Coal could be a hydrogen battery, study shows
Scientists at Penn State University have found that coal, a fossil fuel, could be used to store hydrogen gas, a clean source of energy.
This could help us reduce our dependence on fossil fuels.
Shimin Liu, an associate professor at Penn State, explained that coal could act like a “geological hydrogen battery.” That means we could inject and store hydrogen energy in coal and then use it when needed.
Hydrogen is a clean fuel that could be used in areas that require a lot of energy, such as transportation, power generation and manufacturing. Before we can use hydrogen across the board, however, there are still challenges to be overcome.
One of these challenges is finding a way to store hydrogen efficiently and cheaply.
The Penn State team believes geological formations like coal could be a good solution. Coal has been extensively researched and we have been producing gas from it for almost 50 years. That means we understand it well and already have the infrastructure to work with it.
To test this idea, the scientists studied eight types of coal from different parts of the United States.
They wanted to see how much hydrogen each type could hold. They found that all eight species can store significant amounts of hydrogen, with certain Virginia and Pennsylvania coal species performing the best.
Coal could be a prime choice for storing hydrogen because it can store more hydrogen than other materials and because we already have the infrastructure to work with it.
In addition, coal is widespread throughout the country and near populated areas.
The best storage locations for hydrogen could be methane reservoirs in the coal seam. These are areas where we have already extracted natural gas from coal. Like methane, hydrogen could be injected into the coal and stick there. These areas often have a layer of shale or mudstone that traps the hydrogen until we need to use it.
To carry out their experiments, the scientists had to construct special equipment because coal interacts differently with hydrogen than with other gases. They found that certain types of coal are good candidates for storing hydrogen.
The discovery could bring new economic opportunities to coal mining communities while helping build hydrogen infrastructure in the United States.
Future research will focus on how quickly hydrogen can be injected from and pumped out of coal.
Source: Penn State University.