超声波-微波对杉木锯屑液化的强化效应研究

以正辛醇为溶剂、浓硫酸为催化剂，探讨了超声波-微波（UW-MW）辅助对杉木锯屑液化的强化作用，考察了工艺参数的影响，并对液化产物进行了表征分析。研究结果表明：超声波-微波具有很好的传质传热强化效应，与传统液化相比，杉木锯屑超声波-微波辅助液化反应时间从60 min缩短至20 min,液化率提高了5.24%。在溶剂与锯屑质量比值6、催化剂H₂SO₄浓度0.6 mol/L时，杉木锯屑液化率达到64.30%;适当添加γ-戊内酯可提高液化率，γ-戊内酯用量40%时液化率达81.17%。液化过程中，少量熔融状物质沉积在残渣（SR）表面，阻碍了原料的进一步液化；纤维素与半纤维素的降解产物主要为小分子糖类等物质，富集在水相产物（WS）中；木质素的降解产物主要由芳香族等物质组成，分布在生物油（BO）产物中。

Intensification Effect of Ultrasonic-microwave on Liquefaction of Fir Sawdust

The intensification effect of ultrasonic-microwave(UW-MW)assisted on the liquefaction of fir sawdust was discussed by using n-octanol as a solvent and sulfuric acid as a catalyst.The influence of process parameters on the liquefaction ratio was investigated,and the liquefied products were characterized and analyzed.The experimental results showed that ultrasonic-microwave had a good effect on the mass and heat transfer enhancement effect.Compared with the traditional liquefaction,the reaction time of sawdust ultrasonic-microwave assisted liquefaction was shortened from 60 min to 20 min,and the liquefaction ratio increased by 5.24%.Under the conditions of the mass ratio of solvent to sawdust of 6,the concentration of catalyst of 0.6 mol/L,the liquefaction rate of sawdust reached 64.30%,and the proper addition ofγ-valerolactone could increased the liquefaction rate to 81.17%.In the liquefaction process,a little molten materials gradually deposited on the surface of the solid-residue product(SR),which hindered the further liquefaction of the fir sawdust.The most of degradation products of cellulose and hemicelluloses in the sawdust were mainly small-molecule sugars etc.which were enriched in the water-soluble product(WS).The degradation products of lignin were mainly composed of aromatic etc.substances which were distributed in the bio-oil product(BO).