What is Hydrogen Used For?
Sooo… Hydrogen is just for cars, right?
Hydrogen is one of the most important industrial products we use, but most people have never heard of it. The amount used for vehicles is so small that it won’t fit in any chart compared to other hydrogen uses. Here’s a short list of what else it is currently used for:
1. Critical for humanity use current - Hydrogen is a core ingredient in fertilizer and enables the world to grow food – there is no other pathway to feed the world population, making it the most important thing in your life that you don’t know about
2. High importance current use -Chemicals and refining. For refining, hydrogen is used in a process called hydrocracking that turns heavy oils into much lighter fuels – so we have access to gasoline and diesel at the low prices we have now owing to hydrogen. Hydrogen is a major feedstock for the rest of the chemicals industry as well
3. Sporadic but large use – Rocket fuel. Liquid hydrogen is mixed with liquid oxygen to burn and expand to launch many of our rockets
4. Expanding use- Semiconductor manufacturing can use a significant amount of hydrogen – in fact much of the liquid hydrogen used in the EU is strictly for semiconductor manufacturing (more on liquid vs gas in another post). As the US proceeds further with the CHIPS and Science act, hydrogen demand from this sector will rise
See below the breakdown of major hydrogen use cases in the US from the DOE[1]:
Figure 1: Major uses of hydrogen in the US. “Refining” here means oil refining and other chemicals.
So, no, hydrogen is not just for cars, and cars are such a small use case that it’s a struggle to get it to take off.
For scale, the entire world used about 70 megatons of hydrogen per year in recent years.
Haber-Bosch and Hydrogen for Ammonia:
Measured in number of lives saved or enabled, the Haber-Bosch process ranks at or near the very top. In an undergrad class at Harvard, one of my professors had said that the estimated carrying capacity of the Earth without modern agriculture was somewhere between 500 million and 1 billion, compared to the nearly 8 billion we have now[2]. Indeed, it is estimated that about half the world’s population would not have enough food today without the Haber-Bosch process. Imagine for just one second if your legacy was “I enabled billions of people to live.”
Figure 2: Growth rate of the population over time[3]. In 1906 the Haber-Bosch process was developed. Up until that we had extremely limited natural resources for fertilizer.
Ammonia based fertilizer is a delivery mechanism for nitrogen that plants need to grow. Nitrogen in the atmosphere is inert and not digestible to plants, so it needs to be transformed in a way that can be delivered to plants to grow. Old delivery methods included bat guano and other deposits that had a plant-digestible form of nitrogen, but those were limited and decreasing resources. The Haber-Bosch process combines the nitrogen in the atmosphere with hydrogen to make ammonia (NH3). Fertilizer makes use of ammonia to deliver nitrogen to plants in a way that the plants can digest.
Hydrogen is thus a precursor for a vast majority of fertilizer today. Right now all of this hydrogen comes from splitting natural gas (CH4) into H2. The nitrogen comes from our 78% nitrogen atmosphere.
Every 1 ton of ammonia requires 17.8% hydrogen, so the 150 million tons of ammonia produced in 2020 is about 27 MT of H2 annually of the 70 MT total. This is 74,000 tons per day.
Oil Refining:
Some oil comes out of the ground nearly ready to be used as fuel. Other oil is viscous and is closer to tar than oil. These heavy oils typically are used to make “plastics, petrochemicals, and road surfaces.” Yep, it’s heavy enough to make the tar we use for the roads. But when you hit these heavy oils with high-temperature steam and hydrogen, it “cracks” into lighter molecules – like diesel, jet fuel, and gasoline. This allows low-grade oil to be upgraded to high-grade oil, albeit with additional expense
Figure 3: Oil refinery in Santa Maria, CA[4]
Hydrogen is also used to reduce the sulfur content of fuels – the high sulfur content of many oils will bind with the hydrogen to strip away the sulfur from the fuel, resulting in diesel and oil that means the sulfur requirements to limit sulfur air pollution.
A single refinery will use on the order of 200-300 tons of hydrogen per day.
Hydrogen is also used in the manufacture of most chemicals.
Rocket launches
Most rockets other than SpaceX use liquid hydrogen and liquid oxygen as fuel. A single launch can easily use 20 tons of liquid hydrogen.
In the US, however, the newer launch vessels are using kerosene and moving to liquid natural gas as fuels because these fuels are so inexpensive. There is currently no way to make liquid hydrogen as inexpensive as liquid natural gas in the US, but this is owing to our large and low cost natural gas supply.
Also note that 20 tons of H2 per launch is much smaller than the 300 tons per day that a single refinery uses.
Image from Nasa of a rocket launch - these rockets used liquid hydrogen
Semiconductors
Many of the newer semiconductor fab plants use hydrogen, preferably delivered as liquid since 99.997% purity is guaranteed in this form. In the EU, much of the ~20 tons of per day of liquid hydrogen production (compared to over 200 in the US) is dedicated to semiconductor manufacturing. Note that the EU is not known as a world leader in semiconductor manufacturing, so this relatively small amount is not indicative of total demand.
Some European friends in the semis industry told me that most of the patents related to using hydrogen in semiconductors were filed in the early 2000s, so as these roll of you can expect more hydrogen demand from the semiconductor industry, particularly as the CHIPS and Science act proceeds.
I have seen one estimate that a single large semiconductor manufacturing area (think several plants in one state) would take up to 45 tons per day of hydrogen, but there are zero strong analyses published on this so far.
Vehicles: It would take 400,000 light duty cars or a fleet of 4000 long-haul class-8 semi-trucks (the biggest ones on the road) to equate the demand of a single refinery.
More on this in a future post.
One last use - food and pharma:
You know hydrogenated food products? Think margarine. Oh, and American cheese and anything that uses hydrogenated vegetable oil. So when we eat American cheese slices, they used hydrogen derived from natural gas to make them. Knowing this has not stopped me from making and enjoying many a grilled cheese sandwich.
Another far more critical use is pharma. Most of the pharmaceuticals we take use hydrogen either directly or in a precursor material.
Conclusion:
While you may have barely heard of hydrogen in your daily life and maybe think of it as maybe something in the future of mobility, practically zero of the demand comes from anything you’d directly see in your daily life.
But without hydrogen, about half the world’s population would not exist owing to insufficient food production. There would probably be more wars over food resources, and worse health outcomes generally from less variability of food. Most of the fuel and plastics we use every day also require hydrogen in their production stream.
Practically all of this hydrogen currently comes from natural gas and emits CO2 during manufacture. That can change in the next decade, however, and that change could be led by the US. Or, if we get the latest subsidies wrong, will be led by China much like solar today.
[1] https://www.hydrogen.energy.gov/docs/hydrogenprogramlibraries/pdfs/clean-hydrogen-strategy-roadmap.pdf?Status=Master
[2] Indeed, if we plot the estimated growth of humanity over time and fit it to a standard exponential growth curve (sorry, I’m not explaining this one and it’s well beyond the level of scientific writing I try to use), we see that a break in the
[3] https://www.visualcapitalist.com/cp/population-boom-charting-nearly-8-billion-people/
[4] https://www.slocounty.ca.gov/Departments/Planning-Building/Grid-Items/Community-Engagement/Active-Planning-Projects/Phillips-66-Santa-Maria-Refinery-Demolition-and-Re.aspx
