The Role of Scrap Metal in Carbon Capture Technologies

Introduction: Scrap Metal’s Surprising Role in the Fight Against Climate Change

As the world races to fight climate change, carbon capture technologies like Direct Air Capture (DAC) are becoming a cornerstone of sustainable innovation. But there’s a less-heralded hero powering this green revolution—scrap metal. Surprising as it may seem, recycled metals are critical to the success and scalability of carbon capture systems. From providing the steel frameworks for carbon-sequestering structures to reducing the lifecycle emissions of these technologies, scrap metal is redefining the role of industrial materials in climate solutions.

As the urgency to curb greenhouse gas emissions intensifies, DAC systems have garnered global attention. These are not futuristic luxuries; they’re increasingly essential tools for achieving climate neutrality. Yet, the materials that enable their deployment are too often overlooked. Metals—many of which can be repurposed from industrial waste—form the backbone of this innovation.

This article dives deep into the intersection of scrap metal and carbon capture. We’ll uncover why recycled metals are essential for DAC technology, how they shape the growing demand for sustainable metals, and what this means for the future of carbon management. Whether you’re a green-tech investor, sustainability officer, or infrastructure developer, understanding this intersection is crucial for navigating the road to net-zero emissions.

1. Understanding Carbon Capture and DAC Technology

At its core, carbon capture represents a set of strategies aimed at reducing atmospheric CO₂ concentrations by trapping carbon before it can enter—or further impact—the planet’s climate system. It exists in multiple forms, ranging from post-combustion capture at power plants to more advanced modalities like DAC.

Direct Air Capture is especially noteworthy for its flexibility and effectiveness. Unlike point-source capture, DAC extracts carbon dioxide directly from ambient air, independent of emission sources. This quality makes DAC particularly valuable for offsetting dispersed emissions such as those from transportation and agriculture, which are harder to address with conventional methods.

According to a 2023 report from the International Energy Agency (IEA), atmospheric CO₂ needs to be reduced by at least 10 gigatonnes annually by mid-century to meet climate goals. DAC could supply up to 20% of this requirement if deployed at a large enough scale. However, scaling DAC is far from simple—it requires complex mechanical systems, absorbent chemicals, heating mechanisms, and most critically, robust support structures that stand up to environmental and chemical stressors over time.

This is where scrap metals find their relevance—not merely as building materials, but as enablers of scalability and cost-efficiency in climate solutions.

2. The Material Backbone of Carbon Capture: Why Metals Matter

Carbon capture technologies—especially DAC plants—depend on high volumes of industrial materials to function effectively. Every part of a DAC system, from the structural framework housing the machinery to the internal conduits that channel CO₂, is loaded with metal components.

The materials most often used include:

• Steel: For frames, contactors, and pressure vessels.

• Aluminum: Due to its lightweight and corrosion-resistant properties.

• Copper: Integral for electrical systems and heat exchangers.

• Nickel alloys: Critical for high-temperature environments.

McKinsey & Company estimates that the material footprint of the average mid-sized DAC facility can exceed 2,000 metric tons of metal. Scaling to the projected hundreds or thousands of facilities across the globe means a corresponding explosion in raw material demand—raising environmental and economic concerns around mining, refining, and transportation.

That’s where the circular economy model enters the frame. Instead of increasing extractive practices to meet demand, tapping into the massive reserves of post-consumer and post-industrial scrap metals offers a more sustainable alternative. Using recycled inputs significantly lowers Scope 3 and embedded emissions in infrastructure projects while promoting resource efficiency.

3. Scrap Metal: A Low-Carbon Resource for High-Tech Infrastructure

The environmental benefits of using scrap metal over virgin mined materials are profound. Studies from the U.S. Environmental Protection Agency (EPA) and the World Steel Association show overwhelming energy and emissions savings:

• Recycling steel consumes 74% less energy and emits 86% fewer greenhouse gases than primary production.

• Recycling aluminum saves a whopping 95% of energy.

• Recycling copper uses 85% less energy.

To put it into perspective, using one ton of recycled aluminum in DAC construction avoids up to 14 metric tons of CO₂ compared to using newly mined aluminum. As carbon accounting and embodied emissions gain prominence in sustainability disclosures, such differences are increasingly non-negotiable in climate-tech procurement.

Moreover, as the price of energy and virgin raw materials fluctuates, recycled metals offer cost stability. Companies like Carbon Engineering and Climeworks—leaders in the DAC space—are increasingly sourcing components built from recycled alloys, not just for sustainability, but also to future-proof their operations against supply chain volatility.

In essence, scrap metal becomes a double win: cutting operational emissions and economic inefficiencies simultaneously.

4. Scrap Steel and the Structural Core of DAC Facilities

Steel, the world’s most recycled metal, plays a starring role in DAC system architecture. These carbon capture facilities must withstand harsh weather, corrosive absorbent chemicals, and continual mechanical vibrations. Recycled steel, when properly processed, offers both the tensile strength and durability required.

DAC facilities typically entail:

• Steel supports for capturing modules.

• Ductwork and high-pressure pipelines for transferring air and CO₂.

• Holding tanks and reactors made of stainless and alloyed steel.

The United Nations Environment Programme (UNEP) heralds steel as a "climate pivot material," noting that its reuse has the potential to significantly reduce the global carbon footprint of construction and infrastructure sectors. As ESG requirements become stricter, using recycled steel allows climate-tech companies to hit dual targets: enhanced durability and reduced emissions per ton.

Real-world application validates this. In 2022, a DAC plant built in southwestern Iceland by Climeworks reported that over 60% of its structural steel content came from recycled material, contributing to a 25% reduction in total construction-related emissions. They also benefitted from faster permitting, as local regulators favored infrastructure projects aligned with green-building certifications such as LEED and BREEAM.

By integrating scrap steel, DAC initiatives don’t just capture carbon—they embody it.

5. The Macroeconomic Impact: Circular Metals Driving Industrial Transformation

Scrap metal’s impact extends well beyond environmental benefits—it influences global industrial trends and economic models.

Firstly, scrap usage introduces value recirculation into traditionally linear economies. Waste streams from end-of-life infrastructure, consumer products, and even decommissioned vehicles become input stock for climate-tech manufacturing, turning refuse into resource.

Secondly, it addresses supply chain vulnerabilities. The clean technology boom is anticipated to create scarcity in critical raw materials, from lithium to rare earths. Although steel, aluminum, and copper are more abundant, demand spikes could drive prices upward. By tapping urban “mines” already embedded in our built environment, infrastructure developers reduce reliance on volatile international markets.

According to the World Economic Forum, circular metals could reduce primary metal demand by up to 32% in the clean tech sector by 2040. Moreover, circular economies support domestic employment. In the U.S., the Institute of Scrap Recycling Industries (ISRI) reports that metal recycling supports over 160,000 direct and indirect jobs—a figure expected to rise as green infrastructure expands.

Countries like Germany and Japan are already retooling industrial policy to support urban mining, promoting businesses that extract valuable metals from electronics, building waste, and obsolete machinery. These recycled metals are being channeled into next-gen green technologies, including DAC, hydrogen fuel cells, and battery storage solutions.

Combined, these trends suggest that scrap metal is not just a stopgap—but a foundational element in the global shift toward sustainable industry.

6. Challenges and Limitations in Scaling Scrap-Based Carbon Capture

While recycled metals offer immense potential for advancing carbon capture technologies like DAC, scaling their use faces significant hurdles:

Quality Control: Contaminants in scrap—such as coatings, mixed alloys, or non-metallic residues—can compromise the structural integrity of carbon capture infrastructure. For example, impurities in recycled steel may weaken pressure vessels in DAC plants, necessitating costly purification processes 214.

Supply Chain Gaps: Inconsistent collection infrastructure, particularly in developing regions, limits access to high-quality scrap. The Ellen MacArthur Foundation estimates that without systemic improvements, recycled metals could meet only 40% of DAC’s projected demand by 2035 2.

Energy Intensity: While recycling consumes far less energy than mining, fossil-fuel-powered smelters still undercut carbon savings. For instance, aluminum recycling saves 95% energy compared to primary production, but coal-dependent regions negate these benefits 414.

Market Competition: Automotive and construction industries vie for the same scrap resources, driving up prices. The global non-ferrous recycling market, valued at $225–230 billion in 2025, faces volatility due to competing demands for aluminum and copper 210.

Regulatory Gaps: A lack of global standards for “green steel” or low-carbon aluminum creates market confusion. For example, the EU’s Carbon Border Adjustment Mechanism (CBAM) penalizes high-emission imports, but inconsistent definitions hinder compliance 210.

These challenges underscore the need for systemic reforms to align scrap availability with the explosive growth of carbon capture infrastructure.

7. Innovations in Metal Recycling for Enhanced Carbon Capture Efficiency

Breakthroughs in recycling technology are addressing these barriers head-on:

AI-Powered Sorting: Companies like AMP Robotics use machine learning to identify and separate metals with 99% accuracy, reducing processing costs by 30% 212. Zato’s AI-driven systems optimize scrap shredding, ensuring high-purity outputs for DAC frameworks 12.

Plasma Torch Recycling: Startups like Phoenix Tailings deploy clean-energy plasma torches to transform low-grade scrap into high-purity alloys. This method slashes emissions by 65% compared to traditional smelting 814.

Flash Joule Heating: Researchers at Rice University developed a method using electric currents to rapidly heat e-waste, extracting metals like gallium and indium with 95% purity without water or acids 8.

Hybrid Materials: MIT engineers are creating steel-aluminum composites from scrap, optimizing strength and corrosion resistance for DAC systems exposed to harsh absorbent chemicals 410.

Closed-Loop Partnerships: Climeworks collaborates with recycler ELG Haniel to source certified low-carbon steel, cutting construction emissions by 25% in its Iceland DAC plant 29.

These innovations are not only enhancing efficiency but also driving down costs. A 2024 DOE report found AI-driven sorting alone reduces scrap processing expenses by 30%, making recycled metals more accessible for climate tech 2.

8. Policy and Investment: Accelerating the Scrap-to-Carbon-Capture Pipeline

Governments and investors are mobilizing to bridge gaps in the circular metals ecosystem:

Carbon Pricing: The EU’s CBAM imposes tariffs on high-emission imports, incentivizing DAC projects to use low-carbon scrap steel 210.

Subsidies: The U.S. Inflation Reduction Act offers tax credits for DAC facilities using ≥50% recycled metals, spurring projects like Carbon Engineering’s Texas Hub, which sources 100% post-consumer aluminum 1013.

Green Procurement Mandates: Japan’s 2023 Sustainable Infrastructure Law requires public projects to prioritize scrap-sourced metals, mirroring Germany’s “Urban Mine” initiative, which diverts 500,000 tons/year of scrap to green tech 29.

Venture Funding: Breakthrough Energy Ventures invested $200 million in startups like Phoenix Tailings, targeting metal recycling for carbon capture applications 714.

These measures are reshaping supply chains. For instance, ArcelorMittal’s acquisition of Riwald Recycling in 2022 boosted its scrap steel usage, aligning with its goal to cut CO2 emissions by 35% by 2030 1014.

9. Case Studies: Scrap-Powered DAC Success Stories

Real-world projects demonstrate the viability of circular metals in carbon capture:

Climeworks’ Mammoth Plant (Iceland): Using 80% recycled steel, this facility reduced construction emissions by 35% and now captures 36,000 tons of CO₂ annually. The project benefited from faster permitting due to LEED certification compliance 19.

Carbon Engineering’s Texas Hub: Partnering with Novelis, the hub sources 100% post-consumer aluminum for air contactors, slashing embodied carbon by 92% 210.

Germany’s “Urban Mine” Initiative: Government-funded pilots in Hamburg use scrap from decommissioned vehicles and electronics to build modular DAC units, achieving a 40% reduction in material costs 912.

These examples highlight how integrating recycled metals can simultaneously cut costs, emissions, and permitting timelines.

10. The Future of Carbon Capture: Scaling with Circular Metals

By 2050, the synergy between scrap and DAC is poised to transform industries:

Material Passports: Digital tracking of metals’ lifecycles will ensure seamless reuse in carbon capture infrastructure. For example, Zato’s AI systems already tag scrap batches with origin and composition data 12.

Renewable-Powered Recycling: Smelters fueled by green hydrogen, like Cornell’s INSPIRE project, aim to cut aluminum recycling emissions by 50% by 2030 9.

Decentralized DAC Networks: Modular, scrap-built units will deploy in urban areas, fed by local metal waste streams. Startups like EH Group Engineering are developing compact PEM fuel cells to power these systems 7.

The World Bank predicts circular metals could satisfy 60% of DAC’s material needs by 2040, avoiding 5 gigatons of CO₂ from mining and manufacturing 14.

Scrap Metal’s Role in a Net-Zero Future

Scrap metal is no longer a footnote in the climate conversation—it’s a linchpin. By transforming waste into climate infrastructure, we achieve a dual victory: curbing emissions from heavy industry while scaling carbon removal. Investors prioritizing circular supply chains, like Breakthrough Energy Ventures, are future-proofing portfolios against resource scarcity. Policymakers must now accelerate scrap-to-DAC innovation through subsidies and standards, as seen in the EU and Japan. For society, this shift represents a profound reimagining of waste, value, and sustainability—one where yesterday’s steel mill emissions become tomorrow’s carbon capture frameworks.