The method breaks down into 4 principal levels, in keeping with Prometheus’s investor supplies.
In the 1st step, industrial followers attract air and blow it via a mixture of water and different compounds, which McGinnis says might embrace sodium carbonate. That then readily reacts with carbon dioxide molecules within the air, shifting a lot of the carbonate to bicarbonate.
The ensuing resolution then strikes right into a battery-like cell with a membrane within the center and electrodes on both finish, which makes use of electrical energy to spark a sequence of chemical reactions that produce advanced alcohols. It’s outfitted with a catalyst based mostly on know-how licensed from Oak Ridge Nationwide Laboratory. In an earlier description, that lab mentioned it had developed a catalyst produced from tiny carbon spikes embedded with copper nanoparticles. When a voltage was utilized, it transformed carbon dioxide dissolved in water into ethanol “with a yield of 63%.”
Prometheus’s carbon nanotube membranes come into play in step three, separating the alcohols from the water.
And in a closing step, completely different catalysts are used to mix the alcohols and convert them into artificial gasoline, diesel, or jet gasoline. In 2020, Prometheus licensed separate know-how from the Oak Ridge lab that can be utilized to provide jet gasoline from ethanol, via a multistep course of that depends on a novel although unspecified catalyst.
The general course of is considerably completely different from the one different corporations changing captured carbon into fuels are taking. As McGinnis defined in a Joule commentary, the Prometheus methods can function underneath customary atmospheric strain and at room temperature. The know-how additionally avoids the warmth power wanted to provide concentrated carbon dioxide in addition to the capital prices of an electrolyzer devoted to producing hydrogen. As an alternative, the corporate claims, it will possibly synthesize alcohols straight from carbon dioxide dissolved in water, after which convert these into customary fuels.
In the event that they’ve certainly found out how to do that, it “might result in important power and price financial savings,” says Evan David Sherwin, a postdoctoral researcher at Stanford who produced the Environmental Science & Expertise examine.
One of many final slides within the investor supplies reveals a Prometheus-branded gasoline station, with a purple neon “Zero Web Carbon” signal promoting gasoline costs of $3.50 a gallon and diesel at $3.75, nicely beneath present common US costs.