Future operation of the GB high-pressure gas network with hydrogen

Azimipoor, Amirreza 2025. Future operation of the GB high-pressure gas network with hydrogen. PhD Thesis, Cardiff Universty. Item availability restricted.

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Abstract

The UK has the ambition to Utilise the existing high-pressure gas network infrastructure for hydrogen (H2) gas transportation. This thesis presents a comprehensive study on using the Great Britain (GB) high-pressure gas network for hydrogen transmission, employing a detailed, unsteady-state simulation model of GB high-pressure gas network developed in Synergi Gas software. The impacts of hydrogen transmission via the grid were investigated through three studies. The first study examined centralised hydrogen injection, where hydrogen was injected at 20% volumetric concentration at nine natural gas supply points. The second study explored distributed hydrogen injection, where hydrogen produced using excess wind energy was injected at 28 wind farm locations at 20% volumetric concentration cap. Subsequently, the transmission of pure hydrogen through the existing high-pressure gas network was also investigated. Comparison of the injection studies revealed that distributed hydrogen injection leads to inhomogeneous and varying hydrogen concentrations in different locations of the grid and across the time horizon. The case studies indicated that while the high-pressure gas network can accommodate 20% volumetric hydrogen without compromising pressure or significantly affecting compressor energy consumption, transmitting pure hydrogen increased compressor energy consumption and reduced linepack levels. Further analysis focused on use of deblending technologies in the GB high-pressure gas network. Deblending refers to technologies that separate hydrogen and natural gas to deliver a specific concentration of gas to the end-user. The case studies considered deblending for gas delivery to power stations (requiring natural gas free of hydrogen), industrial sites (requiring pure hydrogen), and Local Distribution Zones (LDZs) (requiring natural gas with a fixed 20% hydrogen volumetric rate). The cost of deblending varied based on the type of gas demanded by the end-user. As Industrial sites demanded pure hydrogen, large volumes of mixed gas were processed to produce pure hydrogen, leading to a high specific energy consumption. Delivering gas to other end-users produced significantly lower specific energy consumption, suggesting that deblending is more practical for delivering to power stations and LDZs

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Schools > Engineering
Uncontrolled Keywords:	1. Natural Gas Network 2. Hydrogen Network 3. Hydrogen blending 4. Dynamic simulation 5. Deblending hydrogen and Natural Gas 6. Linepack profiles
Date of First Compliant Deposit:	25 February 2026
Last Modified:	26 Feb 2026 09:10
URI:	https://orca.cardiff.ac.uk/id/eprint/184704

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