Techno-economic and life cycle assessment of power-to-formic acid production using direct air capture and green hydrogen

Abstract

The chemical industry is responsible for a significant portion of global carbon emissions. Defossilising the chemical industry is crucial for achieving climate change targets. Carbon capture and utilisation (CCU) has emerged as a promising alternative for chemicals production. Formic acid is increasingly important in the global economy as a versatile chemical used in agriculture, food preservation, and as a potential hydrogen storage.

To this direction, this study assesses the environmental and the economic performance of producing formic acid (FA) through a Power-to-Formic Acid (PtFA) process, focusing on the utilisation of green hydrogen and carbon dioxide captured from direct air capture (DAC). A cradle-to-gate life cycle assessment (LCA) was conducted, focusing on the climate change, fossil depletion and water consumption, using the ReCiPe Midpoint (H) while the minimum selling price (MSP) has been used as the main economic indicator.

The economic assessment identified the DAC and the electrolyser as the major contributors to Capital expenditures (CAPEX), while catalyst and electricity cost are the main Operating expenditures (OPEX) contributors. The resulted MSP of the PtFA is more than two times higher than the price of the conventional FA, at £1290 per tonne vs £560 per tonne, respectively. Additionally, the LCA revealed that the PtFA process reduces by 92% the CO₂eq. emissions compared to the conventional production process (190.72 vs. 2190 kg CO₂eq./tonne FA), uses 94% less water, and consumes 92% fewer fossil resources. The primary drivers of carbon emissions are the chemicals consumed in FA synthesis, and electricity generation.

This study provided new and important information regarding a sustainable chemical industry and it is the first attempt to holistically assess from a technical, economic and environmental perspective a PtFA process that contributes to the defossilisation efforts of the chemicals sector.