A Reversible Liquid Hydrogen Carrier System Based on Ammonium Formate and Captured CO2

Recipient Washington State University (PI: Hongfei Lin)

Abstract Hydrogen economy has the potential to be a 2,500 Billion US$ business by 2050. Renewable hydrogen can fully decarbonize power sector, transportation, and industrial heat. However, based on the current state of technology, transportation and storage of hydrogen is a key component that is impeding the wide spread development of a hydrogen economy. Herein, the goal of this project is to demonstrate a commercially promising reversible liquid hydrogen carrier system based on ammonium formate and captured CO2. This technology enables hydrogen to be stored in chemical form of ammonium formate in aqueous solutions through the catalytic hydrogenation of ammonia captured CO2 over the palladium (Pd) on carbon catalyst at near room temperature. The release of H2 from the catalytic dehydrogenation of ammonium formate solutions can be carried out over the same carbon supported Pd catalyst under mild conditions. The resulting ammonium formate based hydrogen carrier system has a long life-time and a high volumetric energy density, and is highly flexible, low cost, and exceptionally compatible with the existing CO2 capture infrastructure. Besides, this system was made of liquid organic compounds that are abundant, cheap, easily handled, and not hazardous. The liquid hydrogen carrier system proposed here has a tremendous potential to introduce a cost-effective approach to address the bottleneck of advancing hydrogen economy. Within the 3-year period, the project objective is to build a prototype ammonium formate-based hydrogen uptake and release system and evaluate its techno-economic potential for commercialization.

This project will include:

• 1) develop the second-generation Pd on nitrogen-doped carbon catalyst with improved stability
• 2) optimize both the CO2-to-formate and the formate-to-power processes to maximize the hydrogen uptake and release rates
• 3) conduct techno-economic analysis and life-cycle assessment of the ammonium formate based hydrogen storage system and its integration with natural gas power plant and PEM fuel cell.

A truly commercially viable ammonium formate based hydrogen storage system will provide a cost-competitive and carbon-neutral solution for large-scale H2 storage and transport, which will fulfill the EERE's H2@scale initiative targets.