Many people across the world have tried to harness carbon dioxide to use in place of fossil fuels. Carbon dioxide has had problems when it has been attempted to be used as fuel because it had low efficiency or it produced a toxic, flammable or hard to handle fuel. Researchers at MIT and Harvard University have developed an efficient process that can convert carbon dioxide into a solid or liquid fuel that can be stored and can be used like hydrogen or methane to generate electricity.

The processes transformed the electrochemical conversion of the gas into a solid formate powder which is then used in a fuel cell to produce electricity. According to news.MIT.edu the researchers expect it to be scalable so that it could provide emissions-free heat and power to individual homes and even be used in industrial or grid-scale applications. Old methods were far less efficient as they had to capture the CO2 then turn it into calcium then heat it to use for fuel for feedstock such as carbon monoxide. The old method reached 20% efficiency whereas the new method reached over 90%. It does this by first converting the carbon dioxide into an intermediate form, liquid metal bicarbonate allowing it to be stored for years or even decades.

According to news.MIT.edu CO2 is converted into solid formate crystals with a carbon efficiency of greater than 96%, as confirmed in the team’s lab-scale experiments. Although the solid fuel is much heavier than pure hydrogen, when the weight and volume of the high-pressure gas tanks needed to store hydrogen is considered, the end result is an electricity output nearly the same for a given storage volume. The researchers have said Initial household applications might involve an electrolyzer unit about the size of a refrigerator to capture and convert the carbon dioxide into formate. The formate would be stored underground or on the roof top which could be used to provide power and heat when needed by mixing it with water and putting it inside of a fuel cell.