锯末快速热解气的在线催化裂解

采用Py-GC/MS装置对锯末进行快速热解并对热解气进行在线检测，研究了HZSM-5分子筛和SBA-15介孔催化剂对热解气进行在线催化裂解的效果。结果表明，热解气经HZSM-5催化裂解后，乙酸、羟基乙醛、呋喃类以及酚类物质的产率都大幅降低，同时形成了大量的芳香烃产物，主要是甲苯和二甲苯;而热解气经SBA-15催化裂解后，乙酸产率降低、羟基乙醛产率稍有降低、呋喃类和酚类物质的产率增加，只检测到了极少的烃类产物。由此可知，这两种催化剂对热解气有着不同的催化裂解效果：HZSM-5具有较好的催化脱氧功效;而SBA-15则基本不具有催化脱氧形成烃类产物的能力，但其介孔结构能够允许生物质裂解过程中形成的分子较大的低聚物进入其中并发生二次裂解，从而形成小分子产物。

In situ catalytic cracking of sawdust fast pyrolysis vapors

Fast pyrolysis of sawdust was performed and the pyrolysis vapors were analyzed with on-line pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS).Two catalysts, zeolite HZSM-5 and mesoporous SBA-15, were tested to determine their actions on the pyrolysis vapors.The catalytic cracking of the pyrolysis vapors with HZSM-5 significantly decreased the yields of acetic acid, hydroxyacetaldehyde, furans and phenols, and meanwhile a lot of aromatic hydrocarbons were formed, mainly toluene and xylenes.The catalytic cracking of the pyrolysis vapors with SBA-15 decreased the yield of acetic acid, slightly decreased the yield of hydroxyacetaldehyde, and increased the yields of furans and phenols.The results indicated that the two catalysts exhibited different catalytic cracking actions on the pyrolysis vapors.HZSM-5 was highly active in deoxygenation of the pyrolysis vapors.SBA-15 possessed very little activity to catalyze the pyrolysis vapors to form hydrocarbons, but its mesoporous structure allowed cracking of large molecules to smaller sawdust compounds.