This machine captures carbon dioxide in the air and converts it into methane fuel. It could be installed in offices, allowing workers to think more clearly. (Image Credit: Soletair)


Soletair Power, a Finnish start-up, developed an air filtration and purification system that captures carbon dioxide in the air and converts it into useable fuel. This system can be utilized in an office building, serving hundreds of people who work there. It was originally built for the 2020 World Expo in Dubai, United Arab Emirates. A gas-powered espresso machine, which is built into Soletair’s system, performs the conversion.


The value proposition of the first part of this machine is pretty clear. In an office building full of workers, carbon dioxide can accumulate, and higher concentrations could affect their ability to think clearly. This could be solved either by bringing in air from the outdoors or filtering out CO2, which is what Soletair’s machine does.


The CO2 could just be sent outside or used to create seltzer. Instead, the rest of the machine transforms carbon dioxide into methane fuel, but it could be switched for a liquid fuel process. Since the carbon is sourced from the air, these fuels could be carbon-neutral.


The carbon capture technology being utilized in the system is a smaller version of the ones designed for combustion power plants. Air passes through a chamber filled with small granules containing amines. These granules are periodically cycled through a heating process. The temperature needs to be just below 120°C. This ensures the steam coming from the heating system and/or electric heating element is sufficient.  The amine granules then release the carbon dioxide they’re storing, which collects in the storage tank. Afterward, the granules can absorb additional carbon dioxide.


Two-thirds of this machine, measuring 2 m tall, 5 m long and 1 m wide, is responsible for converting carbon dioxide into usable fuel. An electrolyzer separates water to produce hydrogen gas. Afterward, hydrogen is mixed with carbon dioxide in a methanation reactor, creating pure methane gas.

This device is designed to work with a standard HVAC flow of 3m³ of air per second. It can operate in an office building with hundreds of workers. In Soletair’s office, the machine takes in air with around 500 parts per million CO2 and cuts the concentration in half.


However, it’s unusual to produce fuel in an office building. It might be beneficial if there’s an on-site need for it, such as heating or vehicle use. It could also be sent to a public supply network, which is similar to net metering of solar power but for gas. Essentially, this could offset costs.


Companies like Carbon Engineering, which designs carbon-capture facilities, are exploring the air to fuel concept. As for all types of carbon capture, setting a price on carbon emissions could enhance the economics of expenditures, reducing emissions.


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