玉米秸秆乙醇低聚糖纯化及热稳定性研究

Study on Purification and Thermal Stability of Ethanol Oligosaccharides from Corn Stover

中文关键词:  秸秆低聚糖  乙醇法制浆  热稳定性  低聚糖纯化

Key Words:corn stover oligosaccharides  ethanol pulping  thermal stability  oligosaccharide purification

中文摘要:

      本研究以从玉米秸秆乙醇法制浆废液中提取的乙醇低聚糖为原料，将其进行树脂纯化并分级得到分子质量在200~1000 D的低聚糖，通过测试不同升温速率下低聚糖的热稳定性能，并结合非线性拟合计算，得到低聚糖的热解活化能（E）和指前因子（lnA）。结果表明，在非等温程序下提纯分级所得低聚糖分解温度范围为160~300 ℃，灰分较多会降低低聚糖的热稳定性。分级处理所得未纯化低聚糖（O₀）、脱盐低聚糖（B₀）、脱色低聚糖（C₀）和脱盐+脱色低聚糖（D₀）对应的E分别为46.52、60.55、43.12和52.28 kJ/mol，lnA分别为4.03、7.70、2.98和5.47 min^-1。本研究及结果有助于选择合适的生产工艺参数，优化提取纯化工艺，为开发提取新方法提供借鉴。

Abstract:

      In this study， ethanol oligosaccharides extracted from the waste liquid of corn stover ethanol pulping as raw materials were purified by resins， and fractionated to obtain the components with molecular weight of 200~1000 D. By testing the thermal stability of oligosaccharides at different heating rates and calculating by nonlinear fitting， the pyrolysis activation energy （E） and pre-exponential factors （lnA） of oligosaccharides were obtained. The results showed that the decomposition temperature range of purified and fractionated oligosaccharides was 160~300 ℃ under non-isothermal procedures， and the thermal stability of oligosaccharides decreased when the ash content increased. The E values of unpurificated oligosaccharides O₀， desalinated oligosaccharides B₀， decolorized oligosaccharides C₀ and desalinated and decolorized oligosaccharides D₀ after fractionation were 46.52， 60.55， 43.12 and 52.28 kJ/mol， respectively， and the pre-exponential factors （lnA） were 4.03， 7.70， 2.98 and 5.47 min^-1， respectively. This study and results could provide reference for the purification and the selection of technological parameters.