As part of its climate ambitions, the European Union proposes a target for 2040 of a net reduction in greenhouse gas emissions of 90 % compared to 1990 levels.

1. The EU's strategic framework for sustainable carbon removal (CDR)

This strategic shift recognizes that, in addition to drastic emission reductions, permanent carbon dioxide removal (CDR) is essential to achieving climate neutrality. Direct Air Capture (DAC) coupled with geological storage (DACCS) technology represents a key tool for neutralizing emissions from hard-to-decarbonize sectors. Unlike nature-based solutions that only provide temporary storage, DACCS offers permanent CO2 removal with millennium stability.

It is critical for the integrity of climate policy to distinguish between „durable“ and „non-durable“ CDR. While methods such as afforestation store carbon for only tens to hundreds of years and face risks of re-release, only durable methods with storage stable for millennia are permissible for offsetting fossil fuel emissions. According to the current Industrial Carbon Management Strategy (ICM) estimates that more than 250 Mt CO2 per year will need to be captured and processed in the EU by 2040. Of this, around 75 Mt CO2 must be permanent removals through BECCS and DACCS, while the rest is for capture for industrial use (CCU) and fossil CCS. The Net Zero Emissions Industry Act (NZIA) already sets a target of 50 Mt CO2 per year of storage capacity by 2030, which provides the necessary infrastructure base for the technical implementation of DAC.

2. Technological differentiation: S-DAC versus L-DAC

The technical essence of capturing CO2 from the atmosphere lies in the contact of ambient air with a chemical medium that selectively binds CO2 molecules. The choice of medium – solid sorbent or liquid solvent – fundamentally determines not only the architecture of the devices, but also their energy profile and operational flexibility.

Detailed comparison of dominant technological approaches:

• S-DAC (Solid-DAC):
  • It uses solid chemical sorbents based on amines.
  • Modularity: The devices are highly modular, which allows for mass production and faster technological learning.
  • Temperature requirements: The sorbent regeneration takes place at low temperatures (80 – 120 °C), which opens up the possibility of integration with industrial waste heat, geothermal energy or low-potential solar heat.
• L-DAC (Liquid-DAC):
  • It uses liquid solutions (e.g. potassium hydroxide).
  • Scalability and economies of scale: The technology benefits from massive centralized operations where classical chemical engineering principles and economies of scale are applied.
  • Established processes: It uses widely available industrial materials, but requires extreme regeneration temperatures in the calciner (approximately 900 °C), which significantly limits the choice of energy sources.

Table: Advantages and disadvantages of S-DAC vs. L-DAC

Property	S-DAC (Solid-DAC)	L-DAC (Liquid-DAC)
Scalability	High through modularity (series production)	High through the size of the operation (economies of scale)
Regeneration temperature	Low (80 – 120 °C)	High (approximately 900 °C)
Speed of innovation	Faster thanks to modular design	Slower (high capital intensity of units)
Materials	Specialized solid sorbents	Common industrial chemicals
Key advantage	Integration with waste heat	Proven industrial processes and stability

The technical parameters of these methods directly determine the cost structure, with different energy requirements being the main dividing element between the CAPEX and OPEX profiles of both routes.

3. Techno-economic analysis: CAPEX, OPEX and cost effectiveness

Current cost estimates for DAC technologies show a high degree of uncertainty, typical of the transition from first demonstration projects (FOAK) to serial implementation (NOAK). Cost reduction will depend on the "learning-by-doing" effect and supply chain optimization.

Comparison of estimated costs (€/t CO2) for DACCS

Technology	FOAK costs (range)	Median FOAK	NOAK costs (projection)	Median NOAC
L-DACCS	€200 – €900	€360 – €640	€100 – €600	€210 – €330
S-DACCS	€600 – €2400	1230 – 1480 €	€100 – €1200	~360 €

Note: Data includes both capture and geological storage (CS).

Analysis of OPEX components reveals fundamental differences in the cost structure. When S-DACCS the dominant factor is the cost of regular sorbent replacement, which degrades during the cycling process, plus the electricity consumption for the fans. In the case of L-DACCS is dominated by fuel/high-temperature energy costs and fixed OPEX associated with the maintenance of large industrial aggregates and rotating machinery.

Achieving the target of removing 40 Mt CO2 per year in the EU by 2040 will require capital mobilisation in the estimated range EUR 12-24 billion. This estimate is highly sensitive to the rate of technological progress and the availability of cheap carbon-free energy.

4. Energy intensity and environmental risks

The energy profile of a DAC is a critical determinant of its environmental integrity. If the process were to use energy with a high emission intensity, the benefits of capture would be negated.

Energy requirements:

• Thermal energy: S-DAC (80 – 120 °C) vs L-DAC (~900 °C). The high temperature of L-DAC requires either gas combustion with subsequent emission capture or advanced electric heaters.
• Electricity: Both methods show significant consumption for driving fans pumping huge volumes of air with low CO2 concentration (~420 ppmv).

Environmental risks and site requirements: DAC requires less land than bioenergy solutions, but carries different risks:

1. Water consumption: A critical factor especially for L-DAC, where evaporation occurs in cooling systems.
2. Chemical substances: Risk of sorbent leakage or emissions from solvent decomposition.
3. Location: The ideal location must combine access to an abundance of cheap renewable energy, proximity to a geological repository (minimizing transport), and the availability of a skilled workforce.

5. Technology Readiness Level (TRL) and market reality

Although DAC technologies are presented as ready, their true industrial maturity is still in the demonstration stage. According to the in-depth assessment (Table 9), both dominant pathways – S-DAC (adsorption) and L-DAC (absorption) – are at TRL 6. Current efforts are aimed at achieving TRL 7-8 in the near future through larger projects.

Key players and projects:

1. Climeworks (Switzerland): Pioneering S-DAC with operations in Iceland, using geothermal energy.
2. Carbon Engineering (Canada): The main representative of L-DAC technology with an orientation towards large-capacity solutions.
3. Removr (Norway): It focuses on integrating S-DAC with the Norwegian energy grid and storage in the North Sea.

However, market reality in 2023 lags behind needs: less than 100,000 were removed by permanent methods. 1.3 million tons of CO2. The market is highly concentrated, with the Microsoft accounts for more than two-thirds of total global demand after a resilient CDR. Current capacity is well below the level needed for 2040, requiring immediate policy acceleration.

6. Integrity and Risks: Preventing Double Counting and Greenwashing

The credibility of carbon removals depends on transparency. Without strict mechanisms, there is a risk of „double counting,“ where the same ton of CO2 removed is claimed by a corporation for its ESG goals and by a state for its nationally determined commitments (NDCs). This directly undermines the integrity of global climate efforts.

Key integrity requirements:

• Independent MRV: The establishment of a robust and transparent monitoring, reporting and verification (MRV) system is a political necessity to prevent greenwashing.
• Individual goals: The recommendation for SBTi and ISO is to require companies to set separate targets for emissions reduction and separate targets for CDR (they must not be combined).
• DAC usage: The technology should be reserved exclusively for residual emissions in sectors where there is no other technical alternative to decarbonisation.

7. Strategic recommendations for investment decision-making

DAC technologies are a strategic imperative for the EU's climate portfolio. Although the costs of FOAK projects are high, DACCS represents the only scalable way to permanently neutralise fossil emissions. Success depends on current investments in R&D, which will reduce future costs through technological learning.

Key recommendations for investors and policymakers:

1. Integration into the EU ETS: Gradual integration of permanent removals into the ETS while maintaining strict limits to protect the priority of emission reductions.
2. Infrastructure priority: Massive support for CO2 transport networks and the development of geological storage sites in line with the NZIA objectives (250 Mt total need by 2040).
3. Acceleration of permitting: Using NZIA mechanisms to shorten administrative deadlines so that start-ups are not hampered by disproportionate bureaucracy.
4. Financial benchmarking: The EU Innovation Fund must introduce schemes comparable to American DAC Hubs model, which provides up to 50 % CAPEX support for strategic projects.
5. Differentiated financing: Creating specific calls for DACCS/BECCS within Horizon Europe, instead of linking them to broad categories of low-carbon technologies.
6. Market transparency: Implementation of the CRCF (Carbon Removals and Carbon Farming) framework for clear certification of removals and elimination of double counting.

Investments in DAC today do not just represent the purchase of technology, but a strategic investment in building the future global carbon management infrastructure that will be a critical pillar of the global economy after 2040. JRi&CO2AI