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Making Gasoline from Carbon Dioxide

"Aided by a catalyst, the electrons react with carbon dioxide to form carbon monoxide at the electrode. ... To make a fuel, the carbon monoxide can be combined with hydrogento create syngas in a well-known technology called the Fischer-Tropsch process, which has been widely used to make gasoline from coal."

Chemists have shown that it is possible to use solar energy, paired with the right catalyst, to convert carbon dioxide into a raw material for making a wide range of products, including plastics and gasoline.

Understanding a history on the making of gasoline part 1

After seeing this video from the past let's see someone who's actually doing it.

Solar splitter: An amber-colored semiconductor (gallium phosphide), together with metal contacts, is part of a new device that uses solar energy to split carbon dioxide to make carbon monoxide. Researchers at the University of California, San Diego (UCSD), recently demonstrated that light absorbed and converted into electricity by a silicon electrode can help drive a reaction that converts carbon dioxide into carbon monoxide and oxygen. Carbon monoxide is a valuable commodity chemical that is widely used to make plastics and other products, says Clifford Kubiak, professor of chemistry at UCSD. It is also a key ingredient in a process for making synthetic fuels, including syngas (a mixture largely of carbon monoxide and hydrogen), methanol, and gasolineThe work is part of a growing effort to find practical uses for carbon dioxide, a leading greenhouse gas, says Philip Jessop, professor of chemistry at Queen’s University, in Ontario, Canada. Converting carbon dioxide into carbon monoxide is difficult to do, which Jessop says makes the UCSD work impressive and exciting.At least at first, such a process will not make a significant impact on reducing greenhouse gases in the atmosphere–that would take quite large-scale operations, Kubiak says. But “any chemical process that you can develop that uses CO₂ as a feedstock, rather than having it be an end product, is probably worth doing.” He adds that “if chemical manufacturers are going to make millions of pounds of plastics anyway, why not make them from greenhouse gases rather than making tons of greenhouse gases in the process?”

The system may also be part of a solution to a continuing problem with solar energy. For solar panels to be useful when the sun isn’t shining, the electricity they produce has to be stored. A potentially practical way of doing that is by converting the electrical energy into chemical energy. One popular approach is to use solar cells to produce hydrogen, which could then be used in fuel cells. But hydrogen gas is much more difficult to transport and store than are liquid fuels, such as gasoline, which contain far more energy by volume than hydrogen does. The UCSD system shows that it is possible to use solar energy to make carbon monoxide that then, together with hydrogen, can be converted into gasoline. Currently, carbon monoxide is made from natural gas and coal. But carbon dioxide is a more attractive raw material in part because it’s very cheap–indeed, it’s something industrial companies will pay to get off their hands, Jessop says. “There are very few chemicals which are cheaper than free, and carbon dioxide is one of them,” he says.

History on how gasoline is made

In the prototype device, sunlight passes through carbon dioxide dissolved in a solution before being absorbed by a semiconductor cathode, which converts photons into electrons. Aided by a catalyst, the electrons react with carbon dioxide to form carbon monoxide at the electrode. At the anode–a catalyst made of platinum–water is converted into oxygen.

To make a fuel, the carbon monoxide can be combined with hydrogen to create syngas in a well-known technology called the Fischer-Tropsch process, which has been widely used to make gasoline from coal. With the new process for creating syngas, however, fossil fuels could be unnecessary.

The system–which Kubiak began developing as a way of manufacturing oxygen for manned missions to Mars, which has a carbon-dioxide-rich atmosphere–is still a work in progress. In the first prototype, only about half of the energy needed for the reactions was supplied by the sun, with the rest coming from outside electricity. That’s because the researchers decided to prove the concept using silicon as the semiconductor. They are now working with a gallium-phosphide semiconductor, which has exactly the right electronic properties to drive the necessary reactions using sunlight alone.

At this early stage–Kubiak says that commercial systems could be 10 years away–the efficiency and economics of making fuels this way aren’t known. Kubiak says it’s likely that for large-scale applications, his group will need to use catalyst-coated nanoparticles to increase surface area, speeding up reactions

Scientists have long dreamed of mimicking photosynthesis, by using the energy in sunlight to knit together hydrocarbon fuels from carbon dioxide (CO2) and water. Now, a cheap new chemical catalyst has carried out part of that process with record efficiency, using electricity from a solar cell to split CO2 into energy-rich carbon monoxide (CO) and oxygen. The conversion isn’t yet efficient enough to compete with fossil fuels like gasoline. But it could one day lead to methods for making essentially unlimited amounts of liquid fuels from sunlight, water, and CO2, the chief culprit in global warming.

The new work is “a very nice result,” says John Turner, a renewable fuels expert at the National Renewable Energy Laboratory in Golden, Colorado.

The transformation begins when CO2 is broken down into oxygen and CO, the latter of which can be combined with hydrogen to make a variety of hydrocarbon fuels. Adding four hydrogen atoms, for example, creates methanol, a liquid fuel that can power cars. Over the last 2 decades, researchers have discovered a number of catalysts that enable that first step and split CO2 when the gas is bubbled up through water in the presence of an electric current. One of the best studied is a cheap, plentiful mix of copper and oxygen called copper oxide. The trouble is that the catalyst splits more water than it does CO2, making molecular hydrogen (H2), a less energy-rich compound, says Michael Graetzel, a chemist at the Swiss Federal Institute of Technology in Lausanne, whose group has long studied these CO2-split 

Thanks to a new catalyst, sunlight has been converted into chemical energy with a record 13.4% efficiency.

I-STOCKR/ISTOCKPHOTO

Cheap catalysts turn sunlight and carbon dioxide into fuel

Scientists have long dreamed of mimicking photosynthesis, by using the energy in sunlight to knit together hydrocarbon fuels from carbon dioxide (CO2) and water. Now, a cheap new chemical catalyst has carried out part of that process with record efficiency, using electricity from a solar cell to split CO2 into energy-rich carbon monoxide (CO) and oxygen. The conversion isn’t yet efficient enough to compete with fossil fuels like gasoline. But it could one day lead to methods for making essentially unlimited amounts of liquid fuels from sunlight, water, and CO2, the chief culprit in global warming.

The new work is “a very nice result,” says John Turner, a renewable fuels expert at the National Renewable Energy Laboratory in Golden, Colorado.

The transformation begins when CO2 is broken down into oxygen and CO, the latter of which can be combined with hydrogen to make a variety of hydrocarbon fuels. Adding four hydrogen atoms, for example, creates methanol, a liquid fuel that can power cars. Over the last 2 decades, researchers have discovered a number of catalysts that enable that first step and split CO2 when the gas is bubbled up through water in the presence of an electric current. One of the best studied is a cheap, plentiful mix of copper and oxygen called copper oxide. The trouble is that the catalyst splits more water than it does CO2, making molecular hydrogen (H2), a less energy-rich compound, says Michael Graetzel, a chemist at the Swiss Federal Institute of Technology in Lausanne, whose group has long studied these CO2-splitting catalysts. 

Last year, Marcel Schreier, one of Graetzel’s graduate students, was looking into the details of how copper oxide catalysts work. He put a layer of them on a tin oxide–based electrode, which fed electrons to a beaker containing water and dissolved CO2. Instead of splitting mostly water—like the copper oxide catalyst—the new catalyst generated almost pure CO. “It was a discovery made by serendipity,” Graetzel says.A bright ideaA new catalyst made from copper and tin

 oxides uses electric current from a solar cell to split water (H2O) and carbon dioxide (CO2), creating energy-rich carbon monoxide (CO) that can be further refined into liquid fuels.H2OCOCOOH–O2CO2CO2H+Catalyst-coveredelectrodesMembraneSolar celle–e–SunlightV. 

ALTOUNIAN/SCIENCE

The tin, Graetzel adds, seems to deactivate the catalytic hot spots that help split the water. As a result, almost all the electric current went into making the more desirable CO. Armed with the new insight, Graetzel’s team sought to speed up the catalyst’s work. To do so, they remade their electrode from copper oxide nanowires, which have a high surface area for carrying out the CO2-breaking reaction, and topped them with a single atom-thick layer of tin. As Graetzel’s team reports this week in Nature Energy, the strategy worked, converting 90% of the CO2 molecules into CO, with hydrogen and other byproducts making up the rest. They also hooked their setup to a solar cell and showed that a record 13.4% of the energy in the captured sunlight was converted into the CO’s chemical bonds. That’s far better than plants, which store energy with about 1% efficiency, and even tops recent hybrid approaches that combine catalysts with microbes to generate fuel.

Nate Lewis, a chemist at the California Institute of Technology in Pasadena, says the new result comes on the heels of other recent improvements that use different catalysts to turn CO2 into fuels. “Together, they show we’re making progress,” Lewis says. But he also cautions that current efforts to turn CO2 into fuel remain squarely in the realm of basic research, because they can’t generate fuel at a price anywhere near to that of refining oil.  

Still, exploding supplies of renewable electricity now occasionally generate more power than the grid can handle. So scientists are looking for a viable way to store the excess electricity. That’s likely to drive further progress in storing energy in chemical fuels, Graetzel says.