A Graphical Method for Optimisation of Hydrogen Networks Considering Impurity Removal through Chemical Absorption

Abstract

In refineries, amine-based chemical absorption is an effective technique to treat acid impurities (i.e. H2S and CO2) in hydrogen flows. Therefore, introducing chemical absorption units for acid impurity removal in refinery hydrogen networks could enhance the recovery and reuse of hydrogen, reducing the fresh hydrogen consumption. In this work, a novel pinch-based graphical method is proposed for integration of hydrogen network with chemical absorption untis for impurity removal. The proposed method is able to target the maximum fresh hydrogen saved by introducing impurity removal while minimizing the total flow rate of hydrogen sources fed to the impurity removal unit. Any hydrogen sources in a hydrogen network can be treated as the feedstock of the impurity removal unit. A case study is performed to illustrate the applicability of this graphical method.