Making cement puts a lot of carbon dioxide into the skies.
Rocks far below a Botetourt County cement plant might hold that greenhouse gas in the ground instead.
A Virginia Tech research team is leading a study to find out if those rocks are good for carbon storage. The team’s Project Cardinal will receive a $9 million grant from the U.S. Department of Energy, and another $2.6 million from Roanoke Cement Co., where the research will happen.
If it works out — and researchers won’t know for sure for a few years — it could have the same impact as removing more than 350,000 gas-burning cars from the road, said Ryan Pollyea, a Virginia Tech professor who will lead the effort. It could be a decade before the plant can even store its gaseous byproduct down below.
To start, the team will learn whether rocks at least a mile below the Roanoke Cement site can do the job.
“I think it’s important to temper a little bit of the risk of the unknown because we know how bad the risk of doing nothing is,” said Pollyea, a geosciences professor and director of the newly established Carbon CoLab. “We’ve been talking about climate change. Thirty, 40, 50 years we’ve been doing nothing, and we’re seeing it. …
“Every year, the storms get stronger, the wildfire seasons get longer, droughts are expanding, you know. This isn’t a cure-all, but carbon sequestration is one technology that has the potential to make a positive impact, to move that needle just a little bit farther forward.”
How it could work
Concrete is in most of the world’s construction projects, including roads and buildings. Scientific sources say that producing it, which includes firing its ingredients in kilns, is responsible for at least 8% of man-made carbon dioxide emissions.
Roanoke Cement and its corporate parent, Titan America, already are working on a process to cut emissions by using clay to reduce the amount of heat required and the amount of carbon dioxide released in production. The company is negotiating with the Department of Energy for an award of up to $61.7 million.
That wouldn’t bring the carbon emissions to zero. Project Cardinal, which is a separate effort, could deal with the remaining emissions. It would be like reverse mining, or reverse drilling.
“The carbon comes up with oil and gas. The carbon comes up with limestone products,” Pollyea said. “We’re continually bringing the carbon up. Carbon storage is the idea of putting it back underground.”
So-called reservoir rocks are porous and permeable and can store fluids. Cap rocks prevent fluids from moving, and those are the sort of traps that Pollyea and the team will seek. He said they will target sandstone for reservoir rock and shale for cap rock.
“So what we’re doing in the carbon storage space is we’re looking for rocks that would have those trapping characteristics that we could put CO² into, to keep it out of the atmosphere,” he said.
Virginia Tech and the cement company are partnering with the Southern States Energy Board, research and development firm Advanced Resources International and consulting firm Top Rock Geoscience.
“We’re testing the rocks,” Pollyea said. “We’re trying to image the structure of the rocks to see if the technology would work in the kind of geology that we have here in Southwest Virginia.”
A pre-feasibility study, which won the Energy Department award for Project Cardinal, involved Virginia Tech undergraduate students studying the literature around regional geology: how the rocks were formed, what their structures look like, what their properties are, do they store fluids, he said. A graduate student, Lars Koehn, did computer modeling to determine such outcomes as where carbon dioxide would go if injected below the surface and how it would behave over time.
The team determined that it could possibly work.
“But we need to know more,” Pollyea said. “So we need to drill a deep hole to go and collect that data. We need to do some geophysics, which is like, it’s like an MRI of the earth. … Seismic data collection, geophysical data collection, gives us the ability to image the layers of the earth.”
The study should begin early next year and would last about two years. If it proves out, a third phase would gather more data about whether carbon dioxide could be safely stored at the site. The team would inject water for its tests. After that three- to four-year phase, the project might be in a position to apply to the Environmental Protection Agency for a permit to inject, which could be another two- to three-year wait. Site construction would follow.
“So by the time you actually go through all the feasibility, characterization, permitting, then you have to build the facility … you’re looking at a 10-year window of time before a drop of CO² would ever get underground,” Pollyea said.
The plan is to ultimately drill down about 2 miles for carbon storage at the Botetourt site.
“These kinds of technologies will work in some places. They may not work in others, but we do need to go out and test them because decarbonizing these hard-to-abate sectors is a really important part of trying to make a dent, try to move the needle in … the climate problem.”
Business interests
Titan America has a storage feasibility project underway in the Miami area, as well as the two experiments in Roanoke. Pollyea and Virginia Tech are involved in the Miami one, which the Southern States Energy Board is leading.
“Titan America, as the parent company, is very progressive, from what I’ve seen in their approach to decarbonization,” Pollyea said. “They’re trying to get in front of it and use the tools that the federal government is putting out there to try to move the needle a little bit.”
Chris Bayne, Titan’s director of decarbonization and energy, said that the Norfolk-based company is the first in the United States to install a global standard energy management system. The company is working to move away from coal and petroleum coke and toward natural gas and alternative energy sources.
Titan has a “very systematic road map” to achieve net zero emissions by 2050, he said.
“I think it’s important when people hear that it’s a long way off, it’s not to kick the can down the road,” Bayne said. “It’s that, while there are a lot of technologies available that can help us to decarbonize, many of them still need to be developed, and it takes time. And so that’s where our interest is.
“For example, in Project Cardinal with Virginia Tech, some of these projects need extensive research and development. That’ll take quite a while. So Titan is investing in those research projects in order to … try to identify the more long-term pieces of our road map and how they’ll be implemented.”
Bayne and the company’s corporate engineering offices are based at the Botetourt plant. He said that when anticipating long-term projects, the company wanted research from leaders in the field.
“And that’s how we came in contact with Dr. Pollyea and his team,” he said. “They’ve been an excellent resource to us, and they’re also local. … So it was just a good fit for Titan.”
The university won’t just be providing scientific research, Bayne added. Project Cardinal will develop a comprehensive community benefits plan. It will include community engagement, skilled workforce development, and diversity, equity, inclusion and accessibility initiatives, among other features.
Bipartisan support
Pollyea said that when he put together his proposal for the Department of Energy’s CarbonSAFE program, he reached out to the region’s business and political leaders.
He received what he called strong support from political and administrative figures, including Botetourt County Administrator Gary Larrowe; U.S. Rep. Morgan Griffith, R-Salem; and Democratic U.S. Sens. Mark Warner and Tim Kaine.
“So when I look at carbon storage … I see it as something that, generally speaking, has bipartisan support,” Pollyea said. “And I think that, you know, a changing [presidential] administration will have different funding priorities, but I think that there’s so much momentum right now in this space that it’s going to be an area of continued growth.”
Looking ahead
After years of scientific study and more recent industry buy-in, Project Cardinal and other research are taking early steps in a carbon storage journey that could apply to multiple industries, Pollyea said.
Other possibilities for storage include iron-rich basalt rocks, volcanic stones found above ground. There is no cap stone in this process, but it would involve carbon dioxide dissolving into water, and even dissolving a bit of the rock. From there, it would release some of the magnesium, calcium and iron that mixes with the carbon and create a carbonate mineral.
“Like a calcite, you know, it’s like limescale in your pipes,” he said. “You’re actually permanently immobilizing that CO² because you’re converting it from this gas that can get up into the atmosphere into a mineral that’s not going anywhere.”
A Virginia Tech research associate, Piyali Chanda, is working with the Colorado School of Mines on a theoretical study using data from a mine in that state, he said.
“If you go to Washington, Idaho, Oregon, it’s covered in volcanic rocks, and can those rocks be used for storing CO² through mineralization? And the research that we’re doing here may help answer that,” Pollyea said. “There’s folks at the national laboratories that have big projects out there, kind of like ours here, looking at that problem as well. So there’s this groundswell of real progress on carbon storage through different mechanisms.”
In the coming decades, we might see these efforts developed at real-world scale.
