A team of engineers at the University of Illinois at Chicago has developed a new method to produce green hydrogen from water using only solar energy and agricultural waste, such as manure or husks. This method reduces the energy needed to extract hydrogen from water by 600%, opening new opportunities for the production of sustainable and climate-friendly chemicals.
Innovative Method to Produce Hydrogen from Solar Energy and Agricultural Waste
Hydrogen-based fuels are one of the most promising clean energy sources. However, producing pure hydrogen gas is an energy-intensive process, typically from coal, natural gas, and large amounts of electricity. In a paper published in Cell Reports Physical Science, a multi-institutional team led by UIC engineer Meenesh Singh has revealed a new process for the production of green hydrogen.
Using Biochar to Reduce the Need for Electricity
The method uses a carbon-rich substance called biochar to decrease the amount of electricity needed to convert water into hydrogen. By using renewable energy sources such as solar or wind power and capturing the byproducts for other uses, the process can reduce greenhouse gas emissions to net zero.
«We are the first group to demonstrate that hydrogen can be produced using biomass at a fraction of a volt“said Singh, an associate professor in the department of chemical engineering. «This is a transformative technology«.
Electrolysis and the Use of Biomass
Electrolysis, the process of splitting water into hydrogen and oxygen, requires an electrical current. On an industrial scale, fossil fuels are typically needed to generate this electricity. Recently, scientists have lowered the voltage required for water splitting by introducing a carbon source into the reaction. But this process also uses carbon or expensive chemicals and releases carbon dioxide as a byproduct.
Singh and his colleagues modified this process to use biomass from common waste products. By mixing sulfuric acid with agricultural residue, animal waste or sewage, they create a carbon-rich slurry-like substance called biochar. The team experimented with different types of biochar made from sugarcane husks, hemp waste, paper waste and cow dung. When added to the electrolysis chamber, all biochar varieties reduced the power needed to convert water to hydrogen. The best performer was cow dung, which decreased the electrical requirement six-fold to about one-fifth of a volt.
Efficiency and Environmental Benefits
The power requirements were so low that the researchers were able to power the reaction with a single standard silicon solar cell that generates about 15 milliamps of current at 0.5 volts. That’s less than the amount of energy produced by one AA battery.
It is very efficient, with almost 35% conversion of biochar and solar energy into hydrogen. These are world record numbers; It’s the highest anyone has ever shown.
Rohit Chauhan, co-author and postdoctoral fellow in Singh’s lab.
For the process to be net zero, it must capture the carbon dioxide generated by the reaction. But Singh said this could also have environmental and economic benefits, such as producing pure carbon dioxide to carbonate drinks or converting it into ethylene and other chemicals used in making plastics.
This not only diversifies the use of biowaste, but also allows for the clean production of different chemicals in addition to hydrogen. This economical way of making hydrogen could allow farmers to be self-sufficient in their energy needs or create new sources of income.
Nishithan Kani, a UIC graduate and co-lead author of the paper.
Orochem Technologies Inc., which sponsored the research, has applied for patents on its processes for producing biochar and hydrogen, and the UIC team plans to test the methods on a large scale.
This innovative method for producing hydrogen from solar energy and agricultural waste represents a significant step forward towards sustainability and the reduction of greenhouse gas emissions. By combining technology with renewable energy sources and common waste materials, a door opens to a greener, more self-sufficient economy.
Via uic.edu
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