Study on the performance of petroleum coke after electrolytic desulfurization in NaBr-CH3COOH system

In this paper, CH3COOH is used to adjust the electrolyte, control different acid concentrations, and use the ·OOH, HBrO, BrO3− produced by the electrolyte on the anode to oxidatively desulfurize the petroleum coke particles suspended in the electrolyte. The desulfurized petroleum coke was analyzed by NB/SH/T 0527–2019 indicators and SEM, TGA, XRD, FTIR, and XPS to explore the degree and regularity of desulfurization conditions on the quality of petroleum coke, and explore the mechanism of the desulfurization process. The experimental results show that the NaBr-CH3COOH system has different desulfurization effects under different acid concentration conditions of pH = 2 ~ 6, and the impact on the quality of petroleum coke is also significantly different. A large acid concentration has a high desulfurization yield of petroleum coke. The desulfurization effect is best at pH = 2, and the desulfurization yield can reach 88.92%, but it has a certain impact on the quality indicators of the petroleum coke industry. The heating value of petroleum coke is slightly reduced, and the volatile content the ash yield content has increased compared with the original coke. The change is mainly due to the scission of the branch, the reduction of carbon atoms due to the oxidation reaction, and other side reactions that occur during the electrolytic oxidation reaction, which makes the oxygen content increase and the combustion performance becomes better. XPS analysis results show that the macromolecular structure of petroleum coke is hardly destroyed. According to the changes of oxygen-containing functional groups and sulfur-containing functional groups on the surface of petroleum coke, the mechanism of petroleum coke desulfurization was preliminarily explored.