The aim of the project is to complete a literature review and a technical design assessment to ascertain if existing pipe lining technology could be used in SGN’s LTS network to safely transport hydrogen blends up to 100%. Internal lining technology has been underexploited in the past within onshore gas transportation. This is because permeation through the lining materials into the annular space can cause the liner to collapse. This would be more prevalent due to the properties of hydrogen. Several venting solutions have been attempted but are not suitable when transporting hydrogen. The future strategy of this project to the GB gas network will be to develop lining technology as a viable solution to extend the life of existing assets where the current material is not suitable to transport hydrogen.
Benefits
· The project will provide unique and referenceable information for Network licensees and Industry on a potential new transmission pipeline materials option with 100% hydrogen. The learning gained from the project can be applied to Network Licensees and their network operations to facilitate safe transition to hydrogen from natural gas.
· The literature review and reports will provide a detailed analysis of the design, tools and techniques required for safe deployment of the lining technology
· It can result in extended asset life for materials that have been defined as unsuitable for operation with hydrogen transportation and transmission.
· It will help identify suitably impermeable lining materials, providing additional solutions when trying to solve the issue of hydrogen embrittlement and hydrogen gas escapes.
Learnings
Outcomes
From this project, it became clear that although PE has been used for the transmission of natural gas in the UK for over 50 years, the current PE 100 materials have exceptional crack resistant properties which ensure integrity in service.
Die drawing is a proven technique for the installation of PE liners for demanding oil and gas applications and could be applied in the repurposing of existing steel pipelines for the transmission of blends of natural gas/hydrogen and pure hydrogen.
There are several jointing and end termination techniques already available and widely used by the oil and gas industries, which could be employed in PE liner systems for the transmission of natural gas/hydrogen blends and pure hydrogen.
A significant amount of practical research has been undertaken to demonstrate that exposure of PE to hydrogen would not be expected to adversely affect the service performance.
Although there is a potential risk of collapse of liners due to permeation of gas, this study has demonstrated that it can be predicted and where necessary mitigated against, using appropriate venting methods and through controlled operation of the pipe system.
PE Liners incorporate a barrier layer to reduce or prevent permeation of gas, which could be used in combination with a venting system, appear to be a potentially very promising solution for the transmission of natural gas/hydrogen blends. Further practical assessment of candidate barrier materials would be required to validate their gas permeation characteristics and ensure these characteristics are not adversely affected by the installation process
Lessons Learnt
N/A
