Minimising the Risks Caused by the Leakage of Hydrogen Through Pipelines Through Detection and Prediction

Overview

The Climate Change Act requires significant reductions in emissions by 2050, this will mean that energy will need to be supplied virtually carbon free. Alternatives to carbon based fuels will be required across not only in electricity generation but also in the full energy system: in our buildings, industry and transportation. Hydrogen is set to have a play a key role in the UK’s full energy system and, as such, will be required in extremely large quantities. There are plans to use it as a heating/natural gas replacement solution for UK dwellings, in reducing emissions from industrial heat (for example, in furnaces), as a replacement for the natural gas used in power generation and in hydrogen fuel cell vehicles which could be important for heavy-duty vehicles and shipping.
The most efficient way to transport the large quantities of hydrogen required is by pipeline. The pipeline transport of hydrogen is a fundamental technology that will underpin a large proportion of future applications. The key problem is how to transport the massive volumes of hydrogen from its production sites to its required destinations in a safe manner. The scale of this undertaking has never been attempted before anywhere in the world and presents key scientific challenges which need to be resolved immediately. Hydrogen is a small molecule with high buoyancy which means there is an increased risk of it leaking though pipes and seals during transportation. Even if the amount of hydrogen lost from a pipeline is negligible, if the leak is into a confined space then this, over time, could present a safety risk – hydrogen is an extremely powerful fuel which can ignite with very low energy input. Advanced sensors are required to help quickly and accurately detect hydrogen leaks along pipeline routes. These types of sensors do not exist for pipelines. Early detection and monitoring could help prevent any explosions and could aid understanding of potential failure mechanisms. Based on the failure mechanisms of hydrogen pipelines, novel monitoring systems will be designed and developed through simulation and experimental study. These sensors will have the ability to quickly and efficiently scan the whole length of the pipeline, including seals, to identify any leaks of hydrogen and to send the location to the operator.
The data collected during the project will be used to create a model capable of predicting the expected rate and frequency of hydrogen leakage along a pipeline. This model will be based on a probabilistic approach and will be able to be used by hydrogen pipeline operators and regulatory bodies as part of a risk analysis for transporting large volumes of hydrogen.
The overall aims of the project are to create a hydrogen pipeline leakage frequency model that can used as part of a risk analysis and a mobile sensor which can detect small amounts of hydrogen leaking through a pipeline wall or a connecting seal. To achieve these aims, the project will address four objectives:
1. Investigate the leakage pathways of hydrogen through typical pipeline and seal materials.
2. Create a portable hydrogen detector which is capable of detecting small amounts of hydrogen.
3. Test and refine the sensor using laboratory testing.
4. Using all the collected data laboratory data, create a risk frequency model capable of predicting the expected quantity of leakage from a hydrogen pipelines.

Methodology

The following approaches will be used to address these objectives:
1) A literature review on the pathways of hydrogen leakage through materials, the leakage of hydrogen from static facilities (such as nuclear power plants and hydrogen fuel cells), the expected operating conditions of hydrogen pipelines (including pressure, temperature and flow rate) and the available devices and techniques for monitoring leaks of pipeline cargo (such as natural gas). Ultimately this information will be used in the development novel sensor that is able to scan the whole length of a hydrogen pipeline and identify the locations of any leaks.
2) The mobile sensor will be created able to detect small amounts of hydrogen leaking through a range of plastics, polymers and metals. The model will be benchmarked against existing hydrogen detectors (which are all currently static).
3) A database of hydrogen leakage rates and quantities through a range of materials will be formed by conducting a thorough laboratory testing programme which will cover a range of potential operating pressures and temperatures relevant to future hydrogen pipelines.
4) The database will be used to create a probabilistic model capable of predicting the expected leakage of hydrogen through a pipeline during the course of its operation.
5) To make a wider impact, the results of the project will be presented to relevant hydrogen pipeline operators and regulators in the UK which will include The Health and Safety Executive (HSE) and National Grid.

Project Timeline

Year 1

During the first half year, the student will conduct extensive literature review and obtain any useful information on the mechanisms and detection of hydrogen leakage. In the second half of the year, the student will begin building a mobile sensor capable of detecting very small quantities of hydrogen. The senor will be validated against an existing (static) hydrogen detector.

Year 2

In the second year, the student will finish building the sensor and will undertake an exhaustive series of testing on the rate of hydrogen leakage through a range of materials and material thicknesses under a range of potential operating conditions. In this year, the student will also be encouraged to attend a relevant conference.

Year 3

In this year the student will finish the experimental testing and they will create a model, based on all the previously collected data, capable of predicting the rate and quantity of hydrogen leakage through typical hydrogen pipelines. An international conference will be encouraged to be attended by the student.

Year 3.5

Dissemination of the results of the project which will be in the form of giving talks to relevant industry and regulators, writing publications based on the work done in years 1, 2 and 3 and timely submission of the thesis.

Training
& Skills

The student will receive the necessary training to ensure they are equipped with the technical and research skills needed to support fieldwork and their development as an independent researcher. Training in laboratory testing and programming including delevoping sensors and developing probabilistic models will be provided. The student will also spend time sourcing test materials and may have travel to other sites or other universities.

References & further reading

Committee on Climate Change, Hydrogen in a low-carbon economy, 2018.
W McDowall and M. Eames, Transitions to a UK Hydrogen Economy, UKSHEC Social Science Working Paper No. 19, July 2006.
ARUP, Establishing a Hydrogen Economy. The Future of Energy 2035.
R. Derwent et al, Global environmental impacts of the hydrogen economy, Int. J. Nuclear Hydrogen Production and Application, Vol. 1, No. 1, 2006.
S. Okazaki et al, Sensing characteristics of an optical fiber sensor for hydrogen leak, Sensors and Actuators B: Chemical Volume 93, Issues 1-3, 1 August 2003, Pages 142-147.
N. Javahiraly, Review on hydrogen leak detection: comparison between fiber optic sensors based on different designs with palladium, Optical Engineering, 54(3), 030901 (2015).
A. Ingimundarson et al, Model-Based Detection of Hydrogen Leaks in a Fuel Cell Stack, IEEE Transactions on Control Systems Technology, vol. 16, no. 5, September 2008.
S. Elaoud, L. Hadj-Taieb, E. hadj-Taieb, Leak detection of hydrogen-natural gas mixtures in pipes using the characteristics method of specified time intervals, Journal of Loss Prevention in the Process Industries Volume 23, Issue 5, September 2010, Pages 637-645.

Further Information

Contact details:
Dr Ben Wetenhall, ben.wetenhall@ncl.ac.uk, 0191 208 5532
Prof Gui Yun Tian, g.y.tian@ncl.ac.uk, 0191 208 5151

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