The Calculus on Direct Air Capture

Aerial view coal power plant station in the morning mist, the morning sunrises. coal power plant and environment concept. Coal and steam. Mae Moh, Lampang, Thailand.

In the push to decarbonize, it is crucial that we consider the local implications of new energy technologies. This is true for direct air capture, or DAC, a technology that the Clean Energy Conversions Lab at Penn are studying closely.

Welcome to the stage, Direct Air Capture (DAC). DAC is a technology designed to extract carbon dioxide directly from the surrounding air, playing a vital role in achieving our climate objectives, including those outlined in the Paris Agreement.

But with rapid-scale climate mitigation on our collective minds, it is crucial that we consider the local implications of new energy technologies. This holds true for DAC, which we at the Clean Energy Conversions Lab at the University of Pennsylvania are closely studying.

How DAC Works

While there are many approaches to DAC, most follow this two-step formula:

Step 1: Ambient air flows through building-like structures where CO2 sticks to specially formulated chemicals or surfaces.

Step 2: Trapped CO2 is released by applying heat or electricity in a controlled way. The end result is a separate stream of CO2 that can be compressed and sent to storage, keeping it out of the atmosphere for many years to come.

More About DAC

DAC plants can be located anywhere, but some locations make more sense. Regions with both low-carbon energy potential and CO2 storage potential are ideal. For example, a DAC plant powered by geothermal at a location with on-site underground storage will produce fewer emissions than a DAC plant powered by fossil fuels that also requires transporting CO2 to a distant location.

Benefits of DAC

DAC has almost unlimited potential to remove carbon from the atmosphere. It doesn’t need to be placed on arable land, so it won’t take up valuable land required for crops and other nature-based solutions, like planting trees. DAC is a pathway to durable carbon removal, meaning that when designed properly keeps CO2 out of the atmosphere for a very long time. DAC has a much lower land footprint than some other solutions, meaning it takes up less space. And DAC has the potential to be a strong local economic driver, bringing permanent, good-paying jobs to the area.

This article was written by Peter Psarras, Research Assistant Professor in Chemical and Biomolecular Engineering at Penn Engineering and was first published by the Kleinman Center for Energy Policy at the University of Pennsylvania. Please visit their site to read the full story. It has been reprinted with their permission.