New Hydrogen Generation Method Holds Promise

By Iva Fedorka

Washington State University (WSU) researchers used a small amount of electricity and an ethanol and water mixture to produce hydrogen, an innovation that may allow remote production of the gas.

Like electric vehicles (EVs), hydrogen fuel-cell powered cars don’t emit carbon dioxide but must be refilled at fueling stations. Since the automotive industry is one of the largest polluters, reduced emissions through clean fuel technologies would affect atmospheric and overall pollution worldwide.

The Challenge

Hydrogen gas must be transported under pressure to maintain fueling stations for this alternative and clean automotive fuel. However, transporting and storing hydrogen gas in fuel tanks is a significant economic and safety issue, so hydrogen gas infrastructure is limited in the United States.

The Problem with EVs

Many consumers are opting for hydrogen fuel cell vehicles to minimize the pollution from EVs.

EVs require electricity, and, since nearly 80 percent of the global power supply comes from coal, oil, or other fossil fuels that produce greenhouse gas emissions, EVs have considerable carbon footprints.

Another limitation of EVs is their batteries. Mining for lithium and other battery materials harms the environment when miners pollute natural water sources and destroy mountainsides. Lithium batteries are also difficult to recycle and contribute to electronic waste.

New Technology

The Caustic Aqueous Phase Electrochemical Reforming or CAPER procedure was developed by WSU scientists. Starting with an anode and a cathode, they applied a small electrical current to a mixture of ethanol, water, and a catalyst. The result was pure compressed hydrogen and liquid carbon dioxide.

“The presence of the ethanol in water changes the chemistry,” graduate student Wei-Jyun Wang, a co-lead author on the paper, told ScienceDaily. “We can actually do our reaction at a much lower electrical voltage than is typically needed for pure water electrolysis.”

CAPER consumes less than half the electricity needed for water electrolysis, another method to produce hydrogen. And, instead of compressing the hydrogen afterward, they found it took less energy to compress the liquid ethanol mixture at the outset and produced already compressed and ready-to-use hydrogen gas.

“This is a new way of thinking about how to produce hydrogen gas,” said Su Ha, professor in the Gene and Linda Voiland School of Chemical Engineering and Bioengineering, a corresponding author on the paper published in Applied Catalysis A. “If there are enough resources, I think it has a really good chance of making a big impact on the hydrogen economy in the near future.”

“We’re already using ethanol-containing gasoline at every gas station,” said Ha. “You can imagine that an ethanol water mixture can be easily delivered to a local gas station using our existing infrastructure, and then using our technology, you can produce hydrogen that is ready to pump into a hydrogen fuel cell car. We don’t need to worry about hydrogen storage or transportation at all.”

The researchers are working to scale up the technology and operate it in a continuous manner. They also are working to make use of the carbon dioxide captured in the liquid.