Columbia Engineering assistant professor Danial Esposito and his team have created a floating device capable of producing hydrogen gas (H2) for fuel using sunlight and seawater, minus the CO2 emissions usually produced by this process.
TAKING HYDROGEN FROM SEAWATER
Hydrogen fuel is yet another alternative form of energy than can be utilized to slowly wean the world away from fossil fuels — it’s a zero-emission form of energy, producing only water when burned. The problem, however, is that hydrogen gas (H2) for fuel is produced using a process known as steam methane, which also releases carbon dioxide (CO2), a key factor of global warming. The presence of CO2 lingering behind H2 makes it harder to facilitate its use over solar and wind energy.
Daniel Esposito, assistant professor of chemical engineering at Columbia Engineering, has been looking into a way to use water electrolysis — the process of separating water into hydrogen and oxygen gas (O2) — to produce hydrogen without carbon dioxide coming along for the ride. It took a bit of work, but Esposito and his team have developed a device that can do just that, and it may inspire the creation of larger devices capable of generating larger amounts of hydrogen fuel.
His creation is called a floating photovoltaic (PV) electrolyzer. As of now, it’s still a small lab-based prototype, but the final product would be developed into a complex floating on the ocean with an ironically similar appearance to a deep-sea oil rig. Instead of creating oil, though, this complex would produce H2 using sunlight and seawater.
Most commercial electrolyzers contain membranes that separate hydrogen and oxygen (O2) gases. Yet these membranes are susceptible to the impurities and microorganisms found within seawater, and can be damaged over time. Esposito’s device doesn’t use membranes, and therefore isn’t vulnerable to the same problems.
“The simplicity of our PV-electrolyzer architecture makes our design particularly attractive for its application to seawater electrolysis, thanks to its potential for low cost and higher durability compared to current devices that contain membranes,” said Esposito in a press release.