Indicative GHG balance for formic acid as a hydrogen carrier in transport

Formic acid (CH2O2) is an elementary chemical that can serve as a ‘hydrogen carrier’ for fuel cell powered drive trains. Formic acid can be produced in a conventional chemical process, or in a novel electrochemical CCU (carbon capture and utilisation) process. In order to assess the sustainability merits of the application of formic acid in transport, this brief report contains an indicative greenhouse gas (GHG) footprint analysis, focusing on the GHG emissions of the production and application life cycles. The sustainability merits depend on the applied production routes, CO2 sources and energy sources.

In this short report, indicative greenhouse gas balances of the following production routes are compared:

  • Conventional chemical formic acid production route (from carbon monoxide and water).
  • Electrochemical formic acid production route (from electricity, water and CO2), in two variants that reflect (more or less) the extremes with respect to the applied power source and source of CO2: using largely fossil fuel based electricity (current Dutch power grid mix); and fossil CO2, versus using renewable electricity and a biogenic CO2 source.

In all cases, the comparison is made for application of the formic acid as a transport fuel in public transport buses, where also a comparison with diesel is made.

This study is a preliminary analysis of the power to formic acid life cycle, a more elaborate study is undergoing. The established results are indicative due to the current limited availability of data. In the ongoing study, more application areas are studied (including application in ships, stationary applications), more sensitivities are assessed, the impacts on (decentralized) renewable power systems are detailed, and we will put the technology in perspective of alternative sustainability options. The study is part of the ‘Power 2 Formic Acid’ project conducted under the VoltaChem program, in which CE Delft participates. The P2FA aims to develop the process innovations to bring the electrochemical reactor closer to the market. Other participants in the project are TNO, TU Delft, Coval Energy, Team Fast and Mestverwerking Friesland. The project is supported financially by RVO.