What is DAC?
DAC stands for direct air capture, which is the process of capturing carbon dioxide (CO2) directly from the atmosphere. The concentrated CO2 gas is then compressed and liquified. The compressed CO2 is either permanently sequestered in geologic storage deep underground (~6,800+ feet) or is converted to a usable product. The remaining air is exhausted back into the atmosphere. The DAC unit can be powered by waste heat and/or renewable energy sources.
Why is DAC important?
Direct air capture (DAC) is crucial in addressing climate change because it helps remove excess CO2 from the atmosphere, where human activities have significantly increased emissions beyond the Earth's natural capacity to sequester carbon.
Since the industrial revolution CO2 concentrations have steadily increased in the atmosphere at exponential rates that are not attributable to natural geologic processes (e.g., a supervolcano eruption). Traditional industrial processes, electricity generation, and transpiration sectors have been a large contributing factor to this increase in atmospheric CO2 (a greenhouse gas). Greenhouse gases warm the Earth’s atmosphere similar to how a garden greenhouse is warmer than the outside temperature.
The emission of CO2 occurs naturally via respiration and wildfires and other environmental processes. The sequestration of CO2 also occurs naturally in plants and the oceans. However, for hundreds of years human beings have steadily increased the amount of carbon dioxide we emit into the atmosphere and changed the natural landscape through industrialization and deforestation, reducing natural sequestration potential. Since the industrial revolution, there has been an imbalance of carbon dioxide: the rate of CO2 emitted vastly exceeds the Earth’s natural CO2 sequestering abilities.
It will take a suite of mitigating and adaptation actions to combat climate change. DAC is one of those key mitigation solutions to bring the Earth’s atmosphere back into balance.
What is a DAC Hub?
A DAC hub is a regional scale interconnected network with the mission of reducing atmospheric CO2 at commercial scale.
These are some examples of network partners:
Direct air capture technologies
CO2 utilization technologies
Renewable energy technologies
Carbon sequestration sites
Industrial plant sites with excess waste heat
Government and policy leaders
Community leaders
Developers/investors
Illinois Basin Region
The map on the right is the outline of the Illinois Basin, a geologic subsurface feature. The Illinois Basin is a massive oval depression that underlies roughly 70% of Illinois, extending about 60,000 square miles. Since the early 2000s, there has been strong interest in using the unique geology of the Illinois Basin to permanently store, or sequester, carbon dioxide (CO2).
Image source:
Carbon Capture, Utilization, and Storage in Illinois. Prairie Research Institute
