Storing hydrogen in coal may help clean energy economy, PSU researchers say

Researchers at Penn State University think coal may be the storage solution to developing hydrogen as a clean energy source.

Thursday, Penn State said a team of scientists at the university had potentially found a way to store hydrogen gas, inside coal, like batteries storing energy for future use. The development could address major hurdles in the clean energy supply chain, researchers said.

“We found that coal can be this geological hydrogen battery,” said Shimin Liu, associate professor of energy and mineral engineering at Penn State. “You could inject and store the hydrogen energy and have it there when you need to use it.”

Researchers said storing hydrogen for use as an energy source, and building out the hydrogen infrastructure could make it more affordable and reliable. One way, they said is to use geologic formation, which can store large amounts of hydrogen to meet the peaks and valleys of changing demand.

“Coal is well-studied, and we have been commercially producing gas from coal for almost a half century,” Liu said. “We understand it. We have the infrastructure. I think coal would be the logical place to do geological hydrogen storage.”

In a report published in the journal Applied Energy, the researchers said they tested eight types of coal from across the country to understand sorption and diffusion, as well as how much hydrogen the coal formations could hold. All eight showed considerable sorption properties, with low-volatile bituminous coal from eastern Virginia and anthracite coal from eastern Pennsylvania performing the best.

“I think it’s highly possible that coal could be the very top selection for geological storage from a scientific perspective,” said Liu. “We find that coal outperforms other formations because it can hold more, it has existing infrastructure and is widely available across the country and near populated areas.”

The discovery could bring new economic opportunities to coal regions while helping to create the nation’s hydrogen infrastructure, researchers said. Future work will look at how quickly hydrogen can be injected into coal and pumped back out, the researchers said.