固体酸催化木质素水相降解的试验研究

INFLUENCE OF SOLID ACIDS ON CATALYTIC DEGRADATION OF LIGNIN TO PHENOLIC COMPOUNDS IN AQUEOUS PHASE

对水相环境中,多种固体酸催化剂作用下木质素水相降解生成酚类化学品的反应进行研究,发现在不同固体酸催化剂作用下,木质素转化率为39%~55%,油相产物选择性81.0%~90.6%,单酚类产物选择性为11.6%~25.4%。其中,AC-S催化剂具有较高的油相产物和单酚类产物选择性,条件优化后,其单酚类产物质量收率可达15.7%。通过对多种固体酸催化剂作用下水相降解产物的变化,催化剂表征和反应木质素残渣的FTIR表征,发现具有大比表面积和强酸量的催化剂有利于木质素的转化,而适当的酸性则更有利于获得单酚类产物。

The results showed that under the testing conditions lignin conversion（39%-55%）,selectivity of oil products（81.0%-90.6%） and selectivity of monomeric phenolics（11.6%-25.4%） were varied over various catalysts. TheAC-S was the most suitable catalyst for lignin degradation to product phenolics,and a superior performance obtained was15.7% yield of the monomeric compounds. The catalysts were characterized by Brunauer-Emmett-Teller（BET）analysis andAmmonia temperature programmed desorption（NH_3-TPD）. Fourier transform infrared（FTIR） spectroscopy of solidresidue indicated that lignin was really depolymerized to low molecular weight compounds by catalytic cleavage of etherbonds,especially in AC-S catalyst.