What is photosynthesis in general?
Photosynthesis is the process used by plants, algae and certain bacteria to harness energy from sunlight into chemical energy. Oxygenic photosynthesis functions as a counterbalance to respiration, it takes in the carbon dioxide produced by all breathing organisms and reintroduces oxygen into the atmosphere. After 30 years of research, scientists have made significant progress over the past five years in bringing artificial photosynthesis to the market. Scientists at the California Institute of Technology have created a lab-scale device that converts 10% of the sunlight that reaches it into fuel, according to research published earlier this year. This compares with plants’ ability to convert 1% to 2% of sunlight into sugars and other carbohydrates.
What is artificial photosynthesis?
In nature, plants use sunlight to make carbohydrates from carbon dioxide and water. Artificial photosynthesis seeks to use the same inputs solar energy, water, and carbon dioxide to produce energy-dense liquid fuels. Nocera and Silver’s system uses a pair of catalysts to split water into oxygen and hydrogen, and feeds the hydrogen to bacteria along with carbon dioxide. The bacteria, a microorganism that has been bioengineered to specific characteristics, converts the carbon dioxide and hydrogen into liquid fuels.
Artificial photosynthesis (AP) aims to split water in oceans, and possibly even rivers, into its hydrogen, oxygen, and carbon components using sunlight. Hydrogen produced via AP is readily usable in the fuel cells of electric cars being manufactured right now, and it can also be used to store solar energy. Liquid fuels like hydrogen have a distinct advantage over batteries, as they are lighter and less bulky.
Solar energy is used to split water and carbon dioxide into hydrogen, oxygen and carbon. A catalyst then recombines the molecules to create liquid fuels, such as methanol. Methanol is the simplest hydrocarbon that works in internal combustion engines. China already has already blended it into gasoline at low levels (15% or less) at retail pumps, and has taxi and bus fleets running on high-level blends of 85% methanol or more.
“When we develop a way to economically mimic photosynthesis, the impact on everything from global warming to our global economies is world changing,” says Tim Young, chief executive officer of HyperSolar, a Santa Barbara, California-based company working to produce low cost hydrogen fuel from solar energy.
What can the new system do?
The new system can use pure carbon dioxide in gas form, or carbon dioxide captured from the air which means it could be carbon-neutral, introducing no additional greenhouse gases into the atmosphere. The 10 percent number, that’s using pure CO2. Allowing the bacteria themselves to capture carbon dioxide from the air, he adds, results in an efficiency of 3 to 4 percent still significantly higher than natural photosynthesis. “That’s the power of biology: these bio-organisms have natural CO2 concentration mechanisms.”
Combining the fruits of AP in the right proportions produces methanol, which can fuel combustion engines. China has become the largest consumer of methanol in the world, blending it with gas at levels of 15 percent or less for consumer vehicles at gas stations, and running transit vehicles on blends as high as 85 percent methanol.
A variation on the AP process was also used to metabolically engineer nitrogen-generating bacteria to produce nitrogen-based fertilizer right in soil a technique that could boost crops yields in places without ready access to conventional fertilizers. Eventually, these kinds of bacteria might be able to “breathe in” the hydrogen produced by AP and use it to produce a range of goods, including drugs, fertilizers, fuels, and plastics, all determined by the metabolic engineering of the bacteria.
Speed Bumps
Plants convert only about 1 percent of carbon and water into carbohydrates. That efficiency has increased to about 10 percent in the lab, however, and researchers at Monash University in Melbourne, Australia, have hit a level of 22 percent efficiency. The main challenge presented by AP is that photosynthesis in nature is inefficient. Plants convert only about 1 percent of carbon and water into carbohydrates.
One of the biggest challenges has been figuring out how to split hydrogen and CO2 from water without using fossil fuels, which would undermine the environmental benefits, in a way that isn’t cost-prohibitive. To reduce the cost, significantly higher efficiency than 10% is needed, researchers say, as well as a cheaper catalyst.
“The real challenge is going to be how do you make something like artificial photosynthesis at a reasonable scale and have it work in the real environment,” says Kathy Ayers, vice president for research and development for Proton Onsite, which is developing equipment to produce hydrogen gas for industrial applications.
Making a device that’s long-lasting will also be key to driving costs down, researchers say, and then there’s the challenge of developing manufacturing equipment around the device that can mass produce fuels at a comparable production cost to gasoline.
Potential Pitfall
A variation on the AP process was also used to metabolically engineer nitrogen-generating bacteria to produce nitrogen-based fertilizer right in soil a technique that could boost crops yields in places without ready access to conventional fertilizers. Eventually, these kinds of bacteria might be able to “breathe in” the hydrogen produced by AP and use it to produce a range of goods, including drugs, fertilizers, fuels, and plastics, all determined by the metabolic engineering of the bacteria.
Meanwhile, Gates ever an advocate for new energy technologies in general and AP in particular has founded the Breakthrough Energy Coalition, a global coalition of private investors who intend to supplement government-funded research into clean energy with seed money. He sees development of new forms of energy such as AP an imperative, and hopes that disrupting the energy sector will prompt these kinds of discoveries and positive changes. “We need to surprise them that these alternative ways of doing energy can come along and come along in an economic way,” he told Big Think. “If we are to avoid the levels of warming that are dangerous we need to move at full speed.”
Creating a positive aspects
The institute aims to bring its technology to the market within few years, targeting high end consumers that might currently be considering electric cars like the Tesla. But it’s unclear what the end products will actually be. Researchers are thinking broadly, and say they could be anything from consumer products that make fuel at home, such as a mobile carbon-capture device to regulate oxygen levels in classrooms in order to improve learning, to a commercial factory like a solar-based vodka distillery. Turning carbon dioxide emissions into chemicals, fiber’s and jet fuel.
Finding multiple markets for solar fuels will be critical to reducing their production cost, he adds. If that happens, then solar fuels could become as cheap as conventional fuels like gasoline in 10 years, he predicts.
Gates explanation to it :
“The modern lifestyle we lead depends on huge amount of energy. The fact that we can make steel, that we can have cars, air-conditioning machine, cleaning, cooking rest all is based on energy. You could change the price of one thing, it really lift up the life’s of the poorest people everywhere, it would be the price of energy, they can buy good jobs, they can buy fertiliser’s, they can have lights at night the energy miracle its lot. The modern civilization is primarily based on hydrocarbons that is coal, gasoline, natural gas, and as we burn that it heats up the atmosphere, and that heating changes the climate in a way that creates a terrible threat to particularly the poorest people on the planet.
What we need to do is fund the researchers who are looking at the early stages of these problems, if we look at when, where we had huge success in the past. The government’s been there to fund the most basic research that was good for the digital revolution, where government contracts led to the internet, we need the basic research we need to pair that with people who are willing to fund high risk breakthrough energy competence, and that innovation often research level, they accelerate it, they risk taking and that’s what gives us the chance of solution and that really let us not have to give up. It can only be possible only when we realize the importance of staying together to get resource’s to the poorest.”
