Life cycle assessment of formic acid synthesis utilizing CO2 from direct air capture†

Abstract

This study presents a comprehensive cradle-to-gate life cycle assessment (LCA) of formic acid (FA) synthesis from direct air captured (DAC) carbon dioxide (CO₂) utilizing chemical plant waste heat. The research focuses on a project to implement a low-temperature solid sorbent DAC system co-located with a FA production facility at a fertilizer plant, utilizing industrial waste heat from nitric acid production. This study employs projected operational data from two companies which own the DAC and FA conversion technologies to examine the environmental impacts and benefits of this DAC-to-FA conversion process. By leveraging waste heat and renewable energy, the proposed project demonstrates the environmental advantages of advanced carbon utilization technologies, providing valuable insights for future policy and industrial applications in sustainable chemical manufacturing. Key results indicate that the capture and conversion process, when powered by renewable energy, achieves a net negative global warming potential of −0.806 kg CO₂ eq. per kg FA produced, contrasted against traditional FA production methods which are calculated to emit at best +2.03 kg CO₂ eq. The use of waste heat significantly reduces the energy consumption of the process. Compared to traditional FA production methods, the processes also show substantial reductions in ozone depletion, fossil fuel depletion, and other environmental impacts. The novelty of this study lies in its analysis of DAC technology using projected and actual operational data from a DAC development company, which is unique in academic studies. This enhances the accuracy of the LCA and provides a robust foundation for understanding the environmental impacts and benefits of the proposed system. This study also aims to be the first LCA to analyze the life cycle impacts of DAC-to-FA conversion technology.