Ultrasound field distribution and ultrasonic oxidation desulfurization efficiency

Ultrasonic oxidation desulfurization (UODS) has been considered a promising method for deeply desulfurization technology since it can be carried out using mild conditions. During the last few decades many experimental investigations have been carried out on optimizing the reaction condition such as ultrasonic irradiation time, oxidizing reagents amount, kind of organic acid and so on. But limited work has been reported on the influence of the ultrasonic cavitation field distribution. In this work, the relative intensity of the cavitation events has been measured with the aluminum foil erosion method in a commonly used ultrasonic cleaning vessel both in horizontal and vertical directions. The aluminum foil erosion image was then collected into computer by a scanner. In addition, the image processing program of MATLAB software was used to pretreat the erosion image and find out the positions of the erosion points so that the ratio of the erosion area to the entire area can be calculated which helped to quantify the measurement result since the erosion ratios was the representation of the cavitation intensity. The desulfurization efficiency was then measured in different position of the vessel. The results match well with the cavitation field distribution results which indicate that the cavitation field distribution can be used to guide the UODS process. (C) 2012 Elsevier B.V. All rights reserved.