Numerical simulation of preparation of ultrafine cerium oxides using jet‐flow pyrolysis

Abstract

Abstract Ultrafine rare‐earth oxides (REOs) are widely applied in all fields of daily life, but the conventional preparation methods are limited by a long procedure, low efficiency and severe environmental pollution. Our team has independently developed a jet pyrolysis reactor for the preparation of ultrafine cerium oxides, and this process has theoretical significance and practical application values. In this study, gas–solid pyrolysis reactions inside the jet‐flow pyrolysis reactor were numerically simulated. We performed a coupling computation of the combustion, phase transformation and gas–solid reaction on Fluent and user‐defined functions. We characterized the flows of different phases as well as the compositions and distributive laws of the reactants/products in the reactor. The gas‐phase inlet velocity and dynamic pressure/additional pressure were related by a quadratic function. The velocity at the throat inlet changed the most, and the outlet velocity was very stable. The CeO 2 concentrations were obviously stratified. This study enriches theories of jet‐flow pyrolysis and theoretically underlies the optimization and popularization of self‐developed pyrolysis reactors.