A Validated Flowsheeting Tool for the Study of an Industrial Granulation Process

This work evaluates the capabilities of a complete dynamic simulator developed for a urea granulation circuit (based on fluidized bed technology) to analyze the process sensitivity against different disturbances and to study common operating problems. First, the circuit model is validated by comparing simulation results with plant data from a high capacity industry. On the basis of a sensitivity analysis of the process variables, diverse strategies are explored aiming to solve typical operational challenges (i.e., granulation temperatures that are too high, undesired dust formation, low fluidized bed heights, etc.) by considering different control variables or alternative flowsheet configurations. It is demonstrated that an appropriate fluidization air distribution between the different granulator chambers allows control, within certain limits, of the often too-high fluidized bed temperatures. Furthermore, it is shown that by adjusting the total granulator pressure drop, the fluidized bed levels can be ke...