2018 - Sustainable Industrial Processing Summit & Exhibition
4-7 November 2018, Rio Othon Palace, Rio De Janeiro, Brazil
| Recyclability of Heterogeneous Palladium Catalysts for the Dehydrogenation of Aqueous Formic Acid Axel Kosider1; Patrick Preuster2; Andreas Boesmann1; Peter Wasserscheid1; 1FRIEDRICH-ALEXANDER-UNIVERSITAT, Erlangen, Germany; 2HELMHOLTZ INSTITUTE ERLANGEN-NüRNBERG FOR RENEWABLE ENERGY, Erlangen, Germany; PAPER: 237/Energy/Regular (Oral) SCHEDULED: 16:45/Tue./Asian (60/3rd) ABSTRACT: Our limited supply of fossil fuels leads to an increasing demand for alternative energy sources. A promising and often considered option is hydrogen, because it is a renewable energy source. However, the storage and transportation of hydrogen is inconvenient, complex, and expensive. In addition to physical storage, hydrogen can be stored chemically so that these challenges are circumvented. One possibility is to use formic acid as a chemical hydrogen carrier, which has a hydrogen content of 4.4 wt.-% [1, 2]. Formic acid can be produced from biomass and it is decomposed to hydrogen and carbon dioxide with high selectivity [3]. Heterogeneous palladium catalysts decompose aqueous formic acid at ambient pressure and temperature, so that hydrogen generated from sustainable formic acid can be used as a renewable energy source [4]. However, during the dehydrogenation of formic acid, a drastic decrease in catalytic activity is observed and active centers of the catalyst become poisoned. For economic reasons, regenerating the deactivated material is crucial. We investigate the decomposition of aqueous formic acid at room temperature, as well as deactivation and reactivation of the catalytic active material with commercial heterogeneous palladium catalysts. In batch-experiments, we determine the gas production rate, the gas composition, and the liquid phase composition in order to determine activity and selectivity of the catalysts. Furthermore, the catalyst is treated at different conditions after each experiment in order to examine the regeneration of the poisoned material. Commercial palladium catalysts have high activity and selectivity for the decomposition of aqueous formic acid to hydrogen and carbon dioxide at room temperature and ambient pressure. Poisoning of the active material leads to a strong decrease in activity so that a regeneration is necessary. Post-treatment of the deactivated palladium shows a regeneration of the catalytic active material and facilitates recycling of the precious metal catalyst. References: [1] S. Enthaler, J. von Langermann, T. Schmidt, Energy Environ. Sci. 3 (2010), 1207-1217. [2] M. Yadav, Q. Xu, Energy Environ. Sci. 5 (2012), 9698-9725. [3] P. Preuster, J.Albert, Energy Technol. 6 (2018), 501-509. [4] M. Jeon, D. Han, K. Lee et al., International Journal of Hydrogen Energy 41 (2016), 15453-15461. |
