Thermo-economic analysis of blending hydrogen into natural gas pipeline with gaseous inhibitors for sustainable hydrogen transportation

Hydrogen transportation through a new pipeline poses significant economic barriers and blending hydrogen into existing natural gas pipelines offers promising alternative. However, hydrogen's low energy density and potential material compatibility challenges necessitate modifications to existing infrastructure. This study conducts a comprehensive thermo-economic analysis of natural gas and hydrogen mixtures with and without gaseous inhibitors, evaluating the impact on thermophysical properties (Wobbe index, density, viscosity, energy density, higher and lower heating values), compression power, economic feasibility and storage volume requirement. A pipeline transmission model was developed in Aspen HYSYS to assess these properties, considering major and minor infrastructure modifications. The findings suggest that the addition of 5% carbon monoxide and 2% ethylene as gaseous inhibitors in maintaining desired properties, ensuring compatibility with existing infrastructure and operational processes. The findings also indicate that blending 30% hydrogen increases storage volume by 30-55% while reducing higher and lower heating values by 20-25%. However, the addition of 5% carbon monoxide and 2% ethylene improves the pipeline performance and reduces the carbon emissions by 23-26%, supporting the transition to low-carbon energy systems. The results suggest that hydrogen blending is viable under specific infrastructure modifications, providing critical insights for optimizing pipeline repurposing for sustainable hydrogen transportation.