The best of EcoWatch, right in your inbox. Sign up for our email newsletter!
Bionic Leaf Turns Sunlight Into Liquid Fuel 10 Times Faster Than Nature
By Tim Radford
Scientists in the U.S. claim to have beaten nature at its own game. They have created a “bionic leaf" that exploits sunlight to create biomass—and they say their invention is now 10 times more effective than an oak or maple leaf.
Two separate laboratories at Harvard University have co-operated to devise, enhance and test a system that uses sunlight to split water molecules and feed the hydrogen to bacteria that then produce liquid fuels. The next task is to scale up the experiment to produce carbon neutral fuels to combat climate change.
“This is a true artificial photosynthesis system," Daniel Nocera, a leading researcher in renewable energy who is professor of energy at Harvard said. “Before, people were using photosynthesis for water-splitting, but this is a true A-to-Z system and we've gone well over the efficiency of photosynthesis in nature."
Photosynthesis was perfected by the plant world more than 3 billion years of evolution. It drives the entire living world and it is the primary source of all fossil fuels.
Climate change became a problem only when humans started to extract ancient sunshine in the form of coal, oil and natural gas, stored in the Carboniferous rocks and put it back in the atmosphere.
Just as wood fires from felled timber make no difference to the atmosphere's carbon dioxide levels—because the same forest that shelters the fallen tree will absorb it again—so biofuels converted from surplus maize or sugarcane should, in theory, make no difference to global warming.
So the idea of what the Harvard team call “bionic leaf 2.0" is an attractive one. It could deliver liquid fuels in convenient form that would make no difference to the planet's overall carbon budget. In effect, it could bypass the vegetation stage.
Chemists and engineers the world over are racing to exploit human ingenuity and deliver brilliant solutions, including artificial leaves that can capture carbon dioxide. The challenge is to do so effectively, cheaply and on a massive scale.
Which is why Prof. Nocera's lab teamed up with microbiologists led by biochemist and systems biologist Pamela Silver, of Harvard Medical School.
The scientists report in Science journal that they have devised a hybrid system based on cobalt-phosphorus alloy catalyst partnered with bacteria called Ralstonia eutropha, which splits water into oxygen and hydrogen at low voltages.
The microbes consume the free hydrogen and, in the presence of oxygen and carbon dioxide, begin some organic chemistry. So far, the system has made isobutanol and isopentanol and even a bio-plastic precursor product.
The Harvard scientists say their bionic leaf converts solar energy to biomass with an efficiency of 10 percent. The fastest-growing plants do the same with an efficiency of 1 percent.
What works in a laboratory may be tricky to translate into large-scale production, but the researchers are confident they have something that works.
Prof. Nocera said: “It's an important discovery. It says we can do better than photosynthesis. But I also want to bring this technology to the developing world as well.
“If you think about it, photosynthesis is amazing. It takes sunlight, water and air—and then look at a tree. That's exactly what we did, but we can do it significantly better, because we turn all that energy into a fuel."
YOU MIGHT ALSO LIKE
EcoWatch Daily Newsletter
The world awakened to the hole in the ozone layer in 1985, which scientists attributed it to ozone depleting substances. Two years later, in Montreal, the world agreed to ban the halogen compounds causing the massive hole over Antarctica. Research now shows that those chemicals didn't just cut a hole in the ozone layer, they also warmed up the Arctic.
Formosa Plant May Still Be Releasing Plastic Pollution in Texas After $50M Settlement, Activists Find
On the afternoon of Jan. 15, activist Diane Wilson kicked off a San Antonio Estuary Waterkeeper meeting on the side of the road across from a Formosa plastics manufacturing plant in Point Comfort, Texas.
After Wilson and the waterkeeper successfully sued Formosa in 2017, the company agreed to no longer release even one of the tiny plastic pellets known as nurdles into the region's waterways. The group of volunteers had assembled that day to check whether the plant was still discharging these raw materials of plastics manufacturing.
Malaysia Sends Plastic Waste Back to 13 Wealthy Countries, Says It Won’t Be 'the Rubbish Dump of the World'
The Southeast Asian country Malaysia has sent 150 shipping containers packed with plastic waste back to 13 wealthy countries, putting the world on notice that it will not be the world's garbage dump, as CNN reported. The countries receiving their trash back include the United States, the United Kingdom, France and Canada.