Multi-Scale Modeling of Methanol and Direct Dimethyl Ether Synthesis from CO2-rich Syngas

Methanol and dimethyl ether (DME) are important “Power-to-X (PtX)” products used as intermediates in the production of CO2-neutral base chemicals. New applications in the chemical industry and heavy-duty transportation have led to numerous research activities regarding the synthesis of these two chemicals, in order to maximize the production efficiency. Both methanol and DME can be directly synthesized from H2/CO/CO2 streams derived from a variety of feedstocks.1 However, depending on the source, the COx to H2 ratio varies, which in many cases results in low carbon utilization and loss of catalytic activity. Understanding the mechanisms responsible for loss of catalytic performance would allow for precise optimization of input components and reaction conditions, leading to further improvement of the process efficiency and economic feasibility under variable conditions.

The aim of our research is to develop reliable and flexible reaction mechanisms for catalytic conversion of H2/CO/CO2 to methanol and DME over a wide range of process conditions. Such mechanisms would provide fundamental knowledge in order to contribute to a model-based process design for the production of methanol and DME and future “Power-to-Fuel” processes. ... mehr
In this contribution, we present different modeling approaches ranging from microkinetics based on theoretical studies to formal kinetic models. The kinetic experimental studies for MeOH synthesis are executed on a commercial Cu/ZnO/Al2O3 (CZA) catalyst and self-prepared Cu/ZnO/ZrO2 (CZZ) catalyst at variable reaction conditions. Commercially zeolites serve as dehydrating acid for DME synthesis. Through multiscale modeling, a description of the catalysts behavior under different reaction conditions by kinetic and surface activity models was achieved. The models include the MeOH synthesis from H2/CO/CO2 and the water-gas shift reaction (WGSR).2,3 In addition, the methanol models were extended for the direct DME synthesis by including the methanol dehydration step.

References
[1] S.Wild, S. Polierer, T. Zevaco, D. Guse, M. Kind, S. Pitter, K. Herrera D, J. Sauer. RSC Adv, 11, 2556 (2021)
[2] B. L. de Oliveira Campos, K. Herrera D, S. Wild, F. Studt, J. Sauer, React. Chem. Eng, 6, 868 (2021)
[3] B. L. de Oliveira Campos, K. Herrera D, S. Pitter, J. Sauer, Ind. Eng. Chem. Res, 60, 15074 (2021).