Chemie Ingenieur Technik最新文献

Green methanol is a renewable fuel with great advantages when used in a spark ignition combustion process. Methanol has a comparatively high enthalpy of vaporization, leading to lower combustion temperatures as compared to gasoline combustion, and, hence, lower wall heat losses as well as a reduced tendency to pre-ignition. Therefore, a brake efficiency of more than 40 % (this is comparable to diesel engines!) and furthermore minimal emissions, even at cold start, are possible. The serial combination with an electric powertrain provides a disconnection of the load demand of the powertrain and the operating point of the combustion engine. In this case, a high volumetric and gravimetric power density, easy energy storage and proven infrastructure of fuel distribution are combined with electric driving, high efficiencies, minimal emissions, and a closed carbon cycle for the energy provision.

The system integration of cross-industrial networks in the Carbon2Chem^® project relies on numerical simulations. Hence, this study validates the methanol synthesis loop models vs. the measurements from a demonstration plant, focusing on the thermodynamic, kinetic, and dynamic aspects. The plant can produce up to 500 L per week of methanol from real blast furnace gases of the thyssenkrupp steel plant in Duisburg. Despite its small size, it comprises a recycle gas loop and an original reactor tube of 6 m in length. After validation, the simulation models are used to analyze the dynamic operation limits of the plant, and they are transferred to the model of an industrial size to analyze the operation of cross-industrial networks with volatile boundary conditions.

Catalytic oxygen removal applying a commercial CoMo-based catalyst has attracted scientific attention owing to its catalytic stability towards poisoning components and cost-effectiveness. The catalytic performance of the CoMo catalyst was investigated using statistical optimization techniques. The H₂S concentrations in the sulfidation and reaction mixture are the key factors regulating the optimal values of deoxygenation reaction. The sulfidation process is a key step to generate the active species. The catalyst remains active in the presence of sulfur compounds in the reaction mixture, which is poisoning for other catalyst systems. An increase in the H₂S content enhances the catalytic activity via in-situ sulfidation within the meaning of regeneration during the reaction. Concentrations above 450 ppm H₂S in the reaction mixture result in a nearly complete oxygen conversion and ensure the catalytic stability. At the same time, an increase in the H₂S content favors a high sulfidation degree resulting in the formation of active sites.

A new catalyst test setup on miniplant-scale was planned and built. The setup enables the use of real process gases in the environment of a steel mill or related application and the utilization of synthetic gases with a wide range of gas compositions including trace compounds to investigate the operational limits of gas cleaning catalysts. First investigations focus on oxygen removal from real coke oven gas (COG). The concept not only addresses effects of scale and heat management but also emphasizes the use of real process gases for application-oriented catalyst development in industrial settings.

Im Jahr 2023 begannen insgesamt 8248 Anfänger einen Chemiestudiengang: 1,4 % mehr als im Vorjahr (2022: 8137). Das zeigt die jährliche Statistik für Chemiestudiengänge der GDCh. Die Anzahl der Studierenden, die einen Chemiestudiengang mit einem Master oder dem Ersten Staatsexamen abgeschlossen haben, beläuft sich auf 3483 (2022: 3761). Die Zahl der Promotionen steig nach einem Einbruch im Vorjahr (2022: 1883) im letzten Jahr wieder auf 2040. Der Einstieg ins Berufsleben gelang stellensuchenden Absolventinnen und Absolventen mit abgeschlossener Promotion ähnlich gut wie im Vorjahr.

97 % aller Bachelorabsolventinnen und -absolventen an Universitäten und 75 % an HAW schlossen ein Masterstudium an. Rund 83 % der Master-Absolventen an Universitäten begannen eine Promotion. Dieser Wert ist weiterhin geringer als im langjährigen Mittel (90 %) und scheint sich nun auf ein niedrigeres Niveau eingependelt zu haben.

Der Wert der „echten“ Stellensuchenden dürfte wie in jedem Jahr etwas geringer sein. Aufgrund des Stichtags der Erhebung am 31.12. werden Absolventinnen und Absolventen, die im Januar oder Februar ihre neue Stelle antreten, noch als stellensuchend erfasst.

Die Broschüre „Statistik der Chemiestudiengänge 2023“ steht unter www.gdch.de/statistik als Blätterkatalog zur Verfügung.

The heat transfer limit of heat pipes is investigated by pool boiling experiments in a standard apparatus with a capillary layer placed on a copper tube. The capillary layer is a hollow cylinder made of bronze with a wall thickness of 2 mm and the test fluids are methanol and n-pentane. The setting is comparable to high-flux tubes already investigated in the literature. In dependence on the heat flux, three to four sections with different characteristics are identified. Compared to plain copper tubes, the heat transfer is partially increased by a factor of 12 until the limit is reached at around 70 kW m⁻².

Underground salt caverns allow large hydrogen storage capacities at low specific costs. Such storage is required to balance fluctuating hydrogen supply and constant demand of large consumers as a methanol plant from the Carbon2Chem^® project. The geological and technical feasibility for developing up to 168 Mio. m³ (n.c.) or 595 GWh of working gas capacity until 2040 at a location in the Lower Rhine Bay is described. Various options for realization as well as a novel process for cavern leaching parallel to hydrogen storage operation are evaluated. Further work is required including geological exploration and optimization of brine production. The main hurdles for investment decisions are the political uncertainties on the hydrogen storage market design and on the ramp-up of the hydrogen market.

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