Trial Contact Us
HSE Articles
Back to Resources

The emerging hydrogen industry and its many applications

Written by Sallie O'Rourke

 

 

Most people would have heard a lot of news about hydrogen in recent years. But what it is and how can it be used? This article endeavours to answer those questions, as well as the challenges and opportunities facing the emerging global hydrogen industry.

 

 

 

 

What is hydrogen and how can it be used?

 

 

Hydrogen is the lightest and most abundant element in the universe, and on Earth, it is mostly found as a constituent of other molecules such as water.

 

 

Once separated from other molecules, hydrogen has many potential uses, including as an industrial feedstock (raw material required for an industrial process), to store electricity, as an energy carrier, for heating and cooking, and for the production of ammonia, fertiliser and steel, just to name a few.

 

 

 

 

 

 

The process of separating hydrogen

 

Various methods can be used to separate hydrogen from other molecules, and these methods can be carbon intensive. Global demand for pure hydrogen as of 2018 was around 75 million tonnes and it is primarily sourced from fossil fuels. The CO2 emissions from the production of hydrogen equates to the sum of the total CO2 emissions of the UK and Indonesia (~830 million tonnes per year).

 

Currently, hydrogen used in industry is mostly made by reforming natural gas. Each method for obtaining pure hydrogen has been assigned a colour depending on the hydrogen source material and how it is processed.

 

Here are some of them.

 

Electrolysis powered by renewable energy (green hydrogen)

Green hydrogen is produced using renewable energy sources such as solar, wind or hydroelectric power. Electricity from these renewable sources is used to separate water molecules into oxygen (O2) and hydrogen (H2) in a process called electrolysis. This process has gained a lot of interest globally because it does not emit greenhouse gases to the atmosphere.

 

 

 

 

 

 

 

Hydrogen from natural gas with carbon sequestration (blue hydrogen)

Blue hydrogen is produced using steam reforming. This process uses steam and natural gas (e.g. methane) to produce hydrogen and carbon monoxide, then additional steam (water) is added to convert the carbon monoxide to carbon dioxide and more hydrogen. This process does create carbon emissions, but it is captured rather than being released to the atmosphere. This makes it a better alternative to other carbon-emitting hydrogen production processes

 

 

Hydrogen from coal or natural gas (brown, black grey and turquoise hydrogen)

Brown and black hydrogen is made using fossil fuels (e.g. brown or black coal) using a process called gasification whereby coal is mixed with an oxidant to produce syngas (a mixture of carbon dioxide, hydrogen and carbon monoxide). The syngas is then converted to hydrogen and carbon dioxide by mixing it with steam. This produces a lot of carbon emissions that are released to the atmosphere.

 

Grey hydrogen is produced using the same process as for blue hydrogen (i.e. steam reformation) however, none of the carbon is captured.

 

Turquoise hydrogen is produced using natural gas, where fossil fuels are heated to such a high temperature that it produces hydrogen and solid carbon (pyrolysis of natural gas). This doesn’t release greenhouse gasses to the atmosphere however, the process of obtaining the natural gas does create carbon emissions (e.g. mining and transportation).

 

 

 

 

 

 

 

Electrolysis powered by nuclear energy (pink, purple or red hydrogen)

This process is much like the process for green hydrogen; however, water is split into hydrogen and oxygen via electrolysis using nuclear power. Pink hydrogen produces fewer carbon emissions which makes it an attractive alternative to some high-emissions processes, but it does produce nuclear waste.

 

 

Natural hydrogen (gold or white hydrogen)

White hydrogen refers to natural hydrogen found underground. There is still much to learn about white hydrogen and research and exploration is ongoing. What is known, is that hydrogen can be produced in some geological processes. Hydrogen exploration in South Australia is being undertaken using data from historical bore holes and geological features such as ‘fairy circles’. Further research into natural hydrogen and extraction methods is required.

 

 

 

 

 

 

 

The opportunities and challenges for using hydrogen

Hydrogen presents some opportunities and challenges that require further research and/or development before it can be used large-scale.

 

Opportunities

Decarbonisation of heavy industry

It is difficult for certain industries such as transport and heavy industry to transition to electricity and reduce carbon emissions. Hydrogen could be used to help those industries decarbonise. Hydrogen can be used as a feedstock for ammonia (see below) and methanol production, and also in the production of iron and steel.

 

Steel is currently produced using large amounts of coal as steel-making requires coal to convert iron ore to iron, and heat (using fossil fuels) to convert iron to steel. Low emissions hydrogen can be used to reduce iron ore to iron which would decarbonise the process as it emits only water vapour. However, the green hydrogen industry needs to catch up to meet demand from the steel industry, and changing existing infrastructure is expensive. This may be easier in regions with easy access to renewable energy whereas other steel-making regions may require subsidies to support it.

 

 

 

 

 

 

 

Green ammonia

Ammonia production accounts for 70 to 80% of industrial hydrogen use. Ammonia is produced by the Habor-Boche process which is the reaction of hydrogen and nitrogen under pressure and heat and in the presence of a catalyst to form ammonia. The hydrogen used in this process is usually produced from fossil fuels which, as mentioned above, produces a lot of greenhouse gases. Using green or blue hydrogen could help the industry decarbonise. Green ammonia may also provide opportunities for energy storage, zero-carbon fuel and use as a hydrogen carrier for easier storage and transportation of hydrogen.

 

Hydrogen fuel cells

Interest in hydrogen fuel cells for vehicles has been increasing, with countries such as Korea, the US, UK, China and Japan leading the way. Hydrogen fuel cells convert hydrogen and oxygen to energy through an electrochemical reaction which produces water vapour and heat. Furthermore, hydrogen fuel cells are lighter than electric vehicle batteries and require less time to refuel by comparison. This makes them an attractive option for use in fleets and heavy vehicles which are required to stay on roads for long distances.

 

 

 

 

 

Storage

Hydrogen can be stored as compressed gas or as a liquid. This is suitable for the storage of smaller amounts of hydrogen. However, to store hydrogen on a large scale (which is required because demand for hydrogen will not be static), other storage options will need to be considered for safety and cost-of-storage such as at geological storage sites in underground salt caverns, depleted gas fields, saline aquifers or mined rock caverns.

 

Globally, the few major existing underground hydrogen storage caverns are in the UK and the US. The CSIRO and Future Fuels CRC have undertaken research into potential large-scale geological storage sites in Australia, available technologies and storage capacity. They found that the prospective storage is larger than potential demand for underground hydrogen storage and that there are potentially suitable salt caverns in regional Australia. Other opportunities that are being considered are manmade hard rock caverns. While there are storage opportunities in Australia, they are also met with some challenges and areas for further research as discussed later.

 

Grid stabilisation

Excess energy produced from renewable sources can be used to produce hydrogen which can help stabilise the grid and allow for further renewable connections.

 

 

 

 

 

 

 

Challenges

Cost

A barrier to the uptake of hydrogen production can be the cost associated with hydrogen production systems, especially for the production of green hydrogen using electrolysis. PEM electrolysers (another type of hydrogen electrolyser which is more efficient) depend on metal catalysts such as platinum and iridium and stand-alone water purification systems, making them expensive. Iridium is one of the rarest elements present on earth with the main producers being South Africa, Russia and Zimbabwe. Newer types of electrolysers that do not rely on scarce resources, such as solid oxide electrolysis (SEO), are being developed.

 

Furthermore, pipelines for hydrogen, hydrogen fuel cells and storage tanks also cost more. The initial investment into the infrastructure required for the transition to hydrogen may also provide a barrier.

 

Storage

As mentioned earlier, there are potentially suitable sites for hydrogen storage in Australia, however, the proximity of salt cavern underground storage sites to existing infrastructure such as pipelines presents a challenge. In addition, replacing methane in a depleted gas field with hydrogen will result in only approximately 27% of the available energy from hydrogen compared to methane. There are other challenges to overcome when it comes to understanding underground hydrogen storage including the formation of hydrogen sulphide and microbial changes (i.e. the consumption of hydrogen by microbes in the presence of carbon) and the size and location of the cavern (i.e. smaller sizes are preferred because you need to maintain pressure).

 

Further challenges

There are many other challenges in this emerging industry. The regulation, policies, strategies and safety standards required to support the hydrogen industry need to be developed further, as well as infrastructure, technological and knowledge hurdles to overcome.

 

 

 

 

 

 

 

Hydrogen in Australia

Australia has developed the National Hydrogen Strategy (currently under review) which is intended to keep Australia on track to becoming a global hydrogen leader by 2030 regarding hydrogen export and the decarbonisation of Australian Industries.

 

A report conducted to inform the National Hydrogen Strategy found that Australia has the physical resources to support a large-scale hydrogen industry and carbon capture and storage (CCS) hydrogen. Coastal areas have increased potential for hydrogen production using electrolysis due to infrastructure and resource availability, including desalinated seawater and electrical and port infrastructure. Inland hydrogen production is possible, but there are some challenges including lack of infrastructure, water availability and competing land and resource use.

 

Australia is also:

  • developing partnerships with a number of other countries to develop hydrogen technology, decarbonise and create export and economic opportunities
  • designing a Guarantee of Origin Scheme to track and verify emissions relating to hydrogen
  • building hydrogen hubs so that producers, users and exporters can share infrastructure and expertise
  • improving hydrogen regulation to support hydrogen development and safety throughout the states and territories.

 

 

 

 

 

 

 

References