High-Efficiency Solar Thermal Electrochemical Synthesis of Carbon Nanotubes from Atmospheric CO2: An Economic and Spatial Feasibility Analysis

The urgent need for massive-scale carbon dioxide () removal necessitates technologies that transcend the spatial and temporal limitations of natural carbon sinks. This paper examines the viability of a Solar Thermal Electrochemical Process (STEP) utilizing molten carbonate electrolysis to capture ambient and point-source and synthesize it into high-value graphene nanocarbons (GNCs). By leveraging Concentrated Solar Power (CSP) to provide both direct thermal heating and photovoltaic electricity, the system effectively neutralizes the energy-intensive thermodynamics of splitting. Crucially, this paper introduces the application of the Infinite Fractal Descent (IFD) framework to the reactor's architecture. By applying IFD principles to both the thermal distribution systems and the cathode surface morphology, the reactor achieves unprecedented thermodynamic stability and geometric scaling of active nucleation sites. A comparative spatial analysis demonstrates that an industrial IFD-optimized STEP-C2CNT facility can achieve up to a 100-fold increase in annual carbon removal per acre compared to standard afforestation, transforming carbon capture from an economic liability into a highly profitable industrial asset.