Direct synthesis of formic acid as hydrogen carrier from CO2 for cleaner power generation through direct formic acid fuel cell

Abstract The objective of this work is to develop a process flow modeling for the synthesis of formic acid from CO2 and H2 for energy storage and transport purposes. The use of formic acid as an energy storage medium is promising due to difficulties in hydrogen storage, where formic acid can be stored for a longer time with less losses, and then can be utilized in a direct formic acid fuel cell for cleaner power generation. The process flow is developed using Aspen Plus and Engineering Equation Solver to obtain the energy and mass balances, efficiencies, fuel utilization, and Nernst voltage of the direct formic acid fuel cell. The model is validated against data available in the literature for operating parameters. The results show that the operation parameters such as formic acid formation rate, heat duty, and work values, fuel cell efficiency have a significant influence on the overall performance. The proposed system forms formic acid from gaseous H2 and CO2 with an energy efficiency of about 19%. The formed formic acid is initially stored in a tank for energy storage and then used in a direct formic acid fuel cell to produce about 168 kW power with an energy efficiency of 16% at 0.7 V, 25 °C and 1 bar.