Effect of ultrasound on oil recovery from crude oil containing sludge

<p>To recover oil from crude oil containing sludge is still a research hot topic from the view of sustainability, in which ultrasonic has been proven to be an efficient and environment friendly technique. However, the effect of sludge characteristic on ultrasonic-assisted oil recovery efficiency is little known. In this study, the analysis of variance (ANOVA) was conducted based on six types of crude oily sludge with hydrophilicity and lipophilicity separately and five different ultrasonic operation factors (ultrasonic power (A), frequency (B), time (C), initial temperature (D) and pH (E)). The results showed that the oil recovery efficiency was mainly affected by the ultrasonic power and hydrophilicity of sludge (the highest 92% of oil recovery rate was achieved with the ultrasonic power of 240 W and hydrophilic sludge). Moreover, the wettability, decreased average particle size and increased specific surface area of sludge were found after ultrasonic treatment. Besides, changes in the oil component, such as the decrease of asphaltenes along with an increase of saturates, were also further observed. Therefore, the findings in this study can provide technical support for the practical application of ultrasonic technology in different kinds of oily sludge treatment.</p

Comparative CHRs obtained from GUDC using different cache replacement strategies.

<p>Comparative CHRs obtained from GUDC using different cache replacement strategies.</p

Comparative CHRs obtained from different prefetching algorithms based on multi-user mode.

<p>Comparative CHRs obtained from different prefetching algorithms based on multi-user mode.</p

The datasets parameters used in the experiments.

<p>The datasets parameters used in the experiments.</p

Comparative CHRs obtained from GUDC based on different data sizes.

<p>Comparative CHRs obtained from GUDC based on different data sizes.</p

A performance comparison of various algorithms based on the client-side prefetching mode.

<p>A performance comparison of various algorithms based on the client-side prefetching mode.</p

Comparative CHRs obtained from GUDC based on different global user behaviors.

<p>Comparative CHRs obtained from GUDC based on different global user behaviors.</p

Comparative disk access performance obtained from different algorithms.

<p>Comparative disk access performance obtained from different algorithms.</p