供氢类添加剂与苯氧基乙苯共混热解的反应机理

Co-pyrolysis mechanism of phenethyl phenyl ether with hydrogen donor reagents

采用小型固定台对β-O-4型木质素模型化合物苯氧基乙苯(PPE)进行了不同反应温度下热解以及与不同供氢添加剂下共混热解的研究.利用GC/MS分析热解产物油中芳香族化合物的分布和产率,考察了反应温度和供氢添加剂对热解产物的影响.结果表明,在700℃时,PPE完全热解且单体芳香族产率达到34.78%.在该反应温度下PPE与供氢添加剂共混热解能明显提高单体芳香族产物的产率,其中PPE与甲醇共混热解最高产率为62.62%.不同供氢添加剂因结构的不同对产物的促进效果不同,甲醇能提高苯酚产率至17.33%,丙酮则明显促进了甲苯以及对二甲苯的生成.

Pyrolysis of β-O-4 type lignin model compound phenethyl phenyl ether at different reaction temperatures and co-pyrolysis of PPE（ phenethyl phenyl ether） with different hydrogen donor reagents were conducted in a fixed-bed reactor. The aromatic compounds of pyrolysis products were analyzed by GC/MS（ gas chromatography/mass spectrometer）. The effects of reaction temperature and reaction concentration on pyrolysis product distribution were studied. The results show that PPE is completely pyrolyzed at 700 ℃ and the yield of monomeric aromatics reaches 34. 78%. Yields of monomeric aromatics are significantly increased from the co-pyrolysis process of PPE with hydrogen donor reagents at 700 ℃ and the maximum of 62. 62% with methanol. The promotion of aromatic products is different due to the structures of different hydrogen donor reagents. The addition of methanol can effectively increase the yield of phenol to 17. 33% while the addition of acetone can promote the formation of toluene and p-xylene.