A two-stage desulfurization method for high-sulfur petroleum coke was developed using Na₂CO₃-promoted calcination, followed by ultrasonic-assisted chemical oxidation. Using a Na₂CO₃ to coke mass ratio of 1:4 and an average particle size of 80 µm for the coke, the desulfurization efficiency of the coke reached a maximum of 67.2% using Na₂CO₃-promoted calcination at 900 °C for 2 h with a heating rate of 1°C /min. The total desulfurization after the subsequent ultrasonic-assisted oxidation with nitric acid (65 wt%) reached 93.5% at 80 °C for 12 h using a nitric acid/coke ratio of 20 mL/g. The amounts of sulfur removed by the Na₂CO₃-promoted calcination were 73.4% of the thiophenic sulfur and 59.8% of the sulfoxide, with the total amounts removed after the ultrasonic-assisted oxidation being 93.6 and 93.3% respectively. Na₂CO₃ reacts with H₂S and shifts the chemical equilibrium to remove more sulfur during the calcination. Chemical oxidation converts dibenzothiophenic compounds to water-soluble ones. These jointly increase the desulfurization efficiency of the coke.

利用Na ₂ CO ₃促进的煅烧，然后进行超声辅助化学氧化，开发了一种用于高硫石油焦的两步脱硫方法。使用Na ₂ CO ₃与焦炭的质量比为1：4，并且焦炭的平均粒径为80 µm，在900°C下使用Na ₂ CO ₃促进的煅烧，焦炭的脱硫效率最大为67.2％。以1°C / min的加热速率加热2小时。随后的硝酸/焦炭比为20 mL / g，随后在80°C下用硝酸（65 wt％）进行超声辅助氧化后的总脱硫量达到93.5％。Na ₂ CO ₃去除的硫量促进的煅烧为73.4％的噻吩硫和59.8％的亚砜，超声辅助氧化后去除的总量分别为93.6％和93.3％。Na ₂ CO ₃与H ₂ S反应，并在煅烧过程中改变化学平衡以除去更多的硫。化学氧化将二苯并噻吩化合物转化为水溶性化合物。这些共同提高了焦炭的脱硫效率。