Reaction mechanism of hydrolysis in Supercritical water

超临界水水解反应机理

• 批准号: 11450295
• 负责人: ADSCHIRI Tadafumi
• 金额: $ 9.54万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450295/
• 关键词: Supercritical water; Spectroscopy; Hydrogen bond; Nitrogen containing organic compounds; Reaction rate; Mechanism; Trehalose; Local solvation structure; 水和構造; 局所構造; セロビオース; キノリン; 加水分解; 紫外吸収; スペクトルシフト; 誘電率; 溶媒和

For understanding specific features of reactions in supercritical water, kinetic study was conducted for the hydrolysis of cellulose model compounds by using a flow-type micro-reactor. At supercritical conditions, hydrolysis rate increased with increasing water density. Comparison of the kinetics with water density or proton concentration suggests a reaction mechanism that hydrolysis reaction undergoes via the direct attack of water molecule to the substrate. Through this study, importance of understanding the local hydration structure around a solute has been suggested for evaluating the reaction kinetics and mechanisms in supercritical water. Thus, we evaluated hydration structure around a substrate by using in-situ UV spectroscopy. The shift of the absorption spectrum of nitrogen containing organic compounds has been analyzed to evaluate the hydrogen bonding and solvation structure around the solute. We found the followings; namely degree of hydrogen bonding decreases with increasing temperature (decreasing water density) in subcritical region, and the hydration structure changes greatly around the critical point, and became significant with increasing water density under the supercritical condition.

为了解超临界水中反应的特点，采用流动式微反装置对纤维素模型化合物的水解反应进行了动力学研究。在超临界条件下，水解速率随着水密度的增加而增加。与水密度或质子浓度的动力学的比较表明，水解反应通过水分子对底物的直接攻击进行的反应机理。通过这项研究，重要的是了解周围的溶质的局部水合结构已建议评估在超临界水反应动力学和机制。因此，我们通过使用原位UV光谱法来评估衬底周围的水合结构。分析了含氮有机化合物吸收光谱的位移，评价了溶质周围的氢键和溶剂化结构。我们发现以下几点：即在亚临界区，随着温度的升高（水密度的降低），氢键作用程度降低;在临界点附近，水化结构发生了较大的变化，在超临界条件下，随着水密度的增加，水化结构的变化更加明显。

项目成果

Sasaki et al.: "Cellulose Hydrolysis in SCW to Recover Chemicals"Proceedings of the 1999 AIChE Annual Meeting. (1999)

Sasaki 等人：“SCW 中的纤维素水解以回收化学品”1999 年 AIChE 年会记录。

Mitsuru Sasaki, Keiko Iwasaki, Toru Hamaya, Tadafumi Adschiri, and Kunio Arai: "Super-Rapid Enzymatic Hydrolysis of Cellulose with Supercritical Water Solubilization Pretreatment"Kobunshi Ronbunshu. 58(10). 527-532 (2001)

Mitsuru Sasaki、Keiko Iwasaki、Toru Hamaya、Tadafumi Adschiri 和 Kunio Arai：“超临界水溶解预处理对纤维素的超快速酶水解”Kobunshi Ronbunshu。

Mitsuru Sasaki,Tadafumi Adschiri,and Kunio Arai: ""Dissolution and Hydrolysis of Cellulose in Subcritical and Supercritical Water""Industrial Engineering Chemistry Research. 39(8). 2883-2890 (2000)

Mitsuru Sasaki、Tadafumi Adschiri、Kunio Arai：“纤维素在亚临界和超临界水中的溶解和水解”工业工程化学研究。

佐々木満, 岩崎恵子, 浜谷徹, 阿尻雅文, 新井邦夫: "セルロースの超臨界水可溶化処理による高速酵素加水分解"高分子論文集. 58(10). 527-532 (2001)

Mitsuru Sasaki、Keiko Iwasaki、Toru Hamaya、Masafumi Ajiri、Kunio Arai：“通过超临界水溶解处理实现纤维素的快速酶水解”，聚合物研究杂志 58(10) (2001)。

Kunio Arai and Tadafumi Adschiri: "Importance of Phase Equilibria Understanding Supercritical Fluid Environment"Fluid Phase Equilibria. 158-160. 673-684 (1999)

Kunio Arai 和 Tadafumi Adschiri：“相平衡对理解超临界流体环境的重要性”流体相平衡。