竹木质素的NaOH-乙醇水溶液热降解及产物分析

本研究以NaOH-乙醇水溶液为溶剂体系对竹木质素进行热降解，主要考察了NaOH浓度、反应温度、反应时间、乙醇用量等条件对竹木质素降解转化为酚类化合物的影响。通过GC-MS及FT-IR对降解产物进行分析检测，得出最佳反应条件为：竹木质素5 g，NaOH浓度（基于乙醇水溶液）20 g/L，乙醇10 mL，反应时间2 h，反应温度240℃。在此条件下，降解产物中总的酚类化合物的相对峰面积为73.88%，残渣率为30.67%。竹木质素的降解主要产物是酚类化合物：苯酚（17.98%）、2-甲氧基苯酚（16.49%）及1,2-苯二酚（10.03%）。与现有文献相比，本文竹木质素在碱性乙醇溶剂体系中降解能够获得较高产量的酚类化合物，有望实现竹木质素的高值化利用。

Thermal Degradation of Bamboo Lignin in Alkaline Ethanol Solvent and Product Analysis

The thermal degradation of bamboo lignin in NaOH-ethanol solvent system was studied in this work. The effects of NaOH concentration, reaction temperature, reaction time, and dosage of ethanol on the phenolic products were investigated, respectively. The degradation products were analyzed by GC-MS and FT-IR. The optimum conditions were achieved as follows: mbamoo lignin = 5 g, CNaOH (in alcohol aqueous systems) = 20 g/L, Vethanol = 10 mL, reaction temperature is 240oC and reaction time is 2 h. The total relative peak area of phenolic products in the degradation products was 73.88%, and the yield of residue was 30.67%. The main products of bamboo lignin degradation were phenols, such as phenol (17.98%), 2-methoxyphenol (16.49%) and 1,2-benzenediol (10.03%). The results indicated that higher yield of phenolic products was obtained under the optimized conditions compared with the reports. This work showed the potential to degrade bamboo lignin into high value products in NaOH-ethanol solvent system.