Valorization of Demolition Waste and Biomass Byproduct into Sustainable Building Materials via Carbon Mineralization and 3D Printing

Reducing atmospheric CO 2 is crucial for mitigating climate change and ensuring a sustainable future. The building sector is a major contributor, consuming 40% of global raw materials and accounting for 35% of global energy consumption. As a result, there is a growing demand for more sustainable building materials. Herein, a scalable, energy‐efficient, and low‐emission approach is presented to convert various waste streams into building materials via carbon mineralization and 3D printing. Calcium ions are extracted from recycled concrete using ammonium salt leaching methods and then reacted with CO 2 gas to form high‐purity calcium carbonate through mineralization. This calcium carbonate is formulated into a bio‐based mineral binder by incorporating kraft lignin as a rheological modifier. The binder is further combined with sawdust to produce printable inks for additive manufacturing. The resulting 3D‐printed structures demonstrate robust mechanical properties and modular design potential, making them suitable for non‐load‐bearing building applications. By integrating CO 2 sequestration and renewable materials, this work demonstrates a closed‐loop strategy for carbon capture, waste valorization, and digital fabrication, providing a new avenue for decarbonizing the built environment.