Yesterday, marking OpenAir’s first ever field trip, seven Collectors visited direct air carbon capture startup aircela’s new lab in Manhattan. Aircela co-founder and CEO Dr. Eric Dahlgren and Air Capture Engineer Dr. Sean Parlia showed us the capture and conversion equipment prototypes they’re developing. They also took us up to their roof – complete with a garden and gorgeous views – which will house their capture equipment. The highlight of our visit was a video call with DACC pioneer Dr. Klaus Lackner, Director of the Center for Negative Carbon Emissions at Arizona State University and aircela’s Senior Science Advisor.
Aircela’s goal is to make small, inexpensive, modular units that can capture CO2 from the air, add hydrogen, and convert it to gasoline. The units will be designed to run on intermittent renewable energy, which reinforces the need for low cost since they may only run 8 hours a day, taking 3 times as long to pay off the capital expense. Someone could run a single unit (called a Poplar) at home to generate carbon-neutral gasoline for personal use, or multiple units could be run together for larger installations (called Groves or Forests).
Lackner and Dahlgren emphasized the advantages of small, short-lived units to be incrementally improved upon in new editions (the way laptops and cell phones are), allowing them to move quickly down the cost curve (see this recent analysis by Azarabadi and Lackner.) Rather than scale up to make large units, they plan to scale up by mass-producing small units. Lackner likened the strategy to pooling hundreds of car engines to create a power plant, stating that the current annual production of car engines can generate more power than the entire grid, and at much lower cost. He added that modern automation makes such a plant feasible today.
They also highlighted the cost advantages of liquid fuel over batteries for longer-term energy storage. They acknowledged that the generation of gasoline pits them against the electric vehicle market, but they believe that there will still be a sizable gas-powered vehicle market for decades to come – long enough to achieve low-cost direct air carbon capture.
Aircela plans to develop units with two “dorm refrigerator”-sized components, with the capture component located outside, and a separate conversion component. Their current prototype uses a liquid sorbent of water and potassium hydroxide (KOH) salt, dripped onto a fabric, with a fan blowing air over the fabric. CO2 reacts with the KOH to form K2CO3, which is collected. An electrolyzer releases the CO2 from the salt (which can then be reused) and also splits hydrogen from water. In the conversion component, the hydrogen and carbon will be converted to methanol, then dimethyl ether (DME), and finally gasoline. Dahlgren pointed out that this three-step conversion technology has been commercialized for decades. He’s looking to use as much off-the-shelf equipment as possible and to leverage associated improvements and cost reductions over time.
At the end of the tour, aircela treated us to some excellent neighborhood pizza and high-quality beer – a perfect ending to an inspiring visit. They set a high bar for future field trips!