Research On Biomass Tar Catalytic Cracking

This paper focused on biomass thermochemical conversion technology, mainly the crack of tar. During the process of gasification or cracking tar was the byproduct inevitably, tar is undesirable because of various problems associated with condensation, formation of tar aerosols and polymerization to form more complex structures,which cause problems in the process equipment as well as the engines and turbines used in application of the gasification products. The elimination of tar and purification of tarry gas is a crucial step in the development of biomass gasification. On the basis of technology of purification of hot gas of biomass gasification and catalyst technology, naphthalene was choosen as a model compound of biomass tar, compared water reforming with dry reforming, dry reforming was used in this paper. And pure CaO, MgO,Fe2O3 as tar cracking catalysts. At 900℃, improvement in naphathelene conversion of around 80% was observed over Fe2O3 catalyst, 72% over CaO- MgO, around 69% over MgO, and 64% over CaO. But only 33% naphathalene conversion was observed in laboratory without catalysts. Moreover, the effect of catalysis temperature, residence time, and the size of catalyst particle in naphathelene conversion was also studied. There was no carbon formation in the catalyst after 2 hours. Then apply one set of composition model and Arrhenius for tar catalytic theorem, analysis of experiment datas, calculate reaction speed and activation energy for different catalytic reforming process. The results showed anastomose with experiment. The activation energy of catalysis was reduced from E=173.3kJ/mol to E=92.4kJ/mol.