Microwave assisted liquefaction (MAL) of alkali lignin in ethylene glycol (EG) in the presence of hydrazine was carried out using response surface methodology. Dielectric properties of mixtures of lignin/EG at different hydrazine concentrations were determined to enhance the understanding of the MAL process. MAL parameters were hydrazine concentration (1–3%), temperature (100-180 °C), time (5-45 min) with the maximum microwave heating power limited to 750 W. Lignin/EG ratio was fixed at 1 g:10 ml. Dielectric properties were significantly influenced by hydrazine concentration and temperature. Major products from the liquefaction process (as % of peak areas) were grouped into guaiacol and derivatives (17–42%), Nitrogen compounds (0–27%), and Hydroxylated products (8–22%), and their yields were modelled with polynomial equations. Product yields were significantly influenced by process parameters. Optimum parameters for maximizing yields of guaiacol and nitrogen containing compounds were 0.5%, 180 °C, 25 min and 2.5%, 130, 25 min for hydrazine concentration, temperature, and time, respectively. Low hydrazine concentration increases guaiacol yield at higher temperatures, indicating that at high temperatures hydrazine behaves as a hydrogen donor for lignin liquefaction. The yield of nitrogen containing compounds increases at relatively low temperatures and high concentration of hydrazine. Apart from playing the respective roles of liquefaction solvent and hydrogen donor, EG and hydrazine also take part in the reaction thereby significantly modifying the composition of reaction products. A mechanistic reaction mechanism was proposed to explain the formation of the liquefaction products.

使用响应面分析法，在肼存在下，在乙二醇（EG）中进行碱性木质素的微波辅助液化（MAL）。确定了木质素/ EG混合物在不同肼浓度下的介电性能，以增强对MAL过程的了解。MAL参数为肼浓度（1-3％），温度（100-180°C），时间（5-45分钟），最大微波加热功率限制为750W。木质素/ EG比固定为1 g：10毫升 介电性能受到肼浓度和温度的显着影响。液化过程的主要产品（占峰面积的百分比）分为愈创木酚和衍生物（17–42％），氮化合物（0–27％）和羟基化产品（8–22％），并且对它们的产率进行了建模。与多项式方程。产品产量受到工艺参数的显着影响。对于肼浓度，温度和时间，使愈创木酚和含氮化合物的产率最大化的最佳参数分别为0.5％，180°C，25分钟和2.5％，130、25分钟。低肼浓度可在较高温度下提高愈创木酚的收率，这表明在高温下肼可充当木质素液化的氢供体。含氮化合物的产率在相对较低的温度和较高的肼浓度下增加。除了分别发挥液化溶剂和氢供体的作用外，EG和肼也参与反应，从而显着改变反应产物的组成。