In a groundbreaking development, researchers at Penn State University have proposed a novel model of hydrogen storage: coal. The unexpected suggestion comes as scientists have long identified coal as a contributor to climate change, not a clean fuel source.
Hydrogen, an extremely light and easily dispersed gas, is touted as a fuel of the future due to its environmentally friendly byproduct—water. However, the challenges of safely and efficiently transporting hydrogen have proven substantial. Current solutions such as high-temperature hydrogen storage and low-temperature liquid hydrogen are fraught with safety concerns and high costs.
In response to the challenge of efficiently storing hydrogen, the Penn State research team, led by Associate Professor Shimin Liu of Energy and Mineral Engineering, capitalized on coal’s natural ability to store gases like methane. Building on this potential, they proposed that coal could similarly store hydrogen. To validate this theory—and drawing upon their extensive experience with coal and shale—they designed a special pressurization device to inject hydrogen into the coal.
Their research encompassed the analysis of eight different types of coal from across the United States, revealing that all of them could effectively store hydrogen. The most successful coal types were found to be low-volatile bituminous coal from Virginia and anthracite coal from Pennsylvania, indicating that the ability of coal to capture and store gas depended on its unique composition.
The team further pointed out that contrary to common belief, coal is not a rock but a polymer, rich in carbon with lots of small pores that can store much gas. These characteristics make coal an efficient medium for storing gas. “Coal is like a sponge that can hold many more hydrogen molecules compared to other non-carbon materials,” the researchers noted. Their next goal is to develop coal into a hydrogen-based “battery”, an innovation that would allow for the rapid input and output of different types of hydrogen.
Additionally, the team posits that their research could aid in revitalizing coal communities heavily impacted by the transition towards cleaner energy sources. The coal industry’s workforce, equipped with specialized knowledge and skills, could be repurposed toward managing and operating these proposed coal-hydrogen batteries. This solution would not only address the economic hardships faced by these communities but also contribute towards a greener energy future.
(Image Source: Flickr/Nenad Stojkovic CC BY 2.0)