BMBF Junior Research Group FAIR-H₂

Hydrogen received increasing attention as a sustainable energy vector in the renewable future energy system [1]. Thermochemical processes are currently used to generate hydrogen from biological residues. Nevertheless, these processes typically demand harsh conditions and frequently complex purification of the produced hydrogen is necessary [2].

The BMBF junior research group project FAIR-H2 will develop an alternative process for hydrogen production from biomass, characterized by mild reaction conditions and high biomass utilization level. In this project, funded by the Federal Ministry of Education and Research (BMBF) for six years, formic acid is produced by the OxFa-process from biomass waste and converted to hydrogen and syngas.

The research project focus on two reaction pathways for the generation of pure hydrogen from biomass-derived aqueous formic acid. The one-step pathway involves dehydrogenation of aqueous formic acid to produce hydrogen and carbon dioxide. In the two-step reaction route, the formic acid is first dehydrated, followed by the conversion of the released water and carbon monoxide to carbon dioxide and hydrogen via water-gas-shift-reaction. The main object of both variants is the development of heterogeneous catalyst systems that maintain stable activity during continuous processes. Intelligent process design is used to enhance productivity and precisely adjust the composition of the product gas stream, which consists of CO2, CO, and H2.

High gas purity is crucial for utilizing biogenic hydrogen in energy applications, such as PEM fuel cells. As part of this project, a novel decentralized purification method characterized by mild reaction conditions is being developed. The cyclic purification method is based on separating hydrogen from a mixed gas stream by selectively binding hydrogen to a hydrogen purification liquid (HPL), followed by the reversible dehydrogenation of the liquid carrier compound to release pure hydrogen.

A top priority is the techno-economic and ecological efficiency of the new process method for biogenic hydrogen production. As a consequence, the individual process steps and the overall concept are being evaluated with economic and sustainability considerations. Another part of the project involves constructing a technical demonstration plant for testing hydrogen production from biomass waste under real conditions.

[1]           P. Preuster, A. Alekseev, und P. Wasserscheid, „Hydrogen Storage Technologies for Future Energy Systems“, Annu. Rev. Chem. Biomol. Eng., Bd. 8, Nr. 1, S. 445–471, Juni 2017, doi: 10.1146/annurev-chembioeng-060816-101334.

[2]           F. Kroll, M. Schörner, M. Schmidt, F. T. U. Kohler, J. Albert, und P. Schühle, „Hydrogen production from wet biomass via a formic acid route under mild conditions“, International Journal of Hydrogen Energy, Bd. 62, S. 959–968, Apr. 2024, doi: 10.1016/j.ijhydene.2024.03.163.