Hydrogen Network Synthesis Integrated with Multi-Stage and Multi-Technology Purification System

Hydrogen, a vital resource, is utilized in many process units within the refinery. The purification system is widely used to regenerate and improve hydrogen quality, therefore reducing fresh hydrogen consumption. Pressure swing adsorption (PSA) and membrane separation (MS) technologies are widely utilized for the purification of hydrogen, and the process can be optimized by constructing mathematical models. Thus, at first, a parametric analysis of the purification models is conducted to identify the key variables of these models during the optimization process, which also reveals the necessity of coupling multiple purification units. Then, a superstructure-based hydrogen network (HN) model comprising multi-stage PSA and MS units is constructed, aiming to determine the optimal hydrogen allocation and purification system. This model considers the simultaneous optimization of purification system parameters, including operating pressure, in conjunction with its structural configuration. This case study demonstrates the applicability of the HN model to diverse refinery scenarios. Additionally, compared to using a single purification unit, using a multi-unit purification system can improve purification efficiency and reduce the total cost by 2% to 22%.