石油焦气化反应动力学及其反应性与焦结构的关系

石油焦结构致密，孔隙不发达，灰分及挥发分含量低，导致其气化活性较低。焦结构是影响石油焦气化反应活性高低的重要因素，为阐明石油焦气化反应特性及其与焦结构的关联，采用热重分析仪对镇海石油焦、京博石油焦和胜利石油焦进行CO₂非等温气化反应特性研究，并结合石油焦结构的表征分析，探讨焦结构对气化反应性的影响规律。结果表明：利用比气化速率能够较好地描述3种石油焦的气化反应性差异，气化活性由大到小顺序为胜利石油焦、京博石油焦、镇海石油焦；依据比气化速率随温度的变化规律，可将石油焦的等温气化反应分为慢速、中速、快速3个阶段；石油焦结构分析发现，石油焦气化反应性与焦结构的有序度和CO₂化学吸附量关联性较好，其焦结构有序化程度及其CO₂总吸附量均可用来反映其气化反应性高低；利用比气化速率作为对应恒温气化条件下速率常数计算得到胜利石油焦、京博石油焦和镇海石油焦的气化反应活化能分别为216、245和280 kJ/mol。

Gasification Kinetics of Petroleum Coke and the Relationship Between the Gasification Reactivity and Coke Structure

Petroleum coke is characterized with compact structure, underdeveloped pore structure and low content of ash and volatiles, resulting in relatively low gasification reactivity. As coke structure is an important factor affecting the gasification reactivity of petroleum coke, in order to clarify the gasification characteristics of petroleum coke and its relation with coke structure, thermogravimetric analyzer was used to study the non-isothermal CO₂ gasification characteristics of Zhenhai petroleum coke (ZH), Chambroad petroleum coke (CB) and Shengli petroleum coke (SL), based on which the influence rule of coke structure on the gasification reactivity was discussed through the characterization analysis of petroleum coke structure. The results show that specific gasification rate can be used to better describe the differences in the gasification reactivity of three petroleum cokes, and the gasification activities in descending order are as follows: SL>CB>ZH. According to the law that specific gasification rate changes with temperature, the isothermal gasification of petroleum coke can be divided into three stages: slow reaction stage, medium reaction stage and fast reaction stage. The structural analysis of petroleum coke reveals that its gasification reactivity and the orderliness of coke structure has good correlation with CO₂ chemisorption, and the orderliness of coke structure and total CO₂ absorption can be used to reflect its gasification reactivity. In addition, specific gasification rate, as the rate constant under corresponding isothermal gasification conditions, can be used to calculate activation energies in the gasification reaction of SL, CB and ZH, which are 216, 245 and 280 kJ/mol, respectively.