石油酸酯化反应的动力学

 研究了石油酸在镁铝混合氧化物催化下的酯化反应动力学性质。以精制石油酸和乙二醇为反应物，考察了不同馏程的石油酸酯化率与时间的关系，并计算了该反应的表观反应级数。结果表明，当催化剂含量固定，醇过量的条件下，石油酸酯化反应对石油酸是1级反应。以环己酸为模型化合物，利用红外光谱技术推测镁铝混合氧化物催化酯化反应的机理，认为石油酸首先吸附于催化剂表面，然后与醇发生酯化反应，当石油酸浓度不高时，石油酸在催化剂表面的吸附和活化控制酯化反应速率，其速率方程为r = kC(RCOOH)。

KINETICS ON ESTERIFICATION OF PETROLEUM ACID

The kinetics and mechanism of the petroleum acid esterification catalyzed by Mg/Al composite oxides were investigated. The relationship between esterification ratio and time was studied when refined petroleum acids from different fractions and glycol were used as reactants. Also, the apparent reaction order of this reaction was calculated. It is indicated that the reaction order is one when the content of catalyst is fixed and glycol is superfluous. The mechanism of the esterification reaction catalyzed by Mg/Al composite oxides and based on cyclohexanecarboxylic acid as model compound was studied by IR analysis. It is shown that the petroleum acid firstly absorbs on the surface of catalyst and then esterifies with the glycol. When the concentration of petroleum acid is not high, the esterification rate is controlled by the adsorption and activation of petroleum acid on the surface of catalyst. Its rate equation is r = kC(RCOOH).