The Need for Dynamic Process Simulation: A Review of Offshore Power‐to‐X Systems

The integration of offshore wind energy into Power-to-X (PtX) process chains offers opportunities for the efficient use of renewable energy. This article analyzes different PtX process chain configurations and their adaptation to the offshore environment. However, direct coupling of PtX platforms with fluctuating electrical energy poses major challenges. Dynamic process simulation is presented for analysis of different plant configurations and operating strategies. The article emphasizes the need for interdisciplinary research to consider technological as well as economic and environmental aspects

Towards a novel computer-aided optimization of microreactors: Techno-economic evaluation of an immobilized enzyme system

Immobilized multi-enzyme cascades are increasingly used in microfluidic devices. In particular, their application in continuous flow reactors shows great potential, utilizing the benefits of reusability and control of the reaction conditions. However, capitalizing on this potential is challenging and requires detailed knowledge of the investigated system. Here, we show the application of computational methods for optimization with multi-level reactor design (MLRD) methodology based on the underlying physical and chemical processes. We optimize a stereoselective reduction of a diketone catalyzed by ketoreductase (Gre2) and Nicotinamidadenindinukleotidphosphat (NADPH) cofactor regeneration with glucose dehydrogenase (GDH). Both enzymes are separately immobilized on magnetic beads forming a packed bed within the microreactor. We derive optimal reactor feed concentrations and enzyme ratios for enhanced performance and a basic economic model in order to maximize the techno-economic performance (TEP) for the first reduction of 5-nitrononane-2,8-dione

A Simplified Design Method for the Mechanical Stability of Slit-Shaped Additively Manufactured Reactor Modules

Equipment integrity is an essential aspect of process engineering. Design guidelines facilitate the design and production of safe-to-operate and economic devices. Thin-walled, slit-shaped modules form a subgroup of process engineering devices made via additive manufacturing (AM). Being subject to internal pressure, they have lacked design guidelines until now. We derived a user-centered calculation model for such modules with regular internal structures. It was validated with Finite Element Analysis (FEA) and practical pressure tests for which the modules were manufactured additively. The performance of the calculation could be confirmed, and a design graph was derived. Slit-shaped modules with appropriate internal structures can withstand high pressure at a minimum wall thickness, and they are efficiently fabricated. These structures, being pins, fins, lattice, or heat transfer enhancing fluid-guiding elements (FGEs), occupied approximately 10% of the modules’ internal volume

Downsizing Sustainable Aviation Fuel Production with Additive Manufacturing-An Experimental Study on a 3D printed Reactor for Fischer-Tropsch Synthesis

Sustainable aviation fuels (SAF) are needed in large quantities to reduce the negative impact of flying on the climate. So-called power-to-liquid (PtL) plants can produce SAF from renewable electricity, water, and carbon dioxide. Reactors for these processes that are suitable for flexible operation are difficult to manufacture. Metal 3D printing, also known as additive manufacturing (AM), enables the fabrication of process equipment, such as chemical reactors, with highly optimized functions. In this publication, we present an AM reactor design and conduct experiments for Fischer-Tropsch synthesis (FTS) under challenging conditions. The design includes heating, cooling, and sensing, among others, and can be easily fabricated without welding. We confirm that our reactor has excellent temperature control and high productivity of FTS products up to 800 kgC5+ mcat−3 h−1 (mass flow rate of hydrocarbons, liquid or solid at ambient conditions, per catalyst volume). The typical space-time yield for conventional multi-tubular Fischer-Tropsch reactors is ~100 kgC5+ mcat−3 h−1. The increased productivity is achieved by designing reactor structures in which the channels for catalyst and cooling/heating fluid are in the millimeter range. With the effective control of heat release, we observe neither the formation of hot spots nor catalyst deactivation

A Microstructured Cover Flow Mixer for Hydrothermal Synthesis of ZnO Nanoparticles in Supercritical Water

A microstructured cover flow mixer equipped with two cyclone structures was used for stable continuous hydrothermal synthesis of ZnO nanoparticles from Zn(NO$_3$)$_2$ and NaOH aqueous solutions in supercritical water. The effects of the NaOH/Zn(NO$_3$)$_2$ ratio, Zn(NO$_3$)$_2$ molality, and flow rate on Zn conversion, crystal structure, particle size, particle morphology, and mixer clogging were examined. The advantages of this mixer were identified by comparing with the results obtained using the same chemical conditions with tee-type, cross-type, and central collision-type mixers

Fabrication of Sectionally Permeable Components with Curved Surface by Laser‐Beam Powder‐Bed Fusion

Devices in process engineering often include permeable components. As shown in our recent work for planar components, laser-beam powder bed fusion offers the opportunity to integrate permeable sections into complex monolithic metal parts in one go. This paper extends the approach to components with curved surfaces. Different scan strategies were investigated for their effects on surface morphology and permeability of tubular samples. It was found that in order to ensure consistent properties of a permeable tube, different starting points or rotation of the scan vectors have to be used