Green Hydrogen – An Overview

What is Hydrogen?

Hydrogen is one of the most abundant sources of gas contributing approximately 75% of the gas in our solar system. Hydrogen is found in various things including light, water, air, plants, and animals, however, it is often combined with other elements. The most familiar combination is with oxygen to make water. Hydrogen gas is a colourless, odourless, and tasteless gas which is lighter than air. As it is far lighter than air this means it rises in our atmosphere, meaning it is not naturally found at ground level, but instead must be created. This is done by separating it from other elements and collecting the gas. 

What is Green Hydrogen?

Green hydrogen is produced using electricity to power an electrolyser that separates hydrogen from the water molecule producing oxygen as a by-product. Excess electricity can be used by electrolysis to create hydrogen gas that can be stored for the future. Essentially, if the electricity used to power the electrolysers originates from renewable sources such as wind, solar or hydro, or if it originates from nuclear power – fission or fusion, then the hydrogen produced is green, in which the only carbon emissions are from those embodied in the generation infrastructure. Electrolysers are the most significant technology used for synthesising zero-carbon hydrogen fuel using renewable energy, known as green hydrogen. Green hydrogen and derivatives are an essential solution to the decarbonisation of heavy industry sectors and experts suggest will constitute up to 25% of total final energy use in a net-zero economy. 

Advantages of Green Hydrogen

It is 100% sustainable as it does not emit polluting gases either through combustion or production. Hydrogen can be easily stored thereby allowing it to be used later for other purposes and/or at the time of production. Green hydrogen can be converted into electricity or synthetic gas and can be used for a variety of domestic, commercial, industrial or mobility purposes. Additionally, hydrogen can be mixed with natural gas at ratio of up to 20% without modification of the gas main infrastructure or gas appliances.  

Disadvantages of Green Hydrogen

Although hydrogen is 100% sustainable it currently comes at a high cost than fossil fuels due to renewable energy being more expensive to produce. The overall production of hydrogen requires more energy than some other fuels, so unless the electricity required to produce hydrogen comes from a renewable source the entire process of production may be counterproductive. Additionally, hydrogen is a highly flammable gas, therefore extensive safety measures are essential to prevent leakage and explosions. 

What is The Green Hydrogen Catapult (GHC) and what does it aim to achieve? 

Members of the Green Hydrogen Catapult (GHC) are a coalition of leaders with an ambition to expand and grow Green Hydrogen Development. As of November 2021, they have announced a commitment for 45 GW of electrolysers to be developed with secured financing by 2026 with additional targeted commissioning for 2027. This is a vastly increased ambition as the initial target set by the coalition at the time of its launch in December 2020 was 25 GW. Green hydrogen has been seen as a critical element in creating a sustainable energy future as well as being one of the largest business opportunities in recent times. And has been said to be the key to allowing for the decarbonisation of sectors like steel manufacturing, shipping, and aviation.  

Why Hydrogen is seen as a cleaner future?

We live in a world in which one of the collective sustainability aims is to decarbonise the fuel we use by 2050. To achieve this, decarbonising the production of a significant fuel source like hydrogen, giving rise to green hydrogen, is one of the key strategies as production of non-green hydrogen is currently responsible for more than 2 % of total global CO2 emissions. During combustion, chemical bonds are broken and constituent elements combined with oxygen. Traditionally, Methane gas has been the natural gas of choice with 85% of homes and 40% of the UK’s electricity depending on natural gas. Methane is a cleaner fuel than coal, however, when it is burnt carbon dioxide is produced as a waste product which, on entering the atmosphere, starts contributing to climate change. Hydrogen Gas when burnt only produces water vapour as a waste product, which has no global warming potential. 

The UK Government have seen the use of hydrogen as a fuel and hence hydrogen homes as a way forward for a greener way of living, and have set a target for a thriving hydrogen economy by 2030. Whilst Japan, South Korea and China are on course to make considerable progress in hydrogen economy development with targets set to surpass the UK by 2030. Similarly, the European Commission has presented a hydrogen strategy in which hydrogen could support 24% of Europe’s energy by 2050. 

How Hydrogen is Helping the Gas and Steel Industries to Go Green

Green hydrogen, taken from both low carbon and renewable energy sources, can play a crucial role in taking a company – or a country – closer to carbon neutrality. Common applications in which green hydrogen can be used include:

  • Fuel cells for electric vehicles
  • As the hydrogen in pipeline gas blending
  • In ‘green steel’ refineries that burn hydrogen as a heat source rather than coal
  • In container ships powered by liquid ammonia that is made from hydrogen
  • In hydrogen-powered electricity turbines that can generate electricity at times of peak demand

This post will explore the use of hydrogen in pipeline gas blending and green steel refineries.

Injecting hydrogen into pipelines

Governments and utilities companies worldwide are exploring the possibilities of injecting hydrogen into their natural gas grids, to reduce fossil fuel consumption and limit emissions. Indeed, hydrogen injection into pipelines now features in the national hydrogen strategies of the EU, Australia and the UK, with the EU’s hydrogen strategy specifying the introduction of hydrogen into national gas grids by 2050.

From an environmental point of view, adding hydrogen to natural gas has the potential to significantly reduce greenhouse gas emissions, but to achieve that, the hydrogen must be produced from low-carbon energy sources and renewables. For example, hydrogen generated from electrolysis, bio-waste or fossil fuel sources that use carbon capture and storage (CCS).

In a similar way, countries aspiring to develop a green hydrogen economy can turn to grid injection to stimulate investment and develop new markets. In an effort to kick start its renewable hydrogen plan, Western Australia is planning to introduce at least 10% renewable hydrogen into its gas pipelines and networks, and to bring forward the state’s targets under its renewable hydrogen strategy from 2040 to 2030.

On a volumetric basis, hydrogen has a much lower energy density than natural gas, so end-users of a blended gas would require a higher volume of gas to achieve the same heating value as those using pure natural gas. Simply put, a 5% blending of hydrogen by volume does not directly translate into a 5% reduction in fossil fuel consumption.

Is there any safety risk in hydrogen blending in our gas supply? Let’s examine the risk:

  1. Hydrogen has lower LEL than natural gas, so there is a higher risk of generating a flammable atmosphere with blended gas mixtures.
  2. Hydrogen has lower ignition energy than natural gas and a broad flammable range (4% to 74% in air), so there is higher risk of explosion
  3. Hydrogen molecules are small and move quickly, so any blended gas leak will spread faster and wider than would be the case with natural gas.

In the UK, domestic and industrial heating accounts for half of the UK’s energy consumption and one third of its carbon emissions. Since 2019, the UK’s first project to inject hydrogen into the gas grid has been underway, with trials taking place at Keele University. The HyDeploy project aims to inject up to 20% hydrogen and blend it with the existing gas supply to heat residential blocks and campuses without changing the gas-fired appliances or piping. In this project, Crowcon gas detectors and flue gas analyser are being used to identify the impact of hydrogen blending in terms of gas leak detection. Crowcon’s Sprint Pro flue gas analyser is being used to assess for boiler efficiency.

Crowcon’s Sprint Pro is a professional grade flue gas analyser, with features tailored to meet the needs of the HVAC professional, a robust design, full selection of accessories and 5-year warranty. Read more about the Sprint Pro here.

Hydrogen in the steel industry

Traditional iron and steel production is considered one of the largest emitters of environmental pollutants, including greenhouse gases and fine dust. Steel making processes rely heavily on fossil fuels, with coal products accounting for 78% of these. It is thus not surprising that the steel industry emits around 10% of all global process- and energy-related CO2 emissions.

Hydrogen may be an alternative for steel companies seeking to drastically reduce their carbon emissions. Several steel makers in Germany and Korea are already cutting emissions through a hydrogen reduction steelmaking method that uses hydrogen, not coal, to make steel. Traditionally, a significant amount of hydrogen gas is produced in steel making as a by-product called coke gas. By passing that coke gas through a process called carbon capture and storage (CCS), steel plants can produce significant amount of blue hydrogen, which can then be used to control temperatures and prevent oxidation during steel production.

In addition, steel makers are producing steel products specifically for hydrogen. As part of its new vision of becoming a green hydrogen enterprise, Korean steelmaker POSCO has invested heavily to develop steel products for use in the production, transport, storage and utilisation of hydrogen.

With many flammable and toxic gas hazards being present in steel plants, it is important to understand the cross sensitivity of gases, because a false gas reading could prove fatal. For example, a blast furnace produces a great deal of hot, dusty, toxic and flammable gas consisting of carbon monoxide (CO) with some hydrogen. Gas detection manufacturers that have experience in these environments are well acquainted with the issue of hydrogen affecting electrochemical CO sensors, and thus provide hydrogen-filtered sensors as standard to steel facilities.

To learn more about cross sensitivity, please see our blog. Crowcon gas detectors are used in many steel facilities across the world, and you can find out more about Crowcon solutions in the steel industry here.

References:

  1. Injecting hydrogen in natural gas grids could provide steady demand the sector needs to develop (S&P Global Platts, 19 May 2020)
  2. Western Australia pumps $22m into hydrogen action plan (Power Engineering, 14 Sep 2020)
  3. Green Hydrogen in Natural Gas Pipelines: Decarbonization Solution or Pipe Dream? (Green Tech Media, 20 Nov 2020)
  4. Could hydrogen piggyback on natural gas infrastructure? (Network Online, 17 Mar 2016)
  5. Steel, Hydrogen and Renewables: Strange Bedfellows? Maybe Not… (Forbes.com, 15 May 2020)
  6. POSCO to Expand Hydrogen Production to 5 Mil. Tons by 2050 (Business Korea, 14 Dec 202 0)http://https://www.crowcon.com/wp-content/uploads/2020/07/shutterstock_607164341-scaled.jpg