木质素在超临界甲醇中催化液化的条件优化研究

The study on optimal conditions of lignin catalytic liquefaction in supercritical methanol

研究了在超临界甲醇条件下催化剂用量、料液比、反应时间和反应温度对木质素液化的影响.采用4因素2水平(2~4)全析因设计研究各单因素两两交互作用对木质素液化率的影响.单因素实验结果表明,催化剂用量与木质素质量之比为16.7%时木质素的液化率最高,反应时间和反应温度的增加都会促进木质素的液化,但料液比的增加会降低木质素的液化率.2~4全析因设计表明只有反应温度、反应时间和料液比3个影响因子之间有交互作用.对木质素液化转化率的影响因素:反应温度(A)>反应时间(B)>料液比(D)与反应时间的交互作用>催化剂用量(C)>反应时间和催化剂用量交互作用>反应温度和催化剂用量交互作用>催化剂用量和料液比的交互作用>反应温度和料液比的交互作用.其中反应温度对木质素转化率的贡献率最大,高达85%左右.利用Design-Expert V8.0.6软件得到了超临界甲醇中木质素催化液化的拟合公式:转化率=61.53+8.17A+1.92B-0.99C+3.125×10^(-3)D+0.23AB-0.71AC-0.53AD-0.76BC+1.06BD-0.60CD.

This paper studied the liquefaction of lignin in supercritical methanol under the condition of different reaction temperature,reaction time,mass of catalyst and solid-liquid ratio.It studied the interaction of lignin liquefaction by designed 2~4 factors.The single-factor experiment showed that when the ratio of catalyst to lignin was 16.7% ,the liquefaction rate of lignin was the highest.The increase of reaction time and reaction temperature promoted the lignin liquefaction,but when increased the ratio of liquid to solid decreased the rate of lignin liquefaction.The interactional influence occurred only among the reaction temperature,reaction time and solid-liquid ratio.The result showed that reaction temperature（ A） reaction time（ B） interaction of solid-liquid ratio（ D） and Bmass of catalyst（ C） interaction of B and Cinteraction of A and Cinteraction of C and D interaction of A and D.The most important condition was reaction temperature and the most conversion of lignin was85% .The fitting formula by using Design-Expert V8.0.6 was Conversion = 61.53＋8.17 A＋1.92 B-0.99 C ＋ 3.125 ×10^（-3） D＋0.23 AB-0.71 AC-0.53 AD-0.76 BC＋1.06 BD-0.60 CD.