Gas plant in Pennsylvania explores underground carbon storage

The ability to remove carbon dioxide from the atmosphere and store it somewhere else is a relatively new advancement in the U.S. But it’s one companies are now putting to work for its potential to slow global warming.

In the Chesapeake Bay watershed, the technology is taking root in Pennsylvania and West Virginia. Archaea Energy, a Houston-based company that specializes in extracting methane from landfills to produce natural gas, is testing the viability of capturing the carbon dioxide in the extraction process and injecting it deep underground at its Assai Energy operation at a pair of landfills near Scranton, PA.

Carbon dioxide is a greenhouse gas that absorbs heat and emits it back toward the Earth’s surface. According to the National Oceanic and Atmospheric Administration, atmospheric carbon dioxide is now 50% higher than it was before the Industrial Revolution. More carbon dioxide means a warmer Earth, which leads to extreme weather events.

Nature itself extracts carbon dioxide from the atmosphere and stores or “sequesters” it in a number of ways, most commonly with plants, which absorb the gas, use it as a fuel and exude oxygen. Humans are exploring ways to sequester surplus carbon in the atmosphere in a different way — by capturing it, compressing it into a dense liquid and then injecting it thousands of feet underground into porous rock, where it eventually reverts to mineral form.

Carbon capture and storage has been happening in the U.S. since the 1960s. Initially, carbon injection was used to access oil more easily from some kinds of porous rock. The practice is still in use, but the technology is increasingly looked to as a potential way to combat climate change.

 “The advantage is obvious,” said Emma Bast, a staff attorney with the environmental nonprofit PennFuture. “It helps us get to net zero [for carbon emissions].… Hypothetically, it can reduce some of the levels of carbon dioxide that have already been released into the atmosphere over the last 100 odd years.”

The U.S. has 19 commercial facilities that can capture up to 22 million metric tons of carbon dioxide per year, according to the Global Carbon Capture and Storage Institute. But Jessie Stolark, executive director of the Carbon Capture Coalition, said the world needs to quadruple the current capture capacity to reach the global goal of capturing one billion tons of carbon by 2030.

Pennsylvania’s 2024 Climate Action Plan factors in carbon capture to help meet its goals. The plan aims to reduce its greenhouse gas emissions 50% by 2030, estimating that the state has about 2.4 billion metric tons of carbon dioxide storage capacity underground.

Until last year, when Pennsylvania passed the Carbon Capture and Sequestration Act, companies intending to store carbon geologically needed a federal Class VI permit to do so. But the new law will gradually transfer permitting authority to the state, allowing it in a few years to directly manage storage operations. The U.S. Environmental Protection Agency recently approved a state authority request from West Virginia for Class VI permits.

Pennsylvania environmental groups support a clause that says if the project is in an environmental justice area, the permit requires additional impact assessments and more public participation.

The law also provides funds for projects but allows the state to charge a fee per ton of carbon stored. Conversely, capture and storage operations can earn federal tax credits —though other federal support, like funds from the Inflation Reduction Act, could be threatened due to the Trump administration’s federal fund freeze.

“Regardless of what’s happening at the national level and with federal policymakers, we know that there’s a demand for these lower carbon-intensive products,” Stolark said.

Archaea Energy, which is owned by the London-based oil and gas company BP, has about 50 sites throughout the country that collect gas from decaying waste in landfills and filter out the methane to be sold as natural gas. The facility outside Scranton has been extracting landfill methane since 2023 and has been exploring methods for keeping the carbon dioxide, a byproduct of the process, out of the atmosphere.

The company started drilling in February to gather data, perform analysis and conduct modeling — all necessary to test the site’s suitability for carbon storage. For geologic carbon storage to work, according to Hélène Pilorgé, a research associate at the University of Pennsylvania, it needs to be at least 3,000 feet deep, needs a reservoir made of porous rock like sandstone and have layers of impermeable rock above to seal the deposit.

Complicating the issue is Pennsylvania’s unmapped jumble of unplugged oil wells, which makes it difficult to ensure that carbon dioxide won’t escape through unknown holes, said PennFuture’s Bast. If the gas leaks, it can linger near the ground and threaten human respiratory health.

Bast said carbon storage is not a “silver bullet.” It has yet to be proven to work at a large scale, and the permit process is lengthy. Bast also said solar, wind and other types of renewable energy are clean from the start and remain cheaper and more effective than carbon capture. But it is most helpful for industries like cement production where the essential chemical reactions create carbon dioxide.

Despite reasons to be skeptical of new technology, she said, “I hope that [carbon capture] works.”