Oct-2023

Hydrogen derivatives key to the global renewable energy trade

The role that hydrogen derivatives can play in decarbonising key applications and industries

Nadim Chaudhry
World Hydrogen Leaders

Article Summary

As an energy carrier, when produced using renewables, hydrogen is set to play a pivotal role in decarbonising the world’s energy systems. As a direct fuel, hydrogen can replace fossil-fuels in a wide range of uses including transport, industrial, residential and portable power applications. 

However, the markets for clean hydrogen increase substantially when considering the use of its derivatives; products that can be used as a feedstock for industrial processes, as a way to transport energy over long distances and use in other hard-to-abate applications. 

Green hydrogen derivatives can accelerate fossil fuel phase-out
Storing and transporting hydrogen as a gas can be challenging considering its low energy content by volume and small molecule size. However, hydrogen’s inherent flexibility offers multiple pathways to its end use. The gas can be compressed, liquefied, and reversibly bound into solid materials or liquid organic hydrogen carriers (LOHC).

Hydrogen can also be converted into synthetic green electro-fuels including e-methanol, e-methane and e-ammonia. The principal benefit of converting hydrogen to its derivatives is that the energy density of these products is significantly higher. For example, liquid ammonia has an energy density around eight times that of lithium-ion batteries. Increasing the energy density makes long-distance transport and long-term storage more cost effective. For these reasons, hydrogen derivatives will become a key enabler of the global trade in renewable energy.

Green ammonia
As an energy carrier, e-ammonia has some advantages over hydrogen. It is liquid at minus 33°C (compared to hydrogen which needs a temperature of minus 253°C) and there is expertise in creating infrastructure for storing and transporting it. It can be used to fire gas turbines to generate electricity without emissions. As well as making it cheaper and easier to transport energy, hydrogen derivatives can play a significant part in decarbonising industrial processes.

Nitrogen-based fertilisers are critical for global food production, but their production and use contributes 5% of the world’s greenhouse gas emissions. These emissions can be reduced significantly by synthesising ammonia from hydrogen and nitrogen using renewable energy. The conventional process for producing ammonia, which uses natural gas as a feedstock, is responsible for around 2% of global fossil fuel use and more than 1% of global emissions.

From 2020 to 2022, fertiliser prices increased by a factor of six due to gas price volatility, which is a key driver in the rising cost of food. Developing alternative, green sources of ammonia can help to protect against global food price inflation.

Ashwani Dudeja, President & Director, Green Hydrogen and Ammonia ACME Group sees huge potential for hydrogen derivatives to contribute to more sustainable agriculture and in decarbonising industrial processes: “The existing demand for ammonia as a chemical in fertiliser and chemical industries is a low hanging fruit to achieve decarbonisation without requiring any capital expenditure. Beyond agriculture, ammonia has a significant potential in achieving decarbonisation in the marine sector, which contributes to nearly 3% of global emissions. The possible uses of ammonia in areas like power generation both for co-firing as well as mono firing fuel, road transportation (especially heavy-duty transport) and other industrial applications is very promising as well.

“To begin with, hydrogen and its derivatives, like ammonia, can be used in many of those hard to decarbonise sectors and applications where electrification is not possible – aviation and steel are good examples. Within the electricity sector, these new fuels can be used alongside renewable power generation to smooth supplies and optimise power grids thus achieving higher share of overall power generation.” While an estimated 70% of ammonia is used to produce fertilisers, the remainder plays an important role in other industrial applications including plastics and synthetic fibres.

Angela Kruth, Head of Green Ammonia Technologies believes that string partnerships will play in a key role in unlocking the hydrogen energy transition: “Ammonia is a long-time reliable and faithful workhorse that has enabled our food supply for over a century. Produced from renewable energy and directly utilised in shipping, landside mobile and stationary energy supply applications, as well as production of green chemicals and materials, it is a gamechanger for the energy transition and our key to a fast-track decarbonisation of the global energy system. Unlocking and accelerating the green ammonia transition, however, requires bold first movers and fast followers. They must be supported in initiating the transition and costs, benefits as well as risks must be shared in strong partnerships across the whole value chain of ammonia.”

A recent report forecast by the Faraday Institution (FI) suggests that in 2050 ammonia will be the predominant fuel for UK marine applications, taking 35% of the market. Green ammonia is forecast to be 15 times cheaper than liquid hydrogen. However, FI does not expect ammonia-powered ships to be in use until 2035 due to the need to develop new technology.

Tobias Block, Head of Strategy and Content at the eFuel Alliance, believes that e-fuels offer the best solution to decarbonise the maritime sector: “Shipping is considered a difficult sector to electrify, which makes the use of liquid fuels such as synthetic LNG, e-methanol, e-ammonia or e-diesel without alternative. E-fuels offer the greatest potential for climate-neutral operation for shipping. With the same chemical characteristics as fossil fuels, they can be blended into conventional fuels until they reach full market penetration. By doing so, massive CO₂ savings can already be achieved today. But this requires ambitious political framework conditions worldwide to accelerate the production and marketing of sustainable fuels. At the same time, shipping is a global sector and under enormous competitive pressure. If we want to facilitate a swift market ramp-up of alternative fuels in the maritime sector, sufficient support mechanisms have to be put in place to combat global first-mover disadvantages.”

Green methanol
Green methanol is produced from green hydrogen and carbon dioxide. Today, methanol is one of the most widely produced and important raw materials in the chemical industry. Producing green methanol on an industrial scale can make a significant contribution to the energy transition.

Direct Methanol Fuel Cells already enable the use of methanol in portable generators and vehicles. Liquid green methanol is easy to store, transport and use. Furthermore, its manufacture uses proven technology – there are plants producing green methanol that have been operating for over a decade.

By synthesising green methanol using renewable energy, water and CO₂ from industrial processes, it becomes possible to create a circular system. The water produced is fed back into the electrolyser and the waste heat can be captured and reused, as can the oxygen.