Shafiei Marzieh, Karimi Keikhosro, Zilouei Hamid, Taherzadeh Mohammad J
Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran ; Industrial Biotechnology Group, Institute of Biotechnology and Bioengineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Biomed Res Int. 2014;2014:469378. doi: 10.1155/2014/469378. Epub 2014 Aug 4.
N-Methyl morpholine-N-oxide (NMMO) is an environmentally friendly and commercially applied cellulose solvent that is suggested for pretreatment of lignocelluloses to improve biofuel productions. However, the underlying mechanisms of the improvements have been poorly understood yet. In an attempt to investigate the mechanisms, pinewood powder and chips were pretreated with 85% (w/w) NMMO at 120°C for 1-15 h. The pretreatment improved ethanol production yield from 7.2% (g/g) for the untreated wood powder to 68.1-86.1% (g/g) and from 1.7% (g/g) for the untreated wood chips to 12.6-51.2% (g/g) of theoretical yield. Similarly, the biogas yields of untreated wood chips and powder were improved from 21 and 66 (mL/g volatile solids) by 3.5-6.8- and 2.6-3.4-folds, respectively. SEM micrographs indicated major increase in the wood porosity by the pretreatment, which would confirm increase in the water swelling capacity as well as enzyme adsorption. The analysis of X-ray diffraction showed considerable reduction in the cellulose crystallinity by the pretreatment, while FTIR spectroscopy results indicated reduction of lignin on the wood surface by the pretreatment.
N-甲基吗啉-N-氧化物（NMMO）是一种环境友好且已商业化应用的纤维素溶剂，被建议用于木质纤维素的预处理以提高生物燃料产量。然而，其改善效果的潜在机制尚未得到充分理解。为了探究这些机制，将松木粉和木片在120°C下用85%（w/w）的NMMO预处理1 - 15小时。预处理使乙醇产量从未处理木粉的7.2%（g/g）提高到理论产量的68.1 - 86.1%（g/g），从未处理木片的1.7%（g/g）提高到12.6 - 51.2%（g/g）。同样，未处理木片和木粉的沼气产量分别提高了3.5 - 6.8倍和2.6 - 3.4倍，从21和66（mL/g挥发性固体）提高到相应水平。扫描电子显微镜图像表明预处理使木材孔隙率大幅增加，这证实了木材的水溶胀能力以及酶吸附能力的提高。X射线衍射分析表明预处理使纤维素结晶度显著降低，而傅里叶变换红外光谱结果表明预处理使木材表面的木质素减少。
