Hydrogen from Hydrocarbon
All eyes will be on Germany and the rest of Europe this winter as the European Union phases out Russian gas and oil. It would be a boon for the earth if Europe seized this moment to transition away from fossil fuels but unforunately, all I hear is that Germany is firing up more coal power plants that’s been shut down for a long time. Meanwhile, the other side of the pond is in a celebratory mood since Congress passed the Inflation Reduction Act that contains massive subsidies for both renewable energy and traditional fossil fuels. But few people realize the Act subsidizes hydrogen technologies, and even fewer people know why hydrogen is important. I’d like to bring some attention to what hydrogen is and how it can contribute to decarbonizing the economy.
Our body burns fuel. Just not gasoline
To understand why we need to pay attention to hydrogen and how it comes into the decarbonization picture, we need to take a look at what’s actually happening when something is “burning.” Burning is how we get energy. Whether it’s driving a car or flying a plane, something must burn and give us that energy. It’s not a coincidence that steam engine was the single most important invention that enabled the Industrial Revolution.
But what is burning and what can we burn? Burning, more formally called “combustion,” is a chemical process where typically oxygen meets something else and emits energy. In other words, if something can meet an oxygen atom and create a chemical reaction that releases energy, then that something can burn. This observation (by chemists) is an enormous breakthrough because it completely changes the way we understand what burning is. One immediate consequence is the fact that burning doesn’t have to involve flames, which is what we look for when we hear that something is burning. For example, breathing is burning (inhale oxygen and exhale carbon dioxide like a combustion engine, coincidence?).
- We eat food.
- Our body breaks down the food into glucose (C6H12O6).
- We breathe in oxygen (O2), which gets delivered to cells.
- Cells introduce oxygen to glucose. Glucose then reacts with oxygen (C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP).
- Our body uses ATP for energy.
For your information, ATP (adenosine triphosphate) is an energy-carrying molecule that our body uses as energy currency, but this isn’t important for our discussion of hydrogen. The important thing is that our body burns glucose instead of gasoline, and that’s why you need to eat food.
This understanding of burning adds a lot of things to the laundry list of stuff we can burn. Now, it’s not just firewood or coal. But almost every flammable item has hydrogen, including gasoline. And this is where hydrogen steals the limelight.
The figure below shows three types of “hydrocarbon,” which is a portmanteau for hydrogen and carbon. Any chemical compound consisting of hydrogen and carbon atoms is a hydrocarbon.
As you can see, gasoline has a chain of carbon atoms that hold a lot of hydrogen atoms. When we burn gasoline, what’s really happening under the hood is the hydrogen atoms meet oxygen and release energy. Actually, combustion engines don’t even “burn” gasoline if you’re imagining a fire somewhere inside your car. They merely spray gasoline in the air to induce the chemical reaction with oxygen.
So if hydrogen is doing all the heavy lifting and carbon is just there as a skeleton for hydrogen atoms to cling onto, can’t we use hydrogen directly?
Why Hydrogen is Hard to Use
Now that we’ve seen burning involves hydrogen and oxygen meeting each other and a lot of stuff that we’re already burning has hydrogen in it, you may wonder if it’s possible to collect hydrogen in some way and use it. Hydrogen is the most common element in the entire universe, after all. The problem with that idea is that hydrogen almost never exists by itself. Hydrogen likes to bond with others too much, so it exists as chemical compounds. To use hydrogen, we need to break that chemical bond and extract hydrogen, which can be costly.
Clean and cheap are two birds that wouldn’t die with one stone
Mankind has known how to produce hydrogen for centuries. So the reason we can’t use hydrogen at scale is not because we don’t know how to get it. It’s rather because of the trade-off between the costs and the environmental impact: If it’s cheap, it’s dirty; if it’s green, it’s expensive.
We’re already using a lot of hydrogen. Hydrogen is a key ingredient of ammonia, and ammonia is how we make fertilizers. But we’re getting almost all (~95%) of hydrogen from fossil fuels, through an esoteric chemical process called steam methane reforming (SMR). Ironic, isn’t it? You might be wondering: “You said hydrogen was green and now you’re telling me it’s actually produce by burning natural gas?” Yes, that is how we get most of our hydrogen as of now.
But it doesn’t have to be that way. We’re using natural gas to produce hydrogen because that’s the cheapest way, not because that’s the only way. We can use electricity to split water molecules to extract hydrogen, a process called electrolysis. However, the glaring logical fallacy here is that we’re assuming that we already have electricity. Burning natural gas, oil, or even worse, coal to generate electricity takes us back to square one. Scientists have color-coded hydrogen to indicate its origin. I summarize the most widely used hydrogen colors below:
- Gray - From fossil fuels
- Green - From renewable energy like solar or wind
- Blue - From fossil fuels with carbon capture and storage
- Pink - From nuclear power
Hydrogen economy therefore begins with renewable energy, and its success depends on the overall cost of renewable energy. This is why we’re desperately waiting for technological advances in solar and wind energy to bring down their price tags.
But here’s another thing: We essentially lose energy every time we transform one form of energy into another. When we use electricity to produce hydrogen, we won’t recover the same amount of electricity from the hydrogen we’ve produced. So why should we make hydrogen with that electricity when we can simply use it to power our economy? Answer: intermittency and unscalable electrification.
Renewable energy isn’t constant
Think about solar power. We can’t get solar power after sundown. We must make the most of the daytime to generate electricity. Same thing with wind power. There are seasonal patterns of alternating between strong winds and weak winds. Scientists call this the intermittency problem.
To solve the intermittency of renewable energy sources, energy needs to be stored somewhere. And for the vast majority of things, we use batteries, and that’s perfectly fine. But as I’ll explain next, batteries are just not cut out for some things (e.g., moving big stuff).
If we agree on the necessity of hydrogen for some areas of our economy, we must find a way to make green hydrogen. To that end, renewable energy cannot barely meet the national power demand, it must exceed it by a large margin. The leftover power can be spent on making hydrogen.
We can’t electrify everything
Electrifying stuff has a limit, and the size of passenger cars is probably it. Electrifying anything bigger, even trucks, likely won’t work (well) because of the size of the battery. (Trains are a little different because railroads can be connected to the grid with constant power supply.) Remember when Jeff Bezos went to space on a rocket that used liquid hydrogen fuel? Yeah, batteries can’t shoot rockets into space, but hydrogen can. If rockets sound like a far-fetched story of the future, think of airplanes. Airplanes pump out tons and tons of carbon dioxide into the atmosphere each day. A battery to power a plane would be so damn heavy, it would not only be extremely energy inefficient but also take up a lot of space that could’ve seated many more customers. I won’t belabor the point any further.
Hydrogen Is Not a Silver Bullet
If you’ve made it this far, you might get the impression that hydrogen is amazing and it’s the “one ring/technology to rule them all” in decarbonizing all sectors of our economy. That’s absolutely false. Hydrogen will have an important role to play in taking all of us to a carbon-free society, but that shouldn’t be mistaken as being a substitute for renewable energy sources. Actually, hydrogen is more of a long-term investment, and therefore lacks the urgency we face with the current climate crisis. Here’s why.
- Renewable energy is the mother of all green things. Given the urgency of the climate goals, we might want to prioritize decarbonizing our electricity grid first.
- Green hydrogen is still expensive. If you’ve complained about the recent energy price hike, you won’t be happy to hear how much you’d be paying if everything were hydrogen-powered. (Good news is there have been developments in this front that might potentially make hydrogen cheaper.)
- Hydrogen is a type of gas, and that means it’s not easy to store or transport hydrogen. Natural gas pipelines can be repurposed for hydrogen delivery, but since hydrogen is made from water-splitting, it’s unclear whether transmitting green electricity to the place of usage to create hydrogen would be cheaper than sending hydrogen itself. For farther deliveries, various forms of hydrogen carriers have been proposed. Currently, ammonia is gaining the most traction for how easy it is to liqeufy it. Ammonia is also efficient in terms of carrying lots of hydrogen atoms per volume, compared to liquefied hydrogen and compressed hydrogen. Nevertheless, it’s still more expensive than fossil fuels.
For hydrogen to become affordable, renewable energy needs to scale well, to the point where we have excess green electricity. The price of hydrogen will also depend on the amount of sunlight or wind energy one country has. For example, Australia is suitable for solar energy, since the desert is uninhabitable anyway but has ample sunlight. The United States will also have a lot of sunlight in the west, in states like Arizona and California. The geographical differences and the imbalance of renewable energy will create the kind of inequality we see today between the OPEC+ member states and the rest.
Connecticut Is Doing It All Wrong
As a Connecticut resident, I’d like to bring some attention to the renewable energy policy as implemented by the Connecticut legislature. In a nutshell, Connecticut exemplifies everything that can go wrong with hydrogen subsidies in the Inflation Reduction Act. Take a look at this statute that defines renewable energy, and as a result, determines who gets state subsidies for producing green energy. Clause 20 defines “Class I renewable energy source” as follows:
(A) electricity derived from (i) solar power, (ii) wind power, (iii) a fuel cell, (iv) geothermal, (v) landfill methane gas, anaerobic digestion or other biogas derived from biological sources, (vi) thermal electric direct energy conversion from a certified Class I renewable energy source, (vii) ocean thermal power, (viii) wave or tidal power, (ix) low emission advanced renewable energy conversion technologies, including, but not limited to, zero emission low grade heat power generation systems based on organic oil free rankine, kalina or other similar nonsteam cycles that use waste heat from an industrial or commercial process that does not generate electricity, (x) (I) a run-of-the-river hydropower facility that began operation after July 1, 2003, and has a generating capacity of not more than thirty megawatts, or (II) a run-of-the-river hydropower facility that received a new license after January 1, 2018, under the Federal Energy Regulatory Commission rules pursuant to 18 CFR 16, as amended from time to time, and provided a facility that applies for certification under this clause after January 1, 2013, shall not be based on a new dam or a dam identified by the commissioner as a candidate for removal, and shall meet applicable state and federal requirements, including applicable site-specific standards for water quality and fish passage, or (xi) a biomass facility that uses sustainable biomass fuel and has an average emission rate of equal to or less than .075 pounds of nitrogen oxides per million BTU of heat input for the previous calendar quarter, except that energy derived from a biomass facility with a capacity of less than five hundred kilowatts that began construction before July 1, 2003, may be considered a Class I renewable energy source, or (B) any electrical generation, including distributed generation, generated from a Class I renewable energy source, provided, on and after January 1, 2014, any megawatt hours of electricity from a renewable energy source described under this subparagraph that are claimed or counted by a load-serving entity, province or state toward compliance with renewable portfolio standards or renewable energy policy goals in another province or state, other than the state of Connecticut, shall not be eligible for compliance with the renewable portfolio standards established pursuant to section 16-245a;
First of all, how is this one sentence? Second of all, why is “fuel cell” sitting there as a source of renewable energy? I present to you Doosan Fuel Cell America, a South Korean chaebol, headquartered in South Winsor, CT. What is a South Korean chaebol doing in the U.S.? Glad you asked. Obviously, they’re here to do their business using Connecticut residents’ tax dollars, precisely because renewable energy is defined to include “fuel cells.”
Let’s see how green Doosan’s fuel cells are. I’m scraping from their website verbatim the description of how fuel cells work.
Fuel cells operate without combustion, so they are virtually pollution free. Since the fuel is converted directly to electricity and heat, a fuel cell’s total system efficiency is far higher than conventional power generation equipment. Bottom line: Fuel cells are the future of energy.
Has anyone noticed the gimmickry this devious corporate overlord is using to dodge litigation? Pollution free, not carbon free. Of course, hydrogen itself will be pollution free but the ultimate question surrounding hydrogen isn’t whether it’s pollution free, is it? How are you, Doosan, getting your hydrogen?
At the bottom of that same web page is a download link for a booklet explaining how a fuel cell works. This is their cute little diagram that they’ve hidden inside a booklet.It all starts with natural gas, and even though the booklet doesn’t say how natural gas is converted to hydrogen, it’s most likely steam methane reforming (SMR). Arguably, this may be more energy-efficient than simply burning all that natural gas used for SMR. However, SMR has a bigger carbon footprint than simply burning the same amount of gasoline that would produce the same amount of energy. See the following excerpt from this Forbes article:
… Adding this to the carbon dioxide produced from the natural gas reactions, the total becomes 19.3 metric tons of carbon dioxide produced per million [standard cubic feet (SCF)] of hydrogen. However, the Praxair paper noted that this is the theoretical minimum. Due to heat losses and inefficiencies, the actual number in practice in a large hydrogen plant is 21.9 metric tons. This converts to 9.3 kilograms (kg) of CO2 produced per kg of hydrogen production. One kilogram of hydrogen is the energy equivalent of one gallon of gasoline, which produces 9.1 kg of CO2 when combusted.
So these fuel cells that have bigger carbon footprint than natural gas power plants are taking away Connecticut state government subsidies that are entirely shifted to Connecticut residents who pay electricity bills. These subsidies aren’t even itemized and shown in the electricity bills, and we’re all left to wonder why “delivery” is more expensive than “generation.” And most of us blame Eversource, which does have its fingerprint in every energy-related policy drafted and passed by the state legislature.
Hydrogen is exciting and will ultimately be useful. However, we can’t and shouldn’t give these corporations blank checks so they can continue to deceive ordinary people to pay for dirty technologies. Lost in all this mess is taxpayer money and public trust.