Researchers at the US Dept of Energy's Argonne National Laboratory, working with Northern Illinois University, have discovered a new catalyst that can convert carbon dioxide and water into ethanol with "very high energy efficiency, high selectivity for the desired final product and low cost."
The catalyst is made of atomically dispersed copper on a carbon-powder support, and acts as an electrocatalyst, sitting in a low voltage electric field as water and carbon dioxide are passed over it. The reaction breaks down these molecules, then selectively rearranges them into ethanol with an electrocatalytic selectivity, or "Faradaic efficiency", higher than 90%. The team says this is "much higher than any other reported process."
Once the ethanol is created, it can be used as a fuel additive, or as an intermediate product in the chemical, pharmaceutical and cosmetics industries. Using it as a fuel would be an example of a "circular carbon economy," in which CO2 recaptured from the atmosphere is effectively put back in as it's burned.
If the process is powered by renewable energy, which the researchers say it can be due to its low-temperature, low-pressure operation and easy responsiveness to intermittent power, then great; all you're losing is fresh water, which is its own issue.
Realistically, you're still a lot better off running an EV than a car fueled with gasoline using this ethanol as an additive. While its Faradaic efficiency might be excellent, its overall electrical efficiency won't be; putting the same amount of energy into a battery will get more power to the wheels at the end of the day, because combustion engines are horribly inefficient in comparison to electric powertrains, and there will be additional significant power losses at this catalysis stage, as well as the industrial carbon capture and transport stages.
There's no way of telling at this stage what the costs might be, either. There are already a number of synthetic fuels using catalytically captured carbon dioxide; Carbon Engineering is one firm that pulls CO2 from the air to create a synthetic crude that can be refined into high-purity aviation fuel, for example.
Such synthetic fuels need to compete with regular fossil gasoline on price, so without knowing how the Argonne team's carbon-capture ethanol competes with bioethanol and other sources there, it's hard to place this on the spectrum between "neat result that won't see wide scale use" and "environmentally significant discovery."
The paper is published in Nature Energy.
Source: Argonne National Laboratory
Saying that one's better off putting the energy into a battery is only considering the raw power though.
Building a battery in itself is an extremely resource-intensive (a lithium-ion battery can only give back 2.5 times of the energy invested to create it in its whole life) and requires rare metals that are often (~50%) mined in China in heavy-processes that pollute a lot. And we are expected to run out of them in a near future. Producing biofuel with recyclable/abundant materials while pumping CO2 from the atmosphere beats using batteries by a fair margin IMO.
You can make near pure CO2 and water from burning biomass in O2 making power too , O2 made from electrolyzing water into O2 and H2 at about 80% efficient as using both products.
So now you have efficient CO2 and add some more water and if this catalyst is 90% efficient, earlier ones were just 60% your overall efficiency is around 70% plus the H2 which also can be used to make heat, power at 80% efficiency.
So overall conversion to products needed is very good in the 80% range.
On corn ethanol is provides far better food than corn, a terrible food is. The mash from making ethanol is high quality protein plus corn oil, plastic feedstock and a lot of silage this ethanol, power and heat can be made from.
So stop believing big oil, auto's anti ethanol lies and being a tool for them to get rid of their competition and burn more oil instead.
And does take into account it takes 3kwh to make a gal of gasoline as just the start of the energy to make oil and only 7% of the energy from the oil well to move the car vs 75% from solar, wind in and EV.
So a battery is 80% more efficient that oil overall.
And that is coming way down with Tesla's new dry process and other battery types like LiFe, LiS, metal/air, sodium, other couples.