The hydrogen infrastructure will expand in Finland over the next few years. Safety is an important factor in the construction and operation of the hydrogen transmission pipeline Gasgrid points out.  

Hydrogen has long been used in industry, says Aki Huomo, Head of Process Safety at Gasgrid.

“Hydrogen transmission is not something completely new. Besides which, our long experience with natural gas also helps us to build and operate hydrogen transmission pipelines safely. Hydrogen is, of course, a different gas than natural gas. However, with proper foresight and safety management, hydrogen is just as safe to transport and use as natural gas,” Huomo thinks.

Nevertheless, the properties of hydrogen differ from those of natural gas and hydrogen requires special attention in the event of any leaks.

Materials and equipment are subject to a whole host of requirements when hydrogen flows through pipelines. “The strength of materials, the risk of hydrogen embrittlement and the permeability of hydrogen are some of the things that need to be considered,” Huomo lists.

Safety is the starting point

Hydrogen safety at Gasgrid is based on identifying the risks, potential damage and accident scenarios – and on understanding their implications.

“Risks are managed through planning and forecasting and, of course, through action where required. For example, attention has been paid from the outset to technical solutions and adequate protection zones.”

Robust pipes

“Underground transmission pipes are made of sturdy carbon steel with strong walls. “A welded, fully-sealed structure ensures no leaks,” Huomo says.

The same type of pipes are used on the natural gas side and there have been only a few incidents of pipe damage in Finland over the past 50 years.

Huomo knows that even though excavators pose the greatest risk to pipelines, an excavator bucket with claws causes nothing more than scratches to the side of a pipe.

“The design and construction methods of transmission pipelines have been tried and tested in industry over a long period of time. They are extremely durable,” Huomo adds.

Pipeline safety also includes preventive maintenance, which includes internal inspections of the pipes to ensure that everything is as it should be.

Route planning is part of safety

The plan is that the Finnish hydrogen infrastructure will comprise more than 1,500 km of transmission pipelines. For safety reasons alone, the pipeline routes will avoid population centres and buildings in general.

“Southern Finland, for example, is quite densely populated, but the pipeline routes will be as safe and functional as possible,” Huomo confirms.

“Existing chemicals legislation already requires that pipelines must not pose a risk to the public,” he adds.

Familiar infra

Long experience of natural gas pipelines helps in planning the hydrogen infrastucture. Huomo points out that besides the pipelines themselves, there are many other similar elements, including pumping stations, valve stations, production plants, power and industrial installations along a hydrogen transmission pipeline, just as along a natural gas transmission pipeline.

“In addition, pressure levels and construction principles, for example, are in a similar category.

The location of the transmission pipelines will be visibly marked at the ground level and covered with a thick layer of soil. “Authorisation is required for all construction and working in the vicinity of the pipeline,” Huomo says.

Details related to pipeline construction, such as intersections and, for example, road underpasses, are planned as special cases.

Specific legislation on the way

Unlike natural gas, there is currently no specific legislation for hydrogen transmission pipelines. According to Huomo, this means that, for the time being, natural gas legislation will be relied on, and technical solutions will be borrowed from the natural gas side.

Hydrogen standards already exist in Europe and elsewhere in the world, but some of them also need to be updated.

“Harmonised legislation and standardisation is on the way, and will take the sector far forward,” Huomo says. This will help to harmonise practices, which is what has happened in the natural gas system in the past. It will also help equipment suppliers and other operators to have rules that are as clear and consistent as possible.

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Hydrogen facts

– A non-toxic, odourless and colourless gas that is lighter than air

– Hydrogen is 14 times lighter than air and 6 times lighter than natural gas

– High-pressure leaks are diverted in the direction of the leak

– Hydrogen molecules are smaller than natural gas ones

– Hydrogen has a higher combustion rate at high concentrations than natural gas; consider leakage situations and safety distances

– Large-scale hydrogen transmission, production and use is new, as are the technologies used

– The hydrogen transmission infrastructure requires high-pressure underground pipelines to transport hydrogen over long distances

– A lower-pressure hydrogen distribution infrastucture can be built, for example at a regional level or in the vicinity of industrial plants

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Read more:

Finns believe in the potential of hydrogen – knowledge of hydrogen yet limited

Updated national hydrogen infrastructure route plan announced

 

Text: Sami Anteroinen