采用酸-超声波强化碱预处理稻秆和玉米芯

Acid-ultrasound strengthened alkali pretreatment of rice straw and corncob

通过对原料成分和糖化率的测定,分析了不同预处理方法对稻秆和玉米芯的预处理效果,同时探讨了超声波对生物质结构的强化机制.分别采用XRD衍射和DNS比色法测定超声波强化预处理后的稻秆和玉米芯结晶度变化以及预处理液中的还原糖得率,并进一步分析了超声波对不同成分原料的作用效果.结果表明:在酸-碱耦合的基础上进行超声波强化能在较短的作用时间内使稻秆中半纤维素的质量分数降低20.61%,而使玉米芯中木质素的质量分数降低45.98%.此外,超声波强化预处理后的稻秆和玉米芯的糖化率分别提高了20.18%和9.47%,同时其结构中的(002)晶面衍射峰均有不同程度的增强.这表明对不同成分的原料,超声波均能有针对性地降低木质素或半纤维素的质量分数,而木质素含量对原料结晶结构有着直接的影响.

Performance of different pretreatment of rice straw and corncob were compared and the strengthening mechanism of ultrasound was investigated through raw material component analysis and saccharification rate analysis. The effect of ultrasound on crystalline structure of rice straw and corn- cob was studied by XRD （X-ray diffraction） and DNS （3,5-dinitrosalicylic acid） colorimetry was used for the filtrate after ultrasound pretreatment for the saccharification rate. The results show that the mass percentage of hemicellulose in rice straw is decreased by 20.61% and that of lignin in corn- cob is reduced by 45.98 % after ultrasound radiation for a shorter pretreatment time on the basis of acid and alkali combination. Furthermore, the saccharification rate of rice straw and corncob are en- hanced by 20.18 % and 9.47 %, respectively. Meanwhile, an increase in the peak intensity of （002） plane for both materials are clearly observed after ultrasound pretreatment. It demonstrates that for different raw material the ultrasound is beneficial to the reduction of mass percentag of lignin or hemicellulose, and the former directly affects the crysalline structure.