超氧压法考察柴油氧化衰变特性及动力学研究

Study on oxidative decay characteristics and kinetics of diesel oil with oxygen overpressure

采用超氧压法于不同氧化温度(60,80,90℃)下考察了直馏柴油、加氢裂化柴油、调合成品油3种柴油的氧化衰变特性,测定了柴油的实际胶质含量随氧化时间的变化趋势。以实际胶质为氧化产物拟合得到了3种柴油不同反应温度下的反应速率方程,利用2种动力学分析方法(微分法、积分法)求得调合成品油宏观动力学参数。结果表明:(1)以色度为安定性指标时,加氢裂化柴油>调合成品油>直馏柴油,以实际胶质含量为安定性指标时,直馏柴油>调合成品油>加氢裂化柴油;(2)以实际胶质含量为氧化产物时,采用不同动力学分析方法得到了动力学参数存在差异,采用微分法得到的活化能、指前因子的值均大于积分法所求值,当采用微分法计算反应速率常数k时,微分法和积分法(n=1)计算得到的结果较为理想,相关系数均大于0.9,可根据lnk对1/T线性回归方程估计柴油氧化过程中产生实际胶质的含量。

The oxidative decay characteristics of three kinds of diesel oils i. e. straight-run diesel,hydrocracking diesel and blended diesel were investigated by ASTM D5304 method at different oxidation temperatures（ 60 ℃,80 ℃,90 ℃）. The actual change trend of colloid content with the change of oxidation time of diesel oil was measured. The reaction rate equations of three kinds of diesel oils at different reaction temperatures were obtained with the actual colloid as oxidation product. The macroscopic kinetic parameters of the refined oil were obtained by two kinetic methods（ differential method and integral method）. The results showed that：（ 1） when the colourity was considered as the index for stability,the stability of hydrocracking oil was higher than that of blended diesel whose stability was higher than the blended diesel. When the actual colloid was considered as the index for stability,the stability of straight-run diesel is higher than that of blended diesel whose stability is higher than that of hydrocracking diesel.（ 2） When the actual colloids were oxides,the kinetic parameters from different kinetic analysis are different. The activation energy and the values of the preexponential factor obtained by the differential methods are larger than those obtained by the integral method.When differential methods were used to calculate the reaction rate k,the calculation results by both differential and integral methods（ n = 1） were satisfactory. The relative coefficient was greater than 0. 9. The actual colloid production in diesel oxidation process can be estimated by 1/T linear equation.