Renewable energy is something we all want and strive for, but with our existing technology, it is not always efficient or even feasible.
However, a new method that combines biomass and solar energy conversion could be the next step in providing us with a more efficient way of converting the sun's light into power and storing that energy for use in the future.
Storing solar energy requires hydrogen and so far, the best method to do that is splitting water into hydrogen and oxygen with photoelectrochemical solar cells (PECs). Typically, a PEC has a cathode that produces hydrogen and an anode that produces oxygen as a byproduct. This process is typically slow and inefficient and often requires some electrical energy to work, usually powered by petroleum-based products.
Researchers at the University of Wisconsin-Madison, however, decided to change what happens at the anode of the PEC, reducing the energy it requires and making the process faster. Using biomass conversion at the anode, they converted 5-hydroxymethylfurfural (HMF), a cellulose extracted from plants, to furandicarboxylic acid (FDCA), a molecule used for producing polymers. The process oxidizes HMF at room temperature, using water as the source of oxygen. They used this reaction at the anode part of the PEC, creating hydrogen at the cathode.
"Since the photoelectrochemical cell is built for the purpose of hydrogen production and HMF oxidation simply replaces oxygen production at the anode, in essence, no resources are used specifically for HMF oxidation," says University of Wisconsin-Madison chemistry Professor Kyoung-Shin Choi.
Basically, they used biomass conversion with converted solar energy to create a more efficient way of harnessing hydrogen for storing solar energy. Most importantly, the process doesn't require the use of any petroleum products.
However, there's another bonus with this process: FDCA is a valuable byproduct because of its use in the production of polymers. This, in turn, lowers the overall production cost of hydrogen for solar energy storage.
"When we first started this study, we were not sure whether our approach could be really feasible," says Choi. "However, since we knew that the impact of the study could be high when successful, we decided to invest our time and effort on this new research project at the interface of biomass conversion and solar energy conversion."
It took the researchers nearly two years to set up and perfect their system, which means that any future similar research will have to figure out how to speed up production of the method itself.
Photo: Bart Speelman | Flickr
