A Review on the Recent Scientific and Commercial Progress on the Direct Air Capture Technology to Manage Atmospheric CO₂ Concentrations and Future Perspectives

Abstract

Climate change has been linked to industrial and commercial activities caused by exploitation of fossil fuels for energy needs for over a century now. A significant rise in greenhouse gas (GHG) emissions, majorly CO 2 , has been reported in the last few decades. Global climate change necessitates mitigation of atmospheric CO 2 levels to suitable margins using CO 2 capture mechanisms. Direct air capture (DAC) technology is the most efficient way to mitigate or reduce greenhouse emissions by capturing carbon dioxide directly from the atmospheric air. It is imperative that DAC technology be ramped up quickly in order to meet the climate goal to reduce global temperature rise below 2 °C in the next 30 years. This review focuses on the specifics of various techniques, pilot projects, and commercial facilities for DAC technology deployment. DAC has seen substantial technical improvement in recent years, with commercial firms already functioning in the industry with significant upmarket potential. There are about 19 DAC plants in operation across the world, absorbing around 0.01 Mt CO 2 /year. This review article discusses the various DAC technologies used by the companies, future potential, life cycle assessment, as well as the economic viability of worldwide installation of these facilities. The paper provides details on the application of various sorbents including nanomaterials for current advances in DAC. Lastly, the outlook and perspectives are also presented with the concluding remarks.

Alumina Incorporation in Self-Supported Poly(ethylenimine) Sorbents for Direct Air Capture

“…Most amine sorbents incorporate a temperature-swing adsorption process wherein heat is supplied to desorb the CO 2 at a higher temperature. This thermal regeneration can account for up to 50% of the total operating cost associated with the capture process . Therefore, it is desirable for a sorbent to be regenerated at a lower temperature.…”

“…This thermal regeneration can account for up to 50% of the total operating cost associated with the capture process. 17 Therefore, it is desirable for a sorbent to be regenerated at a lower temperature. Figure 5 a shows the downstream concentration of CO 2 as measured by a gas analyzer after the sorbents saturated with humid (50% R.H.) 400 ppm of CO 2 /N 2 were subjected to a slow temperature-programmed desorption at the rate of 0.5 °C/min in flowing N 2 (90 mL[STP]/min).…”

“…It has been over two decades since the use of direct air capture (DAC) for climate change mitigation was first introduced by Lackner in 1999 . There have been many experimental studies published since then to develop materials to cater to DAC, − and to understand the feasibility of existing materials in the post-combustion flue gas capture technology repository toward DAC. − Focus on DAC has grown exponentially over the last decade, with a myriad of commercial ventures and start-ups entering the field. According to the International Energy Agency (IEA), there are a total of twenty-seven DAC plants commissioned worldwide so far with a total capturing capacity of ∼0.01 Mt CO 2 /year .…”

Life cycle assessment of a direct air capture and storage plant in Ireland

“…Nevertheless, the findings of this study establish Ireland as an ideal candidate for the deployment of a DAC plant in the near future. Taking advantage of the wind and a reliable source of heat from waste, promises to substantially reduce the energy costs associated to the DAC plant operation, specifically, solid sorbent-based technologies 64 . However, this represents the optimal scenario, and not every region within the country may meet the requisite conditions.…”

Enhancing the CO2 Sequestration Potential in Subsea Terrain by Hydrate Formation from Liquid CO2

“…There have been several attempts to mitigate the impact of global climate change caused by rising carbon dioxide (CO 2 ) content in the atmosphere. Human activities are responsible for releasing around 10.22 billion metric tonnes of carbon per year into the atmosphere due to fossil fuel combustion. , Majority of these greenhouse gas emissions (GHG) come from industrial and manufacturing activities. – CO 2 gas is the major contributor to overall GHG emissions along with CH 4 , SO 2 , and other gases. , The rising CO 2 concentrations in the atmosphere drastically impact terrestrial temperature and result in rising sea levels, depleting permafrost and food security challenges due to climate change . Since the 19th century, the earth’s temperature has increased to about 1.1 °C.…”