May-2023

The path to green hydrogen

With the right policy incentives and infrastructure investment in place, green hydrogen can advance clean energy transition.

Honeywell UOP

Article Summary

Hydrogen’s potential as a clean fuel source is tremendous. After all, when hydrogen is burned in a fuel cell, the primary byproduct that’s produced is water vapour. In sufficient quantities, hydrogen fuel could power the electric grid that keeps your lights on, heat the buildings you work and shop in, dramatically reduce the carbon footprint of your vehicles, and continue to play its role as an important feedstock in industries like chemical, petrochemical and steel production that we all depend on.

So, you might wonder: Why isn’t everyone replacing fossil fuels with hydrogen?

Hydrogen itself is a clean-burning, zero-carbon fuel source. But it typically is produced using carbon-dense fuels like natural gas and coal, either directly or as the source of energy used to generate the very large amounts of electricity consumed in clean production methods.

In recent years, approximately 6% of global natural gas and 2% of global coal has gone to hydrogen production, according to the World Economic Forum. The resulting CO2 emissions total about 830 million tons of carbon dioxide per year, equivalent to the combined CO2 emissions of the United Kingdom and Indonesia, according to the same report from the World Economic Forum.
Today’s most common methods of hydrogen production were not designed with innovation and aspects of sustainability in mind. Green hydrogen, on the other hand, is.

What is green hydrogen?
To be considered “green,” hydrogen must be produced using not only a zero-carbon process, but one powered by renewable energy sources like wind and solar.

How do you produce green hydrogen?
The cleanest method of hydrogen production is electrolysis, using an electrically powered electrolyser to separate water (H2O) molecules into hydrogen and oxygen. Additionally, the purity of hydrogen dictates the role it can play within the hydrogen economy, so impurities must be removed from the hydrogen through a separation process.

In a science class, you might have seen this process take place in a small-scale electrolyser, made from a beaker full of water, a couple of metal strips or wires connected to a battery, and two test tubes to collect the separated hydrogen and oxygen.

On an industrial scale, simply choosing renewable energy to power electrolysers results in a green hydrogen production process.

What are the uses of green hydrogen?
Green hydrogen can be used in any application that relies on hydrogen produced with traditional, carbon-intensive methods. That means it can help many industries and processes move toward carbon neutrality including:
• Power generation
• Transportation
• Pharmaceutical manufacturing
• Glass purification
• Petroleum refining
• Semiconductor manufacturing

What are the challenges to green hydrogen production?
Despite all its advantages, there are a few obstacles to overcome on our way to widespread, economically feasible green hydrogen use. Here are some of the challenges:

Electrolysis is a very energy-intensive process.
Until there are widely available, reliable and economical sources of clean power, the cost of producing green hydrogen at scale will remain prohibitive.

Electrolysis is water intensive.
You need a significant supply of water that meets certain purity standards, which could place geographic limitations on the location of green hydrogen production facilities.

The infrastructure needs to be built.
While we have a robust natural gas infrastructure, it can’t easily be repurposed to transport. Hydrogen has a tendency to make steel brittle and subject to fracture, so will likely require dedicated pipelines.

What’s the expected impact of green hydrogen on the global energy transition?
According to the International Energy Agency’s Global Hydrogen Review 2022, overall hydrogen demand worldwide reached 94 million tons in 2021, and is estimated to reach 115 – 130 million tons by 2030. Meeting future demands with existing methods of hydrogen production, while feasible, is not a sustainable solution.

Green hydrogen will be critical in enabling the global energy transition, especially for energy sources that:
• Power vehicles and aircraft
• Heat homes and offices
• Generate electricity
• Decarbonise industrial processes

What’s being done to accelerate green hydrogen production?
Amid the global effort to transition to a less carbon-intensive future, our engineers developed new catalyst-coated membrane (CCM) technology for green hydrogen production that can help drive down production costs by enabling greater electrolyser performance. These catalyst-coated membranes are currently in testing with electrolyser manufacturers, where they’re enabling higher electrolyser efficiency and higher electric current density using breakthrough technology.

In addition to the developments on CCM, our hydrogen purification technology works at high pressure from hydrogen-containing process streams to remove trace contaminants such as oxygen, water and nitrogen. This allows hydrogen to be recovered and upgraded to more than 99.9% purity to meet refining needs.