Integration of Excess Renewable Energy with Natural Gas Infrastructure for the Production of Hydrogen and Chemicals

Abstract

Power to gas (PtG) capitalizes on the free or low-cost power made available during frequent mismatches between power demand and power supply by converting water into hydrogen and oxygen via electrolysis. Current PtG projects vent the oxygen to the atmosphere and utilize the hydrogen for myriad purposes. Although oxygen has relatively little value when compared to hydrogen on a mass basis, the value of oxygen produced via electrolysis is significant compared to the value of the hydrogen due to the composition of water. This work presents a systematic methodology for designing a PtG project which co-utilizes hydrogen and oxygen to manufacture hydrogen and chemicals via integration with the natural gas infrastructure. A case study is developed and solved to demonstrate the applicability of the proposed methodology. The results of the case study show that significant value may be added by utilizing oxygen and the natural gas infrastructure.