Sustainability Evaluation of Ambient-Temperature Biocomposite Additive Manufacturing Using Life Cycle Assessment

Additive manufacturing offers rapid and customizable production, yet conventional plastic-based methods remain energy-intensive and environmentally harmful, often resulting in higher impacts per part than traditional manufacturing. The goal of this study was to evaluate whether upcycled biomaterials, specifically oyster shells, pistachio shells, and clay, could be used as lower-impact alternatives to PLA in 3D printing. The scope included detailed measurement of print parameters for each material and a full life cycle assessment (LCA) of the printed elements, covering printer manufacturing, raw material extraction, transport, operation, and end of life. The results show that ambient-temperature extrusion of these upcycled biomaterials can reduce energy consumption by up to 89% and overall environmental impact by up to 94% (as measured by ReCiPe Endpoint H points) compared to PLA printing. These reductions were observed for the Netherlands and EU contexts, where electricity mixes are relatively clean and recycling rates are high; even greater improvements were observed for the US. Although the printed biomaterial objects exhibit lower mechanical strength, limited waterproofness, and reduced print resolution, they are already suitable for low-load applications such as prototypes and architectural models. Overall, the findings demonstrate that upcycled biomaterial extrusion has strong sustainability potential, outperforming both conventional plastics and bioplastics such as PLA in terms of material impacts and energy use. Continued development of material formulations as well as pre- and post-processing techniques could further expand functionality and support the broader adoption of low-impact 3D printing across a wide range of applications.