BioEnergy International (Austria)

Carbon capture and storage (CCS) technologies, along with CO2 capture and conversion methods, have emerged as crucial research areas to address rising CO2 emissions. In this study, we seek to understand the mechanistic role of amines in enabling lower-energy pathways for CO2 conversion. Our research focuses on the development and analysis of dual-functional materials (DFMs) engineered for the reactive capture and conversion (RCC) of CO2 into methane, utilizing Ru catalysts grafted with amine groups. We employ Density Functional Theory (DFT) calculations using methylamine as a model amine to investigate the impact of amine groups on CO2 methanation on a Ru(0001) surface, both in the presence and absence of amine groups. The amine ligand alters the carbon coordination environment, promoting direct C–O dissociation and potentially destabilizing the CO* adsorbate, thereby reducing the risk of CO poisoning. Additionally, we observe a preference for hydrogenation, although it becomes more energetically uphill in the amine-bound scenario. Our experiments, however, report similar CO2 conversion and CH4 production rates over the synthesized catalysts “Ru/TiO2” and the amine (N-(2-aminoethyl)-3-aminoproplytrimethoxysilane (“diaminosilane”)) deposited catalyst “Diamine−Ru/TiO2”. By constructing comparative reaction-free energy diagrams and performing microkinetic modeling (MKM) simulations, we link our theoretical findings with experimentally observed CO2 uptake, conversion, and methane production rates. A microkinetic model was employed to investigate the anomaly, showing reduced amine–carbon complex coverage and increased CO2 coverage at all temperatures. The MKM simulations consistently confirmed these trends. This comprehensive approach offers key insights into the role of the amine-CO2 bond in methanation, highlighting a pathway toward lower-energy, more efficient CO2 capture and conversion processes.

In this study, we performed a life cycle assessment (LCA) on an emerging lignin upgrading process, namely the production of biobased adipic acid.

For guaiacol deoxygenation under catalytic fast pyrolysis conditions, support acidity increases catalytic activity while support reducibility enhances selectivity to deoxygenated products.

This review highlights Diels–Alder heterogeneous catalysis for the production of biomass-derived aromatic compounds.

Liquefaction of biochar from liquid-phase pyrolysis was carried out in the solvent Tetralin. Tetralin is able to act as hydrogen donor during liquefaction of biochar and is itself rearranged into Naphthalene. Naphthalene must be re-hydrogenated to Tetralin to allow for further use in the liquefaction reaction (chemical loop system). Therefore Naphthalene hydrogenation was investigated, applying a full factorial design of experiments approach. The yield of Tetralin was chosen as response variable, while two-level-factors for temperature (150 °C and 200 °C), pressure (20 bar and 50 bar) and Raney-Nickel catalyst load (5 wt% and 10 wt%) were selected. The Design of Experiments approach showed a rising influence of all three factors in the order: temperature < pressure < catalyst load. The reaction kinetics of the hydrogenation of Naphthalene to Tetralin and Decalin was then investigated at 150 °C and 200 °C. The reaction proceeds stepwise and not in consecutive steps. In a first step Naphthalene reacts selectively with 96% yield to Tetralin, while the reaction of Tetralin to Decalin does not start until all Naphthalene is consumed. The rate-constant of the reaction of Naphthalene to Tetralin is one magnitude higher than that for the reaction of Naphthalene to Decalin. This is in agreement with the findings from the design of experiments approach. The results of these investigations indicate that the chemical-loop system Naphthalene–Tetralin is suitable for usage in the liquefaction of biochar.

Biokraftstoffe der ersten Generation konnen dem Kraftstoff nur begrenzt zugemischt werden (laut Norm EN 590 max. 7 Vol.-%). Aus diesem Grund wird an einem zweistufigen Konzept zur Umwandlung von Biomasse zu flussigen Energietragern gearbeitet. Der erste Prozessschritt, die Flussigphasenpyrolyse, wurde bereits in Vorarbeiten [1] erfolgreich untersucht und wird derzeit in einer Pilotanlage umgesetzt. Dabei wird Lignozellulose bei Umgebungsdruck und erhohter Temperatur zu Gas, wassrigem Pyrolyseol und Pyrolysekohle umgesetzt. Im zweiten Prozessschritt (bioBOOST) soll die Aufwertung der Flussigphasenpyrolyseproduke erforscht werden. Diese Arbeit beschaftigt sich mit der katalytischen Druckhydrierung der Pyrolysekohle. In der Vergangenheit wurden zahlreiche Versuche zur Verflussigung von fossiler Kohle mithilfe verschiedenster Katalysatoren unternommen [2]. Die Verflussigung von biogener Pyrolysekohle fand bis jetztjedoch keinen Eingang in die Literatur. Die Experimente wurden in einem 500-mL Autoklaven durchgefuhrt. Der Reaktor kann bei bis zu 500 °C und 35MPa betrieben werden. Vor der Hydrierung wurde die Pyrolysekohle mit maximal 5% Katalysator gemischt/impragniert und getrocknet. Experimente unter optimalen Bedingungen zeigten Verflussigungsraten der Pyrolysekohle von mehr als 90%.