Carbon Capture, Utilization and Storage (CCUS): Policy Frameworks, 45Q Economics, and Industrial Deployment

CCUS in the Global Decarbonization Portfolio

CCUS encompasses three distinct technological pathways: point-source CCS (capturing CO₂ at industrial emission stacks), Direct Air Capture (DAC, removing CO₂ from ambient air), and Carbon Capture and Utilization (CCU, converting captured CO₂ into chemicals, fuels, or construction materials). IPCC AR6 Working Group III identifies carbon capture technologies as essential for limiting warming to 1.5°C, particularly for hard-to-abate sectors where more than 320 Gt CO₂ of cumulative CCUS deployment is required under Net-Zero Emissions scenarios through 2100 — representing 7–14% of total mitigation effort.

Global CCUS operational capacity reached 49 Mt CO₂/year in 2023 across 41 large-scale facilities (IEA, 2024), with 680 Mt CO₂/year of additional capacity in development pipelines — 75% in the United States following IRA incentive expansion. The investment case has fundamentally shifted: 45Q credit enhancement under IRA provides $85/tonne CO₂ for geological storage and $60/tonne for EOR (Enhanced Oil Recovery) utilization, representing a 70% increase from pre-IRA levels and making point-source CCS economically viable for high-concentration industrial sources above 50,000 tonne CO₂/year capture threshold.

45Q Tax Credit: Structure, Eligibility, and Compliance Architecture

Section 45Q of the Internal Revenue Code, as modified by IRA Section 13104, provides tax credits of $85/tonne CO₂ for geological sequestration, $60/tonne for EOR or industrial utilization, and — transformatively for DAC — $180/tonne for geological storage and $130/tonne for utilization. These credits are available for 12-year periods from facility placed-in-service dates, and under direct pay provisions introduced by IRA, are refundable for tax-exempt entities including cooperatives, municipalities, and tribal governments.

Eligibility requirements include: minimum capture thresholds (18,750 tCO₂/year for industrial sources; 1,000 tCO₂/year for DAC; 500 tCO₂/year for direct air capture with electric generation); EPA Subpart RR Monitoring, Reporting and Verification (MRV) plan approval for geological storage; prevailing wage and apprenticeship requirements for credits above $17/tonne (80% bonus for compliance); and Begin Construction rules comparable to Production Tax Credit safe harbors (physical work of significant nature OR 5% capital expenditure commitment).

Point-Source CCS: Industrial Sector Economics

Cement: Cement clinker production emits approximately 0.85 tonne CO₂/tonne clinker (55% from limestone calcination — a process emission not eliminable by fuel switching). Post-combustion capture using amine scrubbing adds $50–$110/tonne CO₂ to production costs; under 45Q at $85/tonne, cost recovery is possible for large integrated plants above 1 Mt production. Heidelberg Materials’ Brevik project (Norway) and LafargeHolcim’s Richmond plant CCS feasibility study represent frontrunner commercial applications.

Steel: Blast furnace gas contains 20–25% CO₂ by volume, enabling technically mature post-combustion capture at $40–$70/tonne CO₂ for integrated steel facilities. The ArcelorMittal Belgium flagship CCS installation captures 0.5 Mt CO₂/year from blast furnace gas, demonstrating viability at industrial scale. Integration with underground CO₂ storage in North Sea saline aquifer formations (Sleipner model) provides long-term geological sink with site-specific monitoring obligations under EU CCS Directive (2009/31/EC, as amended).

Natural Gas Power Generation: Post-combustion capture on NGCC (Natural Gas Combined Cycle) plants adds 15–25% capital cost premium and reduces plant efficiency by 6–10 percentage points — the “energy penalty.” At current natural gas prices and 45Q incentives, the levelized cost of electricity with CCS reaches $80–$120/MWh versus $55–$75/MWh for NGCC without capture, limiting economic deployment to regions with high carbon pricing or regulated utility cost recovery.

Direct Air Capture: Technology and Scaling Economics

DAC operates at approximately 420 ppm CO₂ concentration (versus 15–25% at point sources), requiring 100–300x more air throughput per tonne captured. Two mature technology routes exist: liquid solvent systems (KOH-based, used by Carbon Engineering/Oxy’s STRATOS plant — 500,000 tCO₂/year capacity, opening 2025) and solid sorbent systems (amine-functionalized materials, used by Climeworks’ Mammoth plant in Iceland — 36,000 tCO₂/year). Current DAC costs range $300–$600/tonne CO₂ for mature liquid systems, with NREL and DOE projecting learning curves to $100–$150/tonne by 2035 under the Carbon Negative Shot initiative ($1B DOE DAC hubs funding).

Voluntary carbon market integration: DAC credits are selling at $250–$600/tonne CO₂ for permanent (>1,000 year) geological storage in voluntary markets (Microsoft, Stripe, Shopify Climate Portfolio purchases). Under ICVCM Core Carbon Principles (CCPs), DAC credits qualify for “carbon removal” designation, distinct from “avoided emissions” — a distinction increasingly material for corporate net-zero claim integrity under SBTi NZS v1.1 and the Voluntary Carbon Markets Integrity Initiative (VCMI) claims code.