Projects

High pressure steel pipelines are essential in enabling a safe natural gas transportation network an overly engineered solution tried and tested over several decades proving the NTS to be a robust nationwide asset. The National Transmission System is used to flow gas every day to keep the lights on and our homes heated by connecting large scale industry cities and towns where the network is dynamic allowing for flexibility and adaptability to various flow demand scenarios. This is done so by utilising over 5000 miles of varying grades and differing sizes of pipelines where the gas can flow build line pack for high energy demand areas and provide a mass energy storage solution.

The NTS is used to limit gas loss manage flow direction facilitate maintenance repair modification testing and commissioning to enable safe and effective start-up and shutdown of our pipelines. We now must further evidence pipeline steel material integrity when subjected to high pressure hydrogen gas this can be done by expanding upon the existing fatigue rig standalone testing at DNV Spadeadam.

Although some pipelines materials that we use today have seen blends and 100% hydrogen within the HYNTS Phase 1 test facility what we have not done is post hydrogen fatigue cycling non destructive testing of materials that have been subject to prolonged high pressure hydrogen. One of the welds that make up the fatigue rig has a known weld defect within it NGT aims to have the welds and the weld defect analysed through various methods of testing such as magnetic particle inspection followed by if necessary standard ultrasonic testing.

In 2022 small scale mechanical characteristic tests were conducted to characterise the mechanical properties of the materials used within the construction of the fatigue rig this testing commenced outputting a standard mechanical property data set the new end of test data post hydrogen exposure will be compared to the original data set from 2022 at the end of fatigue cycling. Testing will establish the effect of trapped hydrogen on ‘standard’ mechanical properties measured To facilitate this DNV will remove all girth welds selected seam welds and fitting welds and store them at low temperature to mitigate loss of hydrogen from within the trap sites..

A technical note will be prepared comparing the results of the weld inspections (internal and external inspections). The note will be used to confirm defect removal for metallographic examination.

A technical report will be prepared summarising the macro and microscopic examinations undertaken confirming defect size (to that reported by UT) and whether the defect was an original feature else created due to the pressure cycle duty of the test vessel and the hydrogen environment.

This project aims to develop a robust evidence-based framework to support the introduction of standardised separation distance tables for 100% hydrogen similar in format and function to those in IGEM/TD/3 for natural gas and hydrogen blends. This will address a gap in current standards for hydrogen. The Institute of Gas Engineers and Managers (IGEM) are providing resource to support the project and to update any necessary standards.

The work will develop a pathway for the biomethane sector to monetise CO2 and identify the role the gas networks can play reducing the long-term cost of gas decarbonisation.

IGEM have received requests from operators to update the hydrogen TD1 / TD13 supplements to take account of outputs from research projects. The project will review and assess the updates required based on findings from completed hydrogen research projects. This will support the repurposing of existing pipelines and installations from Natural Gas to hydrogen and Natural Gas/hydrogen blends with input and support from users/stakeholders and formal approval by IGEM.

The project will also develop a methodology for fracture and fatigue assessments for existing Natural Gas pipelines to be repurposed to hydrogen service. This methodology will assess the impact of blends of hydrogen up to and including 100% hydrogen to determine whether pipeline derating and/or deblending is required. The requirements for the application of this specification should be included in the updates to the IGEM/TD/1 and IGEM/TD/13 hydrogen supplements.

This project seeks to demonstrate the reductions in weld residual stress assumptions that have been suggested by the Phase I Literature Review project. A test programme will be conducted to measure residual stress in pipelines indicative of those on the gas network and subject them to hydrostatic pressures as seen in the period correct commissioning tests. These residual stress results will be fed into a Finite Element Analysis (FEA) model to scale up to other sizes and grades representative of the gas network. Residual stress tests will also be performed on extracted ex-service pipework in order to validate the ‘fresh’ pipeline tests and the FEA modelling.

The use of greener gases such as biomethane are an important part of the UK’s transition to net zero. Underground storage sites for biomethane are critical for balancing seasonal supply and demands for energy. However increased levels of oxygen in biomethane can lead to corrosion of assets in wet gas conditions compromising the integrity of storage facilities. This project will assess in a comparative analysis the technical and economic viability of advanced catalytic and adsorption technologies to reduce oxygen levels in biomethane with corrosion inhibitors to ensure the integrity and longevity of critical storage infrastructure.

This project will see Cenex deliver a feasibility study on hydrogen internal combustion engines (H2ICE) as an alternative to diesel and Fuel Cell Electric Vehicle (FCEV) within WWU’s operational fleet. This project comprises three distinct work packages (WPs) each feeding into a holistic assessment of H2ICE applicability across WWU’s vehicle assets. Cenex will apply its expertise in fleet decarbonisation alternative fuel technologies legislative policy analysis and techno-economic modelling to meet WWU’s scope requirements. All outputs will be suitable for internal strategic review and for sharing externally with partners and stakeholders.

The Sustainable Vehicle Transport (SVT) feasibility study project will undertake a green gas refuelling study specific to SGN’s network areas in Scotland and Southern incorporating biomethane in the form of bio-CNG and the potential for a future hydrogen option. Along with heat transport is a key sector to decarbonise on the journey to net zero. Battery electric vehicles are well suited to small vehicles but for heavy goods vehicles (HGV) and larger commercial vehicles (LCV) like the type that make up the majority of SGN’s operational fleet this may not be the most appropriate technology given the range and on-board power requirements.

This project aims to address major gaps identified in NIA2_SGN0078 which conducted a thorough literature review of the international scientific and industry knowledge base. The work will focus on characterising the hydrogen permeability rate of API Grades X52 and X60 vintage pipelines and welds by analysing the microstructure of each sample investigating the impact of internal corrosion layers and conducting mechanical testing post-exposure.

A correlation exercise will also be conducted to equate gaseous charging with electrochemical charging. The outcome of this work targets an improved industry best-practice for permeation and fracture toughness tests providing a validated benchmark framework with the potential to inform future updates of industry standards and procedures and saving costs on any future material and permeation testing work.

Clean Power 2030 (CP2030) aims for a fully decarbonised electricity system using unabated gas only as backup. This introduces an important challenge: how can the gas transmission network remain viable and deliver flexibility during extreme demand events despite not being utilised most of the time? This project aims to understand how to sustain the gas network technically and economically in a low average high peak demand future focusing on the interaction between gas and electricity systems.