基于TG-FTIR的减压渣油热解特性及动力学研究

Pyrolysis characteristics and kinetics of vacuum residues based on TG-FTIR analysis

采用TG-FTIR对长庆减压渣油(CQVR)和秦皇岛减压渣油(QHDVR)的热解行为及几种典型热解产物(CO2、CO、甲烷、乙烯、C2+脂肪烃和轻芳烃)的释放特性进行了研究。实验结果表明,与CQVR相比,QHDVR具有较低的反应活性和较高的焦炭收率。由于化学组成与结构不同,CQVR和QHDVR的热解气态产物释放曲线呈现出差异性。通过无模式函数法中的Friedman算法对CQVR和QHDVR在转化率为0.20~0.85时的热解表观活化能进行了计算,平均表观活化能分别为173.08 kJ/mol和181.12 kJ/mol。CQVR和QHDVR的表观活化能随转化率的变化趋势表明,CQVR更易发生裂解反应。

The pyrolysis behavior of Changqing vacuum residue(CQVR)and Qinhuangdao vacuum residue(QHDVR)and release characteristics of several typical pyrolysis products(CO2,CO,methane,ethylene,C2+aliphatics and light aromatics)were studied by TG-FTIR.The experimental results indicated that pyrolysis reactivity of QHDVR was lower than that of CQVR,whereas the coke yield of QHDVR was higher than that of CQVR.The CQVR and QHDVR pyrolysis gaseous product release curves were distinct because of the difference in chemical composition and structure.The pyrolysis apparent activation energies of CQVR and QHDVR were calculated in the conversion from 0.20 to 0.85 by the Friedman algorithm in model free method,and the average apparent activation energies of CQVR and QHDVR were 173.08 kJ/mol and 181.12 kJ/mol,respectively.The variation of apparent activation energy with the conversion for CQVR and QHDVR during the pyrolysis process indicated that CQVR was more prone to cracking.