Fuel from thin air with artificial leaves is possible now - New Research

 

The sun's core is so hot, and there is so much pressure, nuclear fusion takes place: hydrogen is changed to helium. Nuclear fusion creates heat and photons (light). The amount of solar heat and light is enough to light up Earth’s day and keep our planet warm enough to support life. But we still cannot capture enough energy from it.

According to Professor Erwin Reisner from Cambridge University, it’s possible to create fuel from thin air with artificial leaves.

Erwin and his team to capture more of that free energy.

Although solar panels are used to convert light from the sun, they have made significant advances in the last several years, becoming cheaper and more efficient, they just provide electricity, not storable liquid fuels, which are still in great demand.

 Professor Reisner raised a question – he said when we have covered that 25%, what do we do next?

Plants are a beautiful and massive inspiration because they have learned over millions of years how to take up sunlight and store the energy in energy carriers.

Reisner believes that artificial photosynthesis will be one part of that energy portfolio over the next two decades.

As we all know, when plants photosynthesis, they take up water and carbon dioxide and use light from the sun to convert these raw materials into the carbohydrates they need for growth.

Reisner and his team want to replicate this, however they don’t really want to make carbohydrates because they make a lousy, so instead of making carbohydrates, they will try to make something that can be more readily used.

An additional problem is that plants aren’t actually terribly good at photosynthesis, converting only around one or two percent of solar energy into fuel.

Therefore the US Department of Energy has concluded that for artificial photosynthesis to be viable economically, efficiency needs to rise to between five and 10%.

How promising this research would be?

Professor Reisner and his team have worked on several approaches, including a system that mimics natural photosynthesis, using enzymes to split water and create hydrogen for fuel.

But the efficiency is still low, and as a gas, hydrogen is difficult to store.

It might be more promising in the long term – the team recently developed a small device that converts sunlight, carbon dioxide and water into oxygen and formic acid, a liquid fuel that has a high energy density.

The device contains a panel that sits in a bath of water and carbon dioxide. Under sunlight, the panel releases electrons, which combine with the carbon dioxide and the protons in the water to make formic acid.

According to Reisner, these systems are like panels or sheets; it’s a fragile device – you can almost think of it as a sheet of paper.

The incredible thing about the device is the fact that it is standalone. It doesn’t require an external power source, nor any top-ups of additional catalysts.

Similar projects – the center for hybrid approaches in Solar Energy to Liquid Fuels (Chase) and the Liquid Sunlight Alliance (Lisa)

Chase the project led by the University of North Carolina at Chapel Hill is working on practical applications similar to the Cambridge device by developing systems that, like solar panels, use semiconductors to absorb light, and then use various different catalysts to convert carbon dioxide to fuel.

A particular focus of this research is the concept of cascade catalysts. Turning carbon dioxide into a usable fuel involves making more than one chemical transformation, and catalysts can handle only one at a time.

The first one does the first step and then passes its products off to the next catalyst. Each one would be operating a very highly selective process and handing off after that individual step to the partner down the road.

Lisa project is taking a more theoretical approach, focused on improving every stage and component of artificial photosynthesis. Potential catalysts and processes are modeled by computers before they’re tried out.

They have a vigorous theory effort, and the theory and the experiment go hand in hand researchers now have the world’s largest database.

 According to Prof Dempsey, the bad news is that they are not likely to see fields full of photosynthesis panels anytime soon, there are still major stumbling blocks.

Bringing together all the technology into one bundle is a problem.

"There's been some incredible science in terms of light-harvesting, in terms of the catalysis that makes the fuel and in terms of managing systems.

 

"But the integration of these individual components into a system capable of artificial photosynthesis is a huge challenge."

 

It's also difficult to ensure that the reactions produce a commercially-viable fuel, with many of the catalysts that can achieve this being too expensive or too inefficient for large-scale use.

"When you're dealing with constant radiation [sunlight] that can cause a reaction that can be highly detrimental and corrosive."

As a result, artificial photosynthesis still can't produce liquid fuel cheaply to compete with fossil fuels. "But the dynamic can change very quickly,

 

Conclusion

The oil price can change, taxation can change. And when things start shifting, at some point in the future, the price of artificial photosynthesis will go down, and the price of fossil fuels will go up.

 

"If you go back 10 years, even the most optimistic predictions for the cost of photovoltaic-derived electricity did not match what happened.

 

 The cost came down by 85%, which is incredible. Once the economy of scale comes in, a lot is possible.