木質纖維素物質是地球上含量最豐富的可再生資源,我們可藉由蒸煮爆碎法將其中的半纖維素部分降解成糖類溶於液體當中,但是有部分的纖維素以及半纖維素會過度過降解成抑制物,需將抑制物去除。 本實驗選用掃流過濾法將抑制物從液體當中去除,為了確定此方法的可行性,先配製與蒸爆液體濃度相同的樣品,測試影響分離效果的變因,包括溫度、掃流流速、壓力、pH值等,找出糖類與抑制物分離效果最佳的條件。 由實驗結果顯示,pH值對醋酸在過濾時有相當大的影響,而對葡萄糖、木糖、木寡糖、HMF、furfural等成分無影響。木寡醣濃度提高時,部分木二糖會因分子間的擠壓而透過濾膜,如要進行濃縮需考慮其濃度影響;醋酸以及HMF在適當的實驗條件下皆能完全透過濾膜分離,而furfural則是在任何實驗條件下其保留率幾乎為定值31%,透過濃縮應能完全除去。仿蒸爆液的實驗樣品在木寡醣濃度20 g/L、掃流速度0.22 m/s,壓力5 bar下有最佳的分離效果,木寡醣保留率92%、醋酸保留率-24%,HMF保留率-833%,furfural保留率30%。
Lignocellulosic biomass is the most abundant renewable resources on earth, the hemicelluloses can partially degraded into saccharides with steam explosion. However, some cellulose and hemicelluloses will be excessive degradation into inhibitors, we must be remove the inhibitors. In this study, we using nanofiltration to remove the inhibitors. In order to determine the feasibility of this method, we prepare the model solutions that similar to the steam explosion liquids, then we test the impact of separation of variables. The variables include temperature, crossflow rate, pressure and pH, to find the best separation condition of the saccharides and inhibitors. From the results of the experimentals, pH has a great influence of acetic acid during the cross-flow filtration, but no effect for glucose, xylose, xylooligosaccharide, HMF and furfural. When the xylooligosaccharide concentration rises, the xylobiose can partially through the membrane by the intermolecular squeeze, if you want to concentrate the xylooligosaccharide liquids, you need to consider the effect of the xylooligosaccharide concentration. In the appropriate experimental conditions, HMF and acetic acid can entirely separate via cross-flow filreation. furfural’s retention maintain as a fixed value 31% in any experimental conditions, by the concentrate process, furfurals should be removed completely. The model solution of steam explosion liquid has the optimum inhibitors separation performance at xylooligosaccharide concertration 20 g/L, cross-flow rate 0.22 m/s, pressure 5 bar, the observed retention of xylooligosaccharides, acetic acid, HMF, furfural were 92%, -24%, -833%, 30%, respectively.