Partial Oxidation of Filter Cake Particles from Biomass Gasification Process in the Simulated Product Gas Environment

摘要

Filtration failure occurs when filter media are blocked by accumulated solid particles. Suitable operating conditions were investigated for cake cleaning by partial oxidation of filter-cake particles (FCPs) during biomass gasification. The mechanism of the FCP partial oxidation was investigated in a ceramic filter and by using thermogravimetric analysis through a temperature-programmed route in a 2 vol % O-2-N-2 environment. Partial oxidation of the FCPs in the simulated product gas environment was examined at 300-600 degrees C in a ceramic filter that was set and heated in a laboratory-scale fixed reactor. Four reaction stages, namely, drying, preoxidation, complex oxidation, and nonoxidation, occurred in the FCP partial oxidation when the temperature increased from 30 to 800 degrees C in a 2 vol % O-2-N-2 environment. Partial oxidation was more effective for FCP mass loss from 275 to 725 degrees C. Experimental results obtained in a ceramic filter indicated that the best operating temperature and FCP loading occurred at 400 degrees C and 1.59 g/cm(2), respectively. The FCPs were characterized before and after partial oxidation by Fourier-transform infrared spectroscopy, scanning electron microscopy, and Brunaeur Emmett Teller analysis. Fourier transform infrared spectroscopy analysis revealed that partial oxidation of the FCPs can result in a significant decrease in C Fin (alkyl and aromatic) groups and an increase in C=O (carboxylic acids) groups. The scanning electron microscopy and Brunaeur Emmett Teller analyses suggest that, during partial oxidation, the FCPs underwent pore or pit formation, expansion, amalgamation, and destruction.