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Direct Air Capture (DAC) technology removes CO2 directly from the atmosphere. Is it climate savior or expensive distraction?
HOW IT WORKS
Solid sorbent DAC: Air passes through filters containing chemicals that bind CO2 Filters heated to release concentrated CO2 CO2 compressed and stored or used Filters regenerated and reused
Liquid solvent DAC: Air contacts liquid chemical solution CO2 absorbed into solution Solution heated to release pure CO2 Solution recycled
MAJOR PLAYERS
Climeworks (Switzerland): World's largest DAC plant: Orca in Iceland Captures 4,000 tons CO2/year Cost: ~$600-800/ton currently Partnered with Microsoft, Stripe, Shopify
Carbon Engineering (Canada): Backed by Bill Gates, Chevron, Occidental Pilot plant in British Columbia Building commercial plant in Texas (1M tons/year) Cost target: $100-150/ton at scale
Heirloom Carbon: Limestone-based approach Faster cycle time than competitors Raised $50M+ from Breakthrough Energy
Global Thermostat: Uses waste heat for regeneration Lower energy requirements claimed Partnerships with ExxonMobil
THE NUMBERS
Current capacity: <0.01 million tons CO2/year globally Needed by 2050: 5-10 billion tons/year (IPCC scenarios) Gap: We need to scale 500,000x in 25 years
Current costs: $400-$1,000 per ton Target costs: $100-$200 per ton needed for viability Path to scale: Manufacturing learning curves, energy cost reductions, policy support
ENERGY REQUIREMENTS
Capturing 1 ton CO2 requires roughly: Solid sorbent: 1.5-2.5 MWh electricity + heat Liquid solvent: 2-3 MWh electricity + heat
Critical: Energy must be carbon-free (renewable/nuclear) or defeats purpose
STORAGE OPTIONS
Geological storage: Inject CO2 underground into porous rock formations Same technology as oil/gas storage Permanent if site selected properly Capacity: Trillions of tons globally
Mineralization: React CO2 with minerals to form solid carbonates Permanent storage, no leakage risk Slower process, more expensive
Utilization: Convert to fuels (synthetic jet fuel, diesel) Building materials (concrete, aggregates) Chemicals and plastics Beverages (carbonation)
Note: Utilization often releases CO2 later (except building materials), so mainly delays rather than removes.
ADVANTAGES
Can address legacy emissions (not just future) Works anywhere (don't need point sources) Land use minimal vs. forests Permanent storage possible Scalable with manufacturing
CHALLENGES
Cost: Still too expensive at scale Energy: Requires massive renewable energy Materials: Sorbent production and replacement Location: Transport CO2 to storage sites Scale: Need gigaton-level deployment
COMPARISON TO ALTERNATIVES
Afforestation/reforestation: Cost: $10-$50/ton Challenges: Land use, permanence, saturation Capacity: ~10 billion tons over decades
Soil carbon: Cost: $20-$100/ton Challenges: Verification, permanence Capacity: ~5 billion tons potential
Biochar: Cost: $30-$120/ton Challenges: Scaling biomass supply Capacity: ~2 billion tons/year potential
Ocean alkalinity: Cost: $50-$150/ton (estimated) Challenges: Environmental impacts unknown Capacity: Very large (gigatons)
POLICY SUPPORT
US 45Q tax credit: $180/ton for DAC with permanent storage $130/ton for DAC with utilization Significantly improves economics
EU Innovation Fund: €10 billion for clean tech including DAC
Voluntary carbon markets: Companies paying $100-$300/ton for DAC credits Stripe, Shopify, Microsoft leading buyers
REALISTIC OUTLOOK
DAC will likely be needed but isn't a silver bullet
Necessary because: Can't eliminate all emissions, need to remove legacy CO2, insurance against climate tipping points
Not sufficient because: Too expensive to replace emissions reductions, massive energy requirements, decades to scale, other nature-based solutions cheaper
Best role: Part of portfolio including emissions cuts, nature-based removal, other CDR technologies
INVESTMENT TRENDS
$3+ billion invested in DAC companies (2020-2025) Venture capital interested but waiting for policy clarity Corporate advance purchases driving development Expect costs to drop 50-70% over next decade with scale
BREAKTHROUGHS NEEDED
Lower-energy sorbents Waste heat utilization Modular designs for mass production Integration with renewable energy CO2 pipeline infrastructure
RESOURCES
Reports: IEA Direct Air Capture Report: iea.org/dac NASEM Carbon Removal Report: nap.edu/carbonremoval
Companies: Climeworks: climeworks.com Carbon Engineering: carbonengineering.com Heirloom Carbon: heirloomcarbon.com
Trackers: CDR.fyi - Carbon removal database Drax Carbon Pulse - Industry news
Research: Carbon180 - Policy and research Breakthrough Energy - Investment focus
DISCUSSION
Is DAC a necessary tool or expensive distraction? Should we invest more in nature-based solutions? What carbon removal approaches are most promising? How do we ensure DAC doesn't delay emissions cuts?
HOW IT WORKS
Solid sorbent DAC: Air passes through filters containing chemicals that bind CO2 Filters heated to release concentrated CO2 CO2 compressed and stored or used Filters regenerated and reused
Liquid solvent DAC: Air contacts liquid chemical solution CO2 absorbed into solution Solution heated to release pure CO2 Solution recycled
MAJOR PLAYERS
Climeworks (Switzerland): World's largest DAC plant: Orca in Iceland Captures 4,000 tons CO2/year Cost: ~$600-800/ton currently Partnered with Microsoft, Stripe, Shopify
Carbon Engineering (Canada): Backed by Bill Gates, Chevron, Occidental Pilot plant in British Columbia Building commercial plant in Texas (1M tons/year) Cost target: $100-150/ton at scale
Heirloom Carbon: Limestone-based approach Faster cycle time than competitors Raised $50M+ from Breakthrough Energy
Global Thermostat: Uses waste heat for regeneration Lower energy requirements claimed Partnerships with ExxonMobil
THE NUMBERS
Current capacity: <0.01 million tons CO2/year globally Needed by 2050: 5-10 billion tons/year (IPCC scenarios) Gap: We need to scale 500,000x in 25 years
Current costs: $400-$1,000 per ton Target costs: $100-$200 per ton needed for viability Path to scale: Manufacturing learning curves, energy cost reductions, policy support
ENERGY REQUIREMENTS
Capturing 1 ton CO2 requires roughly: Solid sorbent: 1.5-2.5 MWh electricity + heat Liquid solvent: 2-3 MWh electricity + heat
Critical: Energy must be carbon-free (renewable/nuclear) or defeats purpose
STORAGE OPTIONS
Geological storage: Inject CO2 underground into porous rock formations Same technology as oil/gas storage Permanent if site selected properly Capacity: Trillions of tons globally
Mineralization: React CO2 with minerals to form solid carbonates Permanent storage, no leakage risk Slower process, more expensive
Utilization: Convert to fuels (synthetic jet fuel, diesel) Building materials (concrete, aggregates) Chemicals and plastics Beverages (carbonation)
Note: Utilization often releases CO2 later (except building materials), so mainly delays rather than removes.
ADVANTAGES
Can address legacy emissions (not just future) Works anywhere (don't need point sources) Land use minimal vs. forests Permanent storage possible Scalable with manufacturing
CHALLENGES
Cost: Still too expensive at scale Energy: Requires massive renewable energy Materials: Sorbent production and replacement Location: Transport CO2 to storage sites Scale: Need gigaton-level deployment
COMPARISON TO ALTERNATIVES
Afforestation/reforestation: Cost: $10-$50/ton Challenges: Land use, permanence, saturation Capacity: ~10 billion tons over decades
Soil carbon: Cost: $20-$100/ton Challenges: Verification, permanence Capacity: ~5 billion tons potential
Biochar: Cost: $30-$120/ton Challenges: Scaling biomass supply Capacity: ~2 billion tons/year potential
Ocean alkalinity: Cost: $50-$150/ton (estimated) Challenges: Environmental impacts unknown Capacity: Very large (gigatons)
POLICY SUPPORT
US 45Q tax credit: $180/ton for DAC with permanent storage $130/ton for DAC with utilization Significantly improves economics
EU Innovation Fund: €10 billion for clean tech including DAC
Voluntary carbon markets: Companies paying $100-$300/ton for DAC credits Stripe, Shopify, Microsoft leading buyers
REALISTIC OUTLOOK
DAC will likely be needed but isn't a silver bullet
Necessary because: Can't eliminate all emissions, need to remove legacy CO2, insurance against climate tipping points
Not sufficient because: Too expensive to replace emissions reductions, massive energy requirements, decades to scale, other nature-based solutions cheaper
Best role: Part of portfolio including emissions cuts, nature-based removal, other CDR technologies
INVESTMENT TRENDS
$3+ billion invested in DAC companies (2020-2025) Venture capital interested but waiting for policy clarity Corporate advance purchases driving development Expect costs to drop 50-70% over next decade with scale
BREAKTHROUGHS NEEDED
Lower-energy sorbents Waste heat utilization Modular designs for mass production Integration with renewable energy CO2 pipeline infrastructure
RESOURCES
Reports: IEA Direct Air Capture Report: iea.org/dac NASEM Carbon Removal Report: nap.edu/carbonremoval
Companies: Climeworks: climeworks.com Carbon Engineering: carbonengineering.com Heirloom Carbon: heirloomcarbon.com
Trackers: CDR.fyi - Carbon removal database Drax Carbon Pulse - Industry news
Research: Carbon180 - Policy and research Breakthrough Energy - Investment focus
DISCUSSION
Is DAC a necessary tool or expensive distraction? Should we invest more in nature-based solutions? What carbon removal approaches are most promising? How do we ensure DAC doesn't delay emissions cuts?