利用H_nXW_(12)O_(40)催化降解碱木质素工艺的研究

利用具有Keggin结构的HnXW12O40（n=3时,X=P;n=4时,X=Si）对工业碱木质素进行催化降解,采用紫外分光光度法和乙酰化结合电位滴定法测定了降解活化后碱木质素的酚羟基和总羟基含量,分别研究了反应温度、反应时间、催化剂用量和溶剂体系等因素对催化降解后碱木质素羟基含量的影响,确定了HnXW12O40降解碱木质素的最佳工艺条件。同时对降解机理进行了初步探讨。

Degradation of Alkaline Lignin Catalyzed by H_nXW_(12)O_(40)

The alkaline lignin was catalytical degraded by using catalyst-H_nXW_(12)O_(40)(n = 3, X = P; n=4,X = Si) which has Keggin structure. The total hydroxyl content of the degraded lignin was determined by means of combining acetylation with potentiometry titration, while the phenolic hydroxyl content was determined by UV spectrophotometry. Factors affecting the hydroxyl content of lignin such as degradation temperature, reaction time, amount of catalyst and the solvent in the system were studied. The optimum condition of alkaline lignin degradation by the H_nXW_(12)O_(40) was identified. And the catalytical degradation mechanism of lignin by H_nXW_(12)O_(40) was also discussed.