Dynamics and control designs for internal thermally coupled distillation columns with different purities, Part 1: Open loop dynamic behaviors

The open loop dynamic behaviors of internal thermally coupled distillation column with four different purities (low-, moderate-, high- and very high-purity) are studied. These dynamic behaviors are characterized by strong asymmetric non-linearity, high sensitivity to operation conditions change and distinct inverse response. With the increase of purity, these dynamic behaviors are intensified and become more complex, which easily lead to the mismatch between linear model and plant and also change the relationship between manipulated and controlled variables.