摘要
从国内外5种不同原油中分离提取正己烷沥青质,分别进行10,15,20,25℃·min-1四个加热速率下的热重分析(TGA),关联系列不同挥发度下的沥青质裂解活化能和指前因子等动力学参数.活化能和指前因子随挥发度变化而变化,指前因子的对数与活化能之间有很好的直线关系,显示出良好的补偿效应,说明沥青质裂解反应由许多具有不同动力学参数的平行反应组成.用活化能分布模型计算了活化能和指前因子的分布函数,该模型能较好地表达沥青质的热裂解特征.
Five kinds of asphaltenes were extracted from different crude oils by n-hexane precipitation. Thermogravimetric analysis (TGA) was carried out for these asphaltenes with four different heating rate of 10, 15, 20 and 25 ℃·min^(-1), respectively. The kinetic parameters, active energy (E) and preexponential factor (k_0), of thermal pyrolysis for asphaltenes at different conversion levels were correlated from the experimental TG data. The conversion-dependent E and k_0 values were obtained. The compensation effect is clearly observed from a straight line of the plot of ln(k_0) versus E. It follows that many parallel reactions with different rate parameters occur simultaneously during the thermal pyrolysis of asphaltenes. The distribution functions, f(E) and k_0(E), were then estimated satisfactorily by the distributed activation energy model (DAEM).
出处
《浙江大学学报（理学版）》
CAS
CSCD
2004年第6期652-656,共5页
Journal of Zhejiang University（Science Edition）
基金
浙江省分析测试基金资助项目(03101).
关键词
沥青质
裂解
动力学
热重分析
asphaltene
pyrolysis
kinetics
thermogravimetric analysis (TGA)
distributed activation energy model (DAEM)
