Theory Versus Reality: The Dirty Hydrogen Story
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The hydrogen myth refuses to go away. The theory is fine — hydrogen when used as a fuel produces no carbon emissions. At most, it results in some water vapor and a little heat. If the world ran on hydrogen, the theory suggests, we could slash carbon and methane emissions and maybe forestall the existential climate crisis that is staring us in the face.
The reality is very different. According to the New York Times, a peer-reviewed study by researchers at Cornell and Stanford has been published in the journal Energy Science & Engineering which finds that most hydrogen used today is extracted from natural gas in a process that requires a lot of energy and emits vast amounts of carbon dioxide. Producing natural gas also releases methane, a particularly potent greenhouse gas.
Before we go on, let’s define our terms. Gray hydrogen comes from coal. Blue hydrogen comes from natural gas. Green hydrogen comes from electrolyzing water. The natural gas industry wants to employ carbon capture to create what it calls “blue” hydrogen, but the researchers find that process still emits more carbon emissions across its entire supply chain than simply burning natural gas directly. Here is the abstract of the study:
Hydrogen is often viewed as an important energy carrier in a future decarbonized world. Currently, most hydrogen is produced by steam reforming of methane in natural gas (“gray hydrogen”), with high carbon dioxide emissions. Increasingly, many propose using carbon capture and storage to reduce these emissions, producing so-called “blue hydrogen,” frequently promoted as low emissions.
We undertake the first effort in a peer-reviewed paper to examine the lifecycle greenhouse gas emissions of blue hydrogen accounting for emissions of both carbon dioxide and unburned fugitive methane. Far from being low carbon, greenhouse gas emissions from the production of blue hydrogen are quite high, particularly due to the release of fugitive methane.
For our default assumptions (3.5% emission rate of methane from natural gas and a 20-year global warming potential), total carbon dioxide equivalent emissions for blue hydrogen are only 9%-12% less than for gray hydrogen. While carbon dioxide emissions are lower, fugitive methane emissions for blue hydrogen are higher than for gray hydrogen because of an increased use of natural gas to power the carbon capture.
Perhaps surprisingly, the greenhouse gas footprint of blue hydrogen is more than 20% greater than burning natural gas or coal for heat and some 60% greater than burning diesel oil for heat, again with our default assumptions. In a sensitivity analysis in which the methane emission rate from natural gas is reduced to a low value of 1.54%, greenhouse gas emissions from blue hydrogen are still greater than from simply burning natural gas, and are only 18%-25% less than for gray hydrogen. Our analysis assumes that captured carbon dioxide can be stored indefinitely, an optimistic and unproven assumption. Even if true though, the use of blue hydrogen appears difficult to justify on climate grounds.
The report goes on to quantify its conclusions in a profusion of abstruse scientific terms that will gladden the heart of any organic chemistry graduate student. If you enjoy reading about moles and megajoules, you will find it fascinating reading. For those who may not have a deep, ingrained love for scientific jargon, the study’s conclusion should suffice:
[The] best-case scenario for producing blue hydrogen, using renewable electricity instead of natural gas to power the processes, suggests to us that there really is no role for blue hydrogen in a carbon-free future. Greenhouse gas emissions remain high, and there would also be a substantial consumption of renewable electricity, which represents an opportunity cost. We believe the renewable electricity could be better used by society in other ways, replacing the use of fossil fuels.
Similarly, we see no advantage in using blue hydrogen powered by natural gas compared with simply using the natural gas directly for heat. As we have demonstrated, far from being low emissions, blue hydrogen has emissions as large as or larger than those of natural gas used for heat. The small reduction in carbon dioxide emissions for blue hydrogen compared with natural gas are more than made up for by the larger emissions of fugitive methane.
Society needs to move away from all fossil fuels as quickly as possible, and the truly green hydrogen produced by electrolysis driven by renewable electricity can play a role. Blue hydrogen, though, provides no benefit. We suggest that blue hydrogen is best viewed as a distraction, something than may delay needed action to truly decarbonize the global energy economy, in the same way that has been described for shale gas as a bridge fuel and for carbon capture and storage in general.
We further note that much of the push for using hydrogen for energy since 2017 has come from the Hydrogen Council, a group established by the oil and gas industry specifically to promote hydrogen, with a major emphasis on blue hydrogen.5 From the industry perspective, switching from natural gas to blue hydrogen may be viewed as economically beneficial since even more natural gas is needed to generate the same amount of heat.
We emphasize that our analysis in this paper is a best-case scenario for blue hydrogen. It assumes that the carbon dioxide that is captured can indeed be stored indefinitely for decades and centuries into the future. In fact, there is no experience at commercial scale with storing carbon dioxide from carbon capture, and most carbon dioxide that is currently captured is used for enhanced oil recovery and is released back to the atmosphere.
Further, our analysis does not consider the energy cost and associated greenhouse gas emissions from transporting and storing the captured carbon dioxide. Even without these considerations, though, blue hydrogen has large climatic consequences. We see no way that blue hydrogen can be considered “green.”
The tragedy here is that billions of dollars in the latest $1 trillion infrastructure bill are earmarked for blue hydrogen research and development. That means a huge chunk of taxpayer dollars will be frittered away on useless projects that have only one purpose — protecting the economic interests of the unnatural gas industry. They are as despicable as the leaders of Toyota, which is paying lobbyists to oppose electric car incentives and infrastructure development.
The researchers say it loud and clear — “Society needs to move away from all fossil fuels as quickly as possible.” That money is just another federal subsidy for fossil fuels which will do exactly the opposite. Clearly, the industry bribed enough senators to get their pet projects included in the bill, something that did not escape the notice of Zachary Shahan. They care not that their products are poisoning the atmosphere and threatening humanity with extinction. In what world does killing your customers make economic sense? If ecocide ever becomes a recognized criminal offense, these industry leaders and their spineless lackeys in Congress will deserve to go to prison.
The absurdity of the capitalist model that places no value on social benefits was made clear in this passage from the 1999 movie The Matrix:
I’d like to share a revelation that I’ve had during my time here. It came to me when I tried to classify your species and I realized that you’re not actually mammals. Every mammal on this planet instinctively develops a natural equilibrium with the surrounding environment but you humans do not.
You move to an area and you multiply and multiply until every natural resource is consumed and the only way you can survive is to spread to another area. There is another organism on this planet that follows the same pattern. Do you know what it is? A virus. Human beings are a disease, a cancer of this planet. You’re a plague and we are the cure.
Perhaps in the age of Covid-19 and its many permutations, that reference to a virus should resonate more powerfully than it did in 1999.
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