稻草超高压爆破前处理研究

Studies on Pretreatment of Rice Straw by Ultra-high Pressure Explosion with a High-pressure Homogenizer

关键词:  超高压爆破  前处理  稻草

Key words:  ultra-high pressure explosion  pretreatment  rice straw

摘要:

应用高压均质技术对稻草进行超高压爆破前处理。稻草粉碎后经1%的NaOH加热处理,保持悬浮状态下通过高压均机实施超高压爆破。结果表明,100MPa爆破使稻草颗粒悬浮液变为粘稠流体,粒度显著变小,超微结构由纤维状变为松软的中空多孔状,纤维素结晶指数降低19.76%,耗碱量增加163.41%。爆破对还原糖、木质素和灰分等成分含量几乎没有影响。处理后每克稻草用5.8FPU的纤维素酶,6.6IU的木聚糖酶和0.5CBU的β-葡萄糖苷酶酶解72h,酶解率达100.09%,较对照提高44.85%。超高压爆破显著破坏了木质纤维的超微结构,增大了酶的作用面积。

Abstract:

Rice straw was treated by Homogenization in a constant suspended state with a homogenizer,a process termed as ultra-high pressure explosion (UHPE).The stalk of rice straw was grinded into powder,heated in 1% NaOH solution,then 100MPa UHPE-treated through a homogenizer under a constant suspended state.The results verified that UHPE changed the suspension of rice straw powder into a stick fluid.The granularity determination and scanning electron microscope observation confirm that UHPE can decrease the granularity of rice straw powder significantly and disrupt the lignocellulosics microstructure of rice straw from a rigid and highly ordered fibril to a distorted,poly-porous and "center empty" structure.UHPE also decreased 19.76% of the crystallinity index of cellulose and increased 163.41% of NaOH comsuming.However,the effect of UHPE on the contents of reduced sugar,lignin and ash was minor.After pretreatment,the enzymatic digestibility of rice straw reached to 100.09%,a complete hydrolysis within 72h by a low enzymes loading,5.8FPU of cellulase,6.6IU of xylanase and 0.5CBU of β-glucosidase per gram substrate,44.85% higher than that of NaOH treated control sample.The result that UHPE disrupted the microstructure of lignocellulosic biomass was not observed in previous investigation.