CO2-based production technologies unveil the possibility of sustainable production in the chemical industry. However, so-called carbon capture and utilization (CCU) options do not inevitably lead to improved environmental performance, which is especially uncertain for emerging technologies compared to present production practices. Thus, far, emerging CCU technologies have been environmentally assessed with conventional life cycle assessment (LCA). Therefore, this study aims to develop a methodology for applying prospective LCA to emerging production technologies from the laboratory to industrial scale. The developed four-step approach for implementing prospective LCA is applied to the case of electrochemical formic acid (FA) production via supercritical CO2 (scCO2) under consideration of different reactor designs to guide process engineers from an environmental standpoint. While using prospective LCA, the underlying modeling approach relies on consequential LCA (cLCA). Fourteen out of the 15 analyzed impact categories (IC) reveal lower environmental impacts for the scale-ups, which are based on the best-case assumptions and on a flow-through regime compared to the conventional FA production. Nevertheless, the impacts of the scale-ups that are based on a batch reactor (BR) and a three compartment cell (TCC) are higher than for the best case and the flow-through reactor scale-up.