Green Hydrogen Transportation–Role of Natural Gas Pipelines

Introduction

Hydrogen is used for several applications across various industries. It is used in oil refining, steel manufacturing, chemical industries, etc. It is also the most abundant element in the universe. Hydrogen which is currently used in various applications is produced from fossil fuels and has a significant amount of CO₂ emissions associated with it. Green hydrogen, being produced from renewables, nuclear or fossil fuels with CCUS, can help to decarbonize various sectors. Several projects are being announced and initiated for green hydrogen production across various countries in the world.

One of the key challenges associated with the use of green hydrogen is the transportation. Converting green hydrogen into liquid hydrogen, storage and transportation using LOHC, and transportation by blending into natural gas are key methods of transporting green hydrogen. These methods have various challenges associated with them and the number of projects are also being run to deal with these challenges. Blending of green hydrogen in natural gas pipelines is for example being tried and experimented by different companies.

Blending of Green Hydrogen in Natural Gas

Green hydrogen can be blended in most natural gas networks at a rate of 6% in terms of volume. This can happen in the absence of sensitive structures or installations on the customer’s premises. The blending of green hydrogen can defray the cost of building dedicated hydrogen pipelines during the early market development phase. With several announcements of the installation of 100MW electrolyzer plants, transportation through natural gas pipelines is expected to play an important role.

There are several developments including project announcements, initiation of pilot projects, funding for the research that is taking place to carry out the blending of green hydrogen in natural gas pipelines. Ameland project, Netherlands did not find that blending hydrogen up to 30% posed any difficulties for household devices like cooking appliances.

HyDeploy Project – UK hydrogen trial underway at Keele University

This is the UK’s first live pilot project under HyDeploy to inject green hydrogen into a gas network which will be utilized for applications like heating of homes and businesses. 20% blend of green hydrogen is being tried in natural gas pipelines is highest in Europe. It is feeding 100 homes and 30 faculty buildings. It is a £7 million project led by Cadent in partnership with Northern Gas Networks with various other key participants.

20% green hydrogen blend in natural gas pipelines across the UK could save up to 6 million tons of CO₂ emissions every year.

Grhyd Project

ENGIE is trialing the injection of green hydrogen into the natural gas distribution network Le Petit village in France, and an NGV refueling station for buses located in the Dunkirk Urban Community. At the start blend of 6%, green hydrogen will be tried and that will be increased over time to 20%. Green hydrogen blended natural gas will be used for operating a fleet of around 50 buses.

ARENA’s funding to Australian Gas Network

ARENA awarded funding of $1.28 million to the Australian gas network to establish the Australian Hydrogen Center (AHC) to explore the feasibility of blending 10% hydrogen into natural gas networks for selected regional towns in South Australia and Victoria. AGN is also undertaking a flagship project which will be operational by mid-2020, where 5% green hydrogen will be blended into a natural gas network for 710 households in Mitchell Park.

Snam increased the hydrogen blend to 10%

Snam doubled the volume of the hydrogen blend in its natural gas transmission network in Contursi Terme (Salerno), to 10% from 5%. This was carried out just a few months after the 5% hydrogen blend was introduced into the natural gas network to directly supply two companies in Contursi. 10% of hydrogen in the natural gas network could mean that 7 billion cubic meters of green hydrogen are introduced into the network every year. This equates to the annual consumption of 3 million households and would result in the reduction of CO₂ emission by 5 million tons.

There are several other projects including ATCO‘s initiation to start the blending of green hydrogen in the natural gas network in Janadakot, Australia, Turkey’s plan to test green hydrogen injection from 2021, Westküste100 green hydrogen project, and Australia’s HyPSA project which are pioneers in the sector.

Challenges Associated with Blending of Green Hydrogen in Natural Gas

Low energy density

The energy density of hydrogen is around 33% of that of natural gas’s energy density and so a 3% blend of hydrogen blend in a natural gas pipeline would reduce the energy content that the pipeline transports by around 2%. This would result in the use of greater gas volumes by end-users to meet given energy needs. Several industries are dependent on carbon contained in natural gas, they would have to use a greater amount of natural gas volumes.

Effect on product quality

Variability in the volume of hydrogen blended into the natural gas stream would have an impact on the operation of equipment designed to accommodate only a narrow range of gas mixtures. Equipment with a lower tolerance for the use of gas mixture will define the tolerance of the overall transmission network. One of the biggest constraints is expected to be in the industrial sector, where much industrial equipment has not been assessed in for hydrogen blending.

Harmonizing blend limits for various countries

Various countries have different blend limits. France has a 6% blend limit of hydrogen, the UK had a blending limit of 0.5% but was increased for specific HyDeploy project to 20%. For countries like Austria and Spain, the blend limit varies between 4% to 6%. Since natural gas is internationally traded, harmonizing blend limits in various countries is important for smooth transportation.

Risk of flames spreading

Hydrogen burns faster than methane gas and the flame is also not bright while burning which could result in the risk of flame spread.

Outlook

The success of various ongoing projects for the blending of hydrogen in the natural gas network can prove an important step towards developing hydrogen economy as blending avoids the significant capital cost involved in developing new transmission and distribution infrastructure separately for hydrogen.

According to the IEA report, there are almost 3 million kilometers of natural gas transmission pipelines around the world and almost 400 bcm of underground storage capacity and if some of this infrastructure can be used for transport of hydrogen, it could be a major boost for the development of green hydrogen. It also states that the transmission of hydrogen by blending it into the natural gas pipeline is generally the cheaper option if the hydrogen needs are transported for distances of less than about 1500 km. Policies and regulations to bring about higher blending levels also need to incorporate strategies for replacing equipment in homes, offices, and factories which would help in further use of green hydrogen blended natural gas.