Abstract: Three recovery processes of LPG from fuel gas in a refinery are studied. On the basis of steady state simulation, the main parameters of each process were optimized, considering the minimum annual total cost as the objective function. The results showed that the process with dividing wall column can achieve 37.66% and 11.35% savings of annual total cost compared with the other two processes, indicating a greater economic advantage. Moreover, the dynamic characteristics of the dividing wall column process of LPG recovery from the refinery fuel gas were investigated. The proposed four-point temperature control structure can effectively handle the feed disturbance and has a good controllability. Therefore, the application of dividing wall column in the process has a very great potential.

Key words: LPG, process design, dividing wall column, dynamic control