蓝桉树皮化学成分及其液化工艺分析

Analysis of Chemical Components and Liquefaction Process of Eucalyptus globulus Bark

对5年生蓝桉树皮进行液化处理,对比分析液化前后蓝桉树皮及其液化残渣的化学成分,以探究蓝桉树皮最佳液化工艺。化学成分测定结果表明,蓝桉树皮纤维素、半纤维素和木质素含量为分别为36.65%、18.98%和45.37%,苯醇抽提物、热水抽提物和1%NaOH抽提物含量分别为10.30%、7.15%和23.64%,灰分含量占7.49%。液化工艺研究表明,浓硫酸催化效果明显优于浓磷酸;蓝桉树皮最佳液化工艺参数为:催化剂为3%浓硫酸,温度为160℃,固液比为1∶5。在该液化条件下,蓝桉树皮液化率为82.8%,液化残渣与原料相比,纤维素含量减少了17.90%,半纤维素含量减少了9.19%,木质素含量减少了15.99%。

For 5-year-old Eucalyptus globulus,the optimal liquefaction bark process was explored by analyzing the chemical components of the bark and its liquefaction residue before and after the liquefaction.The results of chemical component determination showed that the contents of cellulose,hemicellulose and lignin of bark were 36.65%,18.98%and 45.37%,respectively.The contents of benzene-alcohol extractives,hot-water extractives and 1%NaOH extractives were 10.30%,7.15%and 23.64%,respectively.The content of ash accounted for 7.49%.The liquefaction process showed that the catalytic effect of concentrated sulfuric acid was better than concentrated phosphoric acid.The optimum liquefaction parameters were catalytic of 3%concentrated sulfuric acid,temperature of 160℃and liquid-solid ratio of 5∶1.The liquefaction rate was 82.8%under above optimal conditions.Compared with raw materials,the cellulose content,hemicellulose content and lignin content of liquefaction residue reduced by17.90%,9.19%and 15.99%,respectively.