Product tri-section based crude distillation unit model for refinery production planning and refinery optimization

Accuracy of a crude distillation unit (CDU) model has a significant impact on refinery production planning. High accuracy is typically accomplished via nonlinear models which causes convergence difficulties when the entire refinery model is optimized. CDU model presented in this work is a mixed-integer linear model with a modest number of binary variables; its accuracy is on par with rigorous tray to tray CDU models. The model relies on the observation(12) that a line through the middle of the product true boiling point (TBP) curve depends on the crude feed properties and the yields of the adjacent products. Novelty of the product tri-section CDU model is that it does not require models of individual distillation towers comprising the CDU, thereby leading to a much simpler model structure. Significant reduction in the computational effort required for the optimization of nonlinear refinery models is illustrated by comparison with previous work.

Automated summary

A mixed-integer linear model for CDU is proposed in this work, with accuracy comparable to rigorous CDU models, relying on the observation that a line through the middle of the product true boiling point curve depends on crude feed properties and adjacent product yields. The novelty of the product tri-section CDU model lies in its simplicity by not requiring individual distillation tower models within the CDU, leading to significant reduction in computational effort for nonlinear refinery model optimization.