Session: 08-05-03: Energy-Related Multidisciplinary III

Paper Number: 150879

150879 - Energy Autarkic Direct Air Capture of Carbon Dioxide 

Achieving net-zero greenhouse gas emissions will halt the rise of atmospheric CO₂, but active removal is needed to limit global temperature rise to within 1.5 °C of pre-industrial levels. This requires capturing 450-1000 gigatons of CO₂ by the year 2100. Compared with biological CO₂ removal methods, direct air capture (DAC) of CO₂ occupies less land and requires significantly less water. DAC also yields high-purity CO₂ that can be sequestered or chemically converted for long term storage and permanent removal from the carbon cycle. In contrast, biological CO₂ removal, such as in new trees or vegetative matter, only temporarily removes CO₂ from the atmosphere and does not permanently reduce long-term atmospheric CO₂ levels unless new biomass is neutralized and prevented from decaying, being consumed, or burning. However, current DAC technologies face significant limitations due to high costs resulting from low CO₂ adsorbent lifetimes and enormous energy infrastructure requirements. In this talk I will present the design and promising prototype demonstrations of our energy autarkic DAC system that overcomes these challenges resulting in a globally scalable and potentially profitable solution.

Our 100% solar-powered system operates without blowers, external power connections, energy storage, scarce or toxic materials, or the need for special geological features. Because this system is fully decoupled from the grid and other external power, its success is independent of the carbon intensity of the grid as well as the costs and maximum construction rates of new energy infrastructure. Satisfying the globally required 10 gigatons of annual carbon capture will consume the equivalent of 103% of the U.S.’s primary energy production. Therefore, any DAC technology relying on new external energy infrastructure will not be able to scale globally on the necessary timelines. Our system also avoids the excessively high temperatures and other nonequilibrium conditions typical of CO₂ adsorbent regeneration in conventional DAC systems that exacerbate sorbent degradation. As a result, we have shown the sorbents in our system to have projected 20 to 30-year service lifetimes. This enables total system levelized carbon capture costs as low as $90 per ton under optimal conditions and surpasses the U.S. ‘Carbon Negative Shot’ 2030 goal of $100 per ton.

This talk will present the operating principles of the design and show the results of our month-long prototype tests in real outdoor and sometimes cloudy and rainy conditions without any external power. I will discuss current limitations and future work, including key system-level designs and materials-level scientific questions that we as a community still need to address to enable further improvement of this and related DAC technologies.

Presenting Author: Sean Lubner Boston University

Presenting Author Biography: Dr. Sean Lubner is an assistant professor in BU’s Mechanical Engineering department and Materials Science and Engineering division. He is a core faculty member of the Institute for Global Sustainability (IGS) and the recipient of an AFOSR Young Investigator Program (YIP) award and BU’s Dean’s Catalyst award. Before joining BU, Prof. Lubner was a research scientist at MIT and a Seaborg Fellow research scientist at Lawrence Berkeley National Laboratory. Dr. Lubner’s group specializes in nano-to-macro thermal energy transport and conversion, and has worked on a variety of energy-related systems including biomedical devices, electrochemical and thermal energy storage systems, solid state energy conversion devices, machine learning models, water desalination, and CO2 capture. Dr. Lubner works extensively with both industry and academia, and holds numerous joint patents and publications.

Authors:

Jian Zeng Lawrence Berkeley National Lab
Hsinhan Tsai University of California, Berkeley
Tae Lim Lawrence Berkeley National Lab
Hannes Albers Boston University
Hanna Breunig Lawrence Berkeley National Lab
Jeffrey Long University of California, Berkeley
Ravi Prasher Lawrence Berkeley National Lab
Sean Lubner Boston University