PRETREATMENT OF BAMBOO WITH SODIUM HYDROXIDE/UREA SOLUTION AT LOW TEMPERATURE FOR AN EFFECTIVE BIOETHANOL PRODUCTION:CHARACTERIZATION OF THE CELLULOSIC RICH FRACTION
Ball-milled bamboo (Neosinocalamus affinis) was subjected to sodium hydroxide/urea solution pretreatment at a low temperature followed by sequential extractions to isolate cellulosic rich fractions for further utilization. The de-waxed bamboo was first ball-milled for 48 h and sonicated using ultrasonic irradiation in ethanol solution at 20 oC for 0, 5, 15, 35, and 50 min, respectively. Then the samples were dissolved with 7％ NaOH/12％ urea solutions at –12 oC, followed by successive extractions with ethanol, dioxane, and dimethyl sulfoxide (DMSO). The yields of the cellulosic rich fractions ranged from 75.1 to 77.7％. In addition, the structural features of the cellulosic rich fractions were characterized with a set of spectroscopy and wet chemistry methods including FT IR, CP/MAS 13C NMR, XRD, SEM, sugar analysis, etc. Based on the chemical analysis, the composition of the cellulosic rich fraction did not change significantly, though there was a higher proportion of glucose and xylose, compared to the un-treated sample. Furthermore, the viscosity and degree of polymerization (DP) of the cellulosic rich fractions increased slightly as the ultrasonic irradiation time was prolonged. CP/MAS 13C NMR showed that the cellulosic rich fractions contained a mixture of crystallized cellulose I and amorphous cellulose. Besides, more loosened structure with more surface area was examined by SEM. The results indicated that the combined treatments did not degrade the cellulose significantly, but defibrillated the bamboo mill effectively, which facilitated the enzymatic hydrolysis for bioethanol production.
bamboo cellulose NMR SEM sodium hydroxide /urea XRD
Li Mingfei Fan Yongming Xu Feng Sun Runcang
Institute of Biomass Chemistry and Technology,Beijing Forestry University, Beijing, China Institute of Biomass Chemistry and Technology,Beijing Forestry University, Beijing, China State Key
国际会议
广州
英文
1336-1339
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）