Wiki - All about hydrogen

Updated on 7 June 2024

Grey hydrogen

Grey hydrogen, a widely used yet environmentally controversial commodity, is produced through a process called steam methane reforming (SMR). In this method, natural gas, primarily composed of methane, reacts with high-temperature steam to produce hydrogen and carbon dioxide. While this process is cost-effective, it also results in significant carbon emissions, which are released into the atmosphere, contributing to greenhouse gas accumulation and climate change. More information on this and other hydrogen production methods can be found in this article.

The production of hydrogen with steam reforming has become the standard method in industry due to its relatively low cost and the abundance of natural gas. It plays a crucial role in refining, chemical manufacturing, and as a feedstock in ammonia production for fertilizers. However, the environmental impact of grey hydrogen is important; each ton of hydrogen produced via SMR releases approximately ten tons of CO2, making it a major source of industrial carbon emissions.

Despite its drawbacks, grey hydrogen continues to dominate the hydrogen market, accounting for the majority of global hydrogen production. According to this paper, the share of hydrogen produced from natural gas in 2022 has been about 48%. This dominance is sticky partly due to the established infrastructure and the relatively low production costs compared to alternative methods like green hydrogen, which is produced via electrolysis using renewable energy sources and emits no carbon dioxide.

The reliance on grey hydrogen highlights the broader challenge of transitioning to a more sustainable energy system. To mitigate the environmental impact, some initiatives are exploring carbon capture and storage (CCS) technologies. By capturing and storing the CO2 emissions from grey hydrogen production, these technologies aim to reduce its carbon footprint, potentially transforming it into a lower-emission energy source, often referred to as blue hydrogen.

However, the implementation of CCS is costly and complex, and it does not completely eliminate emissions. Furthermore, such blue hydrogen would still be a non-renewable commodity. As a result, there is a growing emphasis on developing and scaling up green hydrogen production. Green hydrogen, though still more expensive, offers a truly sustainable alternative by leveraging renewable energy sources to produce hydrogen without any associated carbon emissions and without the need of using fossil raw materials.

In conclusion, grey hydrogen represents a significant yet environmentally challenging component of the current commodity landscape. While it provides a cost-effective solution for hydrogen production, its substantial carbon emissions necessitate urgent efforts to transition towards more environmentally friendly alternatives. Investing in renewable energy and advancing technologies like electrolysis are essential steps in reducing the environmental impact of hydrogen production and achieving a more sustainable future.

Delivered hydrogen in cylinder bundles.
Delivered hydrogen such as the hydrogen in these cylinder bundles is today often grey hydrogen.
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