Experimental Study on Rapid Pyrolysis of Biomass to Bio-oil under Mo/ZSM-5 Catalysis

The rapid catalytic pyrolysis of biomass to prepare high-quality bio-oil technology can realize the preparation of chemicals and liquid fuels, and is considered to be one of the effective ways to realize the replacement of fossil energy. However, bio-oil has the disadvantages of complex components, high oxygen content, and difficulty in separation. It needs to be catalytically upgraded before it can be used as an alternative fuel. Therefore, how to develop high-efficiency bio-oil upgrading catalysts to achieve the preparation of high value-added target products is the main bottleneck facing the development of this technology.

ZSM-5 molecular sieve catalysts are widely used in the rapid catalytic pyrolysis of biomass to prepare bio-oil due to their good shape selectivity and aromatization properties. Wang Fei et al. reported the changes in the composition of the three components of biomass and the bio-oil obtained from pine pyrolysis under the catalysis of ZSM-5 molecular sieve. Experimental studies found that the addition of ZSM-5 catalyst effectively reduced the phenol content in Yunnan pine pyrolysis bio-oil , Significantly increase the content of aromatic compounds. Mihalcik et al. studied the effects of mordenite, H-ZSM-5, HY, H-Beta and ferrierite on the catalytic pyrolysis products of biomass and its three major components, and the results showed that microporous H-ZSM-5 The most effective catalysis to produce aromatic compounds. However, during the pyrolysis reaction, the ZSM-5 catalyst has a high coking rate and is easy to deactivate. Metal modification can effectively improve the reaction activity and stability of the ZSM-5 catalyst. Iliopoulou et al. studied the on-line catalytic upgrading of biomass pyrolysis oil by Ni and Co modified HZSM-5, and found that the addition of Ni and Co effectively reduced the oxygen content of the bio-oil, and increased the yield and yield of aromatic compounds. The stability of the catalyst. In addition, in the literature published earlier by the author of this article, it was reported that the metal Fe-modified ZSM-5 catalyst was applied to the rapid pyrolysis of biomass to prepare bio-oil. The study found that the addition of Fe reduced the content of oxygen-containing compounds in the bio-oil and increased To improve the quality of bio-oil, the content of aromatic hydrocarbon compounds is the highest.

In summary, there have been many reports on the application of metal-modified ZSM-5 molecular sieve catalysts to the rapid pyrolysis of biomass, but there are few reports on the influence of Mo-modified ZSM-5 molecular sieve catalysts on the yield and composition of bio-oil. . Therefore, in this experiment, a series of Mo/ZSM-5 catalysts were prepared by the equal volume impregnation method and applied to the rapid pyrolysis of biomass to prepare bio-oil. The Py-GC/MS device was used to focus on the effects of Mo loading, reaction temperature, reaction time, and the mass ratio of catalyst to wood powder, etc., to study the change of bio-oil yield and composition with reaction conditions, which is a biomass catalysis Pyrolysis provides experimental and theoretical basis for preparing high-quality bio-oil.