Bioinspired Lignin-Aluminosilicate Composite for CO₂ Storage

In the effort to decarbonize hard-to-abate industries, the issue of CO₂ emissions from the cement production process must be addressed, primarily due to the calcination reaction and high-temperature requirements. To achieve a sustainable process to produce carbon-neutral construction materials, utilizing nature-abundant resources without relying on calcium oxide chemistry or sintering could be a promising approach. Here, a new method is presented to prepare construction material by strengthening highly abundant kaolinite clay with Kraft lignin at 100 °C. Due to the electrostatic interactions between Kraft lignin and kaolinite particles, the resulting lignin-aluminosilicate composite displayed compressive strengths of up to 20 MPa. Additionally, the simultaneous use of kaolinite and smectite enabled the fabrication of a strong composite, which could store up to 10 g of CO₂ per 1 kg under high-pressure CO₂ treatment at room temperature. Furthermore, the scalability of the proposed method to real-sized bricks and artworks was demonstrated, thereby opening new pathways toward a carbon-negative construction industry.