Hydrogen Purification through a Membrane–Cryogenic Integrated Process: A 3 E's (Energy, Exergy, and Economic) Assessment.

Hydrogen (H₂) is known for its clean energy characteristics. Its separation and purification to produce high-purity H₂ is becoming essential to promoting a H₂ economy. There are several technologies, such as pressure swing adsorption, membrane, and cryogenic, which can be adopted to produce high-purity H₂; however, each standalone technology has its own pros and cons. Unlike standalone technology, the integration of technologies has shown significant potential for achieving high purity with a high recovery. In this study, a membrane–cryogenic process was integrated to separate H₂ via the desublimation of carbon dioxide. The proposed process was designed, simulated, and optimized in Aspen Hysys. The results showed that the H₂ was separated with a 99.99% purity. The energy analysis revealed a net-specific energy consumption of 2.37 kWh/kg. The exergy analysis showed that the membranes and multi-stream heat exchangers were major contributors to the exergy destruction. Furthermore, the calculated total capital investment of the proposed process was 816.2 m$. This proposed process could be beneficial for the development of a H₂ economy. [ABSTRACT FROM AUTHOR]