Quantitative approach to ultrasonic emulsion separation

Abstract

Ultrasound of 2 MHz was irradiated to the emulsion prepared from canola oil and water and flocculation of the oil droplets occurred immediately. By putting the emulsion sample in a thin glass cell and setting it in bath type irradiation equipment, the progress of the separation was quantitatively monitored with the optical absorbance. The use of the cell enables visual observation of the behavior of oil droplets. Pictures show the formation of flocks of the dispersed phase and the appearance of checkered pattern consisting of flocks at a regular interval. The observation indicates that the action of radiation forces on oil droplets, which causes the flocculation. The flocks started to rise after stopping irradiation with holding their shape. The rising rate of the flocks was significantly greater than that of oil droplets in the original emulsion. Ultrasonic irradiation caused a rapid decrease in the absorbance, which expresses a progress of the separation. Effects of two major operation parameters, power and time on the separation degree were examined. The degree improved with increasing power input and irradiation time. The dataset was arranged in a plot of normalized separation degree against the input energy. The plot suggests that effective separation was attained with a lower power input and a longer irradiation time. The plot provides a guide for setting condition for the separation.

Influence Frequency And Time Pretreatment Ultrasound Assited Extraction Of Yield And Quality Virgin Coconut Oil

“…Sampel emulsi menyerap gelombang ultrasound akan mengalami peningkatan suhu dan tekanan, sehingga suhu mengurangi viskositas minyak dan tekanan gelombang mendorong air untuk berpisah dengan minyak (Nii et al, 2009).…”

Development of novel oil recovery methods for petroleum refinery oily sludge treatment

“…The use of centrifugation has been limited to small scales because of the high equipment investment and limitations (Nii, 2009). In addition, centrifugation can bring noise problems (da Silva et al, 2012).…”

“…Amongst them, ultrasonic irradiation represents an emerging and promising technique due to its several inherent merits such as high efficiency, short treatment duration, and chemical-free application (Bendicho et al, 2012;Jin et al, 2012;Li et al, 2013). It has been reported to effectively remove adsorbed materials from solid particles and decrease the stability of water/oil emulsions (Bendicho et al, 2012;Nii et al, 2009;Pilli et al, 2011). The cavitation collapse due to ultrasonic irradiation does not only affect the surface of solid particles but also penetrates into the solid matrix, and could thus improve the separation of oil from solid particles and slurries Abramov et al, 2009).…”

“…Temperature has proven to be an important factor affecting the demulsification of W/0 emulsions (Peng et al, 2012). Increased temperature in oily sludge reduces viscosity and accelerates the settling of water droplets in oily sludge, thus promoting the separation of water and oil (Nii et al, 2009). To investigate the effect of temperature on oily sludge treatment, the oil recovery and salt removal performance of both direct heating and ultrasonic irradiation were further examined.…”

Estudo da intensificação da coalescência de emulsões de água em óleo com a aplicação de onda estacionária de ultrassom.

“…Aliás, a separação acusticamente auxiliada de gotículas de água contidas em emulsões com óleo vem sendo estudada recentemente (PANGU et al, 2009;PARVASI et al, 2013). O progresso da separação pode ser monitorado quantitativamente por meio da absorvância óptica que apresenta diminuição acentuada pela aplicação de irradiação ultrassónica (NII et al, 2009 …”