Effect of ultrasonic frequency on separation of water from heavy crude oil emulsion using ultrasonic baths

Abstract

In this work, a comprehensive study was performed for the evaluation of ultrasound (US) frequency for demulsification of crude oil emulsions. Experiments were performed using ultrasonic baths operating at the following frequencies: 25, 35, 45, 130, 582, 862 and 1146kHz. Synthetic water-in-oil emulsions with 12%, 35% and 50% of water and medians of droplet size distribution (DSD, D(0.5)) of 5, 10 and 25μm were prepared using a heavy crude oil (API density of 19). Crude oil demulsification was achieved at frequencies in the range of 25-45kHz for all tested emulsions. When frequencies higher than 45kHz were applied, no changes in the characteristics of the crude oil emulsions were observed. Demulsification efficiencies of about 65% were achieved at a frequency of 45kHz after 15min of US application (emulsions with original water content of 50% and D(0.5)=10μm). An important aspect is that no addition of chemical demulsifiers was performed, and the demulsification efficiency was considered high, taking into account that the results were obtained using a non-conventional crude oil. Contrary to the normal application of low-frequency US that has been used for emulsification, the proposed approach seems to be a promising technology for water removal from crude oil emulsions.

Using ultrasonic as a new approach for elimination of inorganic scales (NaCl): an experimental study

“…Changes in crude oil characteristics due to ultrasonic wave irradiation are also evaluated (Shi et al 2017). Research has also been conducted into the impact of ultrasonic waves on oil-water emulsions (Ding et al 2016) and their separation (Antes et al 2017). The effects of ultrasonic waves on organic and polymeric deposits are compared in this study; the findings are that ultrasonic waves remove organic deposits much more effectively than they do polymeric deposits (Venkitaraman et al 1995;Roberts et al 2000).…”

An Overview of Recent Advances in State-of-the-Art Techniques in the Demulsification of Crude Oil Emulsions

“…The use of pulsed ultrasonic irradiation techniques for the demulsification of crude oil emulsions was reported by Xie et al [148], who observed the pulse irradiation techniques facilitated water coalescence, thereby improving the demulsification efficiency. Antes et al used ultrasonic baths at different frequencies for the demulsification of crude oil emulsions [149]. Effective demulsification of crude oil with a 65% efficiency was achieved at a frequency range of 25-45 kHz after 15 min.…”

Identification of special features in the electrolysis­cavitation water treatment in pools

“…The issues of water purification from biological and organic pollutants by its cavitation treatment have been given attention in a series of works. Thus, the authors of [12], investigated the effect of various modes of water ultrasonic cavitation treatment on its quality indicators, in particular hardness and acidity. They established that cavitation treatment does not affect the water hardness.…”