Carbon dioxide emissions from fossil fuel combustion are considered a major contributor to climate change. The CO2 emission can be reduced considerably by post-combustion capture of CO2 adsorbed from power plant flue gas using zeolites or MOFs. A particular problem is the strong adsorption of water inside many nanoporous materials. Prominent examples are open metal site MOFs. One objective of the present proposal is to computationally study and characterize the water adsorption phenomena in nano-porous materials. A theoretical model to interpret the water adsorption behavior in the pores of nano-porous materials will be developed, also a working mixed-gas model to predict physical properties of water containing flue gases at various conditions inside nano-pores. Furthermore, the parasitic-energy model will be extended by including water. A parasitic energy look-up tool will be integrated into a full-fledged open source carbon capture platform. In order to design adsorbers/desorbers multi-component self-diffusion and transport-diffusion coefficients of the flue gas components and their mixtures will be calculated. Finally, a technical concept of a fuel carbon capture plant will be designed.

Solvent design and selection with a particular emphasis on their greenness is currently a main focus both in chemo- and biocatalysis. Biocatalysis has traditionally relied on either aqueous- or classical organic media (mainly for hydrolases), or biphasic systems thereof. In this respect, Deep Eutectic Solvents (DESs) have been identified as „the solvents of the 21st century“ and offer a new dimension as ‘Safe- and Green-by-Design’ solvents for biocatalysis. In a nutshell, DESs’ assets are based on their often biogenic origin, and their properties such as melting points below room temperature, low volatility, high thermal stability, tuneability analogous to ionic liquids, biodegradability, large availability at acceptable costs, and straightforward preparation. In particular, the high degree of freedom in designing DESs from a variety of (biogenic) substances enables the creation of a sustainable solvent platform. The enormous potential of DESs for biocatalytic applications has been mainly explored for hydrolases (EC3), after their first application demonstrated in 2008. Different then EC3 enzymes, oxidoreductases (EC1) have only rarely been employed in DESs at predominant amounts. Few examples for the use of alcohol dehydrogenases (ADHs) have been documented (mainly from our previous DFG-funded project) either to demonstrate the use of DESs for organic synthesis while using a DES component as substrate or to understand the effect of different DESs on the activity and stability of a redox enzyme. Redox biocatalysis is still underrepresented for DES-based applications which will be addressed deeply by the interdisciplinary setup of DESiRE. Overall, the here presented follow-up project represents a clear strategy to elucidate the protein-DES-water interactions, which possess a considerable potential for understanding the ADH-catalysis in DESs. Especially the close collaboration between experimental methods and molecular simulations will lead to new insights on different scales. Moreover, this follow-up project will further open new possibilities to evaluate other enzyme classes for the effects of DESs on catalytic performance (activity, stability and selectivity) of enzymes.

Die Produktion von Proteinen als Biopharmazeutika ist ein wichtiger und wachsender Zweig der pharmazeutischen Industrie. Gemäß dem Stand der Technik erfolgt dabei die Aufreinigung der Produkte mittels verschiedener chromatographischer Methoden. Deren Entwicklung basiert für die jeweiligen Produkte auf umfangreichen und aufwendigen experimentellen Arbeiten.In diesem Projekt sollen experimentelle Methoden und molekulardynamische (MD) Simulationen in enger Verknüpfung eingesetzt werden um die Ionenaustauschadsorption von Proteinen zu beschreiben. Experimentell erfolgen eine umfangreiche Charakterisierung vorhandener Adsorbentien und die Beschreibung der vorliegenden Adsorptionseigenschaften. Parallel dazu werden MD-Simulationen der Adsorption durchgeführt und die beschreibenden Parameter der Proteinadsorption am Beispiel des SMA-Modells bestimmt. Dies bietet die Grundlage um anschließend eine optimierte Adsorbensstruktur zu beschreiben.Im Rahmen dieses Forschungsprojekts werden MD Methoden erfolgreich angewendet um die Ionenaustauschadsorption von Proteinen zu beschreiben. Dafür wird ein validiertes Modell zur vollständigen Beschreibung einer Adsorptionsisotherme bei verschiedenen Prozessparametern entwickelt. Dies ermöglicht erstmalig in silico die vollständige Vorhersage der Adsorptionsisothermen von Proteinen. Weiterhin sind die einzelnen Wechselwirkungszentren an den Modellproteinen charakterisiert, so dass auf dieser Basis neue Adsorbentien beschrieben sind, welche verbesserte Adsorptionseigenschaften aufweisen.Nach erfolgreichem Abschluss dieses Projekts ergibt sich die Möglichkeit die erarbeitete Methode auf beliebige Systeme zu übertragen um zukünftig mit geringerem Aufwand die chromatographischen Methoden zur Aufreinigung von pharmazeutisch relevanten Proteinen zu entwickeln.

Die fortschreitende Digitalisierung in der Verfahrenstechnik stellt völlig neue Anforderungen an chemische und biochemische Prozesse, eröffnet aber auch ein enormes Potenzial für eine flexiblere und nachhaltigere Produktion. Sowohl der Wandel der Rohstoffbasis als auch das zunehmende Angebot an erneuerbaren Energien erfordert Prozesse, die in einem globalisierten Markt innerhalb kürzester Zeit auf wechselnde Rohstoffe und Energieangebote reagieren können. Personalisierte Produkte und immer kürzere Zyklen neuer Modellvarianten erfordern flexible Prozesse für kleine Mengen, die schnell und kostengünstig an- und abgefahren werden können. Schärfere Vorgaben von Gesetzgeber und Zulassungsbehörden machen ein tiefes Prozessverständnis im Sinne des „Quality by Design“ unabdingbar. Diese enormen Anforderungen an moderne Prozesse erfordern ein radikales Umdenken in der Gestaltung und Betriebsführung von Reaktoren für die Biotechnologie, Pharmazie und Chemie. Künftig zählt weniger „Economy of Scale“ als vielmehr die Flexibilität der Prozesse.

Acrolein is an important intermediate of the chemical industry with a production volume of several hundred thousand tons per year. Acrolein synthesis is energy intensive and is based on the catalytic oxidation of propylene, which in turn is obtained by steam cracking of crude oil fractions. Goal of this research project is to investigate an alternative synthesis route to acrolein, which is the heterogeneously-catalyzed coupling of methanol and ethanol on iron molybdate catalysts. Both, methanol and ethanol can be obtained from renewable resources, making this synthesis route a potential future green alternative to today’s synthesis from fossil feedstocks. Acrolein yields are still not competitive for industrial application but could be increased based on a solid mechanistic understanding of this reaction. Goal of this research project is to understand the reaction mechanism, active sites, surface adsorbates and the structure-reactivity correlation of the catalyst. The following questions will be answered: 1.) What is the structure of the active sites, where are the active sites on the catalyst surface and how are they distributed along the reactor? 2.) What are the reaction pathways to acrolein and to the undesired side products? Which steps along these pathways are rate determining and which adsorbates are covering the catalyst surface? 3.) What is the kinetics of these steps and is it possible to increase acrolein selectivity and yield by forced periodic modulation of the reactants. To answer these questions, modern spectrokinetic measurement methods will be synergistically coupled with modern modeling methods. Molecular spectroscopy in temperature programmed and modulation excitation mode will be coupled with kinetic and spectroscopic reactor profiling to identify which active sites and surface adsorbates are kinetically relevant and how they are distributed in a plug flow reactor. The experimental kinetic and spectroscopic data lay a fundament for the development of a detailed reaction mechanism and a microkinetic reaction model using modeling tools such as Density Functional Theory, Microkinetic Modeling and Machine Learning Methods. The microkinetic model will then be used to calculate how the reactor has to be operated to achieve optimum acrolein yields. The model predictions will be experimentally verified.

The research project investigates the interaction between physical and chemical processes inside a non-thermal plasma and the catalytic reactions of plasma generated molecules, radicals and atoms at the surface of a solid catalyst. The plasma-catalytic reduction of nitrogen oxides by methane on a Pd/Al2O3/CeO2/ZrO2 catalyst, which is a standard catalyst in automotive catalytic exhaust treatment, will be studied as test reaction. This testbed system is of technical and societal relevance because more than 80% of NOx emissions caused by automotive exhaust are released during cold start, that means when the catalyst has a temperature below 200°C and is unable to activate the rather inert hydrocarbons contained in the exhaust stream as reducing agent for nitrogen oxides. By coupling of a non-thermal plasma, inside which highly reactive atoms, molecules and radicals are formed, with a DeNOx catalyst, very unreactive hydrocarbons such methane can be activated basically at room temperature and the resulting radicals can reduce nitrogen oxide species adsorbed on the catalyst surface to N2, CO2 and H2O. Because radicals are highly reactive with lifetimes on the order of micro- to milliseconds (e.g. CH3 and OH) or milliseconds to seconds (e.g. CH3OO), efficient coupling between plasma and catalyst requires spatial confinement and transport distances in the submillimeter range. To separate and match plasma processes, transport and catalytic reactions in a well defined manner, plasma and catalyst will be connected both in series and in parallel to each other. By feeding the effluent of a non-thermal plasma into a catalyst coated capillary of up to one millimeter inner diameter, reactions can be probed in a systematic manner, which are mediated by comparably long-lived radicals such as CH3OO for example. Reactions mediated by short-lived radicals such as CH3 oder OH, which can only diffuse over very short distances, can be probed systematically by igniting the non-thermal plasma inside narrow channels of 50-1000µm wall distance with the catalyst coated as thin layer at the channel walls. By combining defined catalytic experiments with spatially resolved diagnostic measurements using methods like Laser Induced Fluorescence Spectroscopy or Molecular Beam Mass Spectrometry and with multidimensional plasma modeling, the following key questions in plasma catalysis will be answered: 1) Can confined reactor geometries overcome transport limitations impacting plasma-catalytic chemistry coupling? 2) Which are the key plasma species enabling effective coupling between plasma and catalytic processes and how can their production be controlled? 3) What are the key differences in surface species and reactions during plasma-catalysis compared to thermal catalysis?

Project A02 develops the methodology of quantitative, real-time, 3D Electrical Impedance Tomography (EIT) for process monitoring in the SMART multiphase reactor for catalytic hydrogenolysis of glycerol. In A02, EIT will be combined with synchronized capillary sampling of multiphase flows, converting impedance data into process variables like gas-holdup, bubble size distribution and phase flow rates. An EIT measurement cell will be built featuring a higher number of electrodes (100-400) than existing systems (32) for performing EIT over a frequency range (100 kHz-1 MHz) on water/glycerol/propanediol/hydrogen flows at temperatures up to 250°C and 50 bar H2 pressure. Tailored measurement electronics and reconstruction algorithms will be developed.

Electrowetting of Carbon Nanotube (CNT) Carpets carrying Ru-Cu and Ru-Fe nanoparticles will be developed as method for catalyst reactivity control inside a SMART multiphase reactor for catalytic glycerol hydrogenolysis. A miniaturized reactor module will be developed in project B02, allowing simultaneous fibre-based Raman spectroscopy and hard X-Ray measurements at PETRAIII/DESY including SAXS, XAS, XRF and TXM. Goal is to establish a functional relationship between the shift of Raman bands of the CNT's and the degree of electrowetting as measured by operando X-Ray spectroscopy. Fibre-based Raman spectroscopy can then be used for catalyst reactivity control in the SMART multiphase demonstration reactor for catalytic glycerol hydrogenolysis in project C03.

The kinetics and process parameters of the hydrogenolysis of glycerol to 1,2-propanediol are investigated in a slurry reactor at the beginning of the funding period. The SMART reactor is simultaneously calculated, designed and subjected to a HAZOP, considering the data obtained in the slurry. The final design is worked out in detail and manufactured subsequently. After assembly, the EIT, electrowetting and further measuring and control devices are installed in the reactor. The hydrogenolysis is finally realized in the SMART reactor and the various new components are tested.