Volume 3: Innovative Solutions for Energy Transitions: Part II

Integrated Natural Gas Hydrate Exploitation by CH4-CO2/H2 Replacement with Methane Reforming: Conceptual Process Design and Exergy Analysis Mengying Wang, Hongnan Chen, Chun Deng, Xiaohui Wang, Bei Liu, Changyu Sun, Guangjin Chen, Mahmoud El- Halwagi

Abstract

The conventional methods for methane gasrecovery from hydrate sediments require highinvestment but with low gas production efficiency andmay cause potential environment and securityproblems. But the novel natural gas hydrateexploitation method by CO2/H2 replacement couplingmethane reforming can improve the replacement effectand reduce the cost of gas separation. However, energyconsumption and energy performance have not beeninvestigated thoroughly. This work develops a detailedprocess simulation model and conducts an exergyanalysis for producing hydrogen from the integratednatural hydrate gas exploitation with methanereforming via two different boundaries. Results showthat the exergy ratio of the integrated process is 2.06,exergy efficiency of the hydrogen production process is72.40 %, but exergy efficiency of the integrated processis much lower, which is 26.59 %.

Keywords natural hydrate gas production, hydrogen production, methane reforming, exergy analysis, carbon dioxide sequestration