Simulation of Hydrogen-Methane Separation with Pressure Swing Adsorption

Abstract

The global energy landscape is transforming as it shifts towards sustainability, with a growing emphasis on harnessing renewable energy sources and advancing energy storage technologies. Hydrogen plays a pivotal role in this transition as a versatile and potentially clean energy carrier. To address the seasonal variability of renewable energy generation, surplus renewable energy is converted to hydrogen during the summer, which is subsequently stored in depleted natural gas reservoirs for winter recovery, enabling electricity generation or direct use. A high-pressure, 4-bed Pressure Swing Adsorption (PSA) system was designed to separate hydrogen from the cushion gas containing varying amounts of methane. The main challenge lies in the fluctuating feed conditions encountered during winter recovery, where hydrogen concentration in the stream varies from 70% to 98% at pressures ranging from 25 to 60 bar, as direct feed pressurization is eliminated in favour of energy efficiency. A lab-scale PSA system has been constructed, and its experimental results for hydrogen-methane separation are employed to validate a simulation model and support the scale-up. The simulator, developed as open-source software in MATLAB, accurately captures the dynamic behaviour of the high-pressure PSA system, providing insights into breakthrough curves and system performance under realistic conditions. This research contributes to developing efficient and reliable hydrogen storage solutions that align with the current trends in the evolving energy economy, where hydrogen emerges as a key player in achieving a sustainable and resilient energy future.