改性粉煤灰催化合成苹果酯的研究

以过硫酸铵改性工业废渣粉煤灰为催化剂，对乙酰乙酸乙酯和乙二醇合成苹果酯的催化工艺进行了系统研究。讨论了反应时间、酯醇比、催化剂用量和带水剂用量对酯化率的影响。最佳反应条件为：n（乙酰乙酸乙酯）：n（乙二醇）：1：1．8，催化剂用量为乙酰乙酸乙酯质量的1．5％，带水剂用量为15mL，反应时间3h。在优化条件下反应，苹果酯产率达到95．9％，选择性98．0％以上。实验表明，改性粉煤灰是合成苹果酯的优良催化剂，与其他酸催化剂相比，它还具有活性高、用量少且可重复使用等优点。

Studies on catalytic synthesis of fructone with modified fly ash

The synthesis of fructone from ethyl aeetoacetate and ethylene glycol using fly ash modified by ammonium peroxydisuffate as solid acid catalyst was investigated. Various reaction parameters such as reaction time, ratio of ethyl acetoacetate to ethylene glycol, catalyst amount and water-carrying reagent amount were studied. The optimum reaction conditions were： the molar ratio of ethyl acetoacetate to ethylene glycol is 1 ： 1.8, the quantity of catalyst-1.5 wt.% by weight of ethyl acetaoacetate, amount of eyclohexane-15 mL, and the reaction time will be 3 h. Under this optimum condition, the yield of fructone reaches 95.9%. The experimental results showed that fly ash modified by ammonium peroxydisulfate is an excellent catalyst for synthesis of fructone. Comparaed with other acid catalysts, the sulfonated activated carbon has higher activity, lesser used quantity and reusability.