以纯化分离秸秆酶解液中低聚木糖为目的,以蛋白、木质素去除率和低聚木糖的透过率为评价指标,采用工业化超滤膜分离装置,考察料液浓度、操作压力、温度、pH值对超滤除杂的影响。单因素实验确定初步的工艺条件后,Box-Behnken模型优化得最佳超滤纯化工艺条件为:料液浓度2.24°Bx,操作压力0.18 MPa,温度25℃,pH 7.0。在此条件下,低聚木糖的透过率为92.1%,蛋白去除率67.9%,木质素去除率67.8%,透过液澄清透亮。响应面法分析各因素对超滤提纯效果的影响,其强弱性依次为:料液浓度、pH值、操作压力、操作温度。

Ultrafiltration membrane separation was used to purify xylooligosaccharides(XOS) from straw enzymatic hydrolysis.Protein,lignin removal rates and XOS transmittance were used as evaluation indices,the influence of feed concentration,operating pressure,temperature,and pH on the purification efficiencies were studied.Preliminary extraction conditions were studied by single factor experiment,and then optimized by Box-Behnken model.The results were: feed concentration 2.24 ° Bx,operating pressure 0.18MPa,temperature 25℃,pH 7.0.Under these conditions,XOS transmittance was 92.1%,protein removal rate was 67.9%,and lignin removal rate was 67.8%.The factors of ultrafiltration purification were analyzed by response surface method,the order of importance was: feed concentration,pH value,operating pressure,and operating temperature.This research provides reference for XOS purification process by ultrafiltration separation method.