Simultaneous optimization of heat-integrated crude oil distillation systems

Crude oil distillation is important in refining industry. Operating variables of distillation process have a critical effect on product output value and energy consumption. However, the objectives of minimum energy consumption and maximum product output value do not coordinate with each other and do not lead to the maximum economic benefit of a refinery. In this paper, a systematic optimization approach is proposed for the maximum annual economic benefit of an existing crude oil distillation system, considering product output value and energy consumption simultaneously. A shortcut model in Aspen Plus is used to describe the crude oil distillation and the pinch analysis is adopted to identify the target of energy recovery. The optimization is a nonlinear programming problem and solved by stochastic algorithm of particle warm optimization.

Graphical AbstractA systematic optimization approach is proposed for the maximum annual economic benefit of an existing crude oil distillation system, considering product output value and energy consumption simultaneously. The variables we optimize include the flow rate of four stripping steams (atmospheric column bottom stripping steam FSTC and three side stripping steams FST1, FST2, and FST3) and the D86 95% points of naphtha (DN), kerosene (DK), diesel (DD), AGO (DA) and vacuum diesel (DVD). When maximizing annual economic benefit, the annual economic benefit is the largest compared with situations of minimizing energy consumption and maximizing product output value separately.Figure optionsDownload full-size imageDownload as PowerPoint slide