DeepGreen: Additive Manufacturing of Carbon-Negative Algae Biocomposites

Abstract

As populations rise, the global building stock is predicted to double in floor area in the next 40 years. As a result, the embodied carbon footprint of the construction industry, which the UN has estimated to be 11% of global emissions, becomes a critical impasse in attempts to confront the climate crisis. This dissertation attempts to develop a new material system to address the issue of embodied carbon in construction from both a top-down ecosystem and a bottom-up material perspective. A circular approach to the cultivation of carbon-sequestering microalgal biomass is proposed, and the research develops the technological capacities to 3D print the micron-sized biomass into structural objects. After optimization, the final algae-based material features similar mechanical properties to engineered wood products. The proposed systems exhibit a negative upfront carbon footprint, as the carbon dioxide absorbed by the algae through photosynthesis outweighs the cultivation and manufacturing emissions. Furthermore, analysis shows an immense capacity to grow this biomass as a part of nutrient recovery systems. The dissertation points towards a possible future in which architecture itself is used as a carbon sequestration device, storing tons of atmospheric carbon for the lifetime of the material.