Low-carbon hydrogen production

As the world is searching for ways to limit global warming and decrease the dependence on fossil fuels, hydrogen is a promising possibility. There are several ways to produce low-carbon hydrogen, which can be distributed to the point of application in liquid or gaseous form. However, it is imperative to note that hydrogen is not a source of energy but an energy carrier. Therefore, a prerequisite for reducing carbon emissions using hydrogen is a low-carbon or zero-emission production of hydrogen.

Hydrogen production – green, blue, grey hydrogen, and beyond

The different ways to produce hydrogen are typically referred to as green, blue, and grey (sometimes also turquoise, yellow, and pink) hydrogen. 

Green hydrogen – renewable energies and zero-emissions

Green hydrogen is produced through electrolysis by splitting water molecules into individual elements. During this process, only hydrogen and oxygen is produced. The oxygen can safely be released into the atmosphere as a by-product. Electrolysis requires electrical energy generated through renewables like wind and solar power in the case of green hydrogen. In addition to electrolysis, green hydrogen can also be produced by steam reforming of biomethane and pyrolysis of biogenic feedstocks. Green hydrogen is the cleanest way to produce hydrogen with the lowest possible (close to zero) CO2 emissions.

Blue hydrogen – steam reforming and carbon capture and storage

Blue hydrogen is produced by splitting natural gas into hydrogen and CO2, for example, through steam methane reforming (SMR). The CO2 is not released into the atmosphere but captured in the process and stored. This process of carbon capture and storage (CCS) mitigates the environmental impact.

Grey hydrogen – produced from fossil fuels

Grey hydrogen is produced similar to blue hydrogen from fossil fuels like coal or natural gas. However, carbon emissions are released into the atmosphere, making this technology less environmentally safe.

Other ways to produce hydrogen – turquoise, yellow and pink

There are other ways to produce hydrogen, some of which are worth mentioning.

• Turquoise hydrogen is created through the pyrolysis of methane which is split into solid carbon and hydrogen in a reactor. This process does not produce gaseous CO2 as a by-product, and if renewable energies power the reactor, it is considered CO2-emission neutral.
• Yellow hydrogen is produced similar to green hydrogen, with energy obtained solely through solar power.
• Pink hydrogen is also made through electrolysis, with power coming from nuclear energy.

Challenges and opportunities for low-carbon hydrogen production

The hydrogen market is still in its early stage, but it is gaining significant momentum as governmental and economic frameworks are being built. Especially heavy industries like steel and glass are under pressure to decarbonise and have not many alternatives other than switching from fossil fuels to power-to-x solutions like hydrogen.

Green and low-carbon hydrogen is the goal

The next couple of years will be decisive for the fight against climate change. Moving to green and low-carbon hydrogen is the goal to decarbonise many sectors like heavy transport and industry. Along the way, we will experience similar challenges like we have seen in the e-mobility sector. We need the infrastructure to produce and provide enough hydrogen while at the same time we need the demand for this energy carrier to scale up.

In this phase, grey and blue hydrogen will play a vital role to manage the transition to hydrogen without shortages and without waiting for renewable energy plants to be built first.

The economic efficiency of hydrogen is the key to success

Several factors are influencing the economic efficiency of low-carbon hydrogen; some of the most important ones are:

• Cost of the primary energy carrier (e.g. electricity from renewable energies, natural gas)
• Cost of infrastructure
• Cost of components
• Cost of operation

The first two, costs of energy and hydrogen infrastructure, depend on policymakers as higher CO2-emission prices and subsidies for power-to-X solutions can improve the competitiveness of hydrogen significantly. Many governments in Europe, Asia and North America have strategies in place to support hydrogen (read more in the WEC-Report from LBST here). Therefore, it is likely that hydrogen production will become a lot more economically efficient over the following years, and the availability of green hydrogen will improve.

Costs of components for and operation of hydrogen production will decrease with higher demand. As a result, companies investing early in this field will benefit from a growing global market. However, missing regulations, codes, and standards (RCS) are still creating uncertainty. TÜV SÜD can mitigate the risk for customers through an extensive service portfolio that ensures safety and compliance in this complex market. Through memberships in RCS committees and organisations, we can also help customers get notified of upcoming RCS changes early on.

Hydrogen producers and users – regional differences

Hydrogen has different potential in different regions. Industrialised countries, like Germany, Japan, and the Netherlands, will import hydrogen from other countries with favourable environmental factors for renewable energy production.

Countries like Spain, Australia, and Chile, with a lot of wind and solar power, will be able to produce large quantities of green hydrogen and export their overcapacities.

At the same time, smaller regional projects are popping up on a national scale. For example, in Germany, there are several hydrogen clusters with smaller electrolyser projects. In addition, cities with access to renewable energies are building their own infrastructure to decarbonise sectors like public transport and attract companies that need access to green hydrogen.

at tüv süd, we offer services covering all chain links in the hydrogen value chain