Innovative Method for Hydrogen Production Uses Solar Power and Agricultural Waste
Engineers at the University of Illinois Chicago (UIC) have developed a groundbreaking method to produce hydrogen gas from water using only solar power and agricultural waste, such as manure or husks. This new technique significantly reduces the energy required to extract hydrogen from water by 600%, offering promising opportunities for sustainable, climate-friendly chemical production.
Hydrogen-based fuels are seen as one of the most promising clean energy sources. However, the conventional production of pure hydrogen gas is highly energy-intensive, often relying on coal or natural gas and substantial amounts of electricity.
In a paper published in Cell Reports Physical Science, a team led by UIC engineer Meenesh Singh introduces this innovative process for green hydrogen production.
The new method employs a carbon-rich substance known as biochar, which decreases the electricity needed to convert water into hydrogen. By utilizing renewable energy sources such as solar or wind power and capturing byproducts for other uses, this process can achieve net-zero greenhouse gas emissions.
"We are the first group to show that you can produce hydrogen utilizing biomass at a fraction of a volt," said Singh, an associate professor in the department of chemical engineering. "This is a transformative technology."
Electrolysis, the traditional process of splitting water into hydrogen and oxygen, requires an electric current. At an industrial level, generating this electricity typically involves fossil fuels.
Recent advancements have lowered the voltage required for water splitting by incorporating a carbon source into the reaction. However, these methods still rely on coal or expensive chemicals, releasing carbon dioxide as a byproduct.
Singh and his team have adapted this process to use biomass from common waste products. By mixing sulfuric acid with agricultural waste, animal waste, or sewage, they create a biochar slurry rich in carbon.
The researchers tested various types of biochar made from sugarcane husks, hemp waste, paper waste, and cow manure. All five biochar varieties reduced the power needed to convert water to hydrogen, with cow dung performing the best, reducing the electrical requirement sixfold to roughly a fifth of a volt.
The energy requirements were low enough for the reaction to be powered by a single standard silicon solar cell, generating about 15 milliamps of current at 0.5 volts—less than the power produced by an AA battery.
To achieve net-zero emissions, the process must capture the carbon dioxide generated by the reaction. Singh noted that this could also provide environmental and economic benefits, such as producing pure carbon dioxide for carbonating beverages or converting it into ethylene and other chemicals used in plastic manufacturing.
Orochem Technologies Inc., which sponsored the research, has filed for patents on their processes for producing biochar and hydrogen. The UIC team plans to test the methods on a larger scale.
