Ultrasound-assisted impurity removal from petroleum coke

• Improvement of impurities removal from petroleum coke with ultrasound assistance.
• Evaluation of the effect of main process parameters on the removal rate of iron.
• The mechanism of removal impurity from petroleum coke with ultrasound-assisted was analyzed through SEM results.

In the present study, iron and other impurities element leaching from petroleum coke in the presence of ultrasound were investigated. The parameters investigated were the different types of acid, leaching time, liquid–solid ratio, acid concentration, reaction temperature, ultrasound power and frequency. It has been found that the hydrochloric acid has the largest removal efficiency among the acids investigated. The maximum iron removal rate can be reached at the leaching time of 35 min, liquid–solid ratio of 10 ml/g, acid concentration of 12 wt%, reaction temperature of 50 °C, ultrasound power of 240 W and ultrasound frequency of 80 kHz. The removal efficiency increases considerably, compared to conventional stirring method. The mechanism of removal impurity from petroleum coke with ultrasound-assisted was analyzed through SEM results.