Preparation And Characterization Of Catalysts For Oriented Production Of Olefins From Biomass Pyrolysis Tar

Biomass pyrolysis technology can achieve better utilization of biomass energy,biomass energy is a kind of extremely the development potential of using the technology,but its complicated chemical composition of by-product biomass tar,the unique physical and chemical properties for production bring certain security hidden danger,serious limits its application and industrialization of.As a promising new catalyst,ZSM-5 molecular sieve is widely used in chemical industry.ZSM-5molecular sieve as a carrier catalyst for the synthesis and preparation of new catalysts,to further understand its catalytic transformation properties and expand its application field has important research significance.This thesis is about the preparation of a kind of can improve the biomass pyrolysis tar modified catalysts for olefin yield as a starting point,use of biomass pyrolysis equipment in the laboratory,the test research biomass catalytic pyrolysis tar model compound,is investigated in different Si/Al ratio of ZSM-5 zeolite catalyst as a carrier catalyst,the load of different transition metal catalyst preparation the influence of the synthesis of new type catalyst for pyrolysis tar product,for the preparation of a kind of can improve the biomass pyrolysis tar olefin yield of modified catalyst experimental study provides a scientific basis.The conclusion is as follows.ZSM-5 molecular sieve was synthesized by soft template method.The grain size of ZSM-5 molecular sieve was between 0.2 micron and 1.0 micron.Through characterization analysis of the prepared molecular sieve,it was found that the ZSM-5molecular sieve with Si/Al value of 45/1 was used as a catalyst in the experiment of pyrolysis of tar model naphthalene,showing the best catalytic performance,and the conversion rate of naphthalene was up to 85%.On this basis,the prepared ZSM-5molecular sieve was modified by loading.It was found that the loading of metals Ni and Zn had no effect on the surface morphology characteristics of the molecular sieve,but the crystallinity and grain size of the molecular sieve increased after loading of metal Ni.In the pyrolysis experiment of two kinds of molecular sieve catalysts with different loads prepared,it was found that when the load of Ni was 0.6wt%,modulated naphthalene had the best conversion rate,reaching 93%,while the load of Zn did not significantly improve its catalytic conversion efficiency.After loading two ZSM-5 molecular sieves with different morphologies,it was found that the catalytic performance of the molecular sieves with chessman morphology was improved by loading Ni groups,and the conversion rate of modulates could reach 97%.The experimental results show that the catalytic transformation performance of ZSM-5 molecular sieve can be improved by metal loading modification.The molecular sieves with different morphologies prepared will also have an impact on the load modification results.Therefore,it is of great significance to study the synthesis and preparation of ZSM-5 molecular sieves with different morphologies and conduct different metal load modification on the molecular sieves.