关键词:

微型流化床, 反应动力学, 热分解, 气固反应

Abstract:

A novel micro kinetic analyzer (MFBK) for fluidized bed gas-solid reactions is developed With this MFBK analyzer, the reaction rate and kinetic parameters can be deduced via measuring the timedependent composition changes of its evolved gas.By using a micro fluidized bed reactor, it is expected to enable the on-line feed of particle reactant based on a pulse solid conveying mechanics and the effective suppression of external gas diffusion in the reactor.This MFBK analyzer is evaluated through the decomposition of CaCO₃ powder, giving an apparent activation energy of 142.73 kJ.mol^-1 and a preexponential factor of 399777 s^-1 .This activation energy value is much lower then the TG-measured one of 184.3 kJ.mol^-1 and within the literaturereported range of 120—280 kJ.mol^-1.The measurement also provides a kinetic-model function with a correlation linearity of above 0.99.With this MFBK analyzer, the pyrolysis of coal and biomass at 800℃ is studied.The measured pyrolysis reaction finished in about 15 s, which is very close to the theoretically anticipation.This pyrolysis measurement with the MFBK analyzer can also identify a definite gas release order for typical gas species contained in the pyrolysisformed gas products, which actually can provide a strong evidence for the deep insight in the pyrolysis reaction mechanism.

Key words:

微型流化床, 反应动力学, 热分解, 气固反应