Bifunctional hierarchically-structured porous layered systems for efficient one-step conversion of synthesis gas to fuels in microstructured reactors
- funding: DFG SPP 1570: Porous Media with Defined Porous Structure in Chemical Engineering - Modelling, Applications, Synthesis
Friedrich-Alexander University Erlangen-Nürnberg, Technical Faculty, Institute of Chemical Reaction Engineering (CRT), Erlangen, Germany
Through the use of nanotechnology, hierarchically structured porous layered systems will be prepared from two different catalytic materials. The systems are meant to achieve a favorable implementation of two-step reaction sequences via utilization of synergies from the local neighborhood of the two different types of active sites, as well as from merging two process steps into one.
Due to the excellent heat transfer properties and low mass transport resistance, microstructured reactors provide the option to maintain optimal reaction conditions for a variety of heterogeneously catalyzed reaction, which as a consequence result in enhanced conversion and selectivity while at the same time the reactors can be compact. Such advanced reactors call for highly active catalysts and feasible concepts for their implementation.
In this project, by the example of the synthesis of liquid fuels via two-step reaction sequences, the concept of the synergetic coupling of the subsequent reaction steps on the micro scale shall be investigated. In particular, the research focuses on the direct production of dimethyl ether from synthesis gas via methanol as an intermediate. In this reaction sequence, immediate further reaction of methanol formed at site A (reaction 1) to dimethyl ether at the neighboring site B (reaction 2) yields higher conversion as for sole methanol formation at sites of type A. To achieve this, among other concepts, core-shell particles in the size range up to 150 microns and coatings of microchannels with layer thicknesses between 5-20 µm will be prepared by targeted approaches. The particles consist of a Cu/ZnO/Al2O3 as methanol ZSM-5 type for performing methanol dehydration (see figure). Double layer structures attached to a flat wall as well as multicore-shell structures in the size range of microparticles having multiple Cu/ZnO/Al2O3 cores within a common spherical ZSM-5 matrix will be studied as alternative systems.
The prepared materials will be characterized thoroughly by multiple methods to visualize their structure, morphology and chemical composition even with local resolution, and to probe their catalytic performance. Together with the kinetics of the reaction and the mass transport, these data are used to create detailed simulation models, which will be adopted to optimize the layered structures towards maximum product selectivity or yield. The target is a process as simple and as compact as possible enabling a single-stage operation at high efficiency in terms of matter and energy.
T. L. Sheppard, S. W. T. Price, F. Benzi, S. Baier, M. Klumpp, R. Dittmeyer, W. Schwieger, J.-D. Grunwaldt, In situ Multimodal 3D Chemical Imaging of a Hierarchically-Structured Core@Shell Catalyst at Work, Journal of the American Chemical Society, 139, 2017, 7855-7863, 10.1021/jacs.7b02177
Wenjin Ding, Giulia Baracchini, Michael Klumpp, Wilhelm Schwieger, Roland Dittmeyer, Adsorption Device Based on a Langatate Crystal Microbalance for High Temperature High Pressure Gas Adsorption in Zeolite H-ZSM-5 Journal of Visualized Experiments 114 (2016), 10.3791/54413
Wenjin Ding, Michael Klumpp, Hui Li, Ulrich Schygulla, Peter Pfeifer, Wilhelm Schwieger, Katja Haas-Santo, and Roland Dittmeyer, Investigation of High-Temperature and High-Pressure Gas Adsorption in Zeolite H-ZSM-5 via the Langatate Crystal Microbalance: CO2, H2O, Methanol, and Dimethyl Ether, The Journal of Physical Chemistry C, 2015, 119 (41), 23478-23485, 10.1021/acs.jpcc.5b06591
Wenjin Ding, Michael Klumpp, Seungcheol Lee, Stephanie Reuß, Shaeel A. Al-Thabaiti, Peter Pfeifer, Wilhelm Schwieger, Roland Dittmeyer, Simulation of One-Stage Dimethyl Ether Synthesis over a Core-Shell Catalyst, Chemie Ingenieur Technik, 87(6), 2015, 702-712 10.1002/cite.201400157
Seungcheol Lee, Katja Schneider, Julia Schumann, Aswani K. Mogalicherla, Peter Pfeifer, Roland Dittmeyer, Effect of metal precursor on Cu/ZnO/Al 2 O 3 synthesized by ﬂame spray pyrolysis for direct DME production, Chemical Engineering Science, 138, 2015, 194-202, 10.1016/j.ces.2015.08.021
Wenjin Ding, Hui Li, Peter Pfeifer, Roland Dittmeyer, Crystallite-pore network model of transport and reaction of multicomponent gas mixtures in polycrystalline microporous media, Chemical Engineering Journal, Volume 254, 2014, 545-558, 10.1016/j.cej.2014.05.081
Seungcheol Lee, Tim Boeltken, Aswani K. Mogalicherla, Uta Gerhards, Peter Pfeifer, Roland Dittmeyer, Inkjet printing of porous nanoparticle-based catalyst layers in microchannel reactors, Applied Catalysis A: General, 467, 2013, 69-75, 10.1016/j.apcata.2013.07.002