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Abstract Fluidized bed layering granulation has found application in a wide range of industrial processes, e.g. food, pharmaceutical or fertilizer manufacturing. The quality of the produced granules is a critical factor for subsequent processing steps and depends on individual particle properties like characteristic size, porosity or mechanical stability. Therefore, these properties have to be monitored closely during the process to enable accurately timed intervention by plant operators or the application of suitable feedback control algorithms. In case certain properties are not measurable due to financial or technical limitations, observer techniques can fill the gap and provide reliable estimates for these properties. In this manuscript, observer design is demonstrated and validated for a fluidized bed layering granulation process model represented by a complex set of partial and ordinary differential equations. Furthermore, an inferential integral state feedback controller is designed and applied to the complex nonlinear model.

AbstractThis paper adopts a single-period newsvendor model with supply uncertainties to be used for optimally sizing an electrical energy storage system (EESS) for an apartment house with a photovoltaic (PV) system. Hence, typical inventory cost components and supply chain characteristics are translated to the EESS application. The results show that inventory management and energy storage can be aligned. The optimal size of the EESS takes into account the total cost of the storage system including energetic losses as well as the costs for energy supply from the own energy systems and from the energy supplier.

Floodplain soils and reservoir sediments are known for their fine-grained structure and rich organic-matter substances; therefore, they are able to sorb metals and other potential pollutants, which is is characteristic of their sink function [...]

Increasing wind capacity and capacity factors (CF) are essential for achieving the goals set by the Paris Climate Agreement. From 2010–2012 to 2018–2020, the 3-year mean CF of the global onshore wind turbine fleet rose from 0.22 to 0.25. Wind turbine siting, wind turbine technology, hub height, and curtailed wind energy are well-known CF drivers. However, the extent of these drivers for CF is unknown. Thus, the goal is to quantify the shares of the four drivers in CF development in Germany as a case. Newly developed national power curves from high-resolution wind speed models and hourly energy market data are the basis for the study. We created four scenarios, each with one driver kept constant at the 2010–2012 level, in order to quantify the share of a driver for CF change between 2010–2012 and 2019–2021. The results indicated that rising hub heights increased CF by 10.4%. Improved wind turbine technology caused 7.3% higher CF. However, the absolute CF increase amounted to only 11.9%. It is because less favorable wind turbine sites and curtailment in the later period moderated the CF increase by 2.1% and 3.6%, respectively. The drivers are mainly responsible for perennial CF development. In contrast, variations in wind resource availability drive the enormous CF inter-annual variability. No multi-year wind resource change was detected.

Photovoltaic thermal (PVT) solar collectors can be an effective solution for system output improvement. Photovoltaic thermal collectors naturally have a more expensive receiver than simpler photovo ...

Dieser Tagungsband enthalt die Beitrage des 26. Workshops Computational Intelligence. Die Schwerpunkte sind Methoden, Anwendungen und Tools fur Fuzzy-Systeme, Kunstliche Neuronale Netze, Evolutionare Algorithmen und Data-Mining-Verfahren sowie der Methodenvergleich anhand von industriellen und Benchmark-Problemen. The proceedings of the 26. workshop computational intelligence focus on methods, applications and tools for fuzzy systems, artificial neural networks, evolutionary algorithms and data mining techniques. Umfang: 280 S. Preis: €43.00 | £40.00 | $76.00

The presence of natural gas hydrates at all active and passive continental margins has been proven. Their global occurrence as well as the fact that huge amounts of methane and other lighter hydrocarbons are stored in natural gas hydrates has led to the idea of using hydrate bearing sediments as an energy resource. However, natural gas hydrates remain stable as long as they are in mechanical, thermal and chemical equilibrium with their environment. Thus, for the production of gas from hydrate bearing sediments, at least one of these equilibrium states must be disturbed by depressurization, heating or addition of chemicals such as CO2. Depressurization, thermal or chemical stimulation may be used alone or in combination, but the idea of producing hydrocarbons from hydrate bearing sediments by CO2 injection suggests the potential of an almost emission free use of this unconventional natural gas resource. However, up to now there are still open questions regarding all three production principles. Within the framework of the German national research project SUGAR the thermal stimulation method by use of in situ combustion was developed and tested on a pilot plant scale and the CH4-CO2 swapping process in gas hydrates studied on a molecular level. Microscopy, confocal Raman spectroscopy and X-ray diffraction were used for in situ investigations of the CO2-hydrocarbon exchange process in gas hydrates and its driving forces. For the thermal stimulation a heat exchange reactor was designed and tested for the exothermal catalytic oxidation of methane. Furthermore, a large scale reservoir simulator was realized to synthesize hydrates in sediments under conditions similar to nature and to test the efficiency of the reactor. Thermocouples placed in the reservoir simulator with a total volume of 425 L collect data regarding the propagation of the heat front. In addition, CH4 sensors are placed in the water saturated sediment to detect the distribution of CH4 in the sample. These data are used for numerical simulations for up-scaling from laboratory to field conditions. This study presents the experimental set up of the large scale reservoir simulator and the reactor design. Preliminary results indicate that the catalytic oxidation of CH4 operated as a temperature controlled, autothermal reaction in a countercurrent heat exchange reactor is a safe and promising tool for the thermal stimulation of hydrates. In addition, preliminary results from the laboratory studies on the CO2-hydrocarbon swapping process in simple and mixed gas hydrates are presented.

As a part of various research projects, a methanation pilot plant with a slurry bubble column reactor (SBCR) was commissioned and operated. The plant has a nominal load of a 100 kW methane output (lower calorific value) with a reactor diameter of 260 mm and a reactor length of 2500 mm. First experimental data on the steady-state and dynamic operation of catalytic CO2 methanation are presented. Steady-state results from laboratory-scale studies (<1 kW methane output) published previously were confirmed qualitatively at the pilot plant eliminating wall effects unavoidable in small-scale reactors. As predicted, high H2/CO2 ratios increase CO2 conversion, but excess H2 apparently promotes decomposition of the liquid phase (dibenzyltoluene) used in the bubble column reactor. Additionally, due to the increased reactor dimensions compared to laboratory equipment, it was now possible to observe a thermal response of the SBCR under conditions of rapid gas load changes characteristic of envisaged power-to-gas applications with volatile renewable electricity. As the predicted robustness of the SBCR-concept toward a dynamic operation with fast load changes was demonstrated successfully, it offers an attractive alternative to the established fixed-bed methanation technologies with their inherent limitations on dynamic operability.