MILP Model for the Nonlinear Problem of Optimal Purifier Placement

Abstract

In the refinery, purifiers are widely used in the recovery of hydrogen components of the emissions from hydrogen consumption units. Hydrogen network containing purification units have been optimized and integrated by lots of researchers. However, purifier models such as PSA, membrane separation have nonlinear characteristics. Even if minimizing hydrogen utility, mathematical programming models adopted by most of the researchers belong to the non-convex and nonlinear models, not guaranteeing global optimal solution. On the basis of previous studies, this paper proposes a mixed integer linear programming model to obtain a minimum hydrogen utility consumption. This method can get the inlet flowrate simultaneously. Case studies indicate that this method is effective for both hydrogen and water networks.

Synthesis of Hydrogen Network

“…These include the placement of purifier (Lou et al 2017), strategies of merging compressors (Liang and Liu 2017), flowrate targeting for hydrogen network with single intermediate header (Deng et al 2018), and hydrogen partial pressure correction model (Li and Zhang 2018).…”

“…Purifier models such as PSA and membrane separation have nonlinear characteristics, and the global optimal solution cannot be easily guaranteed. To address the problem, a mixed integer linear programming model is proposed to obtain a minimum flowrate of hydrogen utility and the minimum inlet flowrate of purifier (Lou et al 2017). It avoids solving a nonlinear model and ensures the minimum fresh hydrogen global optimality.…”