微波辅助稀酸降解玉米芯的工艺优化及其效果研究

Study on optimization and effect of microwave assisted dilute acid degradation of corn cob

为提高木质纤维素的利用率及经济效益,以稀酸为催化剂,采用微波辐射相结合的方法对玉米芯进行水解研究。以还原糖得率和原料转化率为指标,通过单因素试验和正交试验考察微波辐射时间、微波功率、酸浓度、固液比和秸秆颗粒大小等对玉米芯水解的影响,利用扫描电镜(SEM)和红外光谱(FT-IR)分析原料及不同方法处理后的水解残渣。结果表明,微波辐射稀酸催化玉米芯水解的最佳工艺条件为:玉米芯粉碎至60~80目,常压,固液比1:8(g/mL),酸浓度13%,微波功率130 W,反应时间20min,该条件下还原糖得率为66.41%、原料转化率为52.70%。SEM及FT-IR分析表明微波辅助稀酸的降解效果较好,反应后玉米芯的表面结构遭到了严重的破坏,其半纤维素基本被水解,同时也有部分纤维素被水解。

In order to improve the utilization rate and economic benefit of lignocellulose, the hydrolysis of corncob was studied by the method of using dilute acid as catalyst under microwave irradiation. Through single factor and orthogonal way , the influences of micro wave radiation time, microwave power, acid concentration, solid-liquid ratio and particle size of corncob were discussed with sugar yield and raw material conversion rate as index ; Raw materials and three methods of treatment of hydrolyzed residue were analyzed by scanning electron microscopy （SEM） and infrared spectroscopy （FT- IR）.The results showed that the optimal reaction conditions were as follow., corncob was crushed to 60-80 mesh, the solid-liquid ratio was 1 ： 8 （g/mL）, the acid concentration was 13%, the microwave power was 130 W, and the reaction time was 20 min. At this time the yield of reducing sugar was 66.41G, the conversion rate of raw materials was 52.70%. SEM and FT-IR analysis showed that the effect of microwave acid was good, and the surface structure of the corncob after the reaction was seriously damaged. In the corncob hy drolytic residue of microwave radiation and dilute acid catalyzed, the hemicellulose was completely hydrolyzed, and some of the cellulose was hydrolyzed.