Researchers in Georgia Tech’s School of Chemical and Biomolecular Engineering (ChBE) are principal investigators on six new projects that have been awarded a total of $4.35 million for studies related to direct air capture science and technology. Direct Air Capture (DAC) is a technology that removes carbon dioxide (CO2) directly from ambient air for use as a feedstock for chemical processes or transformed into a durable substance so that it can be sequestered. Some of the proposed chemical transformations that are possible with this technology include liquid fuels that could serve as “drop-in” replacements for the petroleum-based fuels we use for transportation.
With these recent awards, Georgia Tech researchers, with the support of Georgia Tech’s Strategic Energy Institute (SEI), have launched the Direct Air Capture Center (DirACC) under the guidance of Christopher Jones, Professor and William R. McLain Chair, and Matthew Realff, Professor and David Wang Sr. Fellow. DirACC will create a forum for collaborative research on NETs and DAC, bringing together researchers from across the Institute working in energy, sustainability, policy, and related fields.
For more than a decade, Georgia Tech researchers have worked to develop materials and processes that extract carbon dioxide directly from the atmosphere and transform it into something more durable or useful. In 2008, Jones began collaborating with the founders of a startup company, Global Thermostat, to develop materials and processes for DAC. His group first disclosed the use of hybrid silica/organic amine materials for CO2 capture from ambient air in 2009 at the American Institute of Chemical Engineers Annual Meeting. Global Thermostat’s core technology marries the CO2-sorbing materials developed by Jones’ group with a low energy process for ensuring good air contact with those materials. In 2015, Global Thermostat built their initial R&D facility in Georgia Tech’s Advanced Technology Development Center (ATDC), the nation’s oldest technology incubator. Global Thermostat operated its ATDC facility through the end of 2020, while building technology demonstration projects in Huntsville, Alabama, in 2019 and opening a new R&D facility in Denver, Colorado, in 2020.
In 2010, David Sholl, John F. Brock III School Chair, collaborated with Jones on what is believed to be the first federally funded DAC research project sponsored by the Department of Energy’s National Energy Technology Laboratory. The Camille and Henry Dreyfus Foundation played an early role in sponsoring DAC research at Georgia Tech as well. The foundation has recently produced a short film, featuring Jones, on the concept of DAC in its Chemistry Shorts film series, which is aimed at attracting young people to careers in STEM (chemistryshorts.org).
In 2017-18, Jones co-led a study on DAC technology for inclusion in the U.S. National Academies consensus study on Negative Emissions Technologies and Reliable Sequestration: A Research Agenda. This study adapted a technoeconomic analysis developed by Realff and former Georgia Tech Professor Yoshiaki Kawajiri (Nagoya University). The report explored all the terrestrial ways that CO2 could be removed from the atmosphere, including DAC with geologic sequestration, bioenergy with carbon capture and sequestration (BECCS), carbon mineralization, and coastal, forest, and soil management practices. (nap.edu/read/25259/chapter/1).
In parallel, researchers at Tech have engaged in related technology developments in carbon capture, with large, established technology firms. Examples include projects with ExxonMobil Research and Engineering Company led by Associate Professor Ryan Lively, along with M.G. Finn, professor and chair of the School of Chemistry and Biochemistry and the James A. Carlos Family for Pediatric Technology; William Koros, professor and Roberto C. Goizueta Chair for Excellence in Chemical Engineering; and Realff, focusing on a range of CO2 capture problems. ExxonMobil has supported R&D efforts in CO2 capture at Georgia Tech dating back to 2005. To date, the GT-ExxonMobil relationship has resulted in the graduation of 10 Ph.D. students, the support of five postdoctoral researchers, and has resulted in more than 45 papers and 25 US patents.
Beyond the fundamental science and engineering of DAC, other research efforts at Georgia Tech are modeling the implications of large-scale deployment of negative emissions technologies. Alice Favero, an environmental economist in the School of Public Policy, develops economic models to study how NETs can be balanced with the optimal use of land and other climate mitigation policies. Recently, she has collaborated with Lively and Realff on assessing the global potential for DAC. In this work, the concept of using sustainable Bio-Energy for Carbon Capture and Sequestration (BECCS) processes coupled with DAC technology allows for significantly greater atmospheric CO2 removal and avoids the complexity of connecting the biomass energy facility to the grid. In particular, Favero demonstrated that this technology can work in combination with ecological afforestation efforts that maintain or enhance the natural ecosystem services and avoid converting forested lands into plantations.
Georgia Tech is also conducting research on DAC methods that leverage the photosynthesis of plants other than trees to capture CO2 from the atmosphere to produce chemicals and fuels. Valerie Thomas, the Anderson-Interface Professor of Natural Systems in the H. Milton Stewart School of Industrial and Systems Engineering, has worked with biofuels companies Algenol and LanzaTech to perform life cycle assessments to determine the potential for their technologies to contribute to carbon sequestration. Using life cycle assessment to study biofuel production also reveals the possibility of unexpected impacts and suggests ways that negative consequences can be averted or mitigated.
Climate models now show that reduction of current and future emissions alone will not limit the global average temperature rise to 1.5-2 °C, the level suggested that may allow society to stave off the worst impacts of global climate change. These models suggest that negative emissions technologies, such as direct air capture, will need to be developed and deployed at a large scale to stabilize the climate. Georgia Tech researchers have done pioneering work in this area and are poised to continue advancing the state of the art.