posted on 2015-05-13, 00:00authored byLluvia
M. Ochoa-Estopier, Megan Jobson
This
paper is the third of a three-part series that applies optimization
to maximize the productivity and minimize operating costs of heat-integrated
crude oil distillation systems. The approach presented in this paper
implements simulation models for the distillation process and heat
exchanger network (HEN), and HEN retrofit models into the overall
optimization framework. The optimization approach is formulated in
two levels. In the first level, simulated annealing is used to optimize
the operating conditions of the crude oil distillation unit (e.g.,
distillation products and stripping steam flow rates, pump-around
duties and temperature drops, and furnace exit temperatures) and to
propose HEN structural modifications (e.g., adding, removing, relocating
heat exchangers; adding, removing stream splitters, etc.). The second
level is a nonlinear least-squares problem used to enforce HEN constraints.
Three case studies illustrate the application of this approach to
increase net profit and reduce annualized costs.