沙柳酸催化水解制备乙酰丙酸及分离提纯

以沙柳为原料，硫酸为催化剂，考察了催化剂浓度、反应时间、反应温度、液固比对沙柳水解制备乙酰丙酸得率的影响，通过正交实验方法得到最佳的水解反应条件为：反应温度200 ℃，反应时间90 min，催化剂质量分数9%，液固比（mL∶g）15∶1，乙酰丙酸的最高得率为18.80%；各因素对水解反应影响的大小顺序为：反应时间＞催化剂浓度＞反应温度＞液固比。在静态条件下，用335弱碱性阴离子交换树脂对水解液进行分离提纯，在附吸温度为35 ℃、树脂投料量为15 g、盐酸洗脱剂浓度为0.5 mol/L时，乙酰丙酸的回收率为95.35%。

Preparation of levulinic acid from hydrolysis of Salix psammophila catalyzed by acid and its separation and purification

Preparation of levulinic acid from hydrolysis of Salix psammophila catalyzed by sulfuric acid as catalyst was studied in this paper. The effects of catalyst concentration，reaction time，reaction temperature，liquid-solid ratio on the yield of levulinic acid were investigated. By orthogonal tests，the optimum hydrolysis reaction conditions were as follows：reaction temperature 200℃，reaction time 90 min，catalyst concentration 9%，liquid-solid ratio(mL∶g) 15∶1，the highest yield of levulinic acid was 18.80%，the order of the factors was obtained according to the degree to which they could affect hydrolysis reaction as follows：reaction time > catalytic concentration > reaction temperature > liquid-solid ratio. 335 weak basic anion-exchange resin was used for separation and purification of hydrolysis mixed solution，under the static conditions of adsorption temperature 35 ℃，amount of resin 15 g，eluent concentration (HCl) 0.5 mol/L，recovery of levulinic acid was 95.35%.