Fuel Processing Technology, Vol.141, 2-8, 2016
Characterization of coal char gasification with steam in a micro-fluidized bed reaction analyzer
In this study, the so-called micro-fluidized bed reaction analyzer (MFBRA) was used to characterize the isothermal reaction of char gasification with steam at 0.1 MPa. With minimal inhibition of heat and mass transfer, the article examined the effect of reaction temperature and partial pressure of steam on char gasification behavior and reaction kinetics. It was found that at the experimental temperatures varying in 750-1100 degrees C, the charsteam gasification reaction can be divided into two regions according to temperatures of 750-950 degrees C and 950-1100 degrees C. The reaction was well described by the shrinking core model, and the activation energies of charsteam gasification in such two regions are 166.94 kJ/mol and 79.4 kJ/mol, respectively. The activation energy in the kinetically controlled low-temperature region is very similar to that reported in the literatures, validating the reliability of MFBRA for characterizing char gasification and estimating its kinetics. Furthermore, the reaction order for steam partial pressure was found to be about 0.5 under the tested conditions. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Micro-fluidized bed (MFB);MFBRA;Char-steam gasification;Kinetics;Isothermal differential reaction