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NH3-reducing desulfurization was demonstrated using a high-sulfur coke calcining desulfurization experiment at 1000 °C, and the sulfur chemical reactions of the three aromaticities of thiophene were studied during desulfurization. Results showed that NH3-reducing desulfurization could significantly remove sulfur in the coke, and the best operation temperature was approximately 800 °C, at which more than 80% of organic sulfur could be removed. The physical and chemical indicators of petroleum coke after desulfurization were not affected. Thermodynamic calculation results showed that the desulfurization reaction was more favorable at higher temperatures. However, the reaction was also affected by other factors; thus, the desulfurization efficiency decreased when the desulfurization temperature exceeded 800 °C. This paper presents a specific explanation of this phenomenon.

A real-time mathematical model for the two-dimensional temperature field of petroleum coke calcination in vertical shaft calciner was developed based on computational fluid dynamics. In the modeling process, the petroleum coke discharging process was described by the solid viscous flow, the dynamic heat flux boundary condition was adopted to specify the heat transfer between the flue wall and the gas in the flue, and the Arrhenius equation was used to characterize the pyrolysis process of petroleum coke. The model was validated with both measurement data and data from the literature. The effects of discharge rate per pot, volatile content of green coke, and excess air coefficient on the temperature field of the vertical shaft calciner were investigated with the use of the developed model. The following reasonable operating conditions were obtained: the discharge rate per pot should be less than 90 kg/h, the volatile content of green coke should be in the range of 9–11%, and the excess air coefficient should be in the range of 1.10–1.20. In this work, the governing equations were discretized by using the finite volume method, and the discrete linear equations were solved by using sparse matrix package UMFPACK. The model calculating process takes about less than 15 s. Therefore, the model is beneficial in realizing real-time online temperature detection of petroleum coke calcination in a vertical shaft calciner.

The aim of this work was to establish a mathematical model for the analysis of calcining process of petroleum coke in a 24-pot calciner via computational fluid dynamics (CFD) numerical simulation method. The model can be divided into two main parts (1) heterogeneous reacting flow of petroleum coke calcination in the pot was simulated using a two-fluid model approach where the gas and solid phase are treated as a continuous phases; and (2) the standard turbulence equations combined with the finite rate/eddy-dissipation combustion model and discrete ordinates model were solved for the turbulent gas reacting flow in the flue. The model of the calcining process was implemented in ANSYS Fluent 15.0 (commercial CFD software) and validated by industrial production data. After the validation research, the model has been applied to inspect the distribution features of the temperature field in the furnace, the concentration field of residual moisture and volatiles in the petroleum coke, and the vector velocity field of gas and solid phases. This research can provide a theoretical basis for optimizing the structure and improving the automatic control level of a pot calciner.

Coal gangue is regarded as a potential source of aluminum and silica. In this work, acid leaching behaviors of aluminum, iron, and silica in coal gangue were investigated using hydrochloric acid as leaching agent. Chemical and mineralogical compositions of coal gangue and the leached residue were determined by X-ray diffraction (XRD), X-ray fluorescence, and Fourier transform infrared spectroscopy. XRD results indicated that kaolinite and boehmite were the predominant minerals in coal gangue. During elevated temperature acid leaching, mineral phases gradually decomposed, and aluminum and iron ions were dissolved in the acid leaching solution. However, the carbonaceous material and the product of silica were not dissolved in acid and were abundant in leached residue. The extraction efficiency of Al and Fe from coal gangue depended on coal gangue size, liquid–solid ratio, temperature and leaching time. Extraction efficiency of Al and Fe increased with increased liquid–solid ratio, temperature, and leaching time. Under the same conditions, SiO 2 content in the ash of leached residue also increased. The optimum technological conditions for aluminum and iron extraction were obtained with a coal gangue size of 74 μm at a liquid–solid ratio of 3:1 to react at 180 °C for 4 h. After evaporation and crystallization, selective precipitation by adding sodium hydroxide solution, carbon decomposition, and calcination, alumina with a purity of 98.70% was prepared from acid leaching solution. Finally, a suitable amount of low ash anthracite was introduced to the leached residue, and the product of SiC was produced by carbon thermal reduction method. The product had a yield and purity of 72.72% and 76.01%, respectively.

This paper presents macromolecular models of sulfur-containing Qingdao petroleum. The results were investigated with ultimate analysis, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The models showed that organic sulfur, nitrogen, and oxygen in the coke were mainly in the forms of thiophene-containing polycyclic aromatic hydrocarbon, polycyclic aromatic hydrocarbons containing pyrrole or pyridine, and C═O or C–O–C, respectively. During calcination, the aromaticity of coke increased, with element contents and functional groups changing substantially. Moreover, the models explained the desulfurization mechanism of coke during calcination.