For much of the past decade, the direct air capture (DAC) industry has focused on scaling facilities, improving process efficiency, and reducing energy consumption. As the sector moves toward commercialization, attention is increasingly shifting to another critical component: the materials responsible for capturing carbon dioxide.
A new study from ETH Zurich suggests that some of the answers may come from an unlikely source: food processing waste.
Researchers have developed a carbon capture material derived from protein-rich byproducts generated during dairy and tofu production. While still at the laboratory stage, the work highlights a broader trend emerging across the carbon removal sector. The race to improve direct air capture economics may depend as much on material innovation as on infrastructure scale.
Why Sorbents Matter More Than Ever
Direct air capture faces a fundamental challenge. Carbon dioxide represents only a small fraction of the atmosphere, requiring large volumes of air to be processed to remove meaningful quantities of CO₂.
As a result, capture materials, known as sorbents, play a critical role in determining both performance and cost.
Many existing DAC systems rely on synthetic materials that can be expensive to manufacture, energy-intensive to regenerate, or susceptible to degradation over time. Improving sorbent performance has become one of the industry’s most active areas of research because even incremental gains can significantly influence the overall cost of carbon removal.
For project developers, investors, and industrial emitters evaluating carbon removal strategies, this is becoming an increasingly important consideration.
Turning Industrial Waste Into Carbon Capture Materials
The ETH Zurich team extracted proteins from whey, a byproduct of cheese manufacturing, and residual liquid generated during tofu production. These proteins were transformed into microscopic amyloid structures and combined with potassium hydroxide before being formed into porous capture beads.
The resulting material acts as a carbon dioxide sponge, absorbing CO₂ directly from ambient air.
According to the researchers, the material captured approximately 97 milligrams of CO₂ per gram under testing conditions and demonstrated performance improvements compared with several conventional direct air capture materials.
Equally important, the material maintained functionality through repeated capture and regeneration cycles, addressing one of the most persistent challenges in sorbent development.
The Cost Question Facing Direct Air Capture While capture performance is important, the larger industry question is cost.
Today, one of the biggest contributors to DAC operating expenses is the energy required to regenerate sorbent materials after they become saturated with carbon dioxide.
The ETH Zurich process uses relatively mild chemical regeneration at room temperature through alternating acidic and alkaline treatments. If such approaches can be scaled successfully, they could reduce energy requirements compared with more intensive regeneration methods used elsewhere in the industry.
That possibility is attracting growing attention as developers search for technologies capable of lowering the total cost of carbon removal.
Materials Are Emerging as a Key Cost Lever
The direct air capture industry is increasingly recognizing that future breakthroughs may come from chemistry and materials science as much as from engineering scale.
While large DAC facilities often dominate headlines, commercial success will ultimately depend on a combination of factors including sorbent durability, regeneration efficiency, manufacturing costs, and supply chain availability.
Waste-derived materials offer an additional advantage. They create an opportunity to leverage existing industrial byproducts rather than relying entirely on newly manufactured inputs.
For companies pursuing circular economy initiatives, this approach aligns environmental performance with resource efficiency, an increasingly important consideration for investors and corporate sustainability leaders.
From Laboratory Success to Commercial Reality
The technology remains in the research phase, and significant questions remain regarding manufacturing costs, large-scale deployment, operational performance, and long-term economics.
As with many carbon removal innovations, technical feasibility does not automatically translate into commercial success.
However, the study highlights an important shift within the carbon removal industry. The next generation of direct air capture technologies may depend as much on advances in sorbent materials as on larger facilities and infrastructure investments. Improvements in durability, regeneration efficiency, and manufacturing costs could play a significant role in determining the long-term economics of carbon removal.
Key Takeaway
The future competitiveness of direct air capture may depend as much on advances in sorbent materials as on facility scale. ETH Zurich’s waste-derived capture material is an early example of how materials innovation could help address one of DAC’s biggest challenges: cost.
