Study On Desulfurization Technology Of High-sulfur Petroleum Coke

The growing of sulfur content of petroleum coke in recent years has caused an increasing impact of aluminum electrolysis and carbon industry.The study of high-sulfur petroleum coke desulfurization technology is of great significance to improve the utilization of high-sulfur petroleum and promote the sustainable development of the aluminum electrolytic and carbon industry.With wet-chemical method and high-temperature Catalytic calcination method,the author selected the appropriate desulfurization agent to optimize the desulfurization process of green coke. The main results are as follows:(1) Using hydrochloric acid, nitric acid, concentrated sulfuric acid and phosphoric acid to desulfurize petroleum coke,the results showed that only nitric acid can remove sulfur from petroleum coke; further study found that hydrochloric acid can strength the desulfurization process, and with the addition of hydrochloric acid, the nitric acid desulfurization capability could rapidly increase by16%to44%.(2)Using three type of surfactant to optimize the mixed acid desulfurization process, the results show that surfactant can enhance the desulfurization process and the desulfurization rate can be increased. Further study found that dodecyl trimethyl ammonium bromide (DTAB) was the most capable surfactant to enhance the desulfurization process. With the addition of DTAB, the desulfurization rate could be up to56%,compared with no surfactant,the desulfurization rate increase13%.(3)with alternative the hydrogen ions, chloride ions or nitrate ions, author study the change of desulfurization rate.the results show that with none of hydrogen ions, only chloride ions and nitrate ions could not remove sulfur successfully, while the presence of any one acid, another acid with its corresponding salt substitute, the mixed agents are have good desulfurization capacity.(4)With study the desulfurization process by middle-low temperature Catalytic calcination, the result show that Na2CO3reagent was ability to desulfurize petroleum coke. Used0.8M Na2CO3to leach petroleum coke and calcined the coke at900℃, the desulfurization rate could be up to67%.it was the optimal method of desulfurization process.(5)the Fourier transform infrared spectroscopy(FT-IR) results showed that the organic sulfur in petroleum coke was mostly in the form of thiophene; after desulfurization by wet-chemical or high-temperature cacined, most sulfur could be removed, and the no-removed part was transformed into other form of C-S bond, so, the two method could not remove the sulfur in petroleum coke absolutely.