Design and control for a dividing-wall column with a partial condenser for pretreating an industrial multi-component reformed gasoline mixture

摘要

A dividing-wall column (DWC) was used for pretreating industrial multi-component reformed gasoline (IMCRG). IMCRG consists of 16 components, which are non-aromatics, benzene, toluene, xylenes & ethylbenzene, and heavy aromatics. Rigorous steady-state simulations were conducted using Aspen Plus. Compared with a conventional direct and indirect two-column sequence separation, the reduction in the total annualized cost (TAC) by a DWC can be up to 13.06% (direct sequence) and 24.79% (indirect sequence). To treat the noncondensable gas in the feed, a DWC flowsheet with a partial condenser was considered. Two control structures with a S/L ratio control strategy were proposed to control the DWC. Controllability analyses with respect to feed flow rate and feed composition disturbance were conducted to evaluate the control effect of the two structures by using Aspen Plus Dynamics. Finally, a feasible DWC control structure to pretreat IMCRG was obtained.