Catalytic reaction can be intensified by microstructured reactors. At the same time, highly active catalytic materials should be integrated with micro structured reactors to strengthen the catalytic performance. Compact GtL and BtL systems require a maximum in optimization of the catalyst.

The project is divided into two subjects:

1. Novel bifunctional core-shell and double-layer catalysts for direct DME-synthesis in microreactors

   In this project, bifunctional core-shell catalyst will be integrated in microstructured reactors for direct DME synthesis - a combination of two reactions, methanol synthesis and methanol dehydration. For the application of BtL or GtL the direct di-methyl-ether (DME) synthesis is a special system as it requires a bifunctional catalyst. The two different catalysts for each reaction have to be well combined to one core-shell catalyst. The concept is: synthesis gas diffuses into the core and is converted to methanol. While methanol diffuses out through the shell it gets converted to DME.

   The development of the catalyst core is done in this project by flame-spray pyrolysis while the shell is prepared by hydrothermal synthesis.

   Synthesized core-shell catalyst should be homogeneously distributed in the microreactor. Ink jet printing technology with picoliter scale droplets is developed for depositing the catalyst on the confined microchannels. Well-distributed catalyst layers can enhance the overall performance of the microreactor.

2. Modelling of bifunctional core-shell catalysts for the production of fuels from biomass-based synthesis gas

   This subject is funded by the DFG program Porous media with a defined pore structure - modelling, applications, synthesis.

   Hierarchical bifunctional core-shell catalysts for sequential reactions are considered more in general in this subject. The two considered reaction systems are: the conversion of synthesis gas to methanol combined with the dehydration of methanol to dimethylether and the conversion of synthesis gas to long-chain hydrocarbons in the Fischer-Tropsch synthesis combined with the hydrocracking to obtain diesel or kerosene fractions. Both reaction systems require metallic catalysts for the first reaction step (Cu / Zn for the methanol synthesis and Co for the FT synthesis) and acidic catalysts for the second reaction step (modified zeolites).

   Focus is on the development of a simulation model, which allows detailed description of the coupled reaction and transport processes in such bifunctional core-shell systems and thus optimization of the catalyst preparation. Special attention is paid on the modelling of processes in the shell, which is a polycrystalline zeolite layer with an anisotropic pore system in the individual crystals.