Abstract:
Dividing wall column has the advantage of energy saving and low capital cost compared to the conventional rectifying column. While this method is more flexible than the conventional rectifying column, its control and optimization are more difficult. In this paper, we address the shortcomings of existing dividing wall column methods by introducing an improved calculation method. The minimum operating conditions of the dividing wall column are determined according to the Underwood equation, and the operating parameters such as the number of stages, the feeding stage, side-stream stage, the reflux ratio, and the gas-liquid distribution ratio of the dividing wall column can be quickly determined in combination with design requirements. To verify the effectiveness of the design method, three different Ease of Separability Index (ESI) feed streams are selected, and the results are strictly simulated in HYSYS. The results show that our method is more accurate than previous methods in calculating the composition of the connecting stream between the pre-fractionator and the main column, and the total annual cost is lower.