| Scope and method of study. Two dispersion models for the prediction of conversion in gas-solid fluidized-bed reactors were developed. A new dispersion model, based on the Two-Phase Theory of Fluidization, was developed. The model was written for the prediction of conversion in bubbling fluidized-beds. The model included a new correlation for the estimation of Peclet Numbers for these type of reactors. Conversion data from 328 fluidized-bed experiments from the literature were used in model development and application. Another steady-state, dispersion model was also developed to simulate the operation of an industrial-size Heavy Oil Cracker (HOC) catalyst regenerator. The regenerator operated in the turbulent fluidization regime. The regenerator also operated in the complete-CO-combustion mode. Actual regenerator conditions were used.; Findings and conclusions. For 328 literature conversion experiments, the two-phase dispersion model was able to predict fractional conversion of the gas in a fluidized-bed, on the average, to within {dollar}pm{dollar}0.036. A comparison of this performance with that of a modified bubble-assemblage model showed the new model to give a more accurate description of the extent of reaction in bubbling fluidized-beds. The new turbulent-fluidization model predicted oxygen fractional conversion in the industrial-size Heavy Oil Cracker (HOC) regenerator, on the average, to within {dollar}pm{dollar}0.025. The model predicted the concentrations of oxygen and carbon dioxide in the regenerator flue gas to within {dollar}pm{dollar}0.6 and {dollar}pm{dollar}0.75 mole %, respectively. The model was also used to predict coke on spent catalyst. The HOC regenerator model was presented complete with heat balance equations. |
