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For the study of the transition strategies of continuous chemical processes, both continuity and dynamic characteristics in the physical sense are critical. The continuous transition strategy has a higher information density and can describe the real situation as closely as possible. In addition, the accuracy of the dynamic characteristics is necessary because the process transition is the study of the dynamic system processes. However, existing transition strategies have certain shortcomings. Dynamic optimization can obtain transition strategies with different characteristics but no physical meaning and a frequency domain-based analytical approach can acquire a continuous transition strategy with physical meaning, but its dynamic characteristics are the same. Therefore, by integrating the advantages of the existing strategies, a new transition strategy has been presented, which possesses different dynamic characteristics and continuity synchronous with physical significance. When process transition occurs, the proposed strategy results in less fluctuation and can quickly reach and maintain a steady state. Furthermore, the strategy is also suitable for the rapid application of different transition processes in the same plant. The performance of the transition strategies is evaluated through research on a continuous feed ethylene column.

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As a typical regulation means to realize a large-scale transition of the system condition, the lack of feedback compensation in the transition strategy leads to the fact that it has no moderating effect on interference. In order to ensure the safe and smooth operation of the system, it is necessary to coordinate the transition and control, that is, to achieve the process transition through a closedloop control structure. The existing coordination scheme can meet this demand, but there is a defect of poor anti-interference. To this end, a novel coordination scheme integrating transition with control is proposed in the paper, which alleviates the burden on the feedback control system by adding the manipulated variable reference trajectory. When interferences occur, the proposed coordination scheme can positively respond and compensate for the negative influence of disturbances, allowing the system to quickly return to the desired state. Besides, the corresponding analytical solution method is presented for the new coordination scheme, which avoids the complication of the conventional optimization solution method. Finally, the advantage of our coordination scheme has been effectively verified through the feed fluctuation ethylene column.