The conversion in the injector region increased with rising fluidized bed temperature and decreased with increasing jet velocity.
Reactions in the injector region either led to significant conversion in that zone or an autoignition delay inside the main fluidized bed body. The measured global reaction rates for C2 to C4 n-alkanes were characterized by a uniform Arrhenius expression, while the global reaction rate for methane was significantly slower. The fluidized bed combustion was accurately modeled with first-order global kinetics and two one- phase PFR models in series: one PFR to model the region close to the injector and another to represent the main fluidized bed body. For methane, the measured values of T1 and T2 were significantly higher at 1023 K and above 1123 K, respectively. On the other hand, complete conversion occurred within 0.2 m of the injector at: T2 = 1073 K. For ethane, propane and n-butane, combustion occurred mainly in the freeboard region at bed temperatures below T1 = 923 K. In the first part of this work, the non-premixed combustion of C 1 to C4 n-alkanes with air was investigated inside a bubbling fluidized bed of inert sand particles at intermediate temperatures: 923 K ≤ TB ≤ 1123 K. The main objective is to develop new tools to model and characterize homogeneous gas-phase reactions in this type of reactor. This thesis presents a study on homogeneous gas-phase reactions in fluidized beds. Reactions homogenes en phase gazeuse dans les lits fluidises
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