concept

direct air capture

Also known as: direct air carbon capture and storage, direct air capture, direct CO2 air capture, direct air capture systems, direct air capture technology

Facts (80)

Sources

Impact of carbon dioxide removal technologies on deep ... - Nature nature.com Nature Jun 17, 2021 74 facts

claimCarbon Dioxide Removal (CDR) technologies include Bioenergy with Carbon Capture and Storage (BECCS), Direct Air Capture (DAC), afforestation/reforestation, ocean fertilization, enhanced weathering of minerals, and biochar.

referenceLarsen et al. (2019) outline policies for the United States to advance direct air capture technology.

claimDirect Air Capture (DAC) technologies are powered by the electrical grid rather than a dedicated electricity supply, making it difficult to isolate the precise marginal generation mix powering them.

measurementThe reference capital cost for Direct Air Capture (DAC) is $614 per ton of CO2 per year of capture capacity, with a low-cost sensitivity scenario of $107 per ton of CO2 per year, according to Larsen et al.

referenceHanna et al. published 'Emergency deployment of direct air capture as a response to the climate crisis' in Nature Communications in 2021.

claimSensitivity analyses regarding Direct Air Capture (DAC) costs are conducted to test the impact of uncertainty surrounding learning rates, policy support, and global deployment.

claimBioenergy with Carbon Capture and Storage (BECCS) deployment is spread across a greater variety of regions compared to Direct Air Capture (DAC), with the highest potential occurring in the Gulf, Southeast, Ohio Valley, and portions of the Midwest regions of the United States.

measurementThe crossover point where Direct Air Capture (DAC) becomes more cost-effective than Bioenergy with Carbon Capture and Storage (BECCS) is reached at 105% (-121 Mt-CO2/year) reductions with low biomass resource availability and at 90% reductions (+243 Mt-CO2/year) with low Direct Air Capture costs.

perspectiveDirect Air Capture (DAC) is unlikely to serve as a flexibility resource for renewable integration, contrary to some speculations.

claimBioenergy with Carbon Capture and Storage (BECCS) and Direct Air Capture (DAC) tend toward high-utilization operations and are compatible with a range of low-carbon and high-renewable energy systems.

measurementA lower Direct Air Capture (DAC) capital cost of $107/t-CO2/year increases DAC deployment and decreases Bioenergy with Carbon Capture and Storage (BECCS) investment, resulting in over 340 Mt-CO2/year of DAC removal capacity for the 100% CO2 reduction scenario.

measurementThe analysis assumes a heat requirement of 5.6 MMBtu per ton of CO2 for Direct Air Capture (DAC), based on estimates from Larsen et al.

referenceFasihi et al. published 'Techno-economic assessment of CO2 direct air capture plants' in the Journal of Cleaner Production in 2019.

claimIntegrated assessment models (IAMs) used to investigate carbon dioxide removal options like bioenergy with carbon capture and sequestration (BECCS), direct air capture (DAC), and afforestation lack the technological, temporal, or spatial resolution found in detailed energy systems models.

claimDirect Air Capture (DAC) is unlikely to function as a flexibility resource for renewable energy integration, contrary to some previous speculation.

claimBECCS is the preferred CDR technology up to a 100% CO2 reduction target, but increasing biomass feedstock costs eventually make DAC more economically attractive at the margin for high-CDR-demand scenarios.

perspectiveThe authors recommend that modeling teams and resource planners incorporate Bioenergy with Carbon Capture and Storage (BECCS), Direct Air Capture (DAC), and other Carbon Dioxide Removal (CDR) options into their technology choice sets.

claimDirect Air Capture (DAC) deployment is less evenly distributed across regions compared to Bioenergy with Carbon Capture and Storage (BECCS).

claimCarbon Dioxide Removal (CDR) availability generates cost savings by allowing Direct Air Capture (DAC) and Bioenergy with Carbon Capture and Storage (BECCS) to replace low-capacity-factor assets with higher-utilization assets.

claimThe deployment of Direct Air Capture (DAC) and Bioenergy with Carbon Capture and Storage (BECCS) can lead to approximately net-zero economy-wide CO2 emissions.

claimFor CO2 reductions up to 100%, Bioenergy with Carbon Capture and Storage (BECCS) is preferred to Direct Air Capture (DAC) when both options are available at their reference costs.

claimModeling teams and resource planners should incorporate Bioenergy with Carbon Capture and Storage (BECCS), Direct Air Capture (DAC), and other Carbon Dioxide Removal (CDR) options into their technology choice sets when modeling deep decarbonization and net-zero targets.

measurementElectricity consumption from Direct Air Capture (DAC) is small relative to expected electrification and losses from energy storage, amounting to less than 5% of total load for most scenarios examined in the Nature article 'Impact of carbon dioxide removal technologies on deep decarbonization'.

procedureThe REGEN electric sector model scenarios are run under three carbon dioxide removal (CDR) availability conditions: no CDR, direct air capture (DAC) only, and DAC plus bioenergy with carbon capture and storage (BECCS).

referenceNemet and Brandt published 'Willingness to pay for a climate backstop: liquid fuel producers and direct CO2 air capture' in The Energy Journal in 2012.

measurementElectricity consumption from Direct Air Capture (DAC) is less than 5% of total load in most scenarios examined, which is small relative to expected electrification and losses from energy storage.

measurementDAC consumes 24.8 TWh/year in a 100% CO2 cap case (with 81.1 Mt-CO2/year net removals) and 322 TWh/year in a 140% CO2 cap case (with 1050 Mt-CO2/year net removals), representing 0.42% and 5.39% of projected end-use electricity demand, respectively.

claimBioenergy with Carbon Capture and Storage (BECCS) is preferred to Direct Air Capture (DAC) for achieving up to a 100% CO2 reduction target, but increasing biomass feedstock costs make Direct Air Capture more attractive at the margin for high-CDR-demand scenarios.

claimThe use of Direct Air Capture (DAC) and Bioenergy with Carbon Capture and Storage (BECCS) leads to approximately net-zero economy-wide CO2 emissions.

measurementThe regions with the highest Direct Air Capture (DAC) capacity in the United States are the South Atlantic, California, MISO South, and Texas, which are characterized by lower combined costs.

claimThe investment and operational dynamics of Bioenergy with Carbon Capture and Storage (BECCS) and Direct Air Capture (DAC) are less influenced by market fluctuations from variable renewables compared to other resources because they represent small components of regional power systems.

referenceLarsen et al. (2019) propose policies for the United States to advance direct air capture technology.

measurementIn the study 'Impact of carbon dioxide removal technologies on deep decarbonization strategies', Bioenergy with Carbon Capture and Storage (BECCS) deployment saturates at 110% CO2 reductions (-243 Mt-CO2/year) due to increasing marginal biomass feedstock costs, at which point Direct Air Capture (DAC) becomes the least-cost Carbon Dioxide Removal (CDR) technology.

claimDirect Air Capture (DAC) is powered by the grid rather than a dedicated electricity supply, making it difficult to isolate the precise marginal generation mix powering it, though it is only deployed in the context of a deeply decarbonized generation mix.

measurementBECCS deployment saturates at 110% CO2 reductions (-243 Mt-CO2/year) due to increasing marginal biomass feedstock costs, after which DAC becomes the least-cost CDR technology for further emissions reductions.

measurementIn a 100% CO2 reduction cap scenario, carbon dioxide removal (CDR) lowers advanced nuclear capacity from 117 GW to 47 GW when using Direct Air Capture (DAC) plus Bioenergy with Carbon Capture and Storage (BECCS), or to 73 GW when using DAC only.

claimDirect Air Capture (DAC) is deployed only in the context of a deeply decarbonized generation mix.

measurementThe assumed lifetime for Direct Air Capture (DAC) facilities is 30 years, based on research by Larsen et al. and Fasihi et al.

claimThe 100% CO2 cap case without Carbon Dioxide Removal (CDR) results in net energy storage losses that are over an order of magnitude higher than the electricity use of Direct Air Capture (DAC) in the 100% DAC Only case, because gas turbines are replaced with hydrogen and electrolysis, which have low roundtrip efficiencies.

claimQuantifying the tradeoffs between Direct Air Capture (DAC) and other low/zero/negative-CO2 technologies is a topic for future research.

claimDirect Air Capture (DAC) and Bioenergy with Carbon Capture and Storage (BECCS) reduce costs by replacing low-capacity-factor assets with higher-utilization assets.

referenceThe analysis evaluates scenarios under three Carbon Dioxide Removal (CDR) availability conditions: no CDR, Direct Air Capture (DAC) Only, and DAC + BECCS.

claimLow-temperature solid sorbent designs for Direct Air Capture (DAC) require additional cost reductions to be competitive, but they possess potential for higher learning rates due to modularity and lower energy consumption resulting from lower regeneration temperatures.

claimDirect Air Capture (DAC) is unlikely to function as the flexibility resource for renewable integration that some have speculated, based on the value proposition demonstrated in the Nature article 'Impact of carbon dioxide removal technologies on deep decarbonization'.

claimA carbon dioxide removal (CDR) portfolio could include bioenergy with carbon capture and storage (BECCS), direct air capture (DAC), afforestation/reforestation, ocean fertilization, enhanced weathering of minerals, and biochar.

claimDirect Air Capture (DAC) deployment increases as biomass supply costs rise in scenarios with higher demand for carbon dioxide removal (CDR).

referenceWohland et al. (2018) published 'Negative emission potential of direct air capture powered by renewable excess electricity in Europe' in Earth’s Future, which evaluates the potential for negative emissions using direct air capture technology powered by excess renewable electricity in Europe.

claimThe desirability of Direct Air Capture (DAC) pathways relative to Bioenergy with Carbon Capture and Storage (BECCS) and other low-/zero-/negative-CO2 technologies may be influenced by factors including land use change, water demand, lifecycle environmental impacts, nonelectric decarbonization interactions, and innovation spillovers.

claimWhile Carbon Dioxide Removal (CDR) availability lowers costs, utilizing both Direct Air Capture (DAC) and Bioenergy with Carbon Capture and Storage (BECCS) provides only slightly lower costs than using Direct Air Capture (DAC) alone.

claimWhile gross levelized costs of net CO2 removal are lower for Direct Air Capture (DAC) in the study's assumptions, Bioenergy with Carbon Capture and Storage (BECCS) provides the distinct advantage of producing firm negative-CO2 electricity generation as a coproduct.

claimThe spatial allocation of Carbon Dioxide Removal (CDR) deployment is determined by regional variations in costs and value, although the value of carbon removal for Direct Air Capture (DAC) is assumed to be uniform across regions due to the scenario assumption of a national CO2 cap.

accountResearchers conducted sensitivity analyses on net negative emissions targets for the power sector including Direct Air Capture (DAC), which align with modeled pathways for limiting global warming to 1.5 °C with low overshoot.

measurementThe crossover point where Direct Air Capture (DAC) becomes the least-cost Carbon Dioxide Removal (CDR) technology is reached at 105% reductions (-121 Mt-CO2/year) with low biomass resource availability, and at 90% reductions (+243 Mt-CO2/year) with low Direct Air Capture costs.

claimBioenergy with Carbon Capture and Storage (BECCS) is preferred to Direct Air Capture (DAC) for a net-zero electric sector CO2 target, provided that affordable and sustainably managed bioenergy is available.

claimThe impact of Direct Air Capture (DAC) on electric load is small relative to other factors such as transport electrification, industrial electrification, and net losses from energy storage.

claimBioenergy with carbon capture and sequestration (BECCS) is selected for net-zero electric sector emissions targets, while direct air capture (DAC) deployment increases as biomass supply costs rise.

claimBioenergy with Carbon Capture and Storage (BECCS) deployment is spread across a greater variety of regions compared to Direct Air Capture (DAC) deployment.

claimCarbon dioxide removal (CDR) technologies, including bioenergy with carbon capture and direct air capture, are considered valuable for achieving stringent climate targets.

measurementWhen Direct Air Capture (DAC) is the only available Carbon Dioxide Removal (CDR) option, deployment is 91 Mt-CO2/year for the 100% CO2 reduction scenario at reference costs.

measurementDirect Air Capture (DAC) consumes 24.8 TWh/year in the 100% CO2 cap case (with 81.1 Mt-CO2/year net removals) and 322 TWh/year in the 140% CO2 cap case (with 1050 Mt-CO2/year net removals), representing 0.42% and 5.39% of projected end-use electricity demand, respectively.

measurementThe crossover point where DAC becomes more cost-effective than BECCS is reached at 105% reductions (-121 Mt-CO2/year) when biomass resource availability is low, and at 90% reductions (+243 Mt-CO2/year) when DAC costs are low.

claimDirect Air Capture (DAC) utilization rates in the study scenarios tend to be close to 8000 hours per year, which contradicts the speculation that DAC can be used to integrate variable renewables by operating only during periods of curtailed power.

referenceBreyer, Fasihi, Bajamundi, and Creutzig published an article titled 'Direct air capture of CO2: a key technology for ambitious climate change mitigation' in the journal Joule in 2019.

measurementThe annual policy cost savings for a 100% decarbonization cap are $21.2 billion per year with Direct Air Capture (DAC) only, and $28.3 billion per year with both DAC and Bioenergy with Carbon Capture and Storage (BECCS).

measurementDirect Air Capture (DAC) capital costs are modeled with a reference cost of $614/t-CO2/year and a low-cost sensitivity of $107/t-CO2/year, based on data from Larsen et al. and Fasihi et al.

measurementCDR lowers advanced nuclear capacity in the 100% CO2 cap scenario from 117 GW to 47 GW when using DAC + BECCS, or to 73 GW when using DAC only.

claimThe economic incentives for Direct Air Capture (DAC) investment do not align with operational profiles that would use DAC to integrate variable renewables by absorbing excess power during high-output periods.

referenceThe economic and technical characterization of Direct Air Capture (DAC) in the analysis is based on a high-temperature liquid solvent configuration because it offers lower costs of net CO2 removal compared to other designs, while accounting for natural gas usage for heating and flue gas CO2 capture.

claimThe deployment of Direct Air Capture (DAC) and Bioenergy with Carbon Capture and Storage (BECCS) leads to approximately net-zero economy-wide CO2 emissions in the scenarios analyzed in the study 'Impact of carbon dioxide removal technologies on deep decarbonization strategies'.

claimDirect Air Capture (DAC) is only deployed under conditions with high enough CO2 revenues to run with very high capacity factors, and while it can operate as a flexible load, economic incentives for deployment do not align with such operational profiles except for the highest demand hours.

measurementDirect Air Capture (DAC) electricity use in the 100% DAC Only case is 24.8 TWh/year.

claimHigh-temperature liquid solvent configurations for Direct Air Capture (DAC) offer lower costs of net CO2 removal compared to other designs, when accounting for natural gas heating requirements and flue gas CO2 capture.

claimLow-temperature solid sorbent DAC designs have high potential for capital and maintenance cost reductions through modularity, economies of scale, learning-by-doing from mass production, and technical advances, which can also lower energy requirements.

measurementDirect air capture (DAC) capital costs are modeled at a reference cost of $614/t-CO2/year and a low-cost sensitivity of $107/t-CO2/year, both sourced from Larsen et al.

Could Advanced Reactors Make Carbon Capture Systems More ... energy.gov U.S. Department of Energy Sep 7, 2023 6 facts

claimSolid direct air capture systems can utilize low-temperature heat from nuclear reactors, while liquid direct air capture systems could potentially utilize high-temperature heat from sodium-cooled fast reactors and very high temperature reactors.

measurementAdvanced nuclear reactors could lower the levelized cost of certain direct air capture technologies by up to 13 percent compared to non-nuclear-powered systems.

claimInitial study results confirm that nuclear energy has the potential to reduce carbon dioxide removal costs for direct air capture systems.

claimA U.S. Department of Energy report published on September 7, 2023, indicates that pairing nuclear reactors with carbon dioxide removal technologies, such as direct air capture, shows promise for decarbonization.

claimDirect air capture systems require energy to power fans, pumps, compressors, water cooling systems, and air separation units, as well as heat to drive chemical reactions that regenerate solvents or sorbents and concentrate carbon dioxide.

claimNuclear reactors provide large amounts of carbon-free and constant electricity output, which benefits direct air capture systems.