Carbon Capture and Storage: A Solution for Climate Change?

A white circle reads West Virginia Highlands Conservancy. Since 197. With Spruce trees and a sunset behind.

By John McFerrin

Things are moving into place for West Virginia to go headlong into what is called carbon capture and storage. Before we dive in completely, it would be useful to consider more carefully the technology, its potential benefits and deficiencies.

Carbon capture and storage is a general term that refers to collecting carbon dioxide from some industrial application and using it for some other purpose or storing it deep underground. In theory, at least, it is a better alternative than releasing carbon dioxide into the atmosphere, where it will contribute to global warming.

It could theoretically be used on such things as coal-fired power plants, extending their useful life at a time when concerns about climate change would demand that they be phased out. Right now, however, this may be a gleam in Appalachian Power’s (or the West Virginia Coal Association’s) eye, but nobody has made any public proposals. There may never be any.

The more immediate proposals—ones that are barreling down the track right now—are those from Mountaineer Gigasystems and the larger Appalachian Regional Clean Hydrogen Hub (ARCH2), known as the hydrogen hub. Mountaineer Gigasystems is a complex proposed for Point Pleasant that would use hydrogen for various purposes. It is well on its way, spurred on by a 25 million dollar grant (the euphemism is “forgivable loan”) from the state of West Virginia.

The Appalachian Regional Clean Hydrogen Hub is not a single facility but a series of about fifteen facilities scattered around West Virginia and adjoining states. What these facilities all have in common is that they involve the use or production of hydrogen as a fuel or raw material for other manufacturing. It is supported by grants from the United States Department of Energy.

Meanwhile, over in the Legislature, the trains are running. During its 2023 session, it passed a law allowing carbon dioxide to be stored beneath many of West Virginia’s public lands. The 2024 session is considering legislation that would pave the way for West Virginia to grant approval for the wells to inject carbon dioxide into the ground. Currently, the United States Environmental Protection Agency has that authority.

In a nutshell, West Virginia is all in on hydrogen. Whether this is a good idea depends upon West Virginia’s faith (and at this point, it is faith) that carbon capture and storage works.

Explaining some jargon

While hydrogen is an extremely common element, it does not exist in a pure form in nature. It is always bound up with something. If it is bound up with oxygen, it makes water. If it is bound up with carbon, it makes methane. It is also found in coal. To get hydrogen that we can use, we have to split it from whatever it is bound up with.

Current jargon labels methods used to isolate the hydrogen by colors. If hydrogen is isolated from coal or methane and the carbon dioxide is released to the atmosphere, that is called gray hydrogen. If hydrogen is isolated from methane and the resulting carbon dioxide is captured and stored, that is called blue hydrogen. If hydrogen is separated from water using sustainable sources of energy, that is called green hydrogen.

Both Mountaineer Gigasystems and the Appalachian Regional Clean Hydrogen Hub (ARCH2) plan to use blue hydrogen. Thus, they will use carbon capture and storage.

Does carbon capture and storage work?

Both the Mountaineer Gigasystems proposal and the Appalachian Regional Clean Hydrogen Hub (ARCH2) depend upon methane, the main component of natural gas. The projects plan to take methane and split it into hydrogen and carbon dioxide. They anticipate using the hydrogen and disposing of the carbon dioxide using carbon capture and storage.

In deciding whether carbon capture and storage works, we have to keep our eyes on the prize. The goal is to end up with a fuel—the hydrogen—which we can use without releasing carbon dioxide, either in the burning of the fuel or its production.

The burning of the hydrogen is the easy part. Burning hydrogen does not release any carbon dioxide. So far, so good.

The difficulties arise in producing the hydrogen and then disposing of the resulting carbon dioxide. A molecule of methane—the main component of natural gas—has four molecules of hydrogen and one molecule of carbon. 

If we just burned the methane (as we do now), all that carbon is released to the atmosphere, something we want to avoid in the future. The trick is to split the hydrogen away from the carbon and then get rid of the carbon to some place where it will not contribute to climate change.

If the methane could just somehow jump out of the ground, get to the industrial facility, split itself into carbon and methane, and the carbon jump back in the ground and stay there forever, the problem would be solved. 

But it doesn’t. At every step, there are problems.

There are problems with the methane getting to the spot where it will be split without leaking along the way. These were the subject of a previous Highlands Voice article.

Even assuming the methane does not leak along the way from the well to where it will be split, problems remain. The nearly universal process for splitting methane into carbon and hydrogen is called steam methane reforming. This involves applying heat and pressure to the methane, causing the carbon molecules to split from the hydrogen molecules. 

Generating this heat and pressure is not free; it takes a lot of energy.  

Once the split is accomplished, the resulting carbon dioxide must be compressed until it becomes a liquid. More energy. The liquid is then transported to a storage site, generally by pipeline. This will require energy for pumps, compressor stations, etc. With the Appalachian Regional Clean Hydrogen Hub, the storage is anticipated to be at least 2,500 feet underground. Making that storage space available is what the West Virginia Legislature was up to in 2023 when it authorized selling the space under our public lands for storage of carbon dioxide.

The carbon dioxide does not go down deep underground on its own. Wells must be drilled; the carbon dioxide must be pumped. That takes more energy.

Unless the energy for all these steps comes from unconventional sources (wind, solar, geothermal), producing all that energy will result in the release of carbon dioxide. If, for example, the energy to power the steam methane reforming comes from burning methane, that burning will release carbon dioxide. The same is true of every step in the process (compressing the carbon dioxide, piping it to a storage site, pumping it into the ground). Some of what we have gained by using hydrogen as an energy source instead of methane is lost through the carbon dioxide released in making the hydrogen available. 

The problems with the energy costs involved in moving methane, splitting methane into hydrogen and carbon dioxide, moving and storing carbon dioxide would exist even if the process were one hundred percent efficient. But it isn’t. Very few operating facilities split methane into hydrogen and carbon dioxide and then capture the carbon dioxide. The ones that do this process report rates of carbon dioxide capture of between 53% and 90%.

The Bottom Line

The stated goal of blue hydrogen production and use is to reduce greenhouse gas emissions. To answer this question, engineers at Cornell University looked at the blue hydrogen process and compared it with other sources of energy. Here is what they found:

“Perhaps surprisingly, the greenhouse gas footprint of blue hydrogen is more than 20% greater than that of burning natural gas or coal for heat and some 60% greater than that of burning diesel oil for heat, again with our default assumptions.” 

They reached this conclusion without considering the energy costs of transporting the carbon dioxide to the storage site and pumping it underground. Were they to consider those energy costs, the comparison to coal, natural gas, or diesel oil would be even less favorable to blue hydrogen.

This assumes, of course, current technology and practice. Maybe the oil and gas industry will figure out a way to stop all leaks. Maybe someone will figure out a way to make the separating technology more efficient. Maybe someone will figure out how to make every step less energy-intensive. Right now, however, blue hydrogen is not part of the solution to the problem of climate change.

The Rest of the Story (including the other side)

Much of the information for this story came from Robert Howarth and Mark Jacobson: How Green Is Blue Hydrogen? published in the journal Energy Science and Engineering (2021). To read the whole thing, go to https://onlinelibrary.wiley.com/doi/full/10.1002/ese3.956. It gets pretty nerdy at times (chemical formulas and such) but on the whole it is easy enough for an ordinary human to understand and is recommended for anyone who wants a better understanding of the science of this issue.

The Intergovernmental Panel on Climate Change (IPCC) is the United Nations body for assessing the science related to climate change. In its 2022 report, it had a much more sanguine view of carbon capture than professors Howarth and Jacobson and suggested that it could be part of the solution to climate change.