超声波-微波辅助柠檬酸催化纤维素水解条件

Ultrasonic-microwave assisted citric acid catalytic hydrolysis of cellulose

以柠檬酸为催化剂,采用超声波-微波相结合的辅助手法对自制稻草纤维素进行了水解研究。以还原糖得率为指标,在单因素试验的基础上,通过3因素3水平的正交试验考察了酸浓度、超声波处理时间和微波加热时间对指标的影响。对实验结果进行了极差分析和方差分析,结果表明,最佳反应条件为:柠檬酸浓度20%、超声波处理90 min、微波500 W加热30 min,此时还原糖得率最高,达64.46%。对稻草纤维素原料和水解残渣进行了红外表征,结果显示,水解残渣仍以纤维素的形式存在,可重新水解,提高原料利用率。

Using citric acid as catalyst,straw cellulose was hydrolyzed by ultrasonic-microwave assisted technique. The influence of acid concentration,ultrasonic treatment time and microwave heating time was discussed with reducing sugar yield as index. On the basis of single factor test,the results were analyzed through orthogonal test of three factors with three levels. The highest yield of reducing sugar obtained was up to 64.46%,when citric acid concentration was 20%,ultrasonic treatment time and microwave heating time were 120min and 30min,and microwave power was 500W. IR characterization showed that hydrolysis residue still existed in the form of cellulose and could be re-hydrolyzed to increase the utilization rate of raw materials.