CO₂ Capture from Air: A Breakthrough Sustainable Carbon Source for Synthetic Fuels

Abstract

For the production of carbon-neutral synthetic hydrocarbon fuels, CO₂ is a critical raw material for which a variety of sources exist. Today, industrial ammonia production is amongst the most common sources for CO₂ since the gas is generated as a by-product in a highly concentrated form. Further industrial sources of CO₂ include coal and gas-fired power plants, as well as steel and cement production. As only high purity CO₂ can be used for the production of synthetic fuels, industrial sites need to be equipped with dedicated carbon capture technology. What’s more, such industrial CO₂ sources do not allow for the recapturing of CO₂ from the atmosphere once the synthetic fuels are consumed in the transportation sector. This means the carbon cycle cannot be closed using this method. A viable alternative for sourcing CO₂ is highly concentrated, high purity CO₂ captured directly from the atmosphere through a process called direct air capture (DAC). Of all possible CO₂ sources, only biogenic sources and direct air capture allow for the carbon cycle to be sustainably closed and thus reach truly climate-neutral transportation with internal combustion engines. A further advantage of CO₂ captured from air is that food security is neither interfered with nor put at risk. As such, direct air capture is considered one of the most feasible and promising CO₂ sources for the production of synthetic fuels [3].