What is hydrogen?
Hydrogen (H) is a colourless, odourless, tasteless, and highly flammable gaseous substance, representing the simplest member of the chemical elements. Its atom consists of a nucleus of a single proton with a positive electrical charge, which orbits an electron carrying a negative charge. In standard conditions, it exists as loosely bound hydrogen molecules, each comprising a pair of atoms forming a diatomic molecule, H2.
Notably, the earliest recognised chemical property is its ability to combine with oxygen to produce water (H2O), a trait reflected in its name derived from Greek roots meaning “maker of water”. Despite being the most abundant element in the universe, surpassing even helium, hydrogen forms only around 0.14% of the Earth’s crust by weight. However, it exists in vast quantities within water bodies, including oceans, ice caps, rivers, lakes, and the atmosphere.
It is also ubiquitous in countless carbon compounds, being present in all animal and plant tissues as well as in petroleum. While carbon is often credited with forming the most known compounds, its presence in nearly all carbon compounds and its ability to create numerous compounds with other elements suggest that hydrogen compounds might outnumber those of carbon.
Is hydrogen flammable?
It poses no greater or lesser risk than other flammable fuels, such as fuel or natural gases. Some of its unique characteristics offer safety advantages compared to traditional fuels. However, responsible handling is essential for all flammable substances.
Like fuel and natural gas, hydrogen is flammable and can present hazards under specific circumstances. Nonetheless, it can be managed safely by adhering to simple guidelines and understanding its behaviour. The gas is lighter than air and disperses rapidly. With a diffusion rate 3.8 times faster than natural gas, released hydrogen quickly dilutes into non-flammable concentrations. It ascends twice as fast as helium and six times faster than natural gas, travelling at nearly 45 mph (20 m/s).
Therefore, if in a poorly ventilated space, it swiftly rises and disperses, minimising the risk of accumulation near a leak or individuals using hydrogen-based equipment. Thus, confining hydrogen, being the lightest element, proves challenging, influencing the design of structures in hydrogen-utilising industries to facilitate its upward dispersion in case of a release.
Five areas where hydrogen is used
Hydrogen’s versatility and utility extend across a wide array of industries, contributing to its growing adoption and integration into modern technological advancements. Here’s a closer look at some key sectors where hydrogen plays a significant role:
1) Transportation: Hydrogen is increasingly being utilised as a clean energy source in the transportation sector. Hydrogen fuel cells power various vehicles, including cars, buses, trucks, and trains. These fuel cells convert hydrogen gas into electricity through an electrochemical process, providing a sustainable alternative to traditional internal combustion engines. Additionally, hydrogen is being explored for use in aviation, with research and development efforts focused on developing hydrogen-powered aircraft, which could significantly reduce emissions in the aviation industry.
2) Energy Storage: One of the most promising applications of hydrogen is its role as an energy storage medium. Renewable energy sources such as wind and solar power often generate excess electricity that cannot be immediately utilised. H₂ can be produced through electrolysis using this surplus electricity, storing it in the form of hydrogen gas. This stored hydrogen can then be converted back into electricity when demand is high, providing a reliable and efficient means of energy storage for grid balancing and backup power generation.
3) Industrial Processes: Hydrogen serves as a crucial feedstock in various industrial processes across sectors such as petroleum refining, ammonia production for fertilisers, and methanol production. It is also utilised in food processing, electronics manufacturing, and metal refining. Its use in these processes contributes to increased efficiency, reduced emissions, and overall process optimisation.
4) Power Generation: Hydrogen combustion can be directly used to generate electricity in gas turbines or internal combustion engines. By burning hydrogen, heat is produced, which is then converted into mechanical energy to drive generators and produce electricity. This process offers a low-emission alternative to traditional fossil fuels, helping to reduce greenhouse gas emissions and mitigate climate change.
5) Heating and Cooling: H₂ can be used as a fuel for heating buildings and water, either through combustion or in fuel cells that generate both heat and electricity simultaneously. Additionally, new air conditioning and refrigeration systems are being explored as a sustainable solution for cooling.
Use of hydrogen in the UK
In the United Kingdom, H₂ is increasingly recognised as a key component of the country’s efforts to achieve its climate and energy goals. Many Hubs are opening up in the UK, with one recently having been approved in Bradford.
‘Bradford hydrogen energy hub plans approved’
Plans have been approved to build one of the country’s biggest hydrogen refuelling stations in Bradford. The facility at the Birkshall gas storage site on Bowling Back Lane will have the capacity to produce about 12.5 tonnes per day. Operator Hygen said the site could achieve the decarbonisation equivalent of removing 800 diesel-fuelled buses a day from West Yorkshire’s roads.
Hygen director Jamie Burns said the HyBradford facility would “provide enormous benefits to the people of Bradford”. The project, which has received millions in government funding, is a partnership between Hygen and N-GEN and was approved by Bradford Council this week, according to the Local Democracy Reporting Service. The facility “will provide enormous benefits to the people of Bradford”, Hygen says Hydrogen is increasingly seen as a greener way of fuelling larger vehicles such as HGVs, buses and coaches.
Gareth Mills, managing director at N-Gen, said: “We are extremely proud to be bringing a flagship production facility and significant investment to Bradford. “We expect the facility to be a valuable addition to the Bradford economy, providing a viable way for local businesses to decarbonise, as well as attracting new companies and jobs to the area, by placing the city at the forefront of the transition to clean energy.” Businesses and other users will be able to use refuelling facilities at the site when it opens. Source: BBC News
For further details, download our guide Hydrogen – Will you be using it in the future today!
Written by Rhys Redrup