Steady-state characteristics of autothermal structures with fluidized-bed catalytic reactors

•Steady-state properties of various fluidized-bed autothermal structures are analyzed.•Effect of an external heat exchanger and a flue-gas recycle is evaluated.•The impact of thermal feedback onto autothermicity and multiplicity is analyzed.•Feed preheating permits to extend the region of the autothermal operation.

The paper focuses on the analysis of steady-state properties of autothermal structures with a fluidized bed. The concept of autothermicity is discussed, and typical autothermal structures are presented. A method for the determination of the steady-states of such systems is described. Quantitative analysis of steady-states multiplicity is presented for two autothermal structures, that is a fluidized-bed reactor with an external heat exchanger, and with a partial recirculation of hot gases. A two-phase bubbling bed model is employed to describe quantitatively the behavior of the catalytic fluidized bed. The influence of selected design and operating parameters on steady-state characteristics is analyzed for two simple kinetic models. The effect of these parameter on the desired product yield is evaluated for the multiple-reaction process. The results obtained have both scientific and practical importance.

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