The proposed project addresses the call topic area of ‘low-carbon energy carrier roles in accelerating decarbonisaton pathways’ by characterising the condition of legacy gas (methane) pipeline steels after service exposure. Existing hydrogen embrittlement relationships do not properly consider the effect of steel pedigree on degradation. This research will use the results of detailed characterisation to fully document steel microstructure and rigorously track hydrogen interaction with specific features. The results will be directly relevant to assessing the suitability of the current network for hydrogen gas transport. Moreover, the learnings will inform the design and manufacture of future systems. Support involving the supply of suitable legacy specimens has been obtained from National Grid and EPRI will provide review and input on methods used and aid dissemination of findings.
Benefits
Detailed assessment of the materials microstructure to better inform our decisions on hydrogen injections into the NTS
Learnings
Outcomes
A data report focused on microstructural characterisation of the three pipes supplied (X60 – 1971; X60 – 1998; X80 – 2007) was written. The following investigations were undertaken on the pipe materials in the parent metal, the seam weld and girth weld locations:
· Chemical homogeneity
· Microhardness mapping of welds
· Large area electron backscatter diffraction (EBSD) analysis
· Inclusion analysis
Permeation testing was attempted on the pipes at specific microstructural locations but with limited success due to continual issues with the testing set-up.
A rig for mechanical testing of pipe samples in an electrochemically charged hydrogen environment was designed and built, however no testing was undertaken.
The project value tracking is listed below:
· Maturity
o TRL 2-3. Research project.
· Opportunity
o <25% of single asset class. Project focused on two grades of pipeline steels and three different ages. Intention to explore how results can be extrapolated to other grades and ages.
· Deployment Costs
o £0.00. Project is research into impact of hydrogen on pipeline steels, no technology being developed to be deployed.
· Innovation Cost
o £ 122,166. Cost of innovation project (including internal costs and EPRI contribution).
· Financial Saving
o £0.00. Project is research into impact of hydrogen on pipeline steels, no technology being developed to be deployed. Work will inform repurposing approach and decisions.
· Safety
o 0% improvement. No direct safety benefits identified. Project is research into impact of hydrogen on pipeline steels, no technology being developed to be deployed. Work will inform repurposing approach and decisions.
· Environment
o 0 tonnes CO2e savings. No direct environmental benefits identified. Project is research into impact of hydrogen on pipeline steels, no technology being developed to be deployed. Work will inform repurposing approach and decisions.
· Compliance
o No change. No direct compliance benefits identified.
· Skills & Competencies
o Individuals. Work will augment knowledge of individuals involved in project.
· Future Proof
o Supports business strategy. Results will support operation of future 100% hydrogen and hydrogen-natural gas blends national transmission system.
Lessons Learnt
The following lessons learnt have been captured within this project:
- Availability of required resource (e.g. permeation testing capabilities) to be confirmed prior to project start. For examples, the design, build and commissioning of bespoke hydrogen test facilities is a high-risk activity from a project delivery standpoint.
- Strong relationships are required at all stakeholder levels across projects that involve multiple parties – working level and management levels. This includes regular communication and governance protocols where risks and issues are clearly discussed, and solutions are developed together.
- Offers of support need to be communicated within these chains and escalated when needed.
- Industry experts to be utilised to confirm and inform decision making on test development.
- Decisions regarding cancellation of projects might want to be considered earlier within project delivery if it is clear that supplier might not be able to deliver the scope.
- Consideration might also be given to the number and proportional value of payment milestones. This could potential enable greater leverage over suppliers to deliver as per agreed scope.
