Abstract
A mixed integer nonlinear programming model for the retrofit design of H2 network was proposed, which took the H2 mass fraction, impurity mass fraction and pressure constraints into consideration. By introducing a desulfurization block into the state-space superstructure, the H2S removal unit was incorporated with the H2 removal unit, such as pressure swing adsorption and membrane process, in the proposed model. The superstructure was reduced based on engineering experience. Total annual cost (TAC) was employed as the optimizing object to achieve the cost optimal network. Two scales of retrofit scenarios were investigated. Case study illustrated the applicability and efficiency of the proposed approach.