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考察了不同Si/Al的分子筛H-ZSM-5和具有不同Zn含量的分子筛Zn/ZSM-5中Brnsted酸和路易斯酸性位对纤维素催化热解行为的影响。通过氨气程序升温脱附(NH3-TPD)、吡啶吸附红外光谱、X射线衍射谱(XRD)来表征催化剂的Zn物种的酸性性质。通过热重方法(TG)分析纤维素热解动力学,分别采用气质联用仪(GC-MS)和水分滴定仪来检测生物油的主要成分和含水量。结果表明,生物油的主要成分主要包括左旋葡聚糖(LGA)、左旋葡萄糖酮(LGO)、1,4:3,6-双脱水-β-D-吡喃葡萄糖(DGP)、呋喃化合物如糠醛和2,5-二甲基呋喃、醛类等。H-ZSM-5和Zn/ZSM-5能显著地改变纤维素的热解行为,H-ZSM-5能够增加生物气的产率但减少了生物油和生物炭的产率,并且发现Brnsted酸和路易斯酸性位能调变生物油中某一些特定组分。
The effects of Brnsted acid and Lewis acid sites on the catalytic pyrolysis of cellulose with different Si / Al molecular sieves H-ZSM-5 and Zn-ZSM-5 zeolites with different Zn contents were investigated. The acidic properties of the Zn species in the catalyst were characterized by ammonia temperature programmed desorption (NH3-TPD), pyridine adsorption infrared spectroscopy and X-ray diffraction (XRD). The pyrolysis kinetics of cellulose was analyzed by thermogravimetry (TG). The main components and water content of bio-oil were detected by gas chromatography-mass spectrometry (GC-MS) and moisture titrator respectively. The results showed that the main components of bio-oil mainly include levoglucosan (LGA), levoglucosone (LGO), 1,4: 3,6-dianhydro-β-D-glucopyranose (DGP) Furfural and 2,5-dimethyl furan, aldehydes and the like. H-ZSM-5 and Zn / ZSM-5 can significantly change the pyrolysis behavior of cellulose. H-ZSM-5 can increase the yield of biogas but reduce the yield of bio-oil and biochar. Nsted acid and Lewis acid sites can modify some specific components of bio-oil.