固体酸水解花生壳制备乙酰丙酸工艺条件的优化

Optimization of Technical Condition for Preparing Levulinic Acid from Peanut Shell by Solid Acid Hydrolyzation

采用沉淀-浸渍法制备了不同金属配比的SO42-/TiO2-Al2O3和SO42-/TiO2-Fe2O3固体超强酸催化剂,并研究了其催化水解花生壳制备乙酰丙酸的效果。实验发现n(Ti)∶n(Al)=1∶2的SO42-/TiO2-Al2O3固体酸催化效果最佳。并进一步考察了水解温度、水解时间、固体酸用量和水料质量比对乙酰丙酸得率的影响,在单因素试验的基础上采用响应面法对水解工艺进行优化。结果表明,优化的水解工艺条件为水解温度235℃、水解时间35 min、固体酸用量5.0%、水料质量比16∶1,在该工艺条件下乙酰丙酸得率为24.38%。

SO42-/TiO2-Al2O3 and SO42-/TiO2-Fe2O3 solid superacids of different metal proportions by impregnation and deposition method were prepared and used for the reaction of catalytic hydrolysis of peanut shells to produce levulinic acid(LA).The results showed that the catalyst property of SO42-/TiO2-Al2O3 solid acid was best with the ratio of n(Ti)∶n(Al)=1∶2,and the effects on hydrolysis temperature,hydrolysis time,the amount of solid acid and water-materials mass ratio on the LA yield had been discussed in this thesis.Hydrolysis process was optimized with response surface method on the basis of single factor experiments.The experimental results showed that the optimal conditions as follows: hydrolysis temperature was 235 ℃,hydrolysis time was 35 min,the amount of solid acid was 5.0%,and water-materials mass ratio was 16∶1.Under this condition,the LA yield could reach 24.38%.