Hydrogen: An Introduction

Hydrogen: An Introduction

Interest in Hydrogen as an energy source has soured over the last few years with its potential sustainability qualities and utilization across a wide range of applications. However, what are the qualities of Hydrogen that support this broad range of use cases? This article will provide an introduction to Hydrogen, its qualities, production methods and some of its uses.

Elemental Hydrogen

• Hydrogen is the lightest gas in the world.
• Hydrogen has the highest specific energy of any fuel (not including nuclear) of 120 - 142 MJ / kg of H2
• The chemical energy in 1kg of H2 is 30 x greater than 1 kg of TNT.
• At atmospheric pressure, 1m3 of H2 gas weighs just 0.084 kg
• This density means that Hydrogen has one of the lowest energy densities of all fuels, which explains why hydrogen is required to be stored at high pressure or stored as a liquid.
• Hydrogen liquifies at -253 Deg C. Cooling hydrogen to this temperature can consume in excess of 40% of the energy content of the hydrogen itself.
• Hydrogen has a large explosive window (LEL: 4.0%, UEL: 75.0%) meaning that at concentrations between the LEL and UEL fall into the explosive range for H2. ?
• Hydrogen is nontoxic
• Hydrogen is the most abundant element in the world.

Image Source: https://www.nrcan.gc.ca/our-natural-resources/energy-sources-distribution/energy-from-hydrogen-the-basics/23025

?Hydrogen Production

Around the globe there are many different technologies used to produce hydrogen, and these are listed below. Over the coming months I will look to go through each of these different technologies and discuss the technical aspects, advantages and disadvantages of each of these processes.

Image Source: Steam Methane Reforming https://www.engineering-airliquide.com/project-delivery-services-references/steam-methane-reforming-plant-germany

Safety Concerns

Hydrogen as any fuel has associated safety concerns. These will be discussed in detail with associated standards and regulations in a following article.

• Hydrogen embrittlement resulting in premature cracking being caused by the presence and diffusion of hydrogen atoms and stresses in a susceptible material.
• Material compatibility issues and related mechanical characteristics are an issue due to the low temperature requirements for liquid hydrogen storage.
• Cold temperatures have a risk of burns and frostbite
• Susceptibility to bubbling and splashing
• As with all fuels explosions and fires are a risk. This is of great importance with hydrogen due to the large window between the LEL (Lower Explosive Limit) and UEL (Upper Explosive Limit)
• Due to H2 gas storage pressures (200 Bar up to 900 Bar) there are associated high pressure safety hazards and associated H2 storage standards. This is inclusive of drop tests, tensile tests and pressure tests.
• H2 leaks and build up in process areas
• The use of electrical equipment in explosive atmospheres, requiring strict management of all equipment being utilised in the process and storage areas must meet specific standards (IEC 60079-10-1)

Utilisation of Hydrogen

• Direct fuel source into gas lines to reduce the carbon footprint of gas supply.
• Food Processing: Hydrogenation of oils to fats
• Use of hydrogen in the glass making industry
• As a fuel source for hydrogen turbines for the purpose of power generation.
• Use of hydrogen as energy storage (Backup power options)
• As a fuel for vehicles (Cars, Busses, Trucks, Trains, Aircraft)
• Indoor usage for forklifts
• As a fuel source for shipping
• Industrial processes such as its use in welding.

Image Source: https://neutronbytes.com/2020/11/12/feds-pump-10m-into-xcel-energy-for-hydrogen-production/

Costs and Supply Chains of Hydrogen

The connectivity of infrastructure for the purpose of the wide use of Hydrogen remains in its infancy, with the macro related supply chains still being developed. The below process diagram provides an approximation of the current cost of Hydrogen through the supply chain from its production, storage, transport and use. (Tranfield, 2021)

The hydrogen energy value chain, from supply to end use. Recreated and updated from IEA (2019), The Future of Hydrogen,?https://www.iea.org/reports/the-future-of-hydrogen .

About the Author

John Tranfield has 15+ years experience in the Petroleum Industry and is currently studying Hydrogen, the hydrogen economy, production technologies and business strategies to exploit the emerging industry.

References

John Tranfield, The micro–meso–macro architecture of a proposed collaborative emergent strategy for the hydrogen market,?Clean Energy, Volume 5, Issue 4, December 2021, Pages 634–643,?https://doi.org/10.1093/ce/zkab032