flotation using extended surfactant: Effects of air bubble parameters and surfactant concentration

Watcharasing

Kongkowit

Chavadej

2009

Separation and Purification Technology

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“…More recent work has used photography [23]- [25][44]- [47], nonisokinetic withdrawal in conjunction with electro-optic detection [48], two needle local probes [49], four fibre optic probes [50] and a Wire Mesh Sensor [21]. The liquids used were almost exclusively water with different chemical dissolved in them, e.g., Na2CO3, NaHCO3, NaOH [43], DEA [44], TEA [45], polymer plus surfactant [46] and surfactant [47].…”

Section: Figmentioning

confidence: 99%

“…Two of them [48,50] used water, the third [57] employed cyclohexane, a liquid with a surface tension much smaller than water and the fourth [51] used a silicone oil which has a low surface tension and a viscosity of 5 times that of water. These four are all from columns of diameter >100 mm and had distributors which were perforated plates with holes of small diameter, 0.5 mm [49,50,52,57].…”

Section: Other (Lower Viscosity)mentioning

confidence: 99%

Characterisation of an analogue liquid for hydrodynamic studies of gas-ionic liquid flows

Azzopardi

Agunlejika

Zhao

et al. 2017

Chemical Engineering Journal

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Ionic liquids are liquid salts at low temperatures (normally less than 100°C). They are powerful solvents with very low vapour pressure. They have great potentials in many applications such as gas absorption and chemical synthesis. However, they are expensive. This limits extensive studies towards establishing phenomenological models. To address this limitation, an analogue liquid, with properties similar to an ionic liquid, has been identified which on the grounds of cost and safety appears to be suitable.In this paper, the hydrodynamic behaviour of an ionic liquid in a bubble column is compared with those of water and other liquids with similar physical properties. Average gas holdup, bubble coalescence, bubble size and specific interfacial area with different liquids are examined. Gas hold-up was determined by monitoring the change of conductivity between two flush mounted rings. The differences in bubble size and coalescence are revealed by analysing the stills taken from a high speed video camera. The dominant flow pattern in a small diameter column with ionic liquids or other fluids having similar viscosity is slug flow. The small bubbles in the liquid slugs make a smaller contribution to the specific interfacial area than Taylor bubbles. It is observed that Taylor bubbles can coalesce. The hydrodynamics of an ionic liquid in a bubble column can be estimated from that of a fluid with similar physical properties.

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Esterification for biodiesel production with a phantom catalyst: Bubble mediated reactive distillation

Zimmerman

Kokoo

2018

Applied Energy

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The initial aim of the paper is to dramatically improve the pretreatment stage of biodiesel production, which converts problematic free fatty acids to fatty acid methyl esters, by introduction of a microbubble mediated reactive distillation stage instead of acid pretreatment. This will shift the conventional esterification process towards completion with a yield higher than 80%, even without high excess methanol. Application of ozone microbubbles has the advantage over acid gas catalysis in that it gives higher conversion and leaves no catalyst residue and requires no further catalyst recovery separation steps (a "phantom" catalyst). Unreacted ozone breaks down into oxygen, so the off-gases are just a humid air stream that can be vented. Importantly, ozonolysis breaks carbon-carbon double bonds into aldehydes and carboxylic acids. Many ester species were found after contacting the feedstock with ozone-rich microbubbles, depending on the molecular structure of the alcohols for the ozonolysis of oleic acid with alcohols, i.e., methanol, ethanol, n-propanol, iso-propanol, and n-butanol. In the case of ozonolysis of used cooking oil mixed with methanol, the results from the GC-MS show that all saturated free fatty acids (including palmitic acid, stearic acid, and myristic acid) are converted to methyl esters within 20 hours of 60°C ozonolysis, whereas trace amounts of these chemicals remain at lower temperatures. The results also show that the conversion of oleic acid to form oleic acid methyl ester is 91.16% after 32 hours of ozonolysis at 60°C. Therefore, the free fatty acid content in used cooking oil is less than 1.33%, which makes it suitable as a reactant for biodiesel production via transesterification. However, this result is different from the result provided by ASTM D974 in that the acid numbers decrease dramatically by 25% at the beginning of ozonolysis followed by a plateau. Moreover, if the fluidic oscillator is used to generate bubbles in ozonolysis of oleic acid mixed with methanol, the results show that the yields of ozonolysis product 1-nonanal increase by 30%. This observation means that ozonolysis of oleic acid is relative to the specific interfacial area, and favoured at low liquid temperatures.

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Measurement of local specific interfacial area in bubble columns via a non-isokinetic withdrawal method coupled to electro-optical detector

Cited by 8 publications

References 30 publications

Motor oil removal from water by continuous froth flotation using extended surfactant: Effects of air bubble parameters and surfactant concentration

Motor oil removal from water by continuous froth flotation using extended surfactant: Effects of air bubble parameters and surfactant concentration

Characterisation of an analogue liquid for hydrodynamic studies of gas-ionic liquid flows

Esterification for biodiesel production with a phantom catalyst: Bubble mediated reactive distillation

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