A reactive distillation process for deep hydrodesulfurization of diesel: Multiplicity and operation aspects

A systematic study of the operating conditions and parameter sensibility under which multiple steady states may occur in a reactive distillation column (RDC) for diesel deep hydrodesulfurization is presented. The multiplicity analysis is performed through bifurcation diagrams for two feed case scenarios. The main variables that affect the steady state behavior are the reflux ratio, the hydrocarbon feed flowrate, the reboiler heat duty, and the catalyst load (liquid holdup). For the first case only a single steady state was found, while in the second case input and output multiplicities were determined. It is shown that the introduction in the feed of the recalcitrant 4,6-DMDBT, plays a crucial role in the RDC design and operation. A set of values of the bifurcation parameters for an appropriate operation of the RDC are recommended to avoid the multiplicity region and to reach the required output targets.